Heart Health

Is Whole Fat Dairy Healthy?

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Is It Dairy Or Diet?

Author: Dr. Stephen Chaney 

CheesesFor years we have been told to select low fat dairy foods. But recent headlines claim, “That’s nonsense. Whole fat dairy foods are healthy.” Are those headlines true?

In previous issues of “Health Tips From the Professor” I have kept you abreast of recent studies suggesting that whole fat dairy foods may not be as bad for us as we thought. I also cautioned you that the headlines may not have accurately represented the studies they described.

Headlines have to be simple. But truth is often more nuanced. If we believed the current headlines, we might be asking ourselves questions like, “Should we ditch the current health guidelines recommending low-fat dairy foods? Are foods like ice cream, sour cream, and cheddar cheese actually be good for us?

To answer these questions, I will look at the study (A Mente et al, European Heart Journal, 44, 2560-2579, 2023) behind the current headlines and put the study into perspective.

Spoiler alert: If I could summarize the study findings in two sentences, they would be, “Whole fat dairy can be part of a healthy diet. But can it be part of an unhealthy diet?”

Stay tuned. I will discuss the science behind that statement below.

How Was This Study Done?

clinical studyThis study started with data collected from the Prospective Urban Rural Epidemiology (PURE) study. The PURE study is an ongoing study correlating diet, lifestyle, and environmental effects on health outcomes. It has enrolled 166,762 individuals, age 35-70, from 21 low-, middle-, and high-income countries on 5 continents.

Habitual food intake was determined using country-specific food frequency questionnaires at the time participants joined the study. Participants (166,762) from the PURE study who had complete dietary information were included in this study and were followed for an average of 9.3 years.

Based on preliminary analysis of data from the PURE study, the authors developed their version of a healthy diet, which they call the PURE diet. Like most other healthy diets, the PURE diet emphasizes fruits, vegetables, legumes, nuts, and fish. However:

  • Based on studies suggesting that whole fat dairy foods can be part of a healthy diet, the PURE diet includes whole fat dairy foods.

This is different from most other healthy diet recommendations.

They went on to develop what they referred to as the PURE healthy diet score by:

  • Determining the median intake for each of the 6 food groups included in their PURE diet (fruits, vegetables, legumes, nuts, fish, and whole fat dairy).
  • Assigning each participant in the study a score of 0 or 1 depending on whether their intake for that food group was below or above the median intake.
  • Adding up the points. Since 6 food groups were included in the PURE diet, this means that each participant in the study was assigned a PURE diet score ranging from 0-6.

Once they had developed a PURE diet score, they expanded their data by including five additional large independent studies that included people from 70 countries. The combined data from all six studies amounted to 245,597 people from 80 countries. Of the people included in the data analysis:

  • 21% came from high income countries.
  • 60% came from middle income countries.
  • 19% came from low-income countries.

This is very similar to the global population distribution. This is a strength of this study because it allowed them to ask whether the PURE diet score worked as well in low-income countries as in high-income countries.

Finally, they correlated the PURE diet score with outcomes like all-cause mortality, heart attack, and stroke.

Is Whole Fat Dairy Healthy?

QuestionsThe authors of this study divided the participants of all 6 studies into quintiles based on their PURE diet score and compared those in the highest quintile (PURE score of ≥ 5) with those in the lowest quintile (PURE score of ≤ 1).

The people in the highest quintile were eating on average 5 servings/day of fruits and vegetables, 0.5 servings/day of legumes, 1.2 servings/day of nuts, 0.3 servings/day of fish, 2 servings/day of dairy (of which 1.4 servings/day was whole fat dairy), 0.5 servings/day of unprocessed red meat, and 0.3 servings/day of poultry.

 

The people in the lowest quintile ate significantly less fruits, vegetables, nuts, fish, and dairy; and slightly less legumes, unprocessed red meat, and poultry than those in the highest quintile.

However, they consumed significantly more refined wheat foods and white rice. This study did not track consumption of highly processed foods, but the high consumption of white flour leads me to suspect they ate a lot more highly processed food.

With that in mind, when the authors compared people with the highest PURE diet scores to those with the lowest PURE diet scores:

  • All-cause mortality was reduced by 30%.
  • Cardiovascular disease was reduced by 18%.
  • Heart attacks were reduced by 14%.
  • Strokes were reduced by 19%.
  • The PURE healthy eating score was slightly better at predicting health outcomes than the Mediterranean, DASH, and HEI (Healthy Eating Index) scores. But the differences were small. So, I still recommend choosing the healthy diet that best fits your preferred foods and your lifestyle.
  • The PURE healthy eating score was significantly better at predicting health outcomes than the Planetary diet score. I will discuss the nutritional inadequacy of “sustainable diets” like the Planetary diet in next week’s “Health Tips From the Professor” article.

Because of the size and design of this study, they were able to make three interesting observations.

  1. The PURE, Mediterranean, DASH, and HEI diet scores were predictive of health outcomes in every country across the globe. You no longer have to wonder if what works in the United States will work in low-income countries and in countries with very different food preferences. Previous studies have not been able to make that claim.

2) You don’t have to be perfect.

    • A 20% increase (one quintile) in PURE score was associated with a 6% lower risk of major cardiovascular events and an 8% lower risk of mortality. In other words, even small improvements in your diet may improve your health outcomes.
    • The health benefits of the PURE diet started to plateau at a score of 3 (with 6 being the highest score). The authors concluded that most of the health benefits were associated with a modestly higher consumption of healthy foods compared to little or no consumption of healthy foods.

Simply put, that means the health benefits gained by going from a moderately healthy diet to a very healthy diet are not as great as the health benefits gained by going from a poor diet to a moderately healthy diet.

[Note: There are still improvements in health outcomes when you go from a moderately healthy diet to a very healthy diet.  My recommendation: “You don’t need to achieve perfection, but you shouldn’t accept mediocrity”.]

3) The PURE diet score was more predictive of health outcomes in some countries than in others.

    • The PURE diet score was more predictive of health outcomes in low-income countries. The authors felt that was because low-income countries started with average PURE scores of 2.1, whereas higher-income countries started with average PURE scores of 3.5.

The authors felt this was another example getting more “bang for the buck” by going from a poor diet to a moderately healthy diet than from a moderately healthy diet to a very healthy diet. (Remember, the health benefits associated with improving PURE diet scores start to plateau at a PURE score of 3.

    • The difference in benefits for low-income countries compared to high-income countries was observed for the Mediterranean, DASH, and HEI diet scores. So, it is probably safe to say for any healthy diet you don’t need to be perfect. You just need to be better.

The authors concluded, “A diet composed of higher amounts of fruit, vegetables, nuts, legumes, fish, and whole fat dairy is associated with a lower risk of cardiovascular disease and mortality in all world regions, especially in countries with lower income where consumption of these foods is low.”

Is It Dairy Or Diet?

CheesesThe headlines are telling us that recommendations to choose low-fat dairy products are out of date. They say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. Let me provide perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context. What do I mean by that? Let’s dig a little deeper into this study.

  • Let’s start with a description of the PURE diet. It is a diet that emphasizes fruits, vegetables, legumes, nuts, and fish. In other words, it is a primarily plant-based diet.
  • Although the authors keep referring to the diet as one that includes whole fat dairy. It would be more accurate to say that it includes dairy, which was 30% low-fat and 70% whole fat.
  • The authors said that removal of any one food group from this combination reduced the predictive power of the PURE diet. In other words, the beneficial effect of 70% whole fat dairy is best seen in the context of a primarily plant-based diet.
  • The PURE diet was most effective at predicting health outcomes in low-income countries where a significant percent of the population consumes a primarily plant-based diet because meats are expensive.

So, a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

To answer that question let’s compare the potential effects of whole fat dairy on a primarily plant-based diet compared to the typical American or European diet.

  • Milk and other dairy foods are excellent sources of calcium, vitamin B12, and iodine and good sources of protein, vitamin D, choline, zinc, and selenium – nutrients that are often low or missing in plant-based diet. And this is true whether the dairy foods are low-fat or whole fat.
  • Primarily plant-based diets tend to be low in saturated fat, so the potential negative effects of adding a small amount of saturated fat to the diet may be outweighed by the beneficial effects of the nutrients dairy foods provide.

On the other hand,

  • The typical American or European diet provides plenty of protein and vitamin B12 and significantly more choline, vitamin D, iodine, and zinc than a plant-based diet. The added nutrients from adding dairy foods to this kind of diet is still beneficial, but the benefits are not as great as adding dairy foods to a primarily plant-based diet.
  • If you read the American Heart Association statement on saturated fats, it does not say that any amount of saturated fat is bad for you. In fact, small amounts of saturated fats play some beneficial roles in our bodies. The American Heart Association says, “Eating too much saturated fat can raise the level of LDL cholesterol in your blood…[which] increases your risk of heart disease and stroke.”
  • Here is where the problem lies. The typical American or European diet already contains too much saturated fat. Whole fat dairy just adds to that excess.

So, the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

The Bottom Line 

Once again, the headlines are telling us that recommendations to choose low-fat dairy products are out of date. The articles say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. In this post I looked at the study behind the most recent headlines and provided perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context.

When you consider diet context a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

When you consider that question the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

For more information on this study, and the science behind my summary of the study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Are All Carbs Bad?

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Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

Author: Dr. Stephen Chaney 

Low carb enthusiasts have been on the warpath against carbohydrates for years.

Almost everyone agrees that sugar-sweetened sodas and highly processed, refined foods with added sugar are bad for us. But low carb enthusiasts claim that we should also avoid fruits, grains, and starchy vegetables. Have they gone too far?

Several recent studies suggest they have. For example, both association studies and randomized controlled studies suggest that total carbohydrate intake is neither harmful nor beneficial for heart health.

In addition, recent studies suggest that free sugar intake is associated with both elevated triglyceride levels and an increase in heart disease risk.

But those studies have mostly looked at free sugar intake from sugar-sweetened sodas. The authors of this study (RK Kelley et al, BMC Medicine, 21:34, 2023) decided to look more carefully at the effect of all free sugars and other types of carbohydrates on triglyceride levels and heart disease risk.

How Was This Study Done?

clinical studyThe 110,497 people chosen for this study were a subgroup of participants in the UK Biobank Study, a large, long-term study looking at the contributions of genetic predisposition and environmental exposure (including diet) to the development of disease in England, Scotland, and Wales.

The participants in this study were aged between 37 and 73 (average age = 56) on enrollment and were followed for an average of 9.4 years. None of them had a history of heart disease or diabetes or were taking diabetic medications at the time of enrollment.

During the 9.4-year follow-up, five 24-hour dietary recalls were performed, so that usual dietary intake could be measured rather than dietary intake at a single time point. The people in this study participated in an average of 2.9 diet surveys, and none of them had less than two diet surveys.

The averaged data from the dietary recalls were analyzed for the amount and kinds of carbohydrate in the diet. With respect to the types of carbohydrate, the following definitions would be useful.

  • The term free sugars includes all monosaccharides and disaccharides added to foods by the manufacturer, cook, or consumer, plus sugars naturally present in honey, syrups, and unsweetened fruit juices.
  • The term non-free sugars includes all sugars not in the free sugar category, mostly sugars naturally occurring in fruits, vegetables, and dairy products.
  • The term refined grains includes white bread, white pasta, white rice, most crackers and cereals, pizza, and grain dishes with added fat.
  • The term whole grains includes wholegrain bread, wholegrain pasta, brown rice, bran cereal, wholegrain cereals, oat cereal, and muesli.

Finally, the study looked at the association of total carbohydrate and each class of carbohydrate defined above with all heart disease, heart attacks, stroke, and triglyceride levels.

Are All Carbs Bad?

Question MarkThe study looked at total carbohydrate intake, free sugar intake, and fiber intake. In each case, the study divided the participants into quartiles and compared those in the highest quartile with those in the lowest quartile.

Using this criterion:

  • Total carbohydrate intake was not associated with any cardiovascular outcome measured (total heart disease risk, heart attack risk, and stroke risk).
  • Free sugar intake was positively associated with all cardiovascular outcomes measured. Each 5% increase in caloric intake from free sugars was associated with a:
    • 7% increase in total heart disease risk.
    • 6% increase in heart attack risk.
    • 10% increase in stroke risk.
    • 3% increase in triglyceride levels.
  • Fiber intake was inversely associated with total heart disease risk. Specifically, each 5 gram/day increase in fiber was associated with a:
    • 4% decrease in total heart disease risk.

The investigators also looked at the effect of replacing less healthy carbohydrates with healthier carbohydrates. They found that:

  • Replacing 5% of caloric intake from refined grains with whole grains reduced both total heart disease risk and stroke risk by 6%.
  • Replacing 5% of caloric intake from free sugars (mostly sugar-sweetened beverages, fruit juices, and processed foods with added sugar) with non-free sugars (mostly fruits, vegetables, and dairy products) reduced total heart disease risk by 5% and stroke risk by 9%.

Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

With these data in mind let’s look at the claims of the low-carb enthusiasts.

Claim #1: Carbohydrates raise triglyceride levels. This study shows:

  • This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake (fruits, vegetables, and whole grains. This study did not measure intake of beans, nuts, and seeds, but they would likely be in the same category).
  • However, this claim is true with respect to foods high in free sugars (sugar-sweetened beverages, fruit juices, and processed foods with added sugar).

Claim #2: Carbohydrates increase heart disease risk. This study shows:

  • That claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.
  • However, this claim is true with respect to foods high in free sugars.

Claim #3: Carbohydrates cause weight gain [Note: Low carb enthusiasts usually word it differently. Their claim is that eliminating carbohydrates will help you lose weight. But that claim doesn’t make sense unless you believed eating carbohydrates caused you to gain weight.] This study shows:

  • This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.
  • Once again, this claim is true with respect to foods high in free sugars.

The data with high fiber carbohydrates was particularly interesting. When the authors compared the group with the highest fiber intake to the group with the lowest fiber intake, the high-fiber group:

  • Consumed 33% more calories per day.
  • But had lower BMI and waste circumference (measures of obesity) than the low-carbohydrate group.

This suggests that you don’t need to starve yourself to lose weight. You just need to eat healthier foods.

And, in case you were wondering, the high fiber group ate:

  • 5 more servings of fruits and vegetables and…
  • 2 more servings of whole grain foods than the low fiber group.

This is consistent with several previous studies showing that diets containing a lot of fruits, vegetables, and whole grains are associated with a healthier weight.

The authors concluded, “Higher free sugar intake was associated with higher cardiovascular disease incidence and higher triglyceride concentrations…Higher fiber intake and replacement of refined grain starch and free sugars with wholegrain starch and non-free sugars, respectively, may be protective for incident heart disease.”

In short, with respect to heart disease, the type, not the amount of dietary carbohydrate is the important risk factor.

What Does This Mean For You?

Questioning WomanForget the low carb “mumbo jumbo”.

  • Carbohydrates aren’t the problem. The wrong kind of carbohydrates are the problem. Fruit juice, sugar-sweetened sodas, and processed foods with added sugar:
    • Increase triglyceride levels.
    • Are associated with weight gain.
    • Increase the risk for heart disease.
  • In other words, they are the villains. They are responsible for the bad effects that low carb enthusiasts ascribe to all carbohydrates.
  • Don’t fear whole fruits, vegetables, dairy, and whole grain foods. They are the good guys.
    • They have minimal effect on triglyceride levels.
    • They are associated with healthier weight.
    • They are associated with a lower risk of heart disease and diabetes.

So, the bottom line for you is simple. Not all carbs are created equal.

  • Your mother was right. Eat your fruits, vegetables, and whole grains.
  • Avoid fruit juice, sodas and other sugar-sweetened beverages, and processed foods with added sugar. [Note: Artificially sweetened beverages are no better than sugar-sweetened beverages, but that’s another story for another day.]

And, if you were wondering why low carb diets appear to work for weight loss, it’s because any restrictive diet works short term. As I have noted previously, keto and vegan diets work equally well for short-term weight loss.

The Bottom Line 

Low carb enthusiasts have been telling us for years to avoid all carbohydrates (including fruits, starchy vegetables, and whole grains) because carbohydrates:

  • Increase triglyceride levels.
  • Cause weight gain.
  • Increase our risk for heart disease.

A recent study has shown that these claims are only true for some carbohydrates, namely fruit juices, sodas and other sugar-sweetened beverages, and processed foods with added sugar.

Whole fruits, vegetables, and whole grain foods have the opposite effect. They:

  • Have a minimal effect on triglyceride levels.
  • Are associated with a healthier weight.
  • Are associated with a lower risk of heart disease and diabetes.

So, forget the low carb “mumbo jumbo” and be sure to eat your fruits, vegetables, and whole grains.

For more information on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Are Low Carb Diets Healthier?

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The “Goldilocks Effect”

Author: Dr. Stephen Chaney

Goldilocks EffectThe low-carb wars rage on. Low-carb enthusiasts claim that low-carb diets are healthy. Many health experts warn about the dangers of low-carb diets. Several studies have reported that low-carb diets increase risk of mortality (shorten lifespan).

However, two recent studies have come to the opposite conclusion. Those studies reported that high carbohydrate intake increased mortality, and low carbohydrate intake was associated with the lowest mortality.

One of those studies, called the Prospective Urban Rural Epidemiology (PURE) study was published a few years ago. It included data from 135,335 participants from 18 countries across 5 continents. That’s a very large study, and normally we expect very large studies to be accurate. The results from the PURE study had low-carb enthusiasts doing a victory lap and claiming it was time to rewrite nutritional guidelines to favor low-carb diets.

Whenever controversies like this arise, reputable scientists are motivated to take another look at the question. They understand that all studies have their weaknesses and biases. So, they look at previous studies very carefully and try to design a study that eliminates the weaknesses and biases of those studies. Their goal is to design a stronger study that reconciles the differences between the previous studies.

A third study published a year later (SB Seidelmann et al, The Lancet, doi.org/10.1016/S2468-2667(18)30135-X was such a study. This study resolved the conflicting data and finally answered the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. You may remember “Goldilocks And The Three Bears”. One bed was too hard. One bed was too soft. But one bed was “just right”. One bowl of porridge was too hot. One was two cold. But one was “just right”. According to this study, the same is true for carbohydrate intake. High carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But moderate carbohydrate intake is “just right”.

How Was The Study Done?

clinical studyThis study was performed in two parts. This first part drew on data from the Atherosclerosis Risk in Communities (ARIC) study. That study enrolled 15,428 men and women, aged 45-64, from four US communities between 1987 and 1989. This group was followed for an average of 25 years, during which time 6283 people died. Carbohydrate intake was calculated based on food frequency questionnaires administered when participants enrolled in the study and again 6 years later. The study evaluated the association between carbohydrate intake and mortality.

The second part was a meta-analysis that combined the data from the ARIC study with all major clinical studies since 2007 that measured carbohydrate intake and mortality and lasted 5 years or more. The total number of participants included in this meta-analysis was 432,179, and it included data from previous studies that claimed low-carbohydrate intake was associated with decreased mortality.

Are Low Carb Diets Healthier?

GravestoneThe results from the ARIC study were:

  • The relationship between mortality and carbohydrate intake was a U-shaped curve.
    • The lowest risk of death was observed with a moderate carbohydrate intake (50-55%). This is the intake recommended by current nutrition guidelines.
    • The highest risk of death was observed with a low carbohydrate intake (<40%).
    • The risk of death also increased with very high carbohydrate intake (>70%).
  • When the investigators used the mortality data to estimate life expectancy, they predicted a 50-year old participant would have a projected life expectancy of:
    • 33.1 years if they had a moderate intake of carbohydrates.
    • 4 years less if they had a low carbohydrate intake.
    • 1.1 year less if they had a very high carbohydrate intake.
  • The risk associated with low carbohydrate intake was affected by what the carbohydrate was replaced with.
    • When carbohydrates were replaced with animal protein and animal fat there was an increased risk of mortality on a low-carb diet. The animal-based low-carb diet contained more beef, pork, lamb, chicken, and fish. It was also higher in saturated fat.Beans and Nuts
    • When carbohydrates were replaced with plant protein and plant fats, there was a decreased risk of mortality on a low-carb diet. The plant-based low-carb diet contained more nuts, peanut butter, dark or whole grain breads, chocolate, and white bread. It was also higher in polyunsaturated fats.
  • The effect of carbohydrate intake on mortality was virtually the same for all-cause mortality, cardiovascular mortality, and non-cardiovascular mortality.
  • There was no significant effect of carbohydrate intake on long-term weight gain (another myth busted).

The results from the dueling meta-analyses were actually very similar. When the data from all studies were combined:

  • Both very low carbohydrate diets and very high carbohydrate diets were associated with increased mortality.
  • Meat-based low-carb diets increased mortality, and plant-based low-carb diets decreased mortality.
  • Once again, the results were the same for total mortality, cardiovascular mortality, and non-cardiovascular mortality.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

The “Goldilocks Effect”

low carb dietThis study also resolved the discrepancies between previous studies. The authors pointed out that the average carbohydrate intake is very different in Europe and the US than in Asian countries and low-income countries.

In the US and Europe mean carbohydrate intake is about 50% of calories and it ranges from 25% to 70% of calories. With that range of carbohydrate intake, it is possible to observe the increase in mortality associated with both very low and very high carbohydrate intakes.

The US and European countries are affluent, which means that low-carb enthusiasts can afford diets high in animal protein.

White rice is a staple in Asian countries, and protein is a garnish rather than a main course. Consequently, overall carbohydrate intake is greater in Asian countries and very few Asians eat a truly low carbohydrate diet. High protein foods tend to be more expensive than high carbohydrate foods. Thus, very few people in developing countries can afford to follow a very low carbohydrate diet, and overall carbohydrate intake also tends to be higher.

Therefore, in Asian and developing countries the average carbohydrate intake is greater (~61%) than in the US and Europe, and the range of carbohydrate intake is from 45% to 80% of calories. With that range of intake, it is only possible to see the increase in mortality associated with very high carbohydrate intake.

Both the studies that low-carb enthusiasts quote to support their claim that low-carb diets are healthy relied heavily on data from Asian and developing countries.ARIC Study

In fact, when the authors of the current study overlaid the data from the PURE study with their ARIC data, there was an almost perfect fit. The only difference was that their ARIC data covered both low and high carbohydrate intake while the PURE study touted by low-carb enthusiasts only covered moderate to high carbohydrate intake.

[I have given you my rendition of the graph on the right. If you would like to see the data yourself, look at the paper.]

Basically, low-carb advocates are telling you that diets with carbohydrate intakes of 30% or less are healthy based on studies that did not include carbohydrate intakes below 40%. That is misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

What Does This Study Mean For You?

QuestionsThere are several important take-home lessons from this study:

  • All major studies agree that very high carbohydrate intake is unhealthy. In part, that reflects the fact that diets with high carbohydrate intake are likely to be high in sodas and sugary junk foods. It may also reflect the fact that diets which are high in carbohydrate are often low in plant protein or healthy fats or both.
  • All studies that cover the full range of carbohydrate intake agree that very low carbohydrate intake is also unhealthy. It shortens the life expectancy of a 50-year-old by about 4 years.
  • The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.
  • Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with previous studies. For more details on those studies, see my article, “Are Any Low-Carb Diets Healthy?”, in “Health Tips From The Professor” or my book, “Slaying The Food Myths”.

The health risks of meat-based low-carb diets may be due to the saturated fat content or the heavy reliance on red meat. However, the risks are just as likely to be due to the foods these diets leave out – typically fruits, whole grains, legumes, and some vegetables.

Proponents of low-carb diets assume that you can make up for the missing nutrients by just taking multivitamins. However, each food group also provides a unique combination of phytonutrients and fibers. The fibers, in turn, influence your microbiome. Simply put, whenever you leave out whole food groups, you put your health at risk.

The Bottom Line

The low-carb wars are raging. Several studies have reported that low-carb diets increase risk of mortality (shorten lifespan). However, two studies published a few years ago have come to the opposite conclusion. Those studies have low-carb enthusiasts doing a victory lap and claiming it is time to rewrite nutritional guidelines to favor low-carb diets.

However, a study published a year later resolves the conflicting data and finally answers the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. According to this study, high carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But, moderate carbohydrate intake is “just right”.

Specifically, this study reported:

  1. Moderate carbohydrate intake (50-55%) is healthiest. This is also the carbohydrate intake recommended by current nutritional guidelines.

2) All major studies agree that very high carbohydrate intake (60-70%) is unhealthy. It shortens life expectancy of a 50-year old by about a year.

3) All studies that cover the full range of carbohydrate intake agree that low carbohydrate intake (<40%) is also unhealthy. It shortens life expectancy of a 50-year old by about 4 years.

4) The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

5) Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with the results of previous studies.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Are Easter Eggs Bad For You?

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Clearing Up The Eggfusion 

Author: Dr. Stephen Chaney

The Easter Bunny will be here soon bringing beautifully decorated eggs for all the children. But wait. Aren’t eggs bad for us? Should we really be encouraging our kids to eat Easter eggs? Maybe we should encourage them to eat Easter candy instead (just kidding).

What is the truth about eggs on our health? Perhaps it’s time for the professor to clear up the “eggfusion” (That’s short for egg confusion). Let me start with a brief historical summary:

  • First there were the warnings that eggs were bad for your heart because egg yolks contained cholesterol, and cholesterol was to be avoided at all costs.
  • Then experts decided that dietary cholesterol wasn’t all that bad for you. It was saturated fats, obesity, and lack of exercise that raised “bad” (LDL) cholesterol levels in your bloodstream.
  • That was followed by several US studies suggesting that eggs in moderation (one per day) did not affect your risk of heart disease.
  • Then a major study claimed that an egg a day actually lowered your risk of heart disease.

