Heart Disease

Is Dairy Bad For Your Heart?

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Is Dairy Right For You? 

Author: Dr. Stephen Chaney

dairy foodsWe have been told for years that dairy foods are good for us. They are part of the USDA five food groups. In fact, they are part of the dietary recommendations of every government and most health organizations across the world.

And dairy foods are nutritious. They are excellent sources of calcium, potassium, protein, and vitamins A and B12. And if they are fortified, they are also an excellent source of vitamin D. Many health experts consider them essential for healthy bones. So, you might be saying, “Case closed. We should all be eating more dairy foods”.

But, not so fast. Many dairy foods are high in saturated fats. In fact, 65% of the fat in dairy foods is saturated. We have known for years that when saturated fats replace polyunsaturated fats in the diet, LDL cholesterol levels increase. And, as I reported in a previous issue of “Health Tips From the Professor” there is excellent evidence that replacing polyunsaturated fats with saturated fats substantially increases the risk of dying from heart attack, stroke, and other forms of heart disease.

The widely accepted message from these studies is that saturated fats raise LDL cholesterol levels and increases our risk of dying from heart disease. If we accept this message, it poses a dilemma. Dairy foods are nutritious. But they are high in saturated fat. What should we do?

The answer from the American Heart Association and most other health organizations is simple. We should eat low-fat dairy foods.

But this is where it gets really confusing. Dairy foods are composed of much more than saturated fats. And you have probably seen the claims that full fat dairy foods don’t increase the risk of heart disease.

So, what is the truth about full-fat dairy foods and heart health? In this issue of “Health Tips From The Professor” I review three recent studies and the recommendations of the Heart Foundation because they shed light on this question.

Is Dairy Bad For Your Heart?

dairy products and heart disease cheeseBefore I answer this question, I should point out that there are two ways of looking at it.

  • As I said above, the studies proving that saturated fats increase the risk of heart disease, substituted saturated fats for polyunsaturated fats and controlled every other aspect of the diet. That has led the American Heart Association and other organizations to recommend that we eat low-fat dairy foods.
  • However, when most people hear that recommendation, they simply substitute low-fat dairy for full-fat dairy foods without changing any other aspect of their diet or lifestyle. The first two studies were designed to see if that approach was effective for reducing heart disease risk.

The first study (KA Schmidt et al, American Journal of Clinical Nutrition, 114: 882-892, 2021) was a randomized controlled trial that compared the effect of low-fat dairy foods and full-fat dairy foods on heart health parameters.

The participants in this study were:

  • Average age = 62
  • 56% male
  • 75% white
  • Average weight = 214 pounds
  • All of them were prediabetic

All participants were told to stick with their usual diets (probably typical American diets) except for the amount and type of dairy foods added to their diet. During the first four weeks they restricted dairy consumption to 3 servings of nonfat dairy/week so they would all be starting with the same amount of dairy consumption. Then they were divided into 3 groups for the 12-week study:

  • Group 1 continued with 3 servings of nonfat dairy/week.
  • Group 2 added 3 servings of low-fat dairy/day to their usual diet.
  • Group 3 added 3 servings of high-fat dairy/day to their usual diet.

At the beginning of the study and again at the end of the 12-week study LDL cholesterol, HDL cholesterol, triglycerides, free fatty acids, and blood pressure were measured. The results were:

  • There was no difference in LDL cholesterol, HDL cholesterol, triglycerides, free fatty acids, or blood pressure in the three groups at the end of 12 weeks.
  • There was no also significant change in LDL cholesterol, HDL cholesterol, triglycerides, free fatty acids, or blood pressure during the study in any of the three groups.

The authors concluded, “A diet rich in full-fat dairy had no effect on fasting lipid profile or blood pressure compared with diets limited in dairy or rich in low-fat dairy. Therefore, dairy fat, when consumed as part of complex whole foods does not adversely affect these classic cardiovascular disease risk factors.”

[Note: The last sentence is key. Remember the “proof” that saturated fats increase LDL levels and increase the risk of heart disease come from studies in which saturated fats were substituted for polyunsaturated fats and every other aspect of the diet was carefully controlled.

In this study, and others like it, the effects of saturated fats are studied in a complex food (dairy) in the presence of an even more complex diet containing many foods that influence the risk of heart disease.]

The second study (J Guo et al, European Journal of Epidemiology 32: 269-287, 2017) was a meta-analysis of Healthy Heart29 studies with 938,465 participants looking at the association of full-fat dairy consumption with the risk of dying from heart disease.

Seven of the 29 studies were conducted in the United States. Of the remaining studies 3 were from Japan and Taiwan, 2 were from Australia, and 17 were from Europe.

The results of the study were:

  • There was no association between full-fat dairy, low-fat dairy, and total dairy consumption and risk of dying from heart disease.

When the results were broken down into individual dairy foods.

  • There was no association between milk consumption and risk of dying from heart disease.
  • Consumption of one serving/day of fermented dairy foods was associated with a 2% decreased risk of dying from heart disease.

The authors concluded, “The current meta-analysis of 29 prospective cohort studies suggested no association of total, high and low-fat dairy and milk with risk of cardiovascular disease. In addition, a possible role of fermented dairy was found in cardiovascular disease prevention, but the result was driven by a single study.” [I would add that this effect, if confirmed by subsequent studies, is extremely small (2%).]

The first two studies do not say that full-fat dairy foods are heart healthy for everyone, as some headlines would have you believe. Instead, these studies show fairly convincingly that simply switching from full-fat to low-fat dairy foods, without changing any other aspect of your diet and lifestyle, is not as effective at decreasing your risk of heart disease as some experts would have you believe.

balance scaleThe third publication (WC Willett and DS Ludwig, New England Journal of Medicine 382: 644-654, 2020) was a review of the effect of dairy foods on our health. One of the authors, Walter C Willett, is one of the top experts in the field. The review covered many topics, but I will focus on the section dealing with the effect of dairy foods on heart health.

This review took a more nuanced look at full-fat dairy foods and examined the effect of substituting full-fat dairy for other protein foods.

The review concludes, “The association of milk with the risk of cardiovascular disease depends on the comparison foods. In most cohort studies [such as the studies described above], no specific comparison was made; by default, the comparison was everything else in the diet – typically large amounts of refined grains, potato products, sugar, and meat.”

The review went on to say that previous studies have shown:

  • “Both full-fat and low-fat dairy foods…were associated with a lower risk [of cardiovascular disease and stroke] than…the same number of servings of red meat but with a higher risk than seen with the same number of servings of fish or nuts.”
  • “Dairy fat…was associated with a higher risk of cardiovascular disease than was polyunsaturated or vegetable fat.”
  • “For persons living in low-income countries where diets are very high in starch, moderate intake of dairy foods may reduce cardiovascular disease by providing nutritional value and reducing glycemic load [the amount of easily digestible carbohydrate in the diet].”

Is Dairy Right For You?

dairy products and heart disease questionsNow I am ready to answer the question posed at the beginning of this article, “Is dairy bad for your heart?” The answer is, “It depends”.

  • As described above, the effect of dairy on heart health depends on our overall diet. It also depends on our lifestyle, our weight, and our health.
  • In addition, clinical studies report averages, and none of us are average. We all have unique diets, lifestyles, health status, and genetic makeup.

So, what does this mean for you? Perhaps it is best summed up by the recommendations of Australia’s Heart Foundation which take health status, lifestyle, and genetic differences into account:

  • A heart healthy diet can include dairy, but it is not essential [with careful planning and/or supplementation you can get your calcium and protein elsewhere].
  • Milk, yogurt, and cheese are considered neutral for heart health, meaning they neither increase nor decrease the risk of heart disease for the average person. However, the recommendations vary depending on health status, genetics, and lifestyle:
    • Low-fat milk, yogurt, and cheese are recommended for people with heart disease or high cholesterol because the fat in dairy foods can raise cholesterol more for these people. [Note: If cholesterol is elevated, it usually means that individual has a hard time regulating blood cholesterol levels because of obesity, genetics, or pre-existing disease. For these individuals, diets high in saturated fat are more likely to increase LDL cholesterol and risk of heart disease.]
    • Full-fat milk, yogurt, and cheese can be part of a heart healthy diet for healthy people provided most of the fat in the diet comes from fish, nuts, seeds, and healthy oils. [Note: Overall diet is important.]
  • Choosing unflavored milk, yogurt, and cheese helps limit the amount of sugar in your diet.
  • Ice cream, cream, and dairy desserts should be eaten only sometimes and in small amounts because they have more sugar and fat, and less protein, vitamins, and minerals than other dairy foods.
  • Butter raises LDL cholesterol levels, especially in people who already have elevated cholesterol.
    • There is no evidence that butter can be part of a heart healthy diet, so you should consider healthier options such as olive oil, avocado, nut butters, and spreads made with healthier oils, such as olive oil.

The Bottom Line

We have been told for years that dairy foods are good for us. They are part of the USDA five food groups. In fact, they are part of the dietary recommendations of every government and most health organizations across the world.

However, dairy foods have been controversial in recent years. Some experts claim that only low-fat dairy products can be heart healthy. Others claim that full-fat dairy foods are just as healthy as low-fat dairy foods.

I shared three recent publications and dietary recommendations from The Heart Foundation that shed light on these controversies.

The first study found that full-fat dairy foods did not increase LDL cholesterol, triglycerides, and other heart disease risk factors.

The second study was a meta-analysis of 29 clinical studies with almost one million people. It found that full-fat dairy foods did not increase the risk of dying from heart disease.

“Case closed”, you might say. However, these studies do not say that full-fat dairy foods are heart healthy for everyone, as some headlines would have you believe. Instead, these studies show fairly convincingly that simply switching from full-fat to low-fat dairy foods, without changing any other aspect of your diet and lifestyle, is not as effective at decreasing your risk of heart disease as some experts would have you believe.

Moreover, these studies do not account for the effect of overall diet, lifestyle, health status, and genetics on the risk of heart disease.

That is why I included the third study in my review. It took the overall diet into account and concluded the effect of full-fat dairy foods on heart disease risk depends on the overall diet.

  • For some diets full-fat dairy increases heart disease risk.
  • For other diets full-fat dairy has no effect on heart disease risk.
  • And for some diets full-fat dairy may even decrease heart disease risk.

Finally, I included recommendations of the Australian Heart Foundation because they included the effect of health status, lifestyle, and genetics in their recommendations.

For more details on the findings of the third study and the recommendations of the Heart Foundation, 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.

Is It Too Late To Change Your Diet?

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You Can Improve Your Health At Any Age

Author: Dr. Stephen Chaney

Fast Food ExamplesIf you are like most Americans, your dietary preferences as an adult are based on the foods your family ate while you were growing up.

  • Your favorite foods…
  • Your comfort foods…
  • The foods you always avoid…

…are based on your family heritage, not on your genes. And if you are like most Americans, your diet isn’t healthy.

  • It’s high in fat and cholesterol…
  • It’s high in sugar and refined carbohydrates…
  • It’s high in processed foods…
  • It’s low in whole, unprocessed foods…
  • It’s high in calories, so your waistline keeps growing.

