cholesterol Archives - Health Tips From The Professor

Are Easter Eggs Bad For You?

April 4, 2023 by Dr. Steve Chaney

Clearing Up The Eggfusion

Author: Dr. Stephen Chaney

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

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

First there were the warnings that eggs were bad for your heart because egg yolks contained cholesterol, and cholesterol was to be avoided at all costs.

Then experts decided that dietary cholesterol wasn’t all that bad for you. It was saturated fats, obesity, and lack of exercise that raised “bad” (LDL) cholesterol levels in your bloodstream.

That was followed by several US studies suggesting that eggs in moderation (one per day) did not affect your risk of heart disease.

Then a major study claimed that an egg a day actually lowered your risk of heart disease.

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

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

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

How Was The Study Done?

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

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

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

Do Eggs Increase Heart Disease Risk?

Here are the main findings from this study.

Each additional half an egg consumed per day (which is equivalent to 3-4 eggs per week) was associated with a:

- 6% increased risk of heart disease. While that doesn’t sound like much, the increased risk was over 13% for one egg per day and almost 27% for two eggs per day.

The increased heart disease risk associated with one half egg per day was greater for:

- Women (13% increase) than men (3% increase).

- People who already had high blood cholesterol (7% increase), not people who already had low cholesterol levels (0% increase). This suggests that the effect of eggs on heart disease risk primarily affects people who are already having trouble controlling their blood cholesterol levels – either due to genetics or due to diet & lifestyle.

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

The association between egg consumption and heart disease risk disappeared after correcting for dietary cholesterol intake.

The association between egg consumption and heart disease risk remained significant after correcting for other components of the diet, such as fats, animal protein, fiber, sodium, or overall “diet quality”. There were 3 main measures of diet quality.

- The Med diet score measures how closely the diet resembles the Mediterranean diet.

- The DASH diet score measures how closely the diet resembles the DASH diet.

- The Healthy Eating Index (HEI) measures how closely the diet aligns with the USDA Dietary Guidelines For Americans. Basically, the HEI recommends a whole food diet containing foods from all 5 food groups with a heavy emphasis on fruits, vegetables, whole grains, and legumes. It also recommends limiting saturated and trans fats, added sugars, and sodium.

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

What Are The Strengths And Weaknesses Of The Study?

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

However, there were some significant weaknesses as well:

Cholesterol and egg consumption were only measured by a single dietary survey when people entered the study. This study assumes they did not change over the course of the study. That is very unlikely. Both cholesterol intake and egg consumption in the US population have waxed and waned over the years, in part due to variations in dietary guidelines.

The measurements of diet quality used were based on US and European food preferences. That is significant because the only studies showing that egg consumption lowers heart disease risk were performed in China and Japan, where the diet is closer to semi-vegetarian than to US or European diets.

Are Easter Eggs Bad For You?

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

The strongest conclusions from the study are:

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

The increased risk of heart disease appears to be almost entirely due to the cholesterol content of eggs.

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

Recent studies in the US and Europe showing eggs do not increase heart disease risk.

Studies in China and Japan (where the diets can best be described as semi-vegetarian) showing that eggs decrease heart disease risk.

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

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

What Did This Study Miss?

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

The kind of fiber found in certain fruits, vegetables, whole grains, and legumes bind to dietary cholesterol, preventing it from being absorbed as it passes through the intestine.

Certain phytonutrients in plant foods affect how dietary cholesterol is utilized by the body.

However, to blunt the effect of dietary cholesterol on blood cholesterol levels the fiber and phytonutrient-containing foods must be consumed at the same meal.

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

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

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

The Professor’s Story

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

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

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

Are Easter Eggs Good For You?

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

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

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

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

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

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

Clearing Up The “Eggfusion”

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

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

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

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

Reduce dietary cholesterol by avoiding eggs or using egg whites.

- Eat eggs in moderation along with fiber- and phytonutrient-rich plant foods that negate the effect of dietary cholesterol on blood cholesterol levels. I recommend oatmeal or beans, nuts or seeds, and fiber rich fruits and vegetables. These should be consumed at the same meal to minimize the effect of the cholesterol in the eggs on blood cholesterol levels. As for Easter eggs, they are a perfect addition to a green salad.