Now, the most recent headlines claim that eggs increase your risk of heart disease, and you should avoid them. No wonder you are experiencing eggfusion. Let me review the latest study and put it into perspective by comparing it to previous studies. Let me clear up the eggfusion.

But let me warn you. This is a bit complex, as the truth often is. When I try to explain the contradictions between major studies on egg consumption and heart health, I think the best analogy might be the tale of the blind men trying to tell what an elephant was like by touching different parts of the elephant. None of them could provide an accurate description because none of them could see the whole elephant.

We need to look at the “whole elephant” to see what these studies missed.

How Was The Study Done?

Heart Disease StudyThis study (WW Zhong et al, JAMA, 321: djw322, 2017) combined the data from 6 clinical trials in the United States that assessed dietary intake and measured cardiovascular health outcomes. In all, these studies included 29,615 adults who were followed for an average of 17.5 years.

The diet of the participants was assessed upon entry into each of the clinical trials. The primary variables derived from the dietary information were cholesterol and egg consumption. Diet was not assessed at later times in these studies.

The primary outcomes measured were heart disease and all-cause mortality. In this study heart disease was an umbrella term that included fatal and non-fatal heart attacks, stroke, heart failure, and death from other heart-related causes.

Do Eggs Increase Heart Disease Risk?

heart attacksHere are the main findings from this study.

  • Each additional half an egg consumed per day (which is equivalent to 3-4 eggs per week) was associated with a:
    • 6% increased risk of heart disease. While that doesn’t sound like much, the increased risk was over 13% for one egg per day and almost 27% for two eggs per day.
  • The increased heart disease risk associated with one half egg per day was greater for:
    • Women (13% increase) than men (3% increase).
    • People who already had high blood cholesterol (7% increase), not people who already had low cholesterol levels (0% increase). This suggests that the effect of eggs on heart disease risk primarily affects people who are already having trouble controlling their blood cholesterol levels – either due to genetics or due to diet & lifestyle.

Of course, the question is whether it was the eggs that increased the risk of heart disease or was it something else in the diet. This study attempted to answer that question by systematically subtracting out other variables that affect heart disease risk to see whether that correction eliminated the association between egg consumption and heart disease risk. When this was done:

  • The association between egg consumption and heart disease risk disappeared after correcting for dietary cholesterol intake.
  • The association between egg consumption and heart disease risk remained significant after correcting for other components of the diet, such as fats, animal protein, fiber, sodium, or overall “diet quality”. There were 3 main measures of diet quality.
    • The Med diet score measures how closely the diet resembles the Mediterranean diet.
    • The DASH diet score measures how closely the diet resembles the DASH diet.
    • The Healthy Eating Index (HEI) measures how closely the diet aligns with the USDA Dietary Guidelines For Americans. Basically, the HEI recommends a whole food diet containing foods from all 5 food groups with a heavy emphasis on fruits, vegetables, whole grains, and legumes. It also recommends limiting saturated and trans fats, added sugars, and sodium.

In simple terms the authors concluded that the effect of eggs on heart disease risk was primarily due to their cholesterol content and was not influenced by other components of the overall diet. [I will revisit this conclusion latter.]

What Are The Strengths And Weaknesses Of The Study?

SkepticThe strengths are obvious. This was a very large study (29,615 participants) and the people enrolled in the study were followed for a long time (an average of 17.5 years). The primary variables in the study (cholesterol consumption, egg consumption, heart disease, and all-cause mortality) were accurately measured in each of the clinical trials included in the study.

However, there were some significant weaknesses as well:

  • Cholesterol and egg consumption were only measured by a single dietary survey when people entered the study. This study assumes they did not change over the course of the study. That is very unlikely. Both cholesterol intake and egg consumption in the US population have waxed and waned over the years, in part due to variations in dietary guidelines.
  • The measurements of diet quality used were based on US and European food preferences. That is significant because the only studies showing that egg consumption lowers heart disease risk were performed in China and Japan, where the diet is closer to semi-vegetarian than to US or European diets.

Are Easter Eggs Bad For You?

thumbs down symbolThis is very large, well designed study that combines the data from 6 clinical trials spanning the years 1974 to 2013.

The strongest conclusions from the study are:

  • In the context of a Western diet (the US diet) egg consumption slightly increases your risk developing heart disease. The increased risk is ~6% for 3-4 eggs/week, ~13% for 1 egg per day, and ~27% for two eggs per day.
  • The increased risk of heart disease appears to be almost entirely due to the cholesterol content of eggs.

The significance of this study needs to be weighed in the context of:

  • Recent studies in the US and Europe showing eggs do not increase heart disease risk.
  • Studies in China and Japan (where the diets can best be described as semi-vegetarian) showing that eggs decrease heart disease risk.

The significance of this study also needs to be weighed in the context of:

  • Studies showing that obesity, saturated fat, and physical inactivity have bigger effects on serum cholesterol levels and heart disease risk than dietary cholesterol from foods like eggs.

What Did This Study Miss?

EggsIf, as this study suggests, the effect of eggs on heart disease risk is due to their cholesterol content, this study (and most previous studies) missed a very important point. The effect of dietary cholesterol on blood cholesterol levels is not strongly affected by the overall composition of the diet. It is affected by the composition of the diet at the time foods containing dietary cholesterol are eaten.

  • The kind of fiber found in certain fruits, vegetables, whole grains, and legumes bind to dietary cholesterol, preventing it from being absorbed as it passes through the intestine.
  • Certain phytonutrients in plant foods affect how dietary cholesterol is utilized by the body.
  • However, to blunt the effect of dietary cholesterol on blood cholesterol levels the fiber and phytonutrient-containing foods must be consumed at the same meal.

Simply put, if your breakfast consists of eggs, sausage, biscuits, and hash browns, the cholesterol in the eggs will likely increase your blood cholesterol level, which in turn increases your risk of heart disease. This will occur even if you eat lots of fruits, vegetables, whole grains, and legumes with your other meals.

If, on the other hand, your breakfast consists of eggs and fiber-rich plant foods like oatmeal and beans, the cholesterol in the eggs will likely have a much smaller effect on your blood cholesterol levels and your heart disease risk.

The fact that previous studies have not looked at what foods were consumed along with the eggs may explain some of the variation in their conclusions about the effect of egg consumption on heart disease risk.

The Professor’s Story

professor owlLet me share my story with you. About 25 years ago, my doctor told me that my cholesterol levels were getting high and wanted to put me on statins. I didn’t take a stain, and I didn’t stop eating eggs for breakfast. I changed breakfast.

Now I soft boil my eggs or fry them in olive oil. I eat them along with oatmeal, which contains a fiber that binds cholesterol, and walnuts, which contain omega-3s and phytonutrients that lower blood cholesterol. I also include whatever fruit is in season. Finally, I take a supplement providing 2 grams of plant stanols and sterols, which blocks cholesterol absorption from the intestine.

My blood cholesterol levels have been low ever since. I have not had to take statins, and I get to enjoy the taste and health benefits of an egg any time I want to. Of course, what worked for me may not work for you. The effect of dietary cholesterol on blood cholesterol levels is also affected by genetics, weight, and fitness, just to name the top three.

Are Easter Eggs Good For You?

thumbs upOnce you get past the cholesterol problem, eggs are a very healthy food.

  1. Studies have shown that egg protein results in improved blood sugar control, better satiety (feeling of fullness), and reduced subsequent food intake in healthy and overweight individuals. In layman’s terms that means egg protein can help you achieve and maintain a healthy weight.

2) Egg yolks are a good source of lutein and zeaxanthin. We think of lutein and zeaxanthin as good for eye health. They also play an important role in protecting against oxidation, inflammation, and atherosclerosis.

3) Egg yolks also contain choline. We think of choline as good for brain and nerves. But, choline and other phospholipids in the yolk also raise HDL levels and enhance HDL function.

4) Eggs are a good source of vitamin A, vitamin D, vitamin B12, riboflavin, selenium and iron.

5) Eggs contain almost twice as much monounsaturated and polyunsaturated fats as saturated fats.

Clearing Up The “Eggfusion”

egg confusion

  1. The latest study suggests that eggs may increase your risk of heart disease, and this is due to their cholesterol content.

2) This study needs to be considered in the context of recent studies in the US showing that egg consumption did not increase heart disease risk and studies in China and Japan showing that egg consumption lowered heart disease risk.

3) It is also important to consider that egg consumption in China and Japan is in the context of a semi-vegetarian diet. This suggests that diet plays a role in determining the effect of egg consumption on heart disease risk.

4) However, if you take this study at face value, there are two things you can do to reduce your risk of heart disease:

  • Reduce dietary cholesterol by avoiding eggs or using egg whites.
    • Eat eggs in moderation along with fiber- and phytonutrient-rich plant foods that negate the effect of dietary cholesterol on blood cholesterol levels. I recommend oatmeal or beans, nuts or seeds, and fiber rich fruits and vegetables. These should be consumed at the same meal to minimize the effect of the cholesterol in the eggs on blood cholesterol levels. As for Easter eggs, they are a perfect addition to a green salad.
    • Eggs are a very healthy food, so I recommend the second option if possible. Get your blood cholesterol levels measured to determine which approach works best for you.

5) Finally, we need to recognize that egg consumption plays a relatively minor role in determining heart disease risk. Other factors play a much larger role in influencing heart disease risk. For example:

    • Smoking, obesity, inactivity, saturated and trans fats significantly increase your risk of heart disease.
    • Omega-3s, antioxidants, and a primarily plant-based diet like the Mediterranean diet significantly decrease your risk of heart disease.

If we wish to reduce our risk of heart disease, this is where we should focus most of our attention. We can minimize the effect of egg consumption on heart disease risk by changing the foods we eat with the eggs. For more information on how to reduce your risk of heart disease, read my books, “Slaying The Food Myths” and “Slaying The Supplement Myths”.

The Bottom Line

1) The latest study suggests that eggs increase your risk of heart disease because of their cholesterol content.

2) This was a very large study. It combined the data from 6 clinical trials spanning the years 1974 to 2013. It followed 29,615 people for an average of 17.5 years. However, it has two significant weaknesses:

  • It only determined cholesterol intake and egg consumption at the time people entered the clinical trials. Both cholesterol intake and egg consumption have waxed and waned considerably over the years covered by these clinical trials.
  • It did not measure what foods were consumed along with the eggs. Foods consumed along with eggs have a strong influence on how much the cholesterol in the eggs influences blood cholesterol levels, which, in turn, influences the effect eggs have on heart disease risk.

3) This study also needs to be considered in the context of recent studies in the US showing that egg consumption did not increase heart disease risk and studies in China and Japan showing that egg consumption lowered heart disease risk.

4) However, if you take this study at face value, there are two things you can do to reduce your risk of heart disease:

  • Reduce dietary cholesterol by avoiding eggs or using egg whites.
  • Eat eggs in moderation along with fiber- and phytonutrient-rich plant foods that negate the effect of dietary cholesterol on blood cholesterol levels. I recommend oatmeal or beans, nuts or seeds, and fiber rich fruits and vegetables. These should be consumed at the same meal to minimize the effect of the cholesterol in the eggs on blood cholesterol levels. As for Easter eggs, they are a perfect addition to a green salad.
  • Eggs are a very healthy food, so I recommend the second option if possible. Get your blood cholesterol levels measured to determine which approach works best for you.

5) Finally, we need to recognize that egg consumption plays a relatively minor role in determining heart disease risk. Other factors play a much larger role in influencing heart disease risk. For example:

  • Smoking, obesity, inactivity, saturated and trans fats significantly increase your risk of heart disease.
  • Omega-3s, antioxidants, and a primarily plant-based diet like the Mediterranean diet significantly decrease your risk of heart disease.

For more information on how to reduce your risk of heart disease, read my books, “Slaying The Food Myths” and “Slaying The Supplement Myths”.

For more details and to learn what the professor does about egg consumption, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

 

 

Which Diets Are Best In 2023?

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Which Diet Should You Choose?

Author: Dr. Stephen Chaney

Emoticon-BadMany of you started 2023 with goals of losing weight and/or improving your health. In many cases, that involved choosing a new diet. That was only 6 weeks ago, but it probably feels like an eternity.

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January.

  • Perhaps the diet isn’t working as well as advertised…
  • Perhaps the diet is too restrictive. You are finding it hard to stick with…
  • Perhaps you are always hungry or constantly fighting food cravings…
  • Perhaps you are starting to wonder whether there is a better diet than the one you chose in January…
  • Perhaps you are wondering whether the diet you chose is the wrong one for you…

If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories.

If you are still searching for your ideal diet, I will summarize the US News & World Report’s “Best Diets In 2023”. For the full report, click on this link.

How Was This Report Created?