You know your diet isn’t healthy, but you keep coasting along through your 30’s and 40’s until…the unthinkable happens. You are diagnosed with a deadly disease, like heart disease, high blood pressure, or diabetes, and your doctor says that unless you change your diet, you are doomed to a short unhealthy life. You have reached a fork in Food Choicesthe road.

Changing the diet you grew up with, the diet you love, is a daunting task. It’s tempting to think, “Why bother…

  • It’s probably too late to change my diet…
  • The damage has already been done…
  • I can’t reverse it now.”

If this scenario describes you or someone you love, you aren’t alone. There are millions of Americans just like you. You want to know whether changing your diet is worth the trouble. You want to know whether it is too late, or whether you can still change your health for the better.

Most clinical studies don’t answer this question. Most clinical studies do a diet assessment at the beginning of the study and look at health outcomes 20 or 30 years later. If they do more than one diet assessment during the study, the purpose of these assessments is to show that most people stick to the same diet throughout the study.

These studies measure the effect of habitual diets on health outcomes. They tell you that good diets lead to good health outcomes, and bad diets lead to bad health outcomes. But they don’t tell you whether changing your diet from bad to good in your 30’s or 40’s can have a significant effect on your health.

Fortunately, a recent study has answered this question. This study (Y Choi et al, Journal of The American Heart Association, 10e020718, 2021) started with people in their mid-20s. It looked at whether changing their diet from bad to good in their 30s and 40s had any effect on their risk of developing heart disease in their 50s and 60s.

How Was This Study Done?

Clinical StudyThe data for this study were obtained from the CARDIA study (Coronary Artery Risk Development in Young Adults). The study enrolled 4946 young adults (average age = 25, 55% female and 45% male, 50% black and 50% white) and followed them for 32 years (average age of participants at the end of the study = 57).

Diet was assessed by a trained interviewer at year 0, year 7 (average age of participants = 32), and year 20 (average age of participants = 45).

Adherence of the participants to a healthy, plant-centered diet was assessed using an analytical tool called APDQS that divided the foods eaten by the participants into 3 groups based on their known influence on heart disease:

1) Beneficial.

    • These foods included fruit, avocado, beans/legumes, green vegetables, yellow vegetables, tomatoes, other vegetables, nuts and seeds, soy products, whole grains, vegetable oil, fatty fish, lean fish, poultry, moderate alcohol, coffee, tea, and low-fat milk/cheese/yogurt.
    • This is what the investigators considered a plant-centered diet. It encompasses diets ranging from vegan to Mediterranean and DASH.

2) Adverse.

    • These foods included fried potatoes, refined grain desserts, salty snacks, pastries, sweets, high-fat red meats, processed meats, organ meats, fried fish/poultry, sauces, soft drinks, whole fat milk/cheese/yogurt, and butter.
    • This could be considered a typical American diet.

3) Neutral.

    • These foods included potatoes, refined grains, margarine, chocolate, meal replacements, pickled foods, lean meats, shellfish, eggs, soups, and fruit juices.
    • These foods are not the healthiest, but the evidence that they have a negative effect on health disease risk is inconclusive.

The participants were divided into 5 quintiles based on adherence to a plant-centered diet, with quintile 1 having the lowest adherence and quintile 5 having the highest adherence to a plant-centered diet.

The effect of diet on heart disease was measured in two ways:

1) The dietary data from years 0, 7 and 20 were averaged and the effect of average adherence to a plant-centered diet on the risk of developing heart disease by the time the participants were 57 was measured. This is similar to the design of most other studies looking at the effect of diet and heart disease.

2) The effect of an improvement in adherence to a plant-centered diet between ages of 32 and 45 on the risk of developing heart disease by age 57 was also measured. This is what makes this study unique. Basically, the investigators were asking if you could eat a bad diet for 30 years or more and still reduce your risk of heart disease by switching to a good diet by the age of 45. That is the question that millions of American are asking themselves right now.

Is It Too Late To Change Your Diet?

Heart Healthy DietAs I described above this study asked two distinct questions:

1) What effect does your habitual diet have on your risk of developing heart disease?

For this portion of the study, the investigators averaged the dietary data collected in years 0, 7, and 20 of the study and ranked the participants diet from 1 to 5 based on their adherence to a plant-centered diet. When they compared the group with best adherence (group 5) with the group with worst adherence (group 1):

    • Adherence to a plant-centered diet reduced their risk of developing heart disease by 48%.
    • This is consistent with previous studies looking at the beneficial effects of plant-centered diets on heart disease.

2) What effect does changing your diet from bad to good when you are in your 30s or 40s have on your risk of developing heart disease? 

For this portion of the study, the investigators compared the dietary data collected at years 7 and 20 (corresponding to average ages 32 and 45 for the participants) and ranked the participants from 1 to 5 based on improved adherence to a plant-centered diet. When they compared the group with best improvement in adherence (group 5) with the group with worst improvement in adherence (group 1):

    • Improved adherence to a plant-centered diet reduced the risk of developing heart disease by 39%.
    • This answers the questions I posed at the beginning of this article. In short, it is never too late to change your diet for the better.

The authors concluded, “In summary, our study shows that long-term consumption of a nutritionally rich plant-centered diet is associated with a lower risk of heart disease. Furthermore, increased [adherence to a] plant-centered diet in young adulthood is associated with a lower subsequent risk of heart disease throughout middle age, independent of the earlier diet quality” [In short, they are saying that changing to a more plant-centered diet in your 30s and 40s reduces your risk of heart disease.]

You Can Improve Your Health At Any Age

I titled this section, “You Can Improve Your Health At Any Age” for a reason. I wanted to make the point that it is never too late to change your diet, and your health, for the better.

Yes, I realize that the study I described above only shows:

  • The effect of changing to a more plant-centered diet in your 30s and 40s.
  • The benefit of changing to a more plant-centered diet on heart disease outcomes.

However, we have ample evidence that changing to a more plant-based diet at any age is likely to reduce the risk of many diseases. For example:

  • There are multiple reports in the literature of people in their 60s and 70s who had a health scare, changed to a more plant-centered diet, and dramatically improved their health.

While neither type of study can be considered definitive by itself, together they suggest it is never too late to change your diet for the better.

But what changes should you make? As I said above, anything from Vegan to Mediterranean or DASH fits the definition of a plant-centered diet (something I have previously referred to as a primarily plant-based diet).

You could choose the plant-centered diet that best fits your preferences and lifestyle and read books or go online to find details and recipes that will help you transition to that diet…or you could simply:

  • Eat more fruit, avocado, beans/legumes, green vegetables, yellow vegetables, tomatoes, other vegetables, nuts and seeds, soy products, whole grains, vegetable oil, fatty fish, lean fish, poultry, moderate alcohol, coffee, tea, and low-fat milk/cheese/yogurt.
  • Eat less fried potatoes, refined grain desserts, salty snacks, pastries, sweets, high-fat red meats, processed meats, organ meats, fried fish/poultry, sauces, soft drinks, whole fat milk/cheese/yogurt, and butter.
  • Eat these foods in moderation: potatoes, refined grains, margarine, chocolate, meal replacements, pickled foods, lean meats, shellfish, eggs, soups, and fruit juices.

The Bottom Line

If you are like most Americans, you know your diet is unhealthy. But it is the diet you grew up with. It’s the diet you love. So, you keep eating it anyway.

Then you have a wake-up call. You find yourself in your doctor’s office, and your doctor is advising you to change your diet. But giving up the diet you love is difficult, and you wonder if it is worth it. Can you really improve your health significantly by changing your diet now, or is it too late? Has the damage already been done?

Fortunately, a recent study has answered these questions. This study started with people in their mid-20s. And it looked at whether changing their diet from bad to good in their 30s and 40s had any effect on their health in their 50s and 60s. This is what the study found.

  • Improved adherence to a plant-centered diet in their 30s and 40s reduced their risk of developing heart disease in their 50s and 60s by 39%.

While this study was very specific in terms of age and disease, I have discussed in the article above why changing to a more plant-based diet at any age is likely to reduce your risk of multiple diseases. In short, it is never too late to change your diet, and your health, for the better.

For more details about this study and how to change your diet for the better, 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.

A Diet To Die For

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Which Diet Is Best? 

Author: Dr. Stephen Chaney

Heart AttackMany clinical studies focus on the benefits or risks associated with individual components of our diet. For example, we have been told:

  • Saturated and trans fats are bad for us and monounsaturated and omega-3 fats are good for us.
  • Sugar and refined carbohydrates are bad for us, but complex carbohydrates are good for us.

However, we don’t eat saturated fats or sugars in isolation. They are part of a diet with many other foods. Do other foods in our diet affect the risks we associate with saturated fat or sugar? We don’t know.

Simply put, we don’t eat foods, we eat diets. We don’t eat saturated fats, we eat diets. It would be more helpful for the average person if research focused on which diets are good and bad for us instead of which foods are good and bad for us.

One recent study (JM Shikany et al, Journal of the American Heart Association, 10:e019158, 2021) did just that. It evaluated the effect of 6 different dietary patterns on the risk of sudden cardiac death (dropping dead from a stroke or heart attack).

  • It turns out that one of the diets significantly increases your risk of sudden cardiac death. I call that one, “A diet to die for”.
  • Another diet significantly decreases your risk of sudden cardiac death. I call that one, “A diet to live for”.
  • The other diets had no significant effect on the risk of sudden cardiac death.

You are probably wondering, “What were the diets?”; “Which diet is best?”; and “Which diet is worst?” I cover that below, but first we should look at how the study was designed.

How Was The Study Designed?

Clinical StudyThe study involved 21,069 participants in the REGARDS (Reasons for Geographical and Racial Differences in Stroke) clinical trial who were followed for an average of 10 years. This clinical trial enrolled:

  • 30% of its participants from what is called the “the stroke belt” (North Carolina, South Carolina, Georgia, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana).
  • 20% of its participants from what is called “the stroke buckle” (the coastal plain of North Carolina, South Carolina, and Georgia).
  • 50% of its participants from elsewhere in the continental United States.

At the beginning of the study, participants were given a medical exam and filled out an extensive questionnaire on diet.

Based on the diet analysis, the participants were ranked for adherence to six dietary patterns.

#1: The Convenience Pattern. This dietary pattern relied heavily on pre-packaged or restaurant meals, pasta dishes, pizza, Mexican food, and Chinese food.

#2: The Plant-Based Pattern. This dietary pattern relied heavily on vegetables, fruits, fruit juice, cereal, beans, fish, poultry, and yogurt.

#3: The Sweets Pattern. This dietary pattern relied heavily on added sugars, desserts, chocolate, candy, and sweetened breakfast foods.

#4: The Southern Pattern. This dietary pattern relied heavily on added fats, fried food, eggs and egg dishes, organ meats, processed meats, and sugar-sweetened beverages.

#5: The Alcohol and Salad Pattern. This dietary pattern relied heavily on beer, wine, liquor, green leafy vegetables, tomatoes, and salad dressing.

#6: The Mediterranean Pattern. Adherence to the Mediterranean dietary pattern was based on the well-established Mediterranean Diet Score.

  • Points are added for beneficial foods (vegetables, fruits, legumes, whole grain cereals, nuts, and fish).
  • Points are subtracted for detrimental foods (meat and dairy).
  • Points are added for a high ratio of monounsaturated fats to saturated fats (think diets rich in olive oil).
  • One point is added for moderate alcohol consumption, Zero or excess alcohol consumption is assigned 0 points.