- Eggs are a very healthy food, so I recommend the second option if possible. Get your blood cholesterol levels measured to determine which approach works best for you.

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

- Smoking, obesity, inactivity, saturated and trans fats significantly increase your risk of heart disease.

- Omega-3s, antioxidants, and a primarily plant-based diet like the Mediterranean diet significantly decrease your risk of heart disease.

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

The Bottom Line

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

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

It only determined cholesterol intake and egg consumption at the time people entered the clinical trials. Both cholesterol intake and egg consumption have waxed and waned considerably over the years covered by these clinical trials.

It did not measure what foods were consumed along with the eggs. Foods consumed along with eggs have a strong influence on how much the cholesterol in the eggs influences blood cholesterol levels, which, in turn, influences the effect eggs have on heart disease risk.

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

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

Reduce dietary cholesterol by avoiding eggs or using egg whites.

Eat eggs in moderation along with fiber- and phytonutrient-rich plant foods that negate the effect of dietary cholesterol on blood cholesterol levels. I recommend oatmeal or beans, nuts or seeds, and fiber rich fruits and vegetables. These should be consumed at the same meal to minimize the effect of the cholesterol in the eggs on blood cholesterol levels. As for Easter eggs, they are a perfect addition to a green salad.

Eggs are a very healthy food, so I recommend the second option if possible. Get your blood cholesterol levels measured to determine which approach works best for you.

Smoking, obesity, inactivity, saturated and trans fats significantly increase your risk of heart disease.

Omega-3s, antioxidants, and a primarily plant-based diet like the Mediterranean diet significantly decrease your risk of heart disease.

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

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

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

What Is The Truth About Low Carb Diets?

August 30, 2022 by Dr. Steve Chaney

Why Is The Cochrane Collaboration The Gold Standard?

Author: Dr. Stephen Chaney

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

They restrict carbohydrate intake to <40% of calories.

They restrict grains, cereals, legumes, and other carbohydrate foods such as dairy, fruits, and some vegetables.

They replace these foods with foods higher in fat and protein such as meats, eggs, cheese, butter, cream, and oils.

When recommended for weight loss, they generally restrict calories.

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

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

Most studies on the benefits of low carb diets compare them with the typical American diet.

- The typical American diet is high in fat, sugar and refined flour, and highly processed foods. Anything is better than the typical American diet.

Most low carb diets are whole food diets.

- Any time you replace sodas and highly processed foods with whole foods you will lose weight and improve your health.

Most low carb diets are highly structured. There are rules for which foods to avoid, which foods to eat, and often additional rules to follow.

- Any highly structured diet causes you to focus on what you eat. When you do that, you lose weight. When you lose weight, your health parameters improve.

- As I have noted before, short term weight loss and improvement in health parameters are virtually identical for the very low carb keto diet and the very low-fat vegan diet.

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

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

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

Why Is The Cochrane Collaboration The Gold Standard?

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

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

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

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

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

High-quality evidence. Further research is unlikely to change their conclusion. This is generally reserved for conclusions backed by multiple high-quality studies that have all come to the same conclusion. These are the recommendations that are most often adopted into medical practice.

Moderate-quality evidence. This conclusion is very likely to be true, but further research could have an impact on it.

Low-quality evidence. Further research is needed and could alter the conclusion. They are not judging whether the conclusion is true or false. They are simply saying more research is needed to reach a definite conclusion.

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

How Was The Study Done?

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

The first group was put on a low carbohydrate diet (carbohydrates = <40% of calories).

The second group was put on a “normal carbohydrate” diet (carbohydrates = 45-65% of calories, as recommended by the USDA and most health authorities).

- The normal carbohydrate diet was matched with the low carbohydrate diet in terms of caloric restriction.

- Both diets were designed by dietitians and were generally whole food diets.

The participants in these studies:

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

The studies were of 3 types:

Short-term: Participants in these studies followed their assigned diets for 3 to <12 months.

Long-term: Participants in these studies followed their assigned diets for >12 to 24 months.