Expert PanelUS News & World Report recruited a panel of 30 nationally recognized experts in diet, nutrition, obesity, food psychology, diabetes, and heart disease to review the 24 most popular diets.

The diets evaluated are not the same each year. Last year they evaluated the top 40 most popular diets. This year they only reviewed the top 24.

That means some good diets were left off the list. For example, the vegan diet is very healthy, but it is also very restrictive. Very few people follow a pure vegan diet, so it didn’t make the top 24 most popular. However, this year’s list did include several primarily plant-based diets that are more popular with the general public.

The panel is also not the same each year. Some experts are rotated off the panel, and others are added. The experts rate each diet in seven categories:

  • How easy it is to follow.
  • Its ability to produce short-term weight loss.
  • Its ability to produce long-term weight loss.
  • its nutritional completeness.
  • Its safety.
  • Its potential for preventing and managing diabetes.
  • Its potential for preventing and managing heart disease.

They converted the experts’ ratings to scores 5 (highest) to 1 (lowest). They then used these scores to construct eleven sets of Best Diets rankings:

  • Best Diets Overall ranks diets on several different parameters, including whether all food groups are included in the diet, the availability of the foods needed to be on the diet and the use of additional vitamins or supplements. They considered if the diet was evidence-based and adaptable to meet cultural, religious, or other personal preferences. In addition, the criteria also included evaluation of the prep and planning time required for the diet and the effectiveness of the diet for someone who wants to get and stay healthy.
  • Best Plant-Based Diets used the same approach as Best Diets Overall to rank the eight plans emphasizing minimally processed foods from plants that were included in this year’s ratings.
  • Best Commercial Diet ratings used the same approach to rank 15 commercial diet programs that require a participation fee or promote the use of branded food or nutritional products.
  • Best Long-Term Weight-Loss Diet ratings were generated by combining the safety of the rate of weight loss promoted and the likelihood of the plan to result in successful long-term weight loss and maintenance of weight loss.
  • Best Fast Weight-Loss Diets were scored on their effectiveness for someone who wants to lose weight in three months or less.
  • Best Diabetes Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for diabetes, the nutritional quality of the diet, and research evidence-based support for the diet.
  • Best Heart-Healthy Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for hypertension and other forms of heart disease, the nutritional quality of the diet, and evidence-based support for the diet.
  • Best Diets for Bone and Joint Health were calculated equally on the effectiveness of the diet for someone who wants to lower their risk factors for inflammation and improve bone and joint health, as well as the nutritional quality and research evidence-based support for the diet.
  • Best Diets for Healthy Eating combines nutritional completeness and safety ratings, giving twice the weight to safety. A healthy diet should provide sufficient calories and not fall seriously short on important nutrients or entire food groups.
  • Easiest Diets to Follow represents panelists’ averaged scores for the relevant lifestyle questions, including whether all food groups are included and if the recommended foods are readily available at the average supermarket.
  • Best Family-Friendly Diets were calculated equally on their adaptability for the whole family, including cultural, religious, and personal preferences, the time required to plan and prep, nutritional value and access to food at any supermarket.

Which Diets Are Best In 2023?

Are you ready? If this were an awards program, I would be saying “Envelop please” and would open the envelop slowly to build suspense.

However, I am not going to do that. Here are the top 3 and bottom 3 diets in each category (If you would like to see where your favorite diet ranked, click on this link.

[Note: I excluded commercial diets from this review. (I have a brief discussion of commercial diets below). If you notice a number missing in my summaries, it is because I eliminated one or more commercial diet from my summary.]

Best Diets Overall 

The Top 3: 

#1: Mediterranean Diet. The Mediterranean diet has been ranked #1 for 6 consecutive years.

#2 (tie): DASH Diet (This diet was designed to keep blood pressure under control, but you can also think of it as an Americanized version of the Mediterranean diet.)

#2 (tie): Flexitarian Diet (A flexible semi-vegetarian diet).

The Bottom 3: 

#20: Keto Diet (A high protein, high fat, very low carb diet designed to achieve ketosis).

#21: Atkins Diet (The granddaddy of the high animal protein, low carb, high fat diets).

#24: Raw Food Diet (A diet based on eating foods that have not been cooked or processed).

Best Plant-Based Diets Overall 

The Top 3: 

#1: Mediterranean Diet.

#2: Flexitarian Diet.

#3: MIND Diet (This diet is a combination of Mediterranean and DASH but is specifically designed to reduce cognitive decline as we age.)

The Bottom 3: 

Since only 8 diets were included in this category, even the bottom 3 are pretty good diets, so I did not include a “list of shame” in this category.

Best Long-Term Weight-Loss DietsWeight Loss

The Top 3: 

#1: DASH Diet

#2 (tie): Volumetrics Diet (A diet based on the caloric density of foods).

#2 (tie): Mayo Clinic Diet (A diet designed to establish lifelong healthy eating habits).

The Bottom 3: 

#22 (tie): Keto Diet.

#22 (tie): Atkins Diet.

#24: Raw Food Diet.

Best Fast Weight-Loss Diets

The Top 3: 

#1: Keto Diet

#2: Atkins Diet

#7 (tie): Mayo Clinic Diet

#7 (tie): South Beach Diet

#7 (tie): Volumetrics Diet

The Bottom 3: 

The diets at the bottom of this list were designed for health and weight maintenance rather than rapid weight loss, so I did not include a “list of shame” in this category.

Best Diabetes Diets

The Top 3: 

#1: DASH Diet

#2: Mediterranean Diet

#3: Flexitarian Diet

The Bottom 3: 

#20: Atkins Diet

#21: Paleo Diet (A diet based on what our paleolithic ancestors presumably ate. It restricts grains and dairy and is heavily meat-based).

#22: Raw Food Diet.

Best Heart-Healthy Diets

Healthy HeartThe Top 3: 

#1: DASH Diet

#2: Mediterranean Diet

#3 (tie): Ornish Diet (A whole food, semi-vegetarian diet designed to promote heart health).

#3 (tie): Flexitarian Diet

The Bottom 3: 

#22 (tie): Raw Foods Diet

#22 (tie): Paleo Diet

#24: Keto Diet

Best Diets for Bone and Joint Health 

The Top 3: 

#1 (tie): DASH Diet

#1 (tie): Mediterranean Diet

#3: Flexitarian Diet

The Bottom 3: 

#21 (tie): Raw Foods Diet

#21 (tie): Paleo Diet

#22: Atkins Diet 

#23: Keto Diet 

Best Diets for Healthy Eating

The Top 3: 

#1: Mediterranean Diet

#2: DASH Diet

#3: Flexitarian Diet

The Bottom 3: 

#22: Keto Diet

#23: Atkins Diet

#24: Raw Foods Diet

Easiest Diets to FollowEasy

The Top 3: 

#1 (tie): Flexitarian Diet

#1 (tie): TLC Diet (This diet was designed by the NIH to reduce cholesterol levels and promote heart health.)

#3 (tie): Mediterranean Diet

#3 (tie): DASH Diet

The Bottom 3: 

#19: Atkins Diet

#20: Keto Diet

#22: Raw Foods Diet

Which Diets Are Best For Rapid Weight Loss?

Happy woman on scaleThere are 2 take-home lessons from the rapid weight loss category:

  1. If you are looking for rapid weight loss, any whole food restrictive diet will do.
    • Last year’s diet analysis included the vegan diet, and both vegan and keto diets ranked near the top of the rapid weight loss category. Keto and vegan diets are both very restrictive, but they are polar opposites in terms of the foods they allow and restrict.
      • The keto diet is a meat heavy, very low carb diet. It restricts fruits, some vegetables, grains, and most legumes.
      • The vegan diet is a very low-fat diet that eliminates meat, dairy, eggs, and animal fats.
    • The Atkins and keto diets toppled this year’s rapid weight loss list, but they were joined by the Mayo Clinic, South Beach, and volumetrics diets. Those diets are also restrictive, but, like the vegan diet, they are very different from the Atkins and keto diets.
    • I did not include commercial diets that rated high on this list, but they are all restrictive in one way or another.

2) Whole food, very low carb diets like Atkins and keto are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.

    • If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss.

Which Diet Should You Choose?

Food ChoicesWith rapid weight loss out of the way, let’s get back to the question, “Which Diet Should You Choose?” My recommendations are:

1) Choose a diet that fits your needs. That is one of the things I like best about the US News & World Report ratings. The diets are categorized. If your main concern is diabetes, choose one of the top diets in that category. If your main concern is heart health… You get the point.

2) Choose diets that are healthy and associated with long term weight loss. If that is your goal, you will notice that primarily plant-based diets top these lists. Meat-based, low carb diets like Atkins and keto are near the bottom of the lists.

  • “Why is that?”, you might ask? The answer is simple. And it’s not that all 30 experts were prejudiced against low carb diets. It’s that the major primarily plant-based diets like Mediterranean, DASH, and flexitarian are backed by long-term clinical studies showing they are healthy and significantly reduce the risk of diabetes, heart disease, and other chronic diseases.
  • On the other hand, there are no long-term studies showing the Atkins and keto diets are healthy long term. And since the Atkins diet has been around for more than 50 years, the lack of clinical evidence that it is healthy long term is damming.

3) Choose diets that are easy to follow. The less-restrictive primarily plant-based diets top this list – diets like Mediterranean, DASH, MIND, and flexitarian. They are also at or near the top of almost every diet category.

4) Choose diets that fit your lifestyle and dietary preferences. For example, if you don’t like fish and olive oil, you will probably do much better with the DASH or flexitarian diet than with the Mediterranean diet.

5) Finally, focus on what you have to gain, rather than on foods you have to give up.

  • On the minus side, none of the diets include sodas, junk foods, and highly processed foods. These foods should go on your “No-No” list. Sweets should be occasional treats and only as part of a healthy meal. Meat, especially red meat, should become a garnish rather than a main course.
  • On the plus side, primarily plant-based diets offer a cornucopia of delicious plant foods you probably didn’t even know existed. Plus, for any of the top-rated plant-based diets, there are websites and books full of mouth-watering recipes. Be adventurous.

What About Commercial Diets?

I chose not to review commercial diets by name, but let me make a few observations.

  • If you look at the gaps in my lists, it should be apparent that several commercial diets rank near the top for fast weight loss, but near the bottom on most healthy diet lists.
  • I do not recommend commercial diets that rely on ready-to-eat, low-calorie, highly processed versions “of your favorite foods”.
    • These pre-packaged meals are expensive. Unless you are a millionaire, you won’t be able to afford these meals for the rest of your life.
    • These pre-packaged meals are not teaching you healthy eating habits that will allow you to keep the weight off.
  • If you wish to spend your hard-earned dollars on a commercial diet, choose a diet that:
    • Relies on whole foods from all 5 food groups.
    • Teaches and provides support for the type of lifestyle change that leads to permanent weight loss.
  • Meal replacement shakes can play a role in healthy weight loss if:
    • They are high quality and use natural ingredients as much as possible.
    • They are part of a holistic lifestyle change program.

The Bottom Line 

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January. If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories. In the article above I summarize the US News & World Report’s “Best Diets In 2023”.

There are probably two questions at the top of your list.

#1: Which diets are best for rapid weight loss? Here are 2 general principles:

  1. If you are looking for rapid weight loss, any whole food restrictive diet will do.

2) If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss. Atkins and keto diets are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.

#2: Which diet should you choose? Here the principles are:

  1. Choose a diet that fits your needs.

2) Choose diets that are healthy and associated with long term weight loss.

3) Choose diets that are easy to follow.

4) Choose diets that fit your lifestyle and dietary preferences.

5) Finally, focus on what you have to gain, rather than on foods you have to give up.

For more details on the diet that is best for you and my thoughts on commercial diets, read the article above.

Which Supplements Are Good For Your Heart?

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How Should You Interpret This Study? 

Author: Dr. Stephen Chaney 

strong heartFebruary is Heart Health month. So, it is fitting that we ask, “What is the status of heart health in this country?” The American Heart Association just published an update of heart health statistics through 2019 (CW Tsao et al, Circulation, 145: e153-e639, 2022). And the statistics aren’t encouraging. [Note: The American Heart Association only reported statistics through 2019 because the COVID-19 pandemic significantly skewed the statistics in 2020 and 2021].

The Good News is that between 2009 and 2019:

  • All heart disease deaths have decreased by 25%.
  • Heart attack deaths have decreased by 6.6%.
  • Stroke deaths have decreased by 6%.

The Bad News is that:

  • Heart disease is still the leading cause of death in this country.
  • Someone dies from a heart attack every 40 seconds.
  • Someone dies from a stroke every 3 minutes.

Diet, exercise, and weight control play a major role in reducing the risk of heart disease. Best of all, they have no side effects. They represent a risk-free approach that each of us can control.

But is there something else? Could supplements play a role? Are supplements hype or hope for a healthy heart?

All the Dr. Strangeloves in the nutrition space have their favorite heart health supplements. They claim their supplements will single-handedly abolish heart disease (and help you leap tall buildings in a single bound).