The study looked at the correlation of these dietary patterns with the incidence of sudden cardiac death during the 10-year study.

A Diet To Die For

deadThe results were striking.

  • The Southern Diet increased the 10-year risk of sudden cardiac death 2.2-fold. Basically, it doubled the risk.
    • In people with no previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2.3-fold.
    • In people with a previous history of heart disease at the beginning of the 10-year study, the Southern Diet increased the risk of sudden cardiac death by 2-fold.
  • The Mediterranean Diet decreased the 10-year risk of sudden cardiac death 41%.
    • In people with no previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 51%. Basically, it cut the risk in half.
    • In people with a previous history of heart disease at the beginning of the 10-year study, the Mediterranean Diet decreased the risk of sudden cardiac death by 23%, but that decrease was not statistically significant.
  • None of the other diets had a significant effect on the 10-year risk of sudden cardiac death.

In the words of the authors, “We identified a trend towards an inverse association of the Mediterranean diet score and a positive association of adherence to the Southern dietary pattern with risk of sudden cardiac death.” [That is a fancy way of saying the Mediterranean diet decreased the risk of sudden cardiac death, and the Southern dietary pattern increased the risk of sudden cardiac death.]

Which Diet Is Best?

AwardThe Mediterranean Diet Is Best: In this analysis of the effects of 6 different dietary patterns on the risk of sudden cardiac death, it is obvious that the Mediterranean diet is best. It cut the risk of sudden cardiac death in half.

This should come as no surprise:

  • I have reported on a previous study showing that the Mediterranean diet decreases the risk of heart disease by 47%.
  • In the Woman’s Health Study the Mediterranean diet decreased the risk of sudden cardiac death by 36%.
  • In the Nurses’ Health Study there was an inverse association between the Mediterranean Diet Score and sudden cardiac death.

The Southern Dietary Pattern Was Worst. It doubled the risk of sudden cardiac death. As someone who grew up in the South, this comes as no surprise to me. Let me count the ways:

  • It starts with a breakfast of fried eggs, grits with “red-eye gravy” (a mixture of ham drippings and coffee), ham or sausage, and biscuits made with lots of lard and sugar.
  • When I was growing up, a snack might be an RC cola and moon pies (look that one up).
  • Dinner might be fried chicken and hushpuppies or fried fish and hushpuppies.
  • Instead of picnics we have pig pickins (which is pretty much what it sounds like).
  • And we boil our vegetables with fatback (pig fat) and sugar.

I could go on, but you get the picture. Don’t get me wrong, I have fond memories of the foods I ate while growing up in the South. I just don’t eat them much anymore.

Why Didn’t The Plant-Based Dietary Pattern Score Better? One of the surprises from this study was that the Plant-Based Dietary Pattern didn’t score better. After all, numerous studies have shown that mostly plant-based diets reduce the risk of heart disease. Why did it strike out in this study?Vegan Foods

My feeling is that the study did not adequately describe a true Plant-Based Dietary Pattern. As I described above, participants following the Plant-Based Dietary Pattern were identified as having above average consumption of vegetables, fruits, fruit juice, cereal, beans, fish, poultry, and yogurt compared to others in this study. I have two concerns with this classification.

  • As described, this is a semi-vegetarian diet, while the best results for reducing heart disease risk are seen with strict vegetarian and lacto-ovo-vegetarian diets.
  • However, my biggest concern is that we don’t know what other foods they were consuming. Were they also consuming convenience foods? Were they consuming sweets? We don’t know.

That is very different from the two dietary patterns that stood out in this study.

  • 50% of the participants in this study came the Southeastern region of the United States. So, when the study identified participants as following a Southern Dietary Pattern based on a few southern foods, it is likely that those participants ate many other southern foods as well.

If 50% of the participants in the study had come from the Loma Linda area of California where vegetarianism is much more common, the study might have done a better job of identifying participants consuming a plant-based diet.

  • While participants consuming the Mediterranean diet were more scattered geographically, the Mediterranean Diet Score used to identify people consuming a Mediterranean diet is much more detailed and has been validated in numerous previous studies.

In short, the Southern and Mediterranean Dietary Patterns may have stood out in this study because they provided a more precise distinction between those consuming a Southern or Mediterranean diet and those following other dietary patterns. If the Plant-Based Dietary Pattern had been more precisely described, it might have shown a statistically significant benefit as well.

The Bottom Line

Many clinical studies focus on the benefits or risks associated with individual components of our diet.

However, we don’t eat foods, we eat diets. It would be more helpful for the average person if research focused on which diets are good and bad for us instead of which foods are good and bad for us.

One recent study did just that. It evaluated the effect of 6 different dietary patterns on the risk of sudden cardiac death (dropping dead from a stroke or heart attack).

  • It turns out that the Southern diet doubles your risk of sudden cardiac death. I call that one, “A diet to die for”.
  • In contrast, the Mediterranean diet cuts your risk of sudden cardiac death in half. I call that one, “A diet to live for”.
  • The other diets had no significant effect on the risk of sudden cardiac death.

For more details on the study, why the Southern diet is so bad for us, and why the Mediterranean diet is so good for us, 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.

Is Low Omega-3 Intake As Bad For You As Smoking?

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What Is The Omega-3 Index And Why Is It Important? 

Author: Dr. Stephen Chaney

deadWe already know that smoking is one of the worst things we can do to our bodies. It dramatically increases our risk of cancer, heart disease, diabetes, and lung diseases, including chronic obstructive pulmonary disease (COPD).

It also leads to premature death. People who smoke regularly die 5 years earlier than those who don’t.

That is the bad news. The good news is that smoking is what is called a “modifiable risk factor”. Simply put, that means it is a risk factor we are in control of. The message has been clear for years.

  • If you don’t smoke, keep it that way.
  • If you do smoke, stop. If you are a smoker, quitting isn’t easy, but it is worth it. The damage caused by smoking can largely be reversed if you stay off cigarettes long enough.

Obesity and diabetes are also modifiable risk factors that have a huge effect on the risk of both heart disease and premature death. People with diabetes die 4 years earlier than those without diabetes. But obesity and diabetes are harder for most people to reverse than smoking.

Diet is another modifiable risk factor, but, in general, its effect on the risk of heart disease and premature death is not as great as smoking and diabetes. But what if there were one component of diet that had huge effect on both heart disease and premature death?

The long chain omega-3 fatty acids (EPA & DHA) might just fill that bill. We already know they significantly reduce the risk of heart disease (see below), but could they also help us live longer? This study (MI McBurney et al, American Journal of Clinical Nutrition, published online June 16, 2021) was designed to answer that question.

Metabolism 101: What Is The Omega-3 Index And Why Is It Important?

professor owlClinical studies on the benefits of omega-3s have been plagued by the question of how to best measure the omega-3 status of the participants.

  • You can ask the participants to fill out a dietary survey and calculate how many omega-3-rich foods they are eating, but:
    • Dietary recall is notoriously inaccurate. People don’t remember everything they ate and have a hard time estimating portion sizes.
  • You can measure omega-3 fatty acids in the blood, but:
    • Blood levels are transient. Omega-3 fatty acids enter the bloodstream from the intestine and then disappear from blood as they are taken up by the cells.
    • Different forms of omega-3s (esters versus acetate, for example) are absorbed from the intestine and taken up by cells at different rates.
  • You can measure the omega-3 content of cellular membranes. This is the best assay for omega-3 status because:
    • The long chain omega-3 fatty acids (EPA and DHA) that have the biggest effect on heart disease risk accumulate in our cell membranes.
    • Omega-3 fatty acids are essential (our bodies can’t make them). That means the omega-3 content of our cell membranes reflect the omega-3 content of our diet. This is one of the cases where the saying, “We are what we eat”, is literally true.
    • The omega-3 content of our cell membranes is relatively stable. It reflects the omega-3 content of our diet over the last few months.
  • In theory, you could measure the omega-3 content of cell membranes from any tissues in the body, but red blood cells can easily be obtained by a simple blood draw, so they are the tissue of choice.

A group lead by Dr. William H Harris standardized this measurement by creating something called the Omega-3 Index. Simply put, the Omega-3 Index is the percentage of EPA and DHA in red blood cell membranes.

It turns out that the Omega-3 Index is an excellent indicator of heart disease risk.

  • An Omega-3 Index of less than 4% is associated with a high risk of heart disease.
  • An Omega-3 Index of more than 8% is associated with a low risk of heart disease.

But could a low Omega-3 Index also be associated with an increased risk of premature death? This is what the current study was designed to find out.

How Was This Study Done?

Clinical StudyThe data for this study were obtained from the ongoing Framingham Offspring Heart Study.

To put this statement into perspective, the original Framingham Heart Study began in 1948 in Framingham Massachusetts with the goal of identifying the factors that contributed to heart disease. It was one of the first major studies to identify the role of saturated fats, elevated blood cholesterol, and elevated blood triglycerides on heart disease risk.

The study is continuing today with the second and third generation descendants of the original study participants. It has also been broadened to include other diseases and additional risk factors, such as the Omega-3 Index.

This study selected 2240 participants from the Framingham Offspring study who had no heart disease and also had Omega-3 Index measurements at the beginning of the study. The study then followed them for 11 years. The goal of the study was to compare the Omega-3 Index with the two most potent risk factors for heart disease (smoking and diabetes) in predicting the risk of premature death.

The characteristics of the participants at the beginning of the 11-year study were:

  • 43% male, 57% female.
  • Average age = 65.
  • 3% were smokers.
  • 8% were diabetic.
  • Average Omega-3-Index = 5.8%. This is slightly higher than the American average of ~5%.

Is Low Omega-3-Intake As Bad For You As Smoking?

omega-3 supplements and heart healthThe participants in the study were divided into 5 quintiles based on their Omega-3 Index.

  • The 20% of the group in the lowest quintile had an Omega-3 Index of <4.2%.
  • The 20% of the group in the highest quintile had an Omega-3 Index of >6.8%.

First, the scientists running the study did a direct comparison of the top three risk factors on the risk of premature death. Here is what they found.

  • The group with the lowest average Omega-3 Index died 4.74 years earlier than the group with the highest average Omega-3 Index.
  • Smokers died 4.73 years earlier than non-smokers.
  • People with diabetes died 3.90 years earlier than people without diabetes.

That means low omega-3 intake was just as bad for the participants in this study as smoking. Even the authors of the study were surprised by this result. They had expected omega-3 fatty acids to be beneficial, but they had not expected them to be as beneficial as not smoking.

Because omega-3 fatty acid intake and smoking were the two most potent risk factors for premature death, the authors looked at the interaction between the two. They found that the predicted 11-year survival was:

  • 85% for non-smokers with high omega-3 intake.
  • 71% for either…
    • Smokers with high omega-3 intake, or…
    • Non-smokers with low omega-3 intake.
  • Only 47% for smokers with low omega-3 intake.

Simply put, this study predicts if you were a 65-year-old smoker with low omega-3 intake, you could almost double your chances of surviving another 11 years by giving up smoking and increasing your omega-3 intake.