Short-term with maintenance: Participants in these studies followed their assigned diets for 3 months followed by a 9-month maintenance phase.

What Is The Truth About Low Carb Diets?

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

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

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

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

Weight loss was not significantly different between low carb and normal carb diets in short-term studies (3 to <12 months), long-term studies (>12 to 24 months), and short-term studies followed by a 9-month maintenance period.

There was also no significant difference in the effect of low carb and normal carb diets on the reduction in diastolic blood pressure and LDL cholesterol.

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

Weight loss was also not significantly different on low carb and normal carb diets.

There was no significant difference in the effect of low carb and normal carb diets on the reduction in diastolic blood pressure, LDL cholesterol, and hemoglobin A1c, a measure of blood sugar control.

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

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

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

What Does This Study Mean For You?

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

In short, this Cochrane Collaboration Report concluded:

Low carb diets (<40% of calories from carbohydrates) are no better than diets with normal carbohydrate content (45-65% of calories from carbohydrates) with respect to weight loss, reduction in heart disease risk factors, and blood sugar control. Dr. Strangelove has been misleading you again.

This finding is equally true for people with and without type 2 diabetes. This calls into question the claim that people with type 2 diabetes will do better on a low carb diet.

The published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

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

Remember that any whole food diet that eliminates sodas and processed foods and restricts the foods you eat will cause you to lose weight. Whole food keto and vegan diets work equally well short-term compared to the typical American diet.

And any diet that allows you to lose weight improves heart health parameters and blood sugar control.

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

The studies included in this Cochrane Collaboration report randomly assigned participants to the low carb and normal carb diets and followed them for 3 to 24 months.

- Both diets were whole food diets designed by dietitians.

- Both diets reduced caloric intake to the same extent.

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

At the 6.4-year mark a recent study reported that the group with the lowest carbohydrate intake had an increased risk of premature death – 32% for overall mortality, 50% for cardiovascular mortality, 51% for cerebrovascular mortality, and 36% for cancer mortality. I will analyze this study in a future issue of “Health Tips From The Professor”.

At the 20-year mark a series of studies reported that:

- Women consuming a meat-based low carb diet for 20 years gained just as much weight and had just as high risk of heart disease and diabetes as women consuming a high carbohydrate, low fat diet.

- However, women consuming a plant-based low carb diet for 20 years gained less weight and had reduced risk of developing heart disease and diabetes as women consuming a high carbohydrate, low fat diet.

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

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

The Bottom Line

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

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

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

The Cochrane Collaboration Report concluded:

Low carb diets (<40% of calories from carbohydrates) are no better than diets with normal carbohydrate content (45-65% of calories from carbohydrates) with respect to weight loss, reduction in heart disease risk factors, and blood sugar control.

This is equally true for people with and without type 2 diabetes.

The published studies on this topic were of moderate quality. This means their conclusion is very likely to be true, but further research could have an impact on it.

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

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

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

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

Is Dairy Bad For Your Heart?

December 7, 2021 by Dr. Steve Chaney

Is Dairy Right For You?

Author: Dr. Stephen Chaney

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.

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?

Before 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 29 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.

The 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?

Now 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

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.

Do Statins Decrease Or Increase The Risk Of Parkinson’s Disease?

October 17, 2013October 1, 2013 by Dr. Steve Chaney

The Fine Print Behind The Misleading Headline

Author: Dr. Stephen Chaney

I hadn’t paid much attention to the headlines saying “Statin Use May Decrease Parkinson’s Risk” until the other day when I happened to glance a couple of lines below the headline and spotted a statement saying “Study Shows That Discontinuation of Statin Therapy Increases Risk of Parkinson’s”.

I immediately said to myself “That’s bizarre. There is a total disconnect between the headlines and the study.” If you really wanted to determine whether statin use reduced the risk of Parkinson’s, you would compare the incidence of Parkinson’s disease in a group of statin users and a matched group who did not use statins.

It turns out those studies have been done, and they were inconclusive – some studies showed a slight increase in Parkinson’s in statin users, some showed a slight decrease, and most showed no correlation between statin use and Parkinson’s.