On the other hand, many doctors will tell you these supplements are a waste of money. They don’t work. They just drain your wallet.

It’s so confusing. Who should you believe? Fortunately, a recent study (P An et al, Journal of the American College of Cardiology, 80: 2269-2285, 2022) has separated the hype from the hope and tells us which “heart-healthy” supplements work, and which don’t.

How Was This Study Done?

Clinical StudyThis was a major clinical study carried out by researchers from the China Agricultural University and Brown University in the US. It was a meta-analysis, which means it combined the data from many published clinical trials.

The investigators searched three major databases of clinical trials to identify:

  • 884 randomized, placebo-controlled clinical studies…
  • Of 27 types of micronutrients…
  • With a total of 883,627 patients…
  • Looking at the effectiveness of micronutrient supplementation lasting an average of 3 years on either…
    • Cardiovascular risk factors like blood pressure, total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides…or…
    • Cardiovascular outcomes such as coronary heart disease (CHD), heart attacks, strokes, and deaths due to cardiovascular disease (CVD) and all causes.

[Note: Coronary heart disease (CHD) refers to build up of plaque in the coronary arteries (the arteries leading to the heart). It is often referred to as heart disease and can lead to heart attacks (myocardial infarction). Cardiovascular disease (CVD) is a more inclusive term that includes coronary heart disease, stroke, congenital heart defects, and peripheral artery disease.]

The investigators also included an analysis of the quality of the data in each of the clinical studies and rated the evidence of each of their findings as high quality, moderate quality, or low quality.

Which Supplements Are Good For Your Heart?

The top 3 heart-healthy supplements in this study were:

Omega-3s And Heart DiseaseOmega-3 Fatty Acids:

  • Increased HDL cholesterol and decreased triglycerides, both favorable risk factors for heart health.
  • Deceased risk of heart attacks by 15%, all CHD events by 14%, and CVD deaths by 7% (see definitions of CHD and CVD above).
  • The median dose of omega-3 fatty acids in these studies was 1.8 g/day.
  • The evidence was moderate quality for all these findings.

Folic Acid:

  • Decreased LDL cholesterol (moderate quality evidence) and decreased blood pressure and total cholesterol (low quality evidence).
  • Decreased stroke risk by 16% (moderate quality evidence).

Coenzyme Q10:

  • Decreased triglycerides (high quality evidence) and reduced blood pressure (low quality evidence).
  • Decreased the risk of all-cause mortality by 32% (moderate quality evidence).
  • These studies were performed with patients diagnosed with heart failure. Coenzyme Q10 is often recommended for these patients, so the studies were likely performed to test the efficacy of this treatment.

There were three micronutrients (vitamin C, vitamin E, and vitamin D) that did not appear to affect heart disease outcomes.

Finally, as reported in previous studies, β-carotene increased the risk of stroke, CVD mortality, and all-cause mortality.

In terms of the question I asked at the beginning of this article, this study concluded that:

  • Omega-3, folic acid, and coenzyme Q10 supplements represent hope for a healthy heart.
  • Vitamin C, vitamin E, and vitamin D supplements represent hype for a healthy heart.
  • β-carotene supplements represent danger for a healthy heart.

But these conclusions just scratch the surface. To put them into perspective we need to dig a bit deeper.

How Should You Interpret This Study?

Question MarkIn evaluating the significance of these findings there are two things to keep in mind.

#1: This study is a meta-analysis and meta-analyses have both strengths and weaknesses.

The strength of meta-analyses is that by combining multiple clinical studies they can end up with a database containing 100s of thousands of subjects. This allows them to do two things:

  • It allows the meta-analysis to detect statistically significant effects that might be too small to detect in an individual study.
  • It allows the meta-analysis to detect the average effect of all the clinical studies it includes.

The weakness of meta-analyses is that the design of individual studies included in the analysis varies greatly. The individual studies vary in things like dose, duration, type of subjects included in the study, and much more.

This is why this study rated most of their conclusions as backed by moderate- or low-quality evidence. [Note: The fact that the authors evaluated the quality of evidence is a strength of this study. Most meta-analyses just report their conclusions without telling you how strong the evidence behind those conclusions is.]

#2: Most clinical studies of supplements (including those included in this meta-analysis) have two significant weaknesses.

  • Most studies do not measure the nutritional status of their subjects prior to adding the supplement. If their nutritional status for a particular nutrient was already optimal, there is no reason to expect more of that nutrient to provide any benefit.
  • Most studies measure the effect of a supplement on a cross-section of the population without asking who would be most likely to benefit.

You would almost never design a clinical study that way if you were evaluating the effectiveness of a potential drug. So, why would you design clinical studies of supplements that way?

With these considerations in mind, let me provide some perspective on the conclusions of this study.

Coenzyme Q10:

This meta-analysis found that coenzyme Q10 significantly reduced all-cause mortality in patients with heart failure. This is consistent with multiple clinical studies and a recent Cochrane Collaboration review.

Does coenzyme Q10 have any heart health benefits for people without congestive heart failure? There is no direct evidence that it does, but let me offer an analogy with statin drugs.

Statin drugs are very effective at reducing heart attacks in high-risk patients. But they have no detectable effect on heart attacks in low-risk patients. However, this has not stopped the medical profession from recommending statins for millions of low-risk patients. The rationale is that if they are so clearly beneficial in high-risk patients, they are “probably” beneficial in low-risk patients.

I would argue a similar rationale should apply to supplements like coenzyme Q10.

Omega-3s:

This study found that omega-3 reduced both heart attacks and the risk of dying from heart disease. Most previous meta-analyses of omega-3s and heart disease have come to the same conclusion. However, some meta-analyses have failed to find any heart health benefits of omega-3s. Unfortunately, this has allowed both proponents and opponents of omega-3 use for heart health to quote studies supporting their viewpoint.

However, there is one meta-analysis that stands out from all the others. A group of 17 scientists from across the globe collaborated in developing a “best practices” experimental design protocol for assessing the effect of omega-3 supplementation on heart health. They conducted their clinical studies independently, and when their data (from 42,000 subjects) were pooled, the results showed that omega-3 supplementation decreased:

  • Premature death from all causes by 16%.
  • Premature death from heart disease by 19%.
  • Premature death from cancer by 15%.
  • Premature death from causes other than heart disease and cancer by 18%.

This study eliminates the limitations of previous meta-analyses. That makes it much stronger than the other meta-analyses. And these results are consistent with the current meta-analysis.

Omega-3s have long been recognized as essential nutrients. It is past time to set Daily Value (DV) recommendations for omega-3s. Based on the recommendations of other experts in the field, I think the DV should be set at 500-1,000 mg/day. I take more than that, but this would represent a good minimum recommendation for heart health.

folic acidFolic acid:

As with omega-3s, this meta-analysis reported a positive effect of folic acid on heart health. But many other studies have come up empty. Why is that?

It may be because, between food fortification and multivitamin use, many Americans already have sufficient blood levels of folic acid. For example, one study reported that 70% of the subjects in their study had optimal levels of folates in their blood. And that study also reported:

  • Subjects with adequate levels of folates in their blood received no additional benefit from folic acid supplementation.
  • However, for subjects with inadequate blood folate levels, folic acid supplementation decreased their risk of heart disease by ~15%.

We see this pattern over and over in supplement studies. Supplement opponents interpret these studies as showing that supplements are worthless. But a better interpretation is that supplements benefit those who need them.

The problem is that we don’t know our blood levels of essential nutrients. We don’t know which nutrients we need, and which we don’t. That’s why I like to think of supplements as “insurance” against the effects of an imperfect diet.

Vitamins E and D:

The situation with vitamins E and D is similar. This meta-analysis found no heart health benefit of either vitamin E or D. That is because the clinical studies included in the meta-analysis asked whether vitamin E or vitamin D improved heart health for everyone in the study.

Previous studies focusing on patients with low blood levels of these nutrients and/or at high risk of heart disease have shown some benefits of both vitamins at reducing heart disease risk.

So, for folic acid, vitamin E, and vitamin D (and possibly vitamin C) the take-home message should be:

  • Ignore all the Dr. Strangeloves telling you that these vitamins are “magic bullets” that will dramatically reduce your risk of heart disease.
  • Ignore the naysayers who tell you they are worthless.
  • Use supplementation wisely to make sure you have the recommended intake of these and other essential nutrients.

β-carotene:

This meta-analysis reported that β-carotene increased the risk of heart disease. This is not a new finding. Multiple previous studies have come to the same conclusion.

And we know why this is. There are many naturally occurring carotenoids, and they each have unique heart health benefits. A high dose β-carotene supplement interferes with the absorption of the other carotenoids. You are creating a deficiency of other heart-healthy carotenoids.

If you are not getting lots of colorful fruits and vegetables from your diet, my recommendation is to choose a supplement with all the naturally occurring carotenoids in balance – not a pure β-carotene supplement.

The Bottom Line 

The Dr. Strangeloves in the nutrition space all have their favorite heart health supplements. They claim their supplements will single-handedly abolish heart disease (and help you leap tall buildings in a single bound).

On the other hand, many doctors will tell you these supplements are a waste of money. They don’t work. They just drain your wallet.

It’s so confusing. Who should you believe? Fortunately, a recent study has separated the hype from the hope and tells us which “heart-healthy” supplements work, and which don’t.

This study was a meta-analysis of 884 clinical studies with 883,627 participants. It reported:

  • Omega-3 supplementation deceased risk of heart attacks by 15% and all cardiovascular deaths by 7%.
  • Folic acid supplementation decreased stroke risk by 16%.
  • Coenzyme Q10 supplementation decreased the risk of all-cause mortality in patients with heart failure by 32%.
  • Vitamin C, vitamin E, vitamin D did not appear to affect heart disease outcomes.
  • β-carotene increased the risk of stroke, CVD mortality, and all-cause mortality.

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Does Magnesium Protect Your Heart?

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Do You Need A Magnesium Supplement?

Author: Dr. Stephen Chaney 

Getting an adequate amount magnesium from our diet should not be a problem. Magnesium is found in a wide variety of foods with the best sources being legumes (beans), nuts, seeds, whole grains, green leafy vegetables, and dairy foods.

The problem is:

  • None of these foods contain enough magnesium by themselves to provide the RDA (420 mg/day for men and 320 mg/day for women) for magnesium. We need to consume a variety of these foods every day – something most Americans aren’t doing.
  • These foods are decent sources of magnesium only in their unprocessed form. And most Americans consume more highly processed foods than whole, unprocessed foods.
  • Two to three servings of dairy provide a decent amount of magnesium, but many Americans are cutting back on dairy. And plant-based dairy substitutes often provide much less magnesium than the dairy food they replace.
  • Finally, green leafy vegetables (iceberg lettuce doesn’t count) don’t make it into the American menu as often as they should.

As a result, recent studies find that at least 50% of Americans are not getting enough magnesium in their diet. In fact, the average magnesium intake in this country is 268 mg/day for men and 234 mg/day for women. And the figures are not very different in other developed countries.

Does it matter? Recent studies have shown that an adequate intake of dietary magnesium is associated with lower risks of cardiovascular diseases (CVD) and all-cause mortality. This may be because of the of role of magnesium in supporting heart muscle contraction, normal heart rhythm, and blood pressure regulation. Adequate magnesium intake is also associated with lower risk of type 2 diabetes.

But what if you have already had a heart attack? Is it too late for magnesium to make a difference? A recent study (I Evers et al, Frontiers in Cardiovascular Medicine, August 12, 2022) was designed to answer this question.

The authors examined the effect of magnesium intake on cardiovascular disease (CVD) mortality, all-cause mortality, and coronary heart disease (CHD) mortality in patients who had experienced a recent heart attack.

[Note: CHD is defined as heart disease due to clogged coronary arteries, such as a heart attack. CVD includes CHD plus diseases caused by other clogged blood vessels, such as strokes and peripheral artery disease].

How Was The Study Done?

clinical studyThe authors used data from a previous study that had enrolled 4,365 Dutch patients aged 60-80 (average age = 69) who had experienced a heart attack within approximately 4 years prior to enrollment and followed them for an average of 12.4 years. All patients were receiving standard post-heart attack drug therapy.

The characteristics of the patients enrolled in the study were as follows:

  • Male 79%, female 21%
  • Average magnesium intake = 302 mg/day
  • Percent magnesium deficient: 72% of men and 67% of women
  • Percent taking magnesium supplements = 5.4%
  • Percent on drugs to lower blood pressure = 90%
  • Percent on statins = 86%
  • Percent on diuretics = 24%

Upon entry into the study the patients were asked to fill out a 203-item food frequency questionnaire reflecting their dietary intake over the past month. Trained dietitians reviewed the questionnaires and phoned the participants to clarify any unclear or missing items. The questionnaires were linked to the 2006 Dutch Food Composition Database to calculate magnesium intake and other aspects of their diets.