In the words of the authors, “Smoking and omega-3 intake seem to be the most easily modified risk factors [for premature death]…Dietary choices that change the Omega-3 index may prolong life.”

The Bottom Line

We know that smoking is deadly, but could low intake of omega-3 fatty acids be just as deadly?

A recent study compared omega-3 intake with the two most potent risk factors (smoking and diabetes) in predicting the risk of premature death. Here is what it found.

  • The group with the lowest average omega-3 intake died 4.74 years earlier than the group with the highest average omega-3 intake.
  • Smokers died 4.73 years earlier than non-smokers.
  • People with diabetes died 3.90 years earlier than people without diabetes.

That means high omega-3 intake was just as beneficial for the participants in this study as not smoking. Even the authors of the study were surprised by this result. They had expected omega-3 fatty acids to be beneficial, but they had not expected them to be as beneficial as not smoking.

Because omega-3 fatty acid intake and smoking were the two most potent risk factors for premature death, the authors looked at the interaction between the two. They found that the predicted 11-year survival was:

  • 85% for non-smokers with high omega-3 intake.
  • 71% for either…
    • Smokers with high omega-3 intake, or…
    • Non-smokers with low omega-3 intake.
  • Only 47% for smokers with low omega-3 intake.

Simply put, this study predicts if you were a 65-year-old smoker with low omega-3 intake, you could almost double your chances of surviving another 11 years by giving up smoking and increasing your omega-3 intake.

In the words of the authors, “Smoking and omega-3 intake seem to be the most easily modified risk factors [for premature death]…Dietary choices that change the Omega-3 index may prolong life.”

For more details about this 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.

Is Nitrate From Vegetables Good For Your Heart?

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Are Nitrates Good For You Or Bad For You? 

Author: Dr. Stephen Chaney

health benefits of beetroot juiceWe have known for years that fruits and vegetables are good for our hearts. We have assumed that was because whole fruits and vegetables are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. But could there be more?

Recent research has suggested that the nitrates found naturally in fruits and vegetables may also play a role in protecting our hearts. Here is what recent research shows:

  • The nitrates from fruits and vegetables are converted to nitrite by bacteria in our mouth and intestines.
    • Fruits and vegetables account for 80% of the nitrate in our diet. The rest comes from a variety of sources including the nitrate added as a preservative to processed meats.
    • Although all fruits and vegetables contain nitrates, the best sources are green leafy vegetables and beetroot. [Beet greens are delicious and also a good source of nitrate, but beetroot is the part of the beet we usually consume.]
  • Nitrite is absorbed from our intestine and converted to nitric oxide by a variety of enzymes in our tissues.
  • Both reactions require antioxidants like vitamin C, which are also found in fruits and vegetables.

Nitric oxide has several heart healthy benefits. For example:

  • It helps reduce inflammation in the lining of blood vessels. Inflammation stimulates atherosclerosis, blood clot formation, and is associated with an increased risk of heart disease.
  • It relaxes the smooth muscle cells that surround our blood vessels. This makes the blood vessels more flexible and helps reduce blood pressure.
  • It prevents smooth muscle cells from proliferating, which prevents them from invading and constricting our arteries. This, in turn, has the potential to reduce the risk of atherosclerosis.
  • It prevents platelet aggregation. This, in turn, has the potential to reduce the risk of heart attack and stroke due to blood clots that block the flow of blood to our heart or brain.

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. This study (CP Bondonno et al, European Journal of Epidemiology, doi.org/10.1007/s10654-021-00747-3) was designed to answer that question.

How Was This Study Done?

Clinical StudyThis study made use of data from the Danish Diet, Cancer, and Health Program. That program enrolled 53,150 participants from Copenhagen and Aarhus between 1993 and 1997 and followed them for an average of 21 years. None of the participants had a diagnosis of cancer or heart disease at the beginning of the study.

Other characteristics of the participants at the time they were enrolled in the study were:

  • 46% male
  • Average age = 56
  • BMI = 26 (20% overweight)
  • Average systolic blood pressure = 140 mg Hg
  • Average diastolic blood pressure = 84 mg Hg

At the beginning of the study, participants filled out a 192-item food frequency questionnaire that assessed their average intake of various food and beverage items over the previous 12 months. The vegetable nitrate content of their diets was analyzed using a comprehensive database of the nitrate content of 178 vegetables. For those vegetables not consumed raw, the nitrate content was reduced by 50% to account for the nitrate loss during cooking.

Blood pressure was measured at the beginning of the study. Data on the incidence (first diagnosis) of heart disease during the study was obtained from the Danish National Patient Registry. Data were collected on diagnosis of the following heart health parameters:

  • Cardiovascular disease (all diseases of the circulatory system).
  • Ischemic heart disease (lack of sufficient blood flow to the heart). The symptoms of ischemic heart disease range from angina to myocardial infarction (heart attack).
  • Ischemic stroke (lack of sufficient blood flow to the brain).
  • Hemorrhagic stroke (bleeding in brain).
  • Heart failure.
  • Peripheral artery disease (lack of sufficient blood flow to the extremities).

Is Nitrate From Vegetables Good For Your Heart?

strong heartIntake of nitrate from vegetables ranged from 18 mg/day (<1/3 serving of nitrate-rich vegetables per day) to 168 mg (almost 3 servings of nitrate-rich vegetables per day). The participants were grouped into quintiles based on their vegetable nitrate intake. When the group with the highest vegetable nitrate intake was compared to the group with the lowest vegetable nitrate intake:

  • Systolic blood pressure was reduced by 2.58 mg Hg.
  • Diastolic blood pressure was reduced by 1.38 mg Hg.
  • Risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Risk of hemorrhagic stroke (bleeding in the brain) was not significantly reduced.

Two other observations were of interest:

  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion. However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.
  • Only about 21.9% of the improvement in heart health could be explained by the decrease in blood pressure. This is not surprising when you consider the other beneficial effects of nitric oxide described above.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Are Nitrates Good For You Or Bad For You?

ConfusionYou are probably thinking, “Wait a minute. I thought nitrates and nitrites were supposed to be bad for me. Which is it? Are nitrates good for me or bad for me?”

It turns out that nitrates and nitrites are kind of like Dr. Jekyll and Mr. Hyde. They can be either good or bad. It depends on the food they are in and your overall diet.

Remember the beginning of this article when I said that the conversion of nitrates to nitric oxide depended on the presence of antioxidants? Vegetables are great sources of antioxidants. So, when we get our nitrate from vegetables, most of it is converted to nitric oxide. And, as I discussed above, nitric oxide is good for us.

However, when nitrates and nitrites are added to processed meats as a preservative, the story is much different. Processed meats have zero antioxidants. And the protein in the meats is broken down to amino acids in our intestine. The amino acids combine with nitrate to form nitrosamines, which are cancer-causing chemicals. Nitrosamines are bad for us.

Of course, we don’t eat individual foods by themselves. We eat them in the context of a meal. If you eat small amounts of nitrate-preserved processed meats in the context of a meal with antioxidant-rich fruits and vegetables, some of the nitrate will be converted to nitric oxide rather than nitrosamines. The processed meat won’t be as bad for you.

What Does This Study Mean For You?

spinachYour mother was right. You should eat your fruits and vegetables!

  • The USDA recommends at least 3 servings of vegetables and 2 servings of fruit a day.
  • Based on this study, at least one of those servings should be nitrate-rich vegetables like green leafy vegetables and beets.
  • If you don’t like any of those, radishes, turnips, watercress, Bok choy, Chinese cabbage, kohlrabi, chicory leaf, onion, and fresh garlic are also excellent sources of nitrate.
  • The good news is that you may not need to eat green leafy vegetables and beets with every meal. If this study is correct, one serving per day may have heart health benefits. That means you can enjoy a wide variety of fresh fruits and vegetables as you try to meet the USDA recommendations.

Finally, if you don’t like any of those foods, you may be asking, “Can’t I just take a nitrate supplement?”

  • For blood pressure, there are dozens of clinical trials, and the answer seems to be yes – especially when the nitrate comes from vegetable sources and the supplement also contains an antioxidant like vitamin C.
  • For heart health benefits, the answer is likely to be yes, but clinical trials to confirm that would take decades. Double blind, placebo-controlled trials of that duration are not feasible, so we will never know for sure.
  • Moreover, you would not be getting all the other health benefits of a diet full of fresh fruits and vegetables. Supplementation has its benefits, but it is not meant to replace a healthy diet.

The Bottom Line

We have known for years that fruits and vegetables are good for our hearts. We have assumed that was because whole fruits and vegetables are low in saturated fats and provide heart-healthy nutrients, phytonutrients, and fiber. But could there be more?

It is well established that nitrates from fruits and vegetables reduce blood pressure. More importantly, they can help slow the gradual increase in blood pressure as we age.

However, few studies have asked whether this reduction in blood pressure translates into improved cardiovascular outcomes. A recent study was designed to answer that question.

When the study compared people with the highest vegetable nitrate intake to people with the lowest vegetable nitrate intake:

  • Blood pressure was significantly reduced.
  • The risk of cardiovascular disease was reduced by 14%.
  • Risk of ischemic heart disease (angina and heart attack) was reduced by 13%.
  • Risk of ischemic stroke (stroke caused by lack of blood flow to the brain) was reduced by 14%.
  • Risk of heart failure was reduced by 17%.
  • Risk of peripheral artery disease was reduced by 31%.
  • Blood pressure and risk of peripheral artery disease decreased with increasing vegetable nitrate intake in a relatively linear fashion.
  • However, the other parameters of heart disease plateaued at a modest intake of vegetable nitrate intake (around one cup of nitrate-rich vegetables per day). This suggests that as little as one serving of nitrate-rich vegetables a day is enough to provide some heart health benefits.

The authors concluded, “Consumption of at least ~60 mg/day of vegetable nitrate (~ one serving of green leafy vegetables or beets) may mitigate risk of cardiovascular disease.”

Of course, you may have heard that nitrates and nitrites are bad for you. I discuss that in the article above.

For more details about this study, information about vegetable nitrate supplements, and what this study 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.

Which Diet Is Best For Your Heart?

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Why Are Dietary Studies So Confusing? 

Author: Dr. Stephen Chaney

heart diseaseYou are concerned about your heart.

  • Perhaps it is because of genetics. Everyone on one side of your family tree had their first heart attack in their mid-forties.
  • Perhaps it is because your doctor has warned you that your heart is a ticking time bomb. Unless you make some drastic changes, you will die of a heart attack in the near future.
  • Perhaps you already have some symptoms of heart disease, and you are scared.

You want to make some changes. You want to protect your heart. What should you do?

The short answer is that a holistic approach is best, and I will share the American Heart Association recommendations below. But let’s start by asking what you should eat. There are two important questions:

#1: Which diet is best for your heart?

  • A whole food vegan diet, the Mediterranean diet, and the DASH diet are all strong contenders for the best heart healthy diet.
  • But there are many other diets that claim to be heart healthy. Some enthusiasts even claim the Paleo and keto diets are heart healthy.
  • The problem is that few studies have compared these diets against each other. That makes it difficult to settle the question of which diet is best for your heart.

#2: Which protein source is best for your heart – plant protein, fish, poultry, or red meat?