The patients were divided into 3 groups based on their energy adjusted magnesium intakes and those in the highest third (>322 mg/day) were compared to those in the lowest third (<238 mg/day) with respect to cardiovascular disease (CVD), all-cause mortality, and coronary heart disease (CHD) mortality.

The comparisons were statically adjusted for fiber intake (most magnesium-rich foods are also high fiber foods), diuretic use (diuretics reduce magnesium levels in the blood), age, sex, smoking, alcohol use, physical activity, obesity, education level, caloric intake, calcium, vitamin D, sodium from foods, potassium, heme iron, vitamin C, beta-carotenoids, polyunsaturated fatty acids, saturated fatty acids, overall diet quality based on the Dutch Dietary Guidelines, systolic blood pressure, kidney function, and diabetes. In other words, the data were adjusted for every conceivable variable that could have influenced the outcome.

Does Magnesium Protect Your Heart?

When those with the highest magnesium intake (>322 mg/day) were compared to those with the lowest intake (<283 mg/day):

  • Cardiovascular disease (CVD) mortality was reduced by 28%.
  • All-cause mortality was reduced by 22%.
  • Coronary heart disease (CHD) mortality was reduced by 16%, but that reduction was not statistically significant.

They then looked at the effect of some variables that might affect CVD risk on the results.

  • Diabetes, kidney function, iron intake, smoking, alcohol use, blood pressure, most dietary components and overall diet quality had no effect on the results.
  • The results were also not affected when patients using a magnesium supplement were excluded from the analysis. This suggests the effect of magnesium from diet and supplementation is similar.
  • However, diuretic use had a significant effect on the results.
    • For patients using diuretics, high magnesium intake versus low magnesium intake reduced CVD mortality by 45%.

How Much Magnesium Do You Need?

Question MarkYou may have noticed that the difference between the highest magnesium intake group and the lowest intake group was, on average, only 39 mg/day. So, the authors also used a statistical approach that utilized data from each individual patient to produce a graph of magnesium intake versus risk of CVD, total, and CHD mortality. For all 3 end points the graphs showed an inverse, linear relationship between magnesium and mortality.

From this, the authors were able to calculate the effect of each 100mg/day increase in magnesium intake on mortality risk. Each 100mg/day of added magnesium reduced the risk of:

  • CVD mortality by 38%.
  • All-cause mortality by 30%.
  • CHD mortality by 33%, and these results were borderline significant.

The inverse relationship between magnesium intake was observed at intakes ranging from around 200 mg/day to around 450 mg/day, which represented the range of dietary magnesium intake in this Dutch population group.

This study did not define an upper limit to the beneficial effect of magnesium intake because the graphs had not plateaued at 450 mg/day, suggesting that higher magnesium intakes might give even better results.

The authors concluded, “We observed a strong, linear inverse association of dietary magnesium with CVD and all-cause mortality after a heart attack, which was most pronounced in patients who used diuretics. Our findings emphasize the importance of an adequate magnesium intake in CVD patients, on top of cardiovascular drug treatment.”

I might add that this is the first study to look at the effect of magnesium on long-term survival after a heart attack.

Do You Need A Magnesium Supplement? 

magnesium supplements benefitsAs I said earlier, the best dietary sources of magnesium are beans, nuts, seeds, whole grains, green leafy vegetables, and dairy foods. And:

  • None of these foods contain enough magnesium by themselves to provide the RDA (420 mg/day for men and 320 mg/day for women) for magnesium.
  • These foods are decent sources of magnesium only in their unprocessed form.

When unprocessed, each of these foods provides 20 to 60 mg of magnesium per serving. If we use an average value of 40 mg/serving, you would need in the range of 8-10 servings/day of these foods in their unprocessed form to meet the RDA for magnesium.

You could get a more accurate estimate of the magnesium content of your diet using the “Magnesium Content of Selected Foods” table from the NIH Factsheet on Magnesium.

Now you are ready to ask yourself two questions:

  1. Does my current diet provide the RDA for magnesium?

2. If not, am I willing to make the dietary changes needed to increase my magnesium levels to RDA levels?

If your answer to both questions is no, you should probably consider a magnesium supplement. A supplement providing around 200 mg of magnesium should bring all but the worst diets up to the recommended magnesium intake.

The current study did not define an upper limit for the beneficial effect of magnesium on survival after a heart attack but suggested that intakes above 450 mg/day might be optimal.

I do not recommend megadoses of magnesium, but intakes from diet and supplementation that slightly exceed the RDA appear to be safe. In their Magnesium Factsheet, the NIH states, “Too much magnesium…does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts in the urine.”

The only concern is that magnesium from supplements is absorbed much more rapidly than magnesium from foods, and this can cause gas, bloating, and diarrhea in some individuals. For this reason, I recommend a sustained release magnesium supplement, so the magnesium is absorbed more slowly.

Finally, we should not consider magnesium as a magic bullet. The current study statistically eliminated every known variable that might affect survival after a heart attack, so it could estimate the beneficial effects of magnesium alone.

However, survival after a heart attack will likely be much greater if diet, exercise, and body mass are also optimized.

The Bottom Line 

Recent studies have shown that an adequate intake of dietary magnesium is associated with lower risks of cardiovascular diseases (CVD) and all-cause mortality.

But what if you have already had a heart attack? Is it too late for magnesium to make a difference? A recent study of heart attack patients in Holland was designed to answer this question.

The authors examined the effect of magnesium intake on cardiovascular disease (CVD) mortality, all-cause mortality, and coronary heart disease (CHD) mortality in patients who had experienced a recent heart attack.

When heart attack patients with the highest magnesium intake (>322 mg/day) were compared to those with the lowest intake (<283 mg/day):

  • Cardiovascular disease (CVD) mortality was reduced by 28%.
  • All-cause mortality was reduced by 22%.
  • Coronary heart disease (CHD) mortality was reduced by 16%, but that reduction was not statistically significant.

The authors went on to look at the inverse linear relationship between magnesium intake and mortality risk. They found that each 100mg/day of added magnesium reduced the risk of:

  • CVD mortality by 38%.
  • All-cause mortality by 30%.
  • CHD mortality by 33%, and these results were borderline significant.

The authors concluded, “We observed a strong, linear inverse association of dietary magnesium with CVD and all-cause mortality after a heart attack…Our findings emphasize the importance of an adequate magnesium intake in CVD patients…”

I might add that this is the first study to look at the effect of magnesium on long-term survival of patients who have suffered a heart attack.

For more details on this study and my discussion of whether you might benefit from a magnesium supplement, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

What Is The Truth About Low Carb Diets?

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Why Is The Cochrane Collaboration The Gold Standard?

Author: Dr. Stephen Chaney 

low carb dietAtkins, South Beach, Whole30, Low Carb, high Fat, Low Carb Paleo, and Keto. Low carb diets come in many forms. But they have these general characteristics:

  • They restrict carbohydrate intake to <40% of calories.
  • They restrict grains, cereals, legumes, and other carbohydrate foods such as dairy, fruits, and some vegetables.
  • They replace these foods with foods higher in fat and protein such as meats, eggs, cheese, butter, cream, and oils.
  • When recommended for weight loss, they generally restrict calories.

What about the science? Dr. Strangelove and his friends tell you that low carb diets are better for weight loss, blood sugar control, and are more heart healthy than other diets. But these claims are controversial.

Why is that? I have discussed this in previous issues of “Health Tips From The Professor”. Here is the short version.

  • Most studies on the benefits of low carb diets compare them with the typical American diet.
    • The typical American diet is high in fat, sugar and refined flour, and highly processed foods. Anything is better than the typical American diet.
  • Most low carb diets are whole food diets.
    • Any time you replace sodas and highly processed foods with whole foods you will lose weight and improve your health.
  • Most low carb diets are highly structured. There are rules for which foods to avoid, which foods to eat, and often additional rules to follow.
    • Any highly structured diet causes you to focus on what you eat. When you do that, you lose weight. When you lose weight, your health parameters improve.
    • As I have noted before, short term weight loss and improvement in health parameters are virtually identical for the very low carb keto diet and the very low-fat vegan diet.

With all this uncertainty you are probably wondering, “What is the truth about low carb diets?”

A recent study by the Cochrane Collaboration (CE Naude et al, Cochrane Database of Systematic Reviews, 28 January 2022) was designed to answer this question.

The Cochrane Collaboration is considered the gold standard of evidence-based medicine. To help you understand why this is, I will repeat a summary of how the Cochrane Collaboration approaches clinical studies that I shared two weeks ago.

Why Is The Cochrane Collaboration The Gold Standard?

ghost bustersWho you gonna call? It’s not Ghostbusters. It’s not Dr. Strangelove’s health blog. It’s a group called the Cochrane Collaboration.

The Cochrane Collaboration consists of 30,000 volunteer scientific experts from across the globe whose sole mission is to analyze the scientific literature and publish reviews of health claims so that health professionals, patients, and policy makers can make evidence-based choices about health interventions.

In one sense, Cochrane reviews are what is called a “meta-analysis”, in which data from numerous studies are grouped together so that a statistically significant conclusion can be reached. However, Cochrane Collaboration reviews differ from most meta-analyses found in the scientific literature in a very significant way.

Many published meta-analyses simply report “statistically significant” conclusions. However, statistics can be misleading. As Mark Twain said: “There are lies. There are damn lies. And then there are statistics”.

The Cochrane Collaboration also reports statistically significant conclusions from their meta-analyses. However, they carefully consider the quality of each individual study in their analysis. They look at possible sources of bias. They look at the design and size of the studies. Finally, they ask whether the conclusions are consistent from one study to the next. They clearly define the quality of evidence that backs up each of their conclusions as follows:

  • High-quality evidence. Further research is unlikely to change their conclusion. This is generally reserved for conclusions backed by multiple high-quality studies that have all come to the same conclusion. These are the recommendations that are most often adopted into medical practice.
  • Moderate-quality evidence. This conclusion is very likely to be true, but further research could have an impact on it.
  • Low-quality evidence. Further research is needed and could alter the conclusion. They are not judging whether the conclusion is true or false. They are simply saying more research is needed to reach a definite conclusion.

This is why their reviews are considered the gold standard of evidence-based medicine. If you are of a certain age, you may remember that TV commercial “When EF Hutton talks, people listen.” It is the same with the Cochrane Collaboration. When they talk, health professionals listen.

How Was The Study Done?

Clinical StudyThe authors of this Cochrane Collaboration Report included 61 published clinical trials that randomized participants into two groups.

  • The first group was put on a low carbohydrate diet (carbohydrates = <40% of calories).
  • The second group was put on a “normal carbohydrate” diet (carbohydrates = 45-65% of calories, as recommended by the USDA and most health authorities).
    • The normal carbohydrate diet was matched with the low carbohydrate diet in terms of caloric restriction.
    • Both diets were designed by dietitians and were generally whole food diets.

The participants in these studies:

  • Were middle-aged.
  • Were overweight or obese.
  • Did not have diagnosed heart disease or cancer.
  • May have diagnosed type-2 diabetes. Some studies selected participants that had diagnosed type 2 diabetes. Other studies excluded those patients.

The studies were of 3 types:

  • Short-term: Participants in these studies followed their assigned diets for 3 to <12 months.
  • Long-term: Participants in these studies followed their assigned diets for >12 to 24 months.
  • Short-term with maintenance: Participants in these studies followed their assigned diets for 3 months followed by a 9-month maintenance phase.

What Is The Truth About Low Carb Diets?

The TruthAll the studies included in the Cochrane Collaboration’s meta-analysis randomly assigned overweight participants to a low carbohydrate diet (carbohydrates = <40% of calories) or to a “normal carbohydrate” diet (carbohydrates = 45-65% of calories) with the same degree of caloric restriction.

If low carb diets have any benefit in terms of weight loss, improving blood sugar control, or reducing heart disease risk, these are the kind of studies that are required to validate that claim.

This is what the Cochrane Collaboration’s meta-analysis showed.

When they analyzed studies done with overweight participants without type 2 diabetes:

  • Weight loss was not significantly different between low carb and normal carb diets in short-term studies (3 to <12 months), long-term studies (>12 to 24 months), and short-term studies followed by a 9-month maintenance period.
  • There was also no significant difference in the effect of low carb and normal carb diets on the reduction in diastolic blood pressure and LDL cholesterol.

Since diabetics have trouble controlling blood sugar, you might expect that type 2 diabetics would respond better to low carb diets. However, when they analyzed studies done with overweight participants who had type 2 diabetes:

  • Weight loss was also not significantly different on low carb and normal carb diets.
  • There was no significant difference in the effect of low carb and normal carb diets on the reduction in diastolic blood pressure, LDL cholesterol, and hemoglobin A1c, a measure of blood sugar control.

Of course, the reason Cochrane Collaboration analyses are so valuable is they also analyze the strength of the studies that were included in their analysis.

You may remember in my article two weeks ago, I reported on the Cochrane Collaboration’s report supporting the claim that omega-3 supplementation reduces pre-term births. In that report they said that the studies included in their analysis were high quality. Therefore, they said their report was definitive and no more studies were needed.

This analysis was different. The authors of this Cochrane Collaboration report said that the published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

What Does This Study Mean For You?

confusionIf you are a bit confused by the preceding section, I understand. That was a lot of information to take in. Let me give you the Cliff Notes version.

In short, this Cochrane Collaboration Report concluded:

  • Low carb diets (<40% of calories from carbohydrates) are no better than diets with normal carbohydrate content (45-65% of calories from carbohydrates) with respect to weight loss, reduction in heart disease risk factors, and blood sugar control. Dr. Strangelove has been misleading you again.
  • This finding is equally true for people with and without type 2 diabetes. This calls into question the claim that people with type 2 diabetes will do better on a low carb diet.
  • The published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

If you are thinking this study can’t be true because low carb diets work for you, that is because you are comparing low carb diets to your customary diet, probably the typical American diet.

  • Remember that any whole food diet that eliminates sodas and processed foods and restricts the foods you eat will cause you to lose weight. Whole food keto and vegan diets work equally well short-term compared to the typical American diet.
  • And any diet that allows you to lose weight improves heart health parameters and blood sugar control.

If you are thinking about the blogs, books, and videos you have seen extolling the virtues of low carb diets, remember that the Dr. Strangeloves of the world only select studies comparing low carb diets to the typical American diet to support their claims.

  • The studies included in this Cochrane Collaboration report randomly assigned participants to the low carb and normal carb diets and followed them for 3 to 24 months.
    • Both diets were whole food diets designed by dietitians.
    • Both diets reduced caloric intake to the same extent.

What about the claims that low carb diets are better for your long-term health? There are very few studies on that topic. Here are two:

  • At the 6.4-year mark a recent study reported that the group with the lowest carbohydrate intake had an increased risk of premature death – 32% for overall mortality, 50% for cardiovascular mortality, 51% for cerebrovascular mortality, and 36% for cancer mortality. I will analyze this study in a future issue of “Health Tips From The Professor”.
  • At the 20-year mark a series of studies reported that:
    • Women consuming a meat-based low carb diet for 20 years gained just as much weight and had just as high risk of heart disease and diabetes as women consuming a high carbohydrate, low fat diet.
    • However, women consuming a plant-based low carb diet for 20 years gained less weight and had reduced risk of developing heart disease and diabetes as women consuming a high carbohydrate, low fat diet.

My recommendation is to avoid low-carb diets. They have no short-term benefits when compared to a healthy diet that does not eliminate food groups. And they may be bad for you in the long run. Your best bet is a whole food diet that includes all food groups but eliminates sodas, sweets, and processed foods.

However, if you are committed to a low carb diet, my recommendation is to choose the low-carb version of the Mediterranean diet. It is likely to be healthy long term.

The Bottom Line 

The Cochrane Collaboration, the gold standard of evidence-based medicine, recently issued a report that evaluated the claims made for low carb diets.

All the studies analyzed in the Cochrane Collaboration’s report randomly assigned overweight participants to a low carbohydrate diet (carbohydrates = <40% of calories) or to a “normal carbohydrate” diet (carbohydrates = 45-65% of calories) with the same degree of caloric restriction.

If low carb diets have any benefit in terms of weight loss, improving blood sugar control, or reducing heart disease risk, these are the kind of studies that are required to validate that claim.

The Cochrane Collaboration Report concluded:

  • Low carb diets (<40% of calories from carbohydrates) are no better than diets with normal carbohydrate content (45-65% of calories from carbohydrates) with respect to weight loss, reduction in heart disease risk factors, and blood sugar control.
  • This is equally true for people with and without type 2 diabetes.
  • The published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

My recommendation is to avoid low carb diets. They have no short-term benefits when compared to a healthy diet that does not eliminate food groups. And they may be bad for you in the long run. Your best bet is a whole food diet that includes all food groups but eliminates sodas, sweets, and processed foods.

However, if you are committed to a low carb diet, my recommendation is to choose the low carb version of the Mediterranean diet. It is likely to be healthy long term.

For more details on the study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Do Calcium Supplements Increase Deaths From Heart Valve Disease?

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What Did This Study Get Wrong?

Author: Dr. Stephen Chaney

Aortic Stenosis“Killer calcium” is back. Once again, we are seeing headlines saying that calcium supplementation increases our risk of dying from heart disease. If you have seen these headlines, you are probably confused.

After all, there have been three major clinical studies looking at the effect of calcium supplementation on heart disease risk. These studies followed close to 100,000 Americans for 10-20 years. And none of the studies found any increase in the risk of developing or dying from heart disease for people taking calcium supplements. For more information on this topic, see an article from “Health Tips From the Professor”.

You are probably wondering, “What is going on? I thought this issue was settled”.

In the first place, this study did not look at heart disease in general, but on a very specific form of heart valve disease called aortic stenosis. Aortic stenosis is a narrowing of the heart valve leading to the aorta. And it is often associated with calcification of the heart valve.

The cause of aortic stenosis is complex, but it is associated with:

  • Chronic inflammation.
  • High cholesterol levels.
  • Tobacco use.
  • Dysregulation of calcium metabolism caused by things like elevated parathyroid levels and end-stage kidney disease.
  • Elevated blood levels of calcium and/or vitamin D.

Because of the role of calcium and vitamin D in aortic stenosis, the current study (N Kassis et al, Heart, Epub ahead of print, 1-9, 2022) was designed to ask whether calcium and vitamin D supplementation influenced the risk of dying from aortic stenosis.

How Was This Study Done?

Heart Disease StudyThe Cleveland Clinic scanned their Echocardiography Database for patients aged 60 years or more who had been diagnosed with mild to moderate aortic stenosis. 2,657 patients met these criteria (average age = 74, 58% men) and were followed for an average of 59 months in their database.

In terms of calcium and vitamin D supplementation:

  • 49% did not supplement.
  • 12.5% supplemented with vitamin D (dose not defined).
  • 38.5% supplemented with calcium (500 – 2,000 mg/day) ± vitamin D.

The study looked at the correlation between vitamin D supplementation and calcium supplementation with:

  • Aortic valve replacement surgery.
  • All-cause mortality* with and without aortic valve replacement surgery.
  • Cardiovascular mortality* with and without aortic valve replacement surgery.

*Note: Since all the patients had aortic stenosis at the beginning of the study, both all-cause and cardiovascular mortality were primarily due to aortic stenosis.

Do Calcium Supplements Increase Deaths From Heart Valve Disease?

Before I describe the results of the study, there are two things you need to know:

  • Vitamin D supplementation did not have a significant effect on any outcome studied, so I will not mention vitamin D in the rest of this article.
  • In the calcium supplementing group, there were only a few people taking calcium supplements without vitamin D. However, their outcomes were the same as for people taking calcium + vitamin D supplements. Therefore, the authors discussed their results in terms of calcium supplementation, not calcium + vitamin D supplementation. I will do the same.

With those two things in mind, here is what the study found.

With respect to the need for aortic valve replacement surgery:

  • Calcium supplementation increased the need for surgery by 50%.

With respect to all-cause mortality:

  • Calcium supplementation increased the risk of death by 31%. When you divided the results into patients who did and did not have aortic valve replacement surgery within the 59-month follow-up of this study:
    • Those who received aortic valve replacement surgery did not have a statistically significant increase in risk of death.
    • Those who did not receive aortic valve replacement surgery had a 38% increased risk of death.

With respect to cardiovascular mortality:

  • Calcium supplementation doubled the risk of death. When you divided the results into patients who did and did not have aortic valve replacement surgery within the 59-month follow-up of this study:
    • Those who received aortic valve replacement surgery did not have a statistically significant increase in risk of death.
    • Those who did not receive aortic valve replacement surgery had a 205% increased risk of death.

The authors concluded, “Supplemental calcium … is associated with lower survival and greater AVR [aortic valve replacement surgery] in elderly patients with mild to moderate AV [aortic stenosis].”

What Did This Study Get Wrong?

thumbs down symbolLet me start by looking at the limitations of this study.

#1: This is a single study. It is a well-designed study, but it is only one study. And, as the authors acknowledge, previous studies have come down on both sides of this issue. Until we have more well-designed studies that come to the same conclusion, we cannot be confident this study is correct.

#2: The results of this study could have been significantly influenced by confounding variables.

For example:

  • End-stage kidney disease is associated with a dysregulation of calcium metabolism that can lead to aortic valve calcification. Patients in the calcium supplementation group had a 2-fold higher incidence of chronic kidney disease and a 10-fold higher incidence of kidney dialysis.
  • There were also significant differences in several diseases and drugs that influence the risk of developing aortic stenosis between the groups.

In the words of the authors, “Given the degree of clinical differences between the groups, there was a risk of residual confounding that may have impacted our findings; we attempted to mitigate this with our statistical model.”

However, as Mark Twain is quoted as saying, “There are lies. There are damn lies. And then there are statistics.”

That is a humorous way of saying we should not put too much faith in statistical manipulations of the data.

#3: They did not measure parathyroid levels. That is a serious omission because elevated parathyroid levels are a major driver of the type of dysfunctional calcium metabolism that could lead to calcification of the aortic valve.

#4: Serum calcium and vitamin D levels were slightly lower in the calcium supplementation group. This is unexpected because aortic stenosis is usually associated with higher serum calcium and vitamin D levels.

The authors speculated this might be due to transient increases in serum calcium levels following supplementation. This is possible for some calcium supplements, but not others.

Specifically, some calcium supplements are marketed on how quickly they get into the bloodstream. But those same supplements often do not provide all the nutrients needed for bone formation. There is always the possibility that excess calcium not used for bone formation might be deposited where we do not want it (such as in the aortic valve).

What Did This Study Get Right?

thumbs up#1: It was a larger, longer lasting study than previous studies on the effect of calcium supplementation on aortic stenosis. Even though it has limitations, we shouldn’t discount it. It might just be correct.

#2: It doesn’t necessarily conflict with the earlier studies showing that calcium supplementation doesn’t increase cardiovascular disease risk. That’s because the design of these studies is very different.

  • The health of the people studied was very different.
    • The earlier studies started with healthy adults and asked whether calcium supplementation increased their risk of developing cardiovascular disease.
    • This study started with people who already had a form of cardiovascular disease associated with abnormal calcium metabolism and asked whether calcium supplementation increased their risk of dying from the disease.
  • The age of the people studied was very different.
    • The earlier studies started with middle-aged adults and followed them for 10-20 years
    • This study started with people in their mid-70’s and followed them for almost 6 years.
  • The type of cardiovascular disease studied was different.
    • The earlier studies included all types of cardiovascular disease.
    • This study focused on a very minor type of cardiovascular disease, aortic stenosis. Aortic stenosis accounts for about 10% of all cardiovascular disease 17% of cardiovascular deaths. There may not have been enough deaths from aortic stenosis in the previous studies to have had a statistically significant effect on the results.

Given all these differences, the results of this study may not be incompatible with the results of previous studies

What Does This Study Mean For You?

There are three important takeaways from this and previous studies:

1) For most Americans calcium supplementation does not increase the risk of cardiovascular disease. That has been shown in three major clinical studies.

2) However, if you have been diagnosed with aortic stenosis, calcium supplementation may increase your risk of needing heart valve replacement or of dying from the disease. This study is not definitive, but I would advise caution.

You may wish to discuss with your doctor how to best balance:

    • The need for calcium supplementation to prevent osteoporosis…
    • With the need to limit calcium supplementation to prevent adverse outcomes from your aortic stenosis.

3) Finally, the authors did not discuss a very significant observation from this study, namely that heart valve replacement reduced the risk of dying from aortic stenosis in people taking calcium supplements.

Aortic valve replacement is the only proven treatment for aortic stenosis. If your doctor recommends aortic valve replacement, you should consider it.

The Bottom Line

A recent study looked at the effect of calcium supplementation for people with aortic stenosis, a rare form of heart disease.

The study found:

  • Calcium supplementation increased the need for aortic valve replacement surgery by 50%.
  • Calcium supplementation increased the risk of all-cause mortality* by 31%. When you divided the results into patients who did and did not have aortic valve replacement surgery during the study:
    • Those who received aortic valve replacement surgery did not have a statistically significant increase in risk of death.
  • Calcium supplementation doubled the risk of cardiovascular mortality*. When you divided the results into patients who did and did not have aortic valve replacement surgery within the 59-month follow-up of this study:
    • Those who received aortic valve replacement surgery did not have a statistically significant increase in risk of death.

*Note: Since all the patients enrolled in this study had aortic stenosis at the beginning of the study, these deaths were primarily due to aortic stenosis.

The authors concluded, “Supplemental calcium … is associated with lower survival and greater AVR [aortic valve replacement surgery] in elderly patients with mild to moderate AV [aortic stenosis].”