  • Plant and fish protein are both strong contenders for the most heart healthy protein.
  • Poultry has the reputation of being more heart healthy than red meat. But this has become controversial. Some recent studies suggest poultry is no better than red meat in terms of heart health.

Fortunately, a recent study (F Petermann-Rocha et al, European Heart Journal, 42: 1136-1143, 2021) has made this comparison. It compared vegetarians, fish eaters, poultry eaters, and red meat eaters for the risk of developing heart disease.

How Was This Study Done?

Clinical StudyThis study made use of data from the UK Biobank program. The UK Biobank program recruited over 500,000 participants (ages 37-73) from England, Wales, and Scotland between 2006 and 2010 and followed them for an average of 8.5 years.

At entry into the program, each participant filled out a touchscreen questionnaire, had physical measurements taken, and provided biological samples.

Dietary intake was assessed based on the touchscreen questionnaire and the average of 5 24-hour dietary recalls. The participants were divided into four groups based on this dietary analysis:

  • Vegetarians (All participants in the study consumed cheese and eggs, so this group would more accurately be described as lacto-ovo-vegetarians).
  • Fish eaters.
  • Poultry eaters.
  • Red meat eaters.

Over the next ~8.5 years, each group was compared with respect to the following heart health parameters:

  • Risk of developing cardiovascular disease (all diseases of the circulatory system).
  • Risk of developing ischemic heart disease (lack of sufficient blood flow to the heart. The most common symptom of ischemic heart disease is angina).
  • Risk of having a myocardial infarction (commonly referred to as a heart attack).
  • Risk of having a stroke.
  • Risk of developing heart failure.

Which Diet Is Best For Your Heart?

The study compared vegetarians, fish eaters, and poultry eaters with red meat eaters with respect to each of the heart disease parameters listed above. The results were:

  • When fish eaters were compared with meat eaters, they had:
    • 7% lower risk of cardiovascular diseases of all types.
    • 21% lower risk of ischemic heart disease (angina).
    • 30% lower risk of myocardial infarction (heart attack).
    • 21% lower risk of stroke.
    • 22% lower risk of heart failure.
  • When vegetarians were compared with meat eaters, they had:
    • 9% lower risk of cardiovascular diseases of all types.
    • Lower, but statistically non-significant, risk of other heart disease parameters.
  • When poultry eaters were compared with meat eaters there were no significant differences in heart disease outcomes.

The authors concluded, “Eating fish rather than meat or poultry was associated with a lower risk of adverse cardiovascular outcomes…supporting its role as a healthy diet that should be encouraged. Vegetarianism was only associated with a lower risk of cardiovascular disease incidence.”

Why Are Dietary Studies So Confusing?

confusionSo, you are probably thinking, “Are diets with fish protein really more heart healthy than diets with plant protein?”

Fish have a lot going for them. They are an excellent source of heart healthy omega-3 fats. And, when substituted for red meat protein, they decrease intake of saturated fats.”

But plant protein has a lot going for it as well. Numerous studies have shown that vegetarian diets are more heart healthy than the typical American diet. And only plant-based diets have been shown to reverse atherosclerosis.

So, why are dietary studies so confusing? The problem is that diets are complex. They have many moving parts. When we focus on one aspect of a diet, we are ignoring the rest of the diet. The food we have focused on may be healthy. But if it is paired with unhealthy foods, the overall diet can still be unhealthy.

The current study is a perfect example of that principle:

  • The participants represented a cross section of the British population. All the “diets” were high in sugar, sugary drinks, saturated fat, and processed meals bought from the supermarket. None of them were optimal.
  • In addition to consuming cheese and eggs, “vegetarians” consumed more crisps, slices of pizza, and smoothie drinks than meat-eaters. [In case you were wondering, the English refer to small thin salty snacks like potato chips as crisps. They reserve the term chips for what we call French Fries.]
  • “Vegetarians” also consumed a lot of highly processed vegetarian alternatives designed to taste like other meat products.
  • On the other hand, fish eaters consumed more fruits and vegetables than meat-eaters. It wasn’t just the fish that made this diet more heart healthy.

In other words, the “vegetarian diet” in this study was not nearly as healthy as the whole food vegetarian diets that have previously been shown to be heart healthy. And the “fish-eaters diet” was healthier than the “meat-eaters diet” because of both the fish and the extra fruits and vegetables these people were consuming.

In the words of the authors, “…As a group, vegetarians consumed more unhealthy foods, such as crisps, than meat eaters. Therefore, vegetarians should not be considered a homogeneous group, and avoidance of meat will not be sufficient to reduce health risk if the overall diet is not healthy.”

My summary:

  • Whole food plant-based diets (the true definition of vegetarianism) are very heart healthy. [Note: The diet in this study was lacto-ovo-vegetarian rather than a true vegetarian diet. However, recent studies have suggested that addition of small amounts of dairy and eggs to a vegetarian diet may make them more heart healthy rather than less heart healthy.]
  • Primarily plant-based diets with fish as the main protein source (otherwise known as pescatarian diets) are also very heart healthy.
  • If you want a healthy heart, choose the one that best fits your preferences and your lifestyle.

A Holistic Approach: The American Heart Association Recommendations

Doctor With Patient

  • If you smoke, stop.
  • Choose good nutrition.
    • Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils, and nuts.
    • Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.
    • Reduce high blood cholesterol and triglycerides.
    • Reduce your intake of saturated fat, trans fat and cholesterol.
  • Lower High Blood Pressure.
  • Be physically active every day.
    • Aim for at least 150 minutes per week of moderate-intensity physical activity per week.
  • Aim for a healthy weight.
  • Manage diabetes.
  • Reduce stress.
  • Limit alcohol.
  • Have a regular physical checkup.

The Bottom Line

A recent study in the United Kingdom compared vegetarians, fish eaters, poultry eaters, and red meat eaters for the risk of developing heart disease and the risk of dying from heart disease. The results were:

  • When fish eaters were compared with meat eaters, they had:
    • 7% lower risk of cardiovascular diseases of all types.
    • 21% lower risk of ischemic heart disease (angina).
    • 30% lower risk of myocardial infarction (heart attack).
    • 21% lower risk of stroke.
    • 22% lower risk of heart failure.
  • When vegetarians were compared with meat eaters, they had:
    • 9% lower risk of cardiovascular diseases of all types.
    • Lower, but statistically non-significant, risk of other heart disease parameters.
  • When poultry eaters were compared with meat eaters there were no significant differences in heart disease outcomes.

The authors concluded, “Eating fish rather than meat or poultry was associated with a lower risk of adverse cardiovascular outcomes…supporting its role as a healthy diet that should be encouraged. Vegetarianism was only associated with a lower risk of cardiovascular disease incidence.”

However, the “vegetarian diet” in this study was not nearly as healthy as the whole food vegetarian diets that have previously been shown to be heart healthy. And the “fish-eaters diet” was healthier than the “meat-eaters diet” because of both the fish and the extra fruits and vegetables this group of people were consuming.

In the words of the authors, “…As a group, vegetarians consumed more unhealthy foods, such as crisps [potato chips], than meat eaters. Therefore, vegetarians should not be considered a homogeneous group, and avoidance of meat will not be sufficient to reduce health risk if the overall diet is not healthy.”

My summary:

  • Whole food plant-based diets (the true definition of vegetarianism) are very heart healthy.
  • Primarily plant-based diets with fish as the main protein source (otherwise known as pescatarian diets) are also very heart healthy.
  • If you want a healthy heart, choose the one that best fits your preferences and your lifestyle.

For more details about this 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.

Do Omega-3s Add Years To Your Life?

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Why Are Omega-3s So Controversial? 

Author: Dr. Stephen Chaney

ArgumentI don’t need to tell you that omega-3s are controversial. Some experts confidently tell you that omega-3s significantly reduce your risk of heart disease and may reduce your risk of cancer and other diseases. Other experts confidently tell you that omega-3s have no effect on heart disease or any other disease. They claim that omega-3 supplements are no better than “snake oil”.

The problem is that each camp of experts can cite published clinical studies to support their claims. How can that be? How can clinical studies come to opposite conclusions on such an important topic? The problem is that it is really difficult to do high quality clinical studies on omega-3s. I will discuss that in the next section.

The question of whether omega-3s affect life span has also been controversial. Heart disease and cancer are the top two causes of death in this country. So, if omega-3s actually reduced the risk of heart disease and cancer, you might expect that they would also help us live longer. Once again, there are studies on both sides of this issue, but they are poor quality studies.

We need more high-quality studies to clear up the controversies surrounding the health benefits of omega-3s. I will report on one such study in this issue of “Health Tips From The Professor”. But first let me go into more depth about why it is so difficult to do high-quality studies with omega-3 fatty acids.

Clinical Studies 101: Why Are Omega-3s So Controversial?

professor owlI have covered this topic in previous issues of “Health Tips From the Professor”, but here is a quick summary.

  1. Randomized, placebo controlled clinical trials (RCTs) are considered the gold standard for evidence-based medicine, but they ill-suited to measure the effect of omega-3s on health outcomes.
    • Heart disease and cancer take decades to develop. Most RCTs are too small and too short to show a meaningful effect of omega-3s on these diseases.
    • To make up for this shortcoming, some recent RCTs have started with older, sicker patients. This way enough patients die during the study that it can measure statistically significant outcomes. However, these patients are already on multiple medications that mimic many of the beneficial effects of omega-3s on heart disease.

These studies are no longer asking whether omega-3s reduce the risk of heart disease. They are really asking if omega-3s have any additional benefits for patients who are already taking multiple medications – with all their side effects. I don’t know about you, but that is not the question I am interested in.

    • Until recently, most RCTs did not measure circulating omega-3 levels before and after supplementation, so the investigators had no idea whether omega-3 supplementation increased circulating omega-3 levels by a significant amount.

And for the few studies where omega-3 levels were measured before and after supplementation, it turns out that for many of the participants, their baseline omega-3 levels were too high for omega-3 supplementation to have a meaningful effect. Only participants with low omega-3 levels at the beginning of the study benefited from omega-3 supplementation.Supplementation Perspective

These studies are often quoted as showing omega-3 supplementation doesn’t work. However, they are actually showing the true value of supplementation. Omega-3 supplementation isn’t for everyone. It is for people with poor diet, increased need, genetic predisposition, and/or pre-existing disease not already treated with multiple medications.

2) Prospective cohort studies eliminate many of the shortcomings of RCTs. They can start with a large group of individuals (a cohort) and follow them for many years to see how many of them die or develop a disease during that time (this is the prospective part of a prospective cohort trial). This means they can start with a healthy population that is not on medications.

This also means that these studies can answer the question on most people’s minds, “Are omega-3s associated with reduced risk of dying or developing heart disease?” However, these studies have two limitations.

    • They are association studies. They cannot measure cause and effect.
    • Ideally, omega-3 levels would be measured at the beginning of the study and at several intervals during the study to see if the participant’s diet had changed during the study. Unfortunately, most prospective cohort studies only measure omega-3 levels at the beginning of the study.

3) Finally, a meta-analysis combines data from multiple clinical studies.

    • The strength of a meta-analysis is that the number of participants is quite large. This increases the statistical power and allows it to accurately assess small effects.
    • The greatest weakness of meta-analyses is that the design of the individual studies included in the meta-analysis is often quite different. This introduces variations that decrease the reliability of the meta-analysis. It becomes a situation of “Garbage in. Garbage out”

The study (WS Harris et al, Nature Communications, Volume 12, Article number: 2329, 2021) I am discussing today is a meta-analysis of prospective cohort studies. It was designed to determine the association between blood omega-3 fatty acids and the risk of:

  • Death from all causes.
  • Death from heart disease.
  • Death from cancer.
  • Death from causes other than heart disease or cancer.

More importantly, it eliminated the major weakness of previous meta-analyses by only including studies with a similar design.

How Was This Study Done?

Clinical StudyThis study was a meta-analysis of 17 prospective cohort studies with a total of 42,466 individuals looking at the association between omega-3 fatty acid levels in the blood and premature death due to all causes, heart disease, cancer, and causes other than heart disease and cancer.

Participants in the 17 studies were followed for an average of 16 years, during which time 15,720 deaths occurred. This was a large enough number of deaths so that a very precise statistical analysis of the data could be performed.

The average age of participants at entry into the studies was 65, and 55% of the participants were women. Whites constituted 87% of the participants, so the results may not be applicable to other ethnic groups. None of the participants had heart disease or cancer when they entered the study.

Finally, the associations were corrected for a long list of variables that could have influenced the outcome (Read the publication for more details).

A strength of this meta-analysis is that all 17 studies were conducted as part of the FORCE (Fatty Acids & Outcomes Research Consortium) collaboration. The FORCE collaboration was established with the goal of understanding the relationships between fatty acids (as measured by blood levels of the omega-3 fatty acids) on premature death and chronic disease outcomes (cardiovascular disease, cancer, and other conditions).

Each study was designed using a standardized protocol, so that the data could be easily pooled for a meta-analysis. In the words of the FORCE collaboration founders:

  1. The larger sample sizes of [meta-analyses] will substantially increase statistical power to investigate associations…enabling the [meta-analyses] to discover important relationships not discernible in any individual study.

2) Standardization of variable definitions and modeling of associations will reduce variation and potential bias in estimates across cohorts.

3) Results will be far less susceptible to publication bias.

Do Omega-3s Add Years To Your Life?

Omega-3sThe meta-analysis divided participants into quintiles based on blood omega-3 levels. When comparing participants with the highest omega-3 levels with participants with the lowest omega-3 levels:

  • Premature death from all causes was decreased by 16%.
    • When looking at the effect of individual omega-3s, EPA > EPA+DHA > DHA.
  • Premature death from heart disease was decreased by 19%.
    • When looking at the effect of individual omega-3s, DHA > EPA+DHA > EPA.
  • Premature death from cancer was decreased by 15%.
    • When looking at the effect of individual omega-3s, EPA > DHA > EPA+DHA.
  • Premature death from causes other than heart disease and cancer was decreased by 18%.
    • When looking at the effect of individual omega-3s, EPA > EPA+DHA > DHA.
  • The differences between the effects of EPA, DHA, and EPA+DHA were small.
  • ALA, a short chain omega-3 found in plant foods, had no effect on any of these parameters.

In the words of the authors: “These findings suggest that higher circulating levels of long chain omega-3 fatty acids are associated with a lower risk of premature death. Similar relationships were seen for death from heart disease, cancer, and causes other than heart disease and cancer. No associations were seen with the short chain omega-3, ALA [which is found in plant foods]”.

What Does This Study Mean For You?

confusionIf you are thinking that 15-19% decreases in premature death from various causes don’t sound like much, let me do some simple calculations for you. The average lifespan in this country is 78 years.

  • A 16% decrease in death from all causes amounts to an extra 12.5 years. What would you do with an extra 12.5 years?
  • A 19% decrease in death from heart disease might not only allow you to live longer, but it has the potential to improve your quality of life by living an extra 15 years free of heart disease.
  • Similarly, a 15% decrease in death from cancer might help you live an extra 12 years cancer-free.
  • In other words, you may live longer, and you may also live healthier longer, sometimes referred to as “healthspan”.

Don’t misunderstand me. Omega-3s are not a magic wand. They aren’t the fictional “Fountain of Youth”.

  • There are many other factors that go into a healthy lifestyle. If you sit on your couch all day eating Big Macs and drinking beer, you may be adding the +12.5 years to a baseline of -30 years.
  • Clinical studies report average values and none of us are average. Omega-3s will help some people more than others.

I will understand if you are skeptical. It seems like every time one study comes along and tells you that omega-3s are beneficial, another study comes along and tells you they are worthless.

This was an extraordinarily well-designed study, but it is unlikely to be the final word in the omega-3 controversy. There are too many poor-quality studies published each year. Until everyone in the field agrees to some common standards like those in the FORCE collaboration, the omega-3 controversy will continue.

The Bottom Line 

A recent meta-analysis looked at the association between omega-3 fatty acid levels in the blood and premature death due to all causes, heart disease, cancer, and causes other than heart disease and cancer.

The meta-analysis divided participants into quintiles based on blood omega-3 levels. When comparing participants with the highest omega-3 levels with participants with the lowest omega-3 levels:

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

In the words of the authors: “These findings suggest that higher circulating levels of long chain omega-3 fatty acids are associated with a lower risk of premature death. Similar relationships were seen for death from heart disease, cancer, and causes other than heart disease and cancer.”

For more details about study and what this study 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.

 

 

Will Plant Proteins Help You Live Longer?

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Is A Vegan Diet Healthiest?

Author: Dr. Stephen Chaney

Fountain Of YouthUnless you are Rip Van Winkle and have been asleep for the past 40 years, you have probably heard that whole food, primarily plant-based diets are good for you.

  • They help you control your weight.
  • They reduce inflammation.
  • They reduce your risk of diabetes and heart disease.
  • They even reduce your risk of some cancers.

But do they help you live longer? If we take that question literally, the answer appears to be no. There is no “Fountain Of Youth”. There are no diets that extend our lives significantly.

However, what if you could reduce your risk of premature death? It would be tragic to have your life cut short by a heart attack or some other major disease. What if you could prevent that?

And what if you could live healthier longer? It would be equally tragic to spend your golden years debilitated by chronic diseases like heart disease, diabetes, or dementia. What if you could delay these diseases and live healthier longer?

The study I discuss this week (Y Sun, Journal of the American Heart Association, 10:e015553, 2021) looks at the effect of different dietary protein sources on premature death.

This study, like many others, suggests that primarily plant-based diets are healthier than meat-based diets. But what does this mean for you? Should you go completely meatless? Is a vegan diet healthier than other plant-based diets? I discuss what we know and what we do not know about the vegan diet compared to other plant-based diets.

How Was This Study Done?

Clinical StudyThe data for this study were drawn from the Women’s Health Initiative (WHI). The Women’s Health Initiative was designed to help identify strategies for preventing heart disease and other diseases in postmenopausal women. It enrolled 161,000 postmenopausal women from 40 sites across the US between 1993 and 1998 and followed them through 2017.

This study excluded women who had heart disease or cancer when they entered the WHI study and women who had incomplete data on either their diet or their use of postmenopausal hormone therapy. They were left with 102,521 women, age 50-79 at time of entry, who were followed for 18 years.

Each woman filed out an extensive dietary survey at the beginning of the study. There were 25,976 deaths during the study. The cause of death was determined by reviewing death certificates, medical records, autopsy reports or by linkage to the National Death Index.

The investigators asked whether women who ate more plant proteins were healthier than those who ate primarily meat protein. To answer this question, they correlated protein sources in the diet with all-cause mortality and deaths from various diseases.

The greatest difficulty with this type of study is that people who eat more plant protein tend to have a healthier diet and a healthier lifestyle. That makes it hard to separate out the benefits of eating plant proteins from benefits associated with other aspects of their diet and lifestyle. So, the authors corrected their data for every factor known to influence the risk of heart disease, diabetes, dementia, and premature death.

Specifically, the data were statistically corrected for age, race/ethnicity, socioeconomic status, hormone use, lifestyle (smoking status, physical activity, and alcohol intake), baseline health status (diabetes and/or high blood cholesterol), family history of heart attack/stroke, dietary factors (calorie intake, dietary fiber intake, whole grain consumption, fruit and vegetable consumption, sugar-sweetened beverage consumption, glycemic load (effect of foods in the diet on blood sugar), and percentage of saturated fats, polyunsaturated fats, monounsaturated fats, and trans fats), and weight (BMI).

In short, the authors corrected for every other factor that could influence disease risk and/or premature death. By doing so, they were able to focus on the effect of protein sources on disease risk and/or premature death.

Will Plant Proteins Help You Live Longer?

Plant ProteinsThe investigators divided the study participants into quintiles with respect the kind and amount of protein they consumed.

  • For animal protein, the intake ranged from 4 ounces/day in the lowest quintile to 9 ounces a day in the highest quintile (For comparison, 3 ounces is roughly equivalent to the size of a deck of cards).
  • For plant protein, the intake ranged from 2 ounces/day in the lowest quintile to 3.5 ounces/day in the highest quintile.
  • When you combine plant and animal protein in these women’s diet, plant protein ranged from 18% of total protein intake in the lowest quintile to 48% of total protein intake in the highest quintile.

When women who had the highest intake for plant protein were compared with women who had the lowest intake of plant protein, the women with the highest plant protein intake had:

  • 12% lower risk of premature death from heart disease.
  • 21% lower risk of premature death from dementia.
  • 9% lower risk of premature death from all causes.

There was an inverse relationship between the amount of plant protein in the diet and premature death. Specifically, every 3 ounces of animal protein that was replaced with 3 ounces of plant protein resulted in:

  • 22% lower risk of premature death from heart disease.
  • 19% lower risk of premature death from dementia.
  • 14% lower risk of premature death from all causes.

The Effect Of Individual Animal Proteins On Mortality

Fatty SteakThe authors also looked at the effect of various animal proteins on premature death. For example:

Red Meat: Women with the highest consumption of red meat had:

  • 14% higher risk of premature death from heart disease.
  • 20% higher risk of premature death from dementia.
  • 10% higher risk of premature death from all causes.

Eggs: Women with the highest consumption of eggs had:

  • 24% higher risk of premature death from heart disease.
  • 14% lower risk of premature death from dementia.
  • 14% higher risk of premature death from all causes.

Dairy: Women with the highest consumption of dairy had:

  • 11% higher risk of premature death from heart disease.

The authors concluded, “In this large prospective cohort study, we found that higher plant protein intake and substitution of animal protein with plant protein were associated with lower risk of all-cause mortality, cardiovascular mortality, and dementia mortality…Our findings support the need for consideration of protein sources, in addition to the amount of protein intake, in future dietary guidelines.”

Is A Vegan Diet Healthiest?

Vegetarian DietYears ago, as my brother-in-law was coming out of anesthesia at the end of quadruple bypass surgery, the first question he asked was, “Does this mean I need to eat tofu?” Obviously, nothing terrified him more than the thought of eating tofu the rest of his life. In the same vein, some of you are probably asking, “Does this mean I need to go vegan?”

The good news is that none of the women in this study were consuming a vegan diet. They were consuming a typical American diet with varying amounts of plant and animal protein. The group with the highest plant protein consumption were still getting 52% of their protein from animal sources.