There are three important takeaways from this and previous studies:

1) For most Americans calcium supplementation does not increase the risk of cardiovascular disease. That has been shown in three major clinical studies.

2) However, if you have been diagnosed with aortic stenosis, calcium supplementation may increase your risk of needing heart valve replacement or of dying from the disease. This study is not definitive, but I would advise caution.

  • You may wish to discuss with your doctor how to best balance:
    • The need for calcium supplementation to prevent osteoporosis…
    • With the need to limit calcium supplementation to prevent adverse outcomes from your aortic stenosis.

3) Finally, the authors did not discuss a very significant observation from this study, namely that heart valve replacement reduced the risk of dying from aortic stenosis in people taking calcium supplements.

Aortic valve replacement is the only proven treatment for aortic stenosis. If your doctor recommends aortic valve replacement, you should consider it.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

The Omega-3 Pendulum

by

Who Benefits Most From Omega-3s? 

Author: Dr. Stephen Chaney

Pendulum
Pendulum

If you were around in the 60’s, you might remember the song “England Swings Like a Pendulum Do”. It was a cute song, but it had nothing to do with pendulums. This week I am talking about something that really does resemble a pendulum – the question of whether omega-3s reduce heart disease risk.

There is perhaps nothing more confusing to the average person than the “truth” about omega-3s and heart disease risk. The headlines and expert opinion on the topic swing wildly between “omega-3s reduce heart disease risk” to “omega-3s have no effect on heart disease risk” and back again. To me these swings resemble the swings of a pendulum – hence the title of this article.

Part of the reason for the wild swings is that journalists and most “experts” tend to rely on the latest study and ignore previous studies. Another contributing factor is that most journalists and experts read only the main conclusions in the article abstract. They don’t read and analyze the whole study.

So, in today’s “Health Tips From the Professor” I plan to:

  • Analyze 3 major studies that have influenced our understanding of the relationship between omega-3 intake and heart disease risk. I will tell you what the experts missed about these studies and why they missed it.
  • Summarize what you should know about omega-3 intake and your risk of heart disease.

Why Is The Role Of Omega-3s In Preventing Heart Disease So Confusing?

SecretsIn answering that question, let me start with what I call “Secrets Only Scientists Know”.

#1: Each study is designed to disprove previous studies. That is a strength of the scientific method. But it guarantees there will be studies on both sides of every issue.

Responsible scientists look at all high-quality studies and base their opinions on the weight of evidence. Journalists and less-responsible “experts” tend to “cherry pick” the studies that match their opinions.

#2: Every study has its flaws. Even high-quality studies have unintended flaws. And I have some expertise in identifying unintended flaws.

I published over 100 papers that went through the peer review process. And I was involved in the peer review of manuscripts submitted by other scientists. In the discussion below I will use my experience in reviewing scientific studies to identify unintended flaws in 3 major studies on omega-3s and heart disease risk.

Next, let me share the questions I ask when reviewing studies on omega-3s and heart disease. I am just sharing the questions here. Later I will share examples of how these questions allowed me to identify unintended flaws in the studies I review below.

#1: How did they define heart disease? The headlines you read usually refer to the effect of omega-3s on “heart disease”. However, heart disease is a generic term. In layman’s terms, it encompasses angina, heart attacks, stroke due to blood clots, stroke due brain bleeds, congestive heart failure, impaired circulation, and much more.

Omega-3s have vastly different effects on different forms of heart disease, so it is important to know which form(s) of heart disease the study examined. And if the study included all forms of heart disease, it is important to know whether they also looked at the forms of heart disease where omega-3s have been shown to have the largest impact.

#2: What was the risk level of the patients in the study? If the patients in the study are at imminent risk of a heart attack or major cardiovascular event, it is much easier to show an effect than if they are at low risk.

For example, it is easy to show that statins reduce the risk of a second heart attack in someone who has just suffered a heart attack. These are high-risk patients. However, if you look at patients with high cholesterol but no other risk factors for heart disease, it is almost impossible to show a benefit of statins. These are low-risk patients.

If it is difficult to show that statins benefit low-risk patients, why should we expect to be able to show that omega-3s benefit low-risk patients?

[Note: I am not saying that statins do not benefit low-risk patients. I am just saying it is very difficult to prove they do in clinical studies.]

#3: How much omega-3s are the patients getting in their diet? The public reads the headlines. When the headlines say that omega-3s are good for their hearts, they tend to take omega-3 supplements. When the headlines say omega-3s are worthless, they cut back on omega-3 supplements. So, there is also a pendulum effect for omega-3 intake.

Omega-3s are fats. So, omega-3s accumulate in our cell membranes. The technical term for the amount of omega-3s in our cellular membranes is something called “Omega-3 Index”. Previous studies have shown that:

    • An omega-3 index of 4% or less is associated with high risk of heart disease, and…
    • An omega-3 index of 8% or more is associated with a low risk of heart disease.

When the omega-3 index approaches 8%, adding more omega-3 is unlikely to provide much additional benefit. Yet many studies either don’t measure or ignore the omega-3 index of patients they are enrolling in the study.

#4: How many and what drugs were the patients taking? Many heart disease patients are taking drugs that lower blood pressure, lower triglycerides, reduce inflammation, and reduce the risk of blood clot formation. These drugs do the same things that omega-3s do. This decreases the likelihood that you can see any benefit from increasing omega-3s intake.

The Omega-3 Pendulum

With all this in mind let’s examine three major double-blind, placebo-controlled studies that looked at the effect of omega-3s on heart disease risk and came to different conclusions. Here is a summary of the studies.

GISSI Study ASCEND Study VITAL Study
11,000 participants 15,480 participants 25,871 participants
Followed for 3.5 years Followed for 7.4 years Followed for 5.3 years
Europe USA USA
Published in 1999 Published in 2018 Published in 2019
Dose = 1 gm/day Dose = 1 gm/day Dose = 1 gm/day
20% ↓ in heart disease deaths No effect on fatal or non-fatal heart attack or stroke Significant ↓ in some forms of heart disease
45% ↓ in fatal heart attack or stroke – as effective as statins Significant ↓ in heart disease risk for some patients

heart attacksAt first glance the study designs look similar, so why did these studies give such different results. This is where the unintended flaws come into play. Let’s look at each study in more detail.

The GISSI Study:

  • The patients enrolled in this study all had suffered a heart attack in the previous 3 months. They were at very high risk of suffering a second heart attack within the next couple of years.
  • Omega-3 intake was not measured in this study. But it was uncommon for Europeans to supplement with omega-3s in the 90’s. And European studies on omega-3 intake during that period generally found that omega-3 intake was low.
  • Patients enrolled in this study were generally taking only 2 heart disease drugs, a beta-blocker and a blood pressure drug.

The ASCEND Study:

  • The patients enrolled in this study had diabetes without any evidence of heart disease. Only 17% of the flawspatients enrolled in the study were at high risk of heart disease. 83% were at low risk. Remember, it is difficult to show a benefit of any intervention in low-risk patients.
  • The average omega-3 index of patients enrolled in this study was 7.1%. That means omega-3 levels were near optimal at the beginning of the study. Adding additional omega-3s was unlikely to show much benefit.
  • Most of the patients in this study were on 3-5 heart drugs and 1-2 diabetes drugs which duplicated the effects of omega-3s.

That means this study was asking a very different question. It was asking whether omega-3s provided any additional benefit for patients who were already taking multiple drugs that duplicated the effects of omega-3s.

However, you would have never known that from the headlines. The headlines simply said this study showed omega-3s were ineffective at preventing heart disease.

Simply put, this study was doomed to fail. However, despite its many flaws the authors reported that omega-3s did reduce one form of heart disease, namely vascular deaths (primarily due to heart attack and stroke). Somehow this observation never made it into the headlines.

The VITAL Study:

  • This study enrolled a cross-section of the American population aged 55 or older (average age = 67). As you might suspect for a cross-section of the American population, most of the participants in this study were at low risk for heart disease. This limited the ability of the study to show a benefit of omega-3 supplementation in the whole population.

However, there were subsets of the group who were at high risk of heart disease (more about that below).

  • This study excluded omega-3 supplement users The average omega-3 index of patients enrolled in this study was 2.7% at the beginning of the study and increased substantially during the study. This enhanced the ability of the study to show a benefit of omega-3 supplementation.
  • Participants in this study were only using statins and blood pressure medications. People using more medications were excluded from the study. This also enhanced the ability of the study to show a benefit of omega-3 supplementation.

The authors reported that “Supplementation with omega-3 fatty acids did not result in a lower incidence of major cardiovascular events…” This is what lazy journalists and many experts reported about the study.

good newsHowever, the authors designed the study so they could also:

  • Look at the effect of omega-3s on heart disease risk in high-risk groups. They found that major cardiovascular events were reduced by:
    • 26% in African Americans.
    • 26% in patients with diabetes.
    • 17% in patients with a family history of heart disease.
    • 19% in patients with two or more risk factors of heart disease.
  • Look at the effect of omega-3s on heart disease risk in people with low omega-3 intake. They found that omega-3 supplementation reduced major cardiovascular events by:
    • 19% in patients with low fish intake.
  • Look at the effect of omega-3s on the risk of different forms of heart disease. They found that omega-3 supplementation reduced:
    • Heart attacks by 28% in the general population and by 70% for African Americans.
    • Deaths from heart attacks by 50%.
    • Deaths from coronary heart disease (primarily heart attacks and ischemic strokes (strokes caused by blood clots)) by 24%.

In summary, if you take every study at face value it seems like the pendulum is constantly swinging from “omega-3s reduce heart disease risk” to “omega-3s are worthless” and back again. There appears to be no explanation for the difference in results from one study to the next.

However, if you remember that even good studies have unintended flaws and ask the four questions I proposed Question Markabove, it all makes sense.

  • How is heart disease defined? Studies looking at heart attack and/or ischemic stroke are much more likely to show a benefit of omega-3s than studies that include all forms of heart disease.
  • Are the patients at low-risk or high-risk for heart disease? Studies in high-risk populations are much more likely to show a benefit than studies in low-risk populations.
  • What is the omega-3 intake of participants in the study? Studies in populations with low omega-3 intake are more likely to show a benefit of omega-3 supplementation than studies in populations with high omega-3 intake.
  • How many heart drugs are the patients taking? Studies in people taking no more than one or two heart drugs are more likely to show a benefit of omega-3 supplementation than studies in people taking 3-5 heart drugs.

When you view omega-3 clinical studies through the lens of these 4 questions, the noise disappears. It is easy to see why these studies came to different conclusions.

Who Benefits Most From Omega-3s?

omega 3s and heart diseaseThe answers to this question are clear:

  • People at high risk of heart disease are most likely to benefit from omega-3 supplementation.
  • People with low omega-3 intake are most likely to benefit from omega-3 supplementation.
  • Omega-3 supplementation appears to have the biggest effect on heart attack and ischemic stroke (stroke due to blood clots). Its effect on other forms of heart disease is less clear.
  • Omega-3 supplementation appears to be most effective at preventing heart disease if you are taking no more than 1 or 2 heart drugs. It may provide little additional benefit if you are taking multiple heart drugs. However, you might want to have a conversation with your doctor about whether omega-3 supplementation might allow you to reduce or eliminate some of those drugs.

What about the general population? Is omega-3 supplementation useful for patients who are at low to moderate risk of heart disease?

  • If we compare omega-3 studies with statin studies, the answer would be yes. Remember that statins cannot be shown to reduce heart attacks in low-risk populations. However, because they are clearly effective in high-risk patients, the medical community assumes they should be beneficial in low-risk populations. The same argument could be made for omega-3s.
  • We also need to recognize that our ability to recognize those who are at high risk of heart disease is imperfect. For too many Americans, the first indication that they have heart disease is sudden death!

When I was still teaching, I invited a cardiologist to speak to my class of first year medical students. He told the students, only partly in jest, that he felt statins were so beneficial they “should be added to the drinking water”.

I feel the same way about omega-3s:

  • Most Americans do not get enough omega-3s in our diet.
  • Our omega-3 index is usually much closer to 4% (high risk of heart disease) than 8% (low risk of heart disease).
  • Many of us may not realize that we are at high risk of heart disease until it is too late.
  • And omega-3s have other health benefits.

For all these reasons, omega-3 supplementation only makes sense.

The Bottom Line

There is perhaps nothing more confusing to the average person than the “truth” about omega-3s and heart disease risk. The headlines and expert opinion on the topic swing wildly between “omega-3s reduce heart disease risk” to “omega-3s have no effect on heart disease risk” and back again. To me these swings resemble the swings of a pendulum – hence the title of this article.

If you take every study at face value, there appears to be no explanation for the difference in results from one study to the next. However, if you recognize that even good studies have unintended flaws and ask four simple questions to expose these flaws, it all makes sense.

For the four questions you should ask when reviewing any omega-3 study and my recommendations for who benefits the most from omega-3 supplementation, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Health Tips From The Professor