This study shows that even people consuming a typical American diet can become healthier by simply swapping out some of the animal protein in their diet with plant protein.

However, you are probably thinking, “Plant protein is good for us, and a vegan diet is 100% plant protein. Does that mean a vegan diet is healthier than other plant-based diets?

The answer is………”Maybe”

If the linear relationship between plant protein consumption and risk of premature death could be extrapolated all the way to 100% plant protein, the answer would be obvious. Vegan diets would be healthier than other plant-based diets. But that extrapolation is an assumption. It might not be true.

For example, some recent studies suggest that completely eliminating meat, eggs, and dairy from your diet may slightly increase your risk of heart disease and stroke:

  • One recent study found that adding 1.4 ounces of fish/day to a primarily vegetarian diet decreases the risk of stroke by 20%.
  • Another study reported that adding one egg/day to a primarily vegetarian diet decreases the risk of heart disease by 12% and stroke by 10-26%.

These studies need to be confirmed, but they do suggest we need to be cautious about assuming that vegan diets are healthier than other primarily plant-based diets. This is why, when I recommend primarily plant-based diets, I include everything from vegan through semi-vegetarian, Mediterranean, and DASH.

They are all healthy diets. My advice is to choose the one that best fits your lifestyle and food preferences. And focus on whole foods, not processed foods.

The Bottom Line 

A recent study asked whether women who ate more plant proteins were healthier than those who ate primarily meat protein. To answer this question, the investigators correlated protein sources in the diet with all-cause mortality and deaths from various diseases.

When women who had the highest intake for plant protein were compared with women who had the lowest intake of plant protein, the women with the highest plant protein intake had:

  • 12% lower risk of premature death from heart disease.
  • 21% lower risk of premature death from dementia.
  • 9% lower risk of premature death from all causes.

There was an inverse relationship between the amount of plant protein in the diet and premature death. Specifically, every 3 ounces of animal protein that was replaced with 3 ounces of plant protein resulted in:

  • 22% lower risk of premature death from heart disease.
  • 19% lower risk of premature death from dementia.
  • 14% lower risk of premature death from all causes.

[Note: A 3-ounce serving is roughly equivalent to a deck of cards.]

The authors concluded, “In this large prospective cohort study, we found that higher plant protein intake and substitution of animal protein with plant protein were associated with lower risk of all-cause mortality, cardiovascular mortality, and dementia mortality…Our findings support the need for consideration of protein sources, in addition to the amount of protein intake, in future dietary guidelines.”

Years ago, as my brother-in-law was coming out of anesthesia at the end of quadruple bypass surgery, the first question he asked was, “Does this mean I need to eat tofu?” Obviously, nothing terrified him more than the thought of eating tofu the rest of his life. In the same vein, some of you are probably asking, “Does this mean I need to go vegan?”

I discuss the answer to that question in the article above.

For more details and a discussion about the vegan diet versus other primarily plant-based diets 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 Diet Sodas Hurt Your Heart?

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Love Your Heart

Author: Dr. Stephen Chaney

confusionHeart healthy diets are confusing.

  • First, we were told that fats, especially saturated fats, were the problem. Then it was carbohydrates.
  • Then, we were told not all carbohydrates were equally bad for us. Sugars were the culprit.
  • Next, we were told not all sugars were bad for us. It was added sugars, especially the sugars added to sodas and other sugary drinks.
  • In fact, most of the clinical studies on the bad effects of sugar have been done with sugar-sweetened sodas.
  • If sugar-sweetened sodas are the problem, then surely diet sodas must be the answer.

Maybe not. In a previous issue of “Health Tips From The Professor” I summarized studies showing that consuming diet sodas was just as likely to be associated with obesity and diabetes as consuming sugar-sweetened sodas.

But what about heart health? Are diet sodas better for your heart than sugar-sweetened sodas? A recent study (E. Chazelas et al, Journal of the American College of Cardiology, 76: 2175-2180, 2020) suggests the answer is no.

How Was The Study Done?

Clinical StudyThis study is part of a much larger French study on the effect of diet on health outcomes called the NutriNet-Sante cohort. The NutriNet-Sante cohort study was started in 2009 and, as the name suggests, makes extensive use of online questionnaires. For example:

  • Participants are asked to fill out online questionnaires on physical activity, socioeconomic status, anthropometric data (height, weight, etc.), and major health events on a regular basis.
  • Every 6 months participants are asked to fill out 3 web-based 24-h dietary records (2 on weekdays and 1 on a weekend).
  • Major health events were validated based on their medical records and France’s national health insurance system (Yes, Big Brother is definitely watching in France).
  • Deaths were validated using France’s national mortality registry.

The study included a total of 104,760 participants with an average age of 42.9 and an average BMI of 23.7 (towards the upper end of the normal range) and followed them for 10 years. [Note: The average BMI for Americans at age 40 is 28.6, which is towards the upper end of the overweight category.]

The study compared consumption of diet drinks and sugary drinks with first-time cases of heart disease events (stroke, heart attack, angina, and angioplasty) during a 10-year period.

  • All first-time cases of heart disease events were combined into a single category for this publication. They will be considered separately in a subsequent publication.
  • Artificially sweetened beverages (diet drinks) were defined as beverages containing non-nutritive sweeteners. Sugary drinks consisted of all beverages containing ≥ 5% sugar (sodas, syrups, 100% juice, and fruit drinks).
  • For both categories of beverages, the participants were divided into non-consumers, low consumers, and high consumers.

Do Diet Sodas Hurt Your Heart?

Fast Food DangersThe results were clear. When high consumers were compared with non-consumers:

  • High consumers of sugary drinks had a 20% increased risk of first-time heart disease events.
  • High consumers of diet drinks had a 32% increased risk of first-time heart disease events.

The authors concluded, “In this cohort, higher intakes of [both] sugary drinks and diet drinks were associated with a higher risk of heart disease, suggesting that artificially sweetened beverages might not be a healthy substitute for sugary drinks.”

I also might point out that if this study had been done in the United States the increased risk of heart disease might have been greater.

That is because the French drink less sugary drinks and diet drinks than Americans.

  • High consumers of both sugary drinks and diet drinks in this study averaged 6 ounces per day.
  • In contrast, the average consumption sugary drinks in the United States is around 17 ounces per day.

Since consumption of sugary drinks is associated with increased incidence of heart disease and we drink more sugary drinks, the increased risk of heart disease in Americans might be greater than the 20% reported in this study.

What Are The Pros And Cons Of This Study?

pros and consOn the plus side, this was a very large and well-designed study.

For example, many studies of this type take a single assessment of the participant’s diet, either at the beginning or end of the study. They have no idea whether the participants changed their diet during the study. This study did a diet assessment every 6 months.

On the minus side, this was an association study. It measured the association of sugary drink and diet drink consumption with heart disease. Association studies have several limitations. Here are the top three:

#1: Confounding variables. Here are a couple of examples:

  • People who are overweight tend to drink more diet drinks than people who are normal weight. Obesity increases the risk of heart disease. Therefore, obesity is a confounding variable. You don’t know whether heart disease increased because the participants drank more diet drinks or because they were obese.
  • People who consume more diet drinks tend also to eat less healthy diets. Unhealthy diets increase the risk of heart disease. Thus, unhealthy diets are also a confounding variable.

The study authors adjusted for confounding variables by statistically correcting the data for:

  • Age, sex, BMI, sugar intake from other dietary sources, smoking status, physical activity, and family history of heart disease.
  • Intakes of alcohol, total calories, fruits & vegetables, red & processed meats, nuts, whole grains, legumes, saturated fat, sodium, and proportion of highly processed food in the diet.
  • Presence of type 2 diabetes, elevated cholesterol or triglycerides, or high blood pressure upon entry into the study.

In short, they did an excellent job of controlling for confounding variables that also affect the risk of heart disease.

#2: Reverse Causation: This is the chicken and egg question. This study measured the association between sugary and diet drink consumption and heart disease. None of the participants in the study had diagnosed heart disease when the 10-year study began.

However, both obesity and sugar consumption have been linked to increased risk of heart disease. What if some participants in the study had been diagnosed with heart disease early in the study and switched to diet drinks to lose weight or reduce sugar intake?

In that case, the diagnosis of heart disease would have caused increased diet drink consumption rather than the other way around. That would be reverse causation.

The study authors took reverse causation into account by excluding participants who experienced a first-time heart disease event in the first 3 years of this 10-year study. In other words, participants had to have been consuming sugary or diet drinks for at least 3 years before their heart disease event for their data to be included in the analysis.

This is considered the gold standard for reducing the influence of reverse causation on the outcome of the study.

#3: Uncertainty About Causation:

Association studies do not provide information on the possible mechanism(s) of the association.

For example, multiple previous studies have shown that people are just as likely to gain weight and develop type 2 diabetes when they consume diet drinks or sugary drinks. However, after years of study, the mechanism(s) of that effect are uncertain.

  • The mechanism may be physiological. However, many physiological mechanisms have been proposed. None have been proven.
  • The mechanism may be psychological. We may feel so virtuous for drinking diet drinks that we think it gives us license to eat more junk food. As a former University of North Carolina colleague once put it, “The problem is that we are using our diet drinks to wash down a Big Mac and fries.”

Association studies also do not prove causation. We cannot say with confidence that diet drink consumption increases our risk of heart disease. Nor can we speculate on the mechanism by which this might occur.

However, as the authors of this study concluded, we can say with confidence that there is no evidence that diet drink consumption decreases the risk of obesity, diabetes, or heart disease.

Love Your Heart

Love Your Heart – Drink Water Rather Than Sugar-Sweetened Or Artificially Sweetened Beverages. 

strong heartIf drinking diet drinks does not decrease your risk of heart disease, what can you do to decrease your risk?

The short answer is to fall in love with water. Water has no calories, no sugar, and no artificial sweeteners. In the study described above, it was the non-consumers of sugary beverages and diet beverages that had the lowest risk of heart disease.

Pure water is, of course, the best alternative. However, if plain water is too boring, try herbal teas. If you crave the fizz of sodas, try unsweetened sparkling water, perhaps infused with a little of your favorite fresh fruit. If you crave the caffeine of sodas, coffee or tea might suit you best, preferably without the sugar and cream. There are just two caveats:

  • Tea and coffee should not be your only source of liquid.
  • It goes without saying that you want to avoid the 500 calorie Starbucks extravaganzas.

Love Your Heart – What About Artificially Sweetened Foods?

If artificially sweetened drinks have no benefit for preventing obesity, diabetes, or heart disease, what about artificially sweetened foods? Do they also have no benefit?

The short answer is that we don’t know. Most of the studies to date have been with artificially sweetened beverages. However, these studies should make us cautious. We should not automatically assume that artificially sweetened foods are beneficial because they contain fewer calories. They may be just as useless as artificially sweetened beverages.

Love Your Heart – A Holistic Approach

With that in mind, here is what the American Heart Association recommends for reducing your risk of heart disease:

  • If you smoke, stop.
  • Choose good nutrition.
    • Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, nuts, and nontropical vegetable oils (ie, avoid coconut and palm oil).
    • Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.
    • [Note: Don’t substitute artificially sweetened beverages for sugar-sweetened beverages. That doesn’t appear to offer any advantage. Drink water instead.]
  • Reduce high blood cholesterol and triglycerides.
    • Reduce your intake of saturated fat, trans fat and cholesterol and get moving.
    • If diet and physical activity don’t get your cholesterol and triglyceride numbers under control, then medication may be the next step.
    • [Note: The American Heart Association recommends changing your diet and physical activity first and only resorting to medications if lifestyle changes don’t work. Diet and exercise do not have side effects. Medications do.]
  • Lower High Blood Pressure.
  • Be physically active every day.
  • Aim for at least 150 minutes per week of moderate-intensity physical activity per week.
  • Aim for a healthy weight.
  • Manage diabetes.
  • Reduce stress.
  • Limit alcohol.

The Bottom Line 

Previous studies have shown that people are just as likely to gain weight and develop type 2 diabetes when they consume artificially sweetened and sugar-sweetened drinks. In this issue of “Health Tips From the Professor” I shared a study showing that artificially sweetened drinks are just as bad for your heart as sugar-sweetened drinks.

These are all association studies. Association studies do not provide information on the possible mechanism(s) of the association.

That means we don’t know why artificially sweetened drinks are bad for your heart.

  • The mechanism may be physiological. However, many physiological mechanisms have been proposed. None have been proven.
  • The mechanism may be psychological. We may feel so virtuous for drinking diet drinks that we think it gives us license to eat more junk food. As a former UNC colleague once put it, “The problem is that we are using our diet drinks to wash down a Big Mac and fries.”

Association studies also do not prove causation. We cannot say with confidence that diet drink consumption increases our risk of heart disease. Nor can we speculate on the mechanism by which this might occur.

However, we can say with confidence that there is no evidence that diet drink consumption decreases the risk of obesity, diabetes, or heart disease.

The authors of this study concluded, “…higher intakes of [both] sugary drinks and diet drinks were associated with a higher risk of heart disease, suggesting that artificially sweetened beverages might not be a healthy substitute for sugary drinks.”

For more details on the study and information on a holistic approach for reducing heart disease risk 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.

 

Is Fructose Good For You Or Bad For You?

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Is It The Fructose Or Is It The Food?

Author: Dr. Stephen Chaney

VillainFructose is the villain of the day. It is #1 on everyone’s “No-No” list. Almost every website, blog, and diet book demonize it. Even authors I highly respect say we should absolutely avoid it.

We are told it causes obesity, diabetes, heart disease, and non-alcoholic fatty liver disease – a disease that was unheard of only a few decades ago. We are told to read labels and avoid any foods with fructose or high-fructose corn syrup listed on their label.

But wait. Isn’t fructose a natural sugar? The answer is, “Yes”. It is the main sugar in fruit and many other naturally sweet whole foods. In fact, there is the same amount of fructose in an 8-ounce soda and a medium apple.

Does that mean that fruits are also bad for us? What is the truth?

Is It The Fructose Or Is It The Food?

AppleLet me put this into perspective for you. I have covered this in detail in a previous issue of Health Tips From The Professor. Here is a brief summary.

  • There are no sugar villains. There are no sugar heroes. Most of your favorite “natural” sugars are chemically and biologically indistinguishable from high-fructose corn syrup. Other natural sugars, like agave sugar, contain more fructose than high-fructose corn syrup.
  • All the studies showing the bad effects of fructose have been done with sodas and/or highly processed foods with added sugar. Let’s be clear. Those foods are bad for you.
  • Fruits, on the other hand, are good for you. You’ve heard the old adage, “An apple a day keeps the doctor away”. A recent study showed that isn’t just an “old wives’ tale”. It is true.

Why is that? Why is fructose in sodas and junk foods bad for us and fructose in fruits good for us?

Part of the answer is that fruits are high in fiber, which slows the release of fructose into the intestine as fruits are digested. In addition, the fructose in fruits is trapped in a cellular matrix, which also slows the release of fructose during digestion.

Sodas and highly processed foods, on the other hand, have nothing to slow the release of fructose. It is immediately available as soon as the food reaches the intestine.

A recent study sheds light on why the rate of fructose release in our intestine may be important. The study showed:

  • When fructose is released slowly our bodies know exactly what to do with it.
    • Most of it is metabolized by the cells that line our intestine, and the rest is metabolized by the liver.
    • In both cases fructose is converted to glucose and slowly released into the bloodstream.
    • This stabilizes blood sugar levels.
  • When fructose is released quickly our bodies are overwhelmed and bad things happen.
    • The intestine passes the excess on to the liver, and the liver converts it to fat rather than glucose.
    • The fat is stored in the liver.
    • This leads to insulin resistance, diabetes, heart disease, and fatty liver disease.

But could the fiber in fruits have other beneficial effects such as supporting populations of beneficial gut bacteria? The study ( J Beisner et al, Nutrients, 12: 3444, 2020) I will focus on today suggests the answer is yes.

How Was The Study Done?

Clinical StudyInvestigators from the University of Hohenheim, Germany recruited 12 healthy female volunteers, ages 20 – 40 (average age = 28).

Each of the subjects was given a series of diets to follow for one week each.

  • Week one was a low fructose diet (10 g of fructose/day). For this diet phase subjects had to avoid sweets, highly processed foods, sodas, and fruits and vegetables containing more than 1 g of fructose per serving.
  • Week two was a high fructose fruit diet (100 g of fructose/day). This diet phase emphasized fructose-rich fruits and vegetables. Sweets, highly processed foods, and sodas had to be avoided.
  • Week three was a repeat of the low fructose diet (10 g of fructose/day).
  • Week four was a high-fructose corn syrup diet (100 g of fructose/day). For this diet phase subjects had to sweeten the food they were eating with a measured amount of high-fructose corn syrup. They also had to avoid fructose-rich fruits and vegetables.

The diets were designed to have around 2,000 calories/day and to have the same amounts of fat (30% of calories), protein (15% of calories), and carbohydrate (55% of calories). However, the fiber content of the diets was very different (around 17 g/day on the low fructose and high-fructose corn syrup diets and around 38 g/day on the high fructose fruit diet).

The subjects were given detailed instructions and training before starting on the 4-week program. They also kept a daily dietary record of everything they ate and drank so the investigators would know how closely they stuck to their dietary instructions.

This experimental design was based on previous studies showing that populations of gut bacteria change within 24-48 hours when you go on a new diet. Stool samples were collected at the end of each week and analyzed for gut bacteria.

Is Fructose Good For You Or Bad For You?

MicrobiomeThe study showed:

  • Consumption of a high-fructose, fruit-rich diet resulted in:
    • An increase in beneficial butyrate-producing bacteria (more about that below).
    • A decrease in bacteria associated with elevated total and LDL cholesterol.
    • Decreased blood levels of total and LDL cholesterol.
  • Consumption of a high-fructose corn syrup diet had the opposite effect. It resulted in:
    • A decrease in beneficial butyrate-producing bacteria.
    • An increase in bacteria associated with elevated total and LDL cholesterol.
    • Increased blood levels of total and LDL cholesterol.

The authors concluded: “We provide evidence that the high-fructose corn syrup diet induces an imbalanced microbiota [gut bacteria] profile characterized by a significantly reduced abundance of beneficial butyrate-producing bacteria and of bacteria known for anti-obesity effects…Despite the high fructose content, the fruit-rich diet shifts the intestinal microbiota composition in a protective manner…”

The authors said that there were probably two mechanisms for the different effects of fructose in high-fructose corn syrup and in fruits.

  • The fiber found in fruit supports the growth of beneficial bacteria in our intestine.
  • When high-fructose corn syrup is present in foods with low fiber content, it is released rapidly in the intestine. As I noted above, the cells that line our intestine become overwhelmed and pass some of that excess fructose on to our liver. However, the authors cited previous studies showing that some of that excess fructose remains in our intestine and supports the growth of unhealthy bacteria.

What Does Butyrate Do?

Question MarkYou are probably wondering what is special about butyrate-producing bacteria. Here is a brief synopsis.

  • Butyrate is a short chain fatty acid. As you might expect from its name, it was originally identified as a constituent of butter.
  • Some species of gut bacteria convert the fats in our diet to butyrate.
    • It is used as a preferred energy source for the cells that line our intestine. Consequently, butyrate production in our intestines has been linked to:
      • Reduced inflammation of the cells lining our intestine, which reduces the risk for diseases like inflammatory bowel disease (IBS) and Crohn’s Disease.
      • Reduced risk of “leaky gut syndrome”.
      • Reduced risk of colon cancer.
    • It is also absorbed into the bloodstream and appears to affect several metabolic pathways. For example, butyrate production in the intestine is associated with:
      • Decreased cholesterol levels.
      • Improved blood sugar control.
      • A healthy body weight.

What Does This Mean For You?

Questioning ManThis was a small study. As the authors noted, larger studies of longer duration are needed to confirm that the effects of fructose on our gut bacteria depend on the food the fructose is in. However, several other studies have come to similar conclusions.

More importantly, this study merely shows that the effect of fructose-containing foods on our gut bacteria is a potential mechanism for explaining why the effect of fructose depends on the food it is in.

There is already overwhelming evidence that fructose in fruits is good for us, while high-fructose corn syrup in sodas and highly processed foods is bad for us.

Does that mean high-fructose corn syrup is villainous? Should we read labels and avoid any food containing high-fructose corn syrup?

I would remind you that the amount of fructose and the relative abundance of fructose and glucose are virtually identical in fruits and high-fructose corn syrup. It is not high-fructose corn syrup that is the problem, it is the foods it is found in.

We don’t need to become compulsive label readers. We just need to eat more foods without labels.

The Bottom Line 

High-fructose corn syrup has been vilified in recent years. However, there is increasing evidence that it is not fructose that is the problem. It is the foods it is found in.

A recent study was designed to test that hypothesis. The investigators fed subjects high fructose diets in which the fructose came either from fruits or high-fructose corn syrup. The amount of fructose was identical in the two diets. The investigators then asked what effect the two diets had on gut bacteria. In short:

  • Consumption of the high-fruit diet increased healthy levels of beneficial gut bacteria and suppressed levels of unhealthy gut bacteria.
  • Consumption of the high-fructose corn syrup diet had the opposite effect. It increased unhealthy bacteria and suppressed beneficial bacteria.

The authors concluded: “We provide evidence that the high-fructose corn syrup diet induces an imbalanced microbiota [gut bacteria] profile characterized by a significantly reduced abundance of beneficial…bacteria and of bacteria known for anti-obesity effects…Despite the high fructose content, the fruit-rich diet shifts the intestinal microbiota composition in a protective manner…”

My take is as follows: This study shows that the effect of fructose-containing foods on our gut bacteria is a potential mechanism for explaining why the effect of fructose depends on the food it is in.

There is already overwhelming evidence that fructose in fruits is good for us, and high-fructose corn syrup in sodas and highly processed foods is bad for us.

Does that mean that high-fructose corn syrup is villainous? Should we read labels and avoid any food containing high-fructose corn syrup?

I would remind you that the amount of fructose and the relative abundance of fructose and glucose is virtually identical in fruits and high-fructose corn syrup. It is not high-fructose corn syrup that is the problem, it is the foods it is found in.

We don’t need to become compulsive label readers. We just need to eat more foods without labels.

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.

Health Tips From The Professor