In that context, this study could equally well have been interpreted as suggesting that statin use increased the risk of Parkinson’s, but somehow none of the headlines mentioned that possibility.

Are Both Possibilities Plausible?

Let’s look at each possibility in detail. The reasoning is complex, but let me try to walk you through it.

Could Statins Decrease The Risk Of Parkinson’s

Parkinson’s is caused by the progressive degeneration of the brain neurons that produce a chemical messenger called dopamine that controls muscle movement. However, the causes of nerve degeneration in Parkinson’s patients are largely unknown.

Genetics may play a small role. Environmental toxins may play a role. But most experts feel that Parkinson’s patients produce an excess of free radicals, and it is the oxidative damage caused by those free radicals that results in the loss of the ability of neurons to produce dopamine.

But even that is not the whole answer. The brain is normally able to use coenzyme Q10, which is very abundant in brain, and other antioxidants to destroy free radicals before they damage brain neurons. Somehow in Parkinson’s patients free radical production and antioxidant production have gotten out of balance.

Advocates of the theory that statins may decrease the risk of Parkinson’s, point out that statins decrease oxidative damage. So if a person was predisposed to developing Parkinson’s and oxidative damage is a major cause of Parkinson’s, it is theoretically possible that statins could slow the progression to Parkinson’s while they were taking the drug. Of course, once they stopped taking the drug the oxidative damage to dopamine-producing neurons would resume and Parkinson’s would eventually develop.

In this model- Let’s call it Model A:

1) Oxidative damage of dopamine-producing neurons was caused by some unspecified external agent.

2) Statins protected the neurons from oxidative damage while they were being used.

3) Once the statin drugs were discontinued oxidative damage resumed and the risk of developing Parkinson’s increased.

This is the model favored by the authors and repeated in all of the headlines you saw.

Could Statins Increase The Risk Of Parkinson’s?

Statins also interfere with the synthesis of cholesterol and coenzyme Q10, and these are both absolutely essential for brain function. Let’s start with cholesterol:

20% of the body’s membrane cholesterol is found in the myelin sheath that coats the brain’s neurons (You can think of the myelin sheath as analogous to the plastic coating that insulates an electrical wire).

Cholesterol can’t cross the blood-brain barrier, which means that the brain cannot utilize cholesterol from the bloodstream . It has to make its own cholesterol.

As for coenzyme Q10:

It is not only a powerful antioxidant. It is also absolutely essential for cellular energy production.

The brain has tremendous energy requirements. The brain accounts for 20% of the energy utilization of our body. Neurons burn 2 times more energy than other cells in our body.

For both of these reasons, many experts have cautioned that statin drugs have the potential to cause neurodegenerative diseases such as Parkinson’s. In this model – Lets call it model B:

1) The statin drugs themselves are damaging the dopamine-producing neurons by inhibiting cholesterol and coenzyme Q10 synthesis in the brain.

2) The antioxidant effects of the statin drugs were masking the damage caused by the statins while the drugs were being used.

3) Once the statin drugs were discontinued the underlying damage was unmasked and the patients quickly developed Parkinson’s.

What Did The Study Actually Show?

The study (Lee et al, Neurology, 81: 410-416, 2013) looked at 43,810 statin users on the island of Taiwan. The Taiwanese Health System keeps extensive records of prescription use and health conditions of everyone on the island. It also requires that statin use be discontinued as soon as the patient reach their target of < 100 mg/dL LDL cholesterol, so they had the perfect population base to study what happens when you discontinue statin therapy.

The results were:

The patients who discontinued statin therapy were 42% less likely to develop Parkinson’s that those who continued on statin therapy. That result is consistent with both models A & B.

The increased risk of developing Parkinson’s when the drug was discontinued was only seen for the statin drugs like simvastatin and atorvastatin that are able to cross the blood brain barrier. That result is actually a bit more consistent with model B (Remember that the brain has to be able to make its own cholesterol and statins block cholesterol production).

When the study compared people using statin drugs to those not using statin drugs there was no significant difference in the prevalence of Parkinson’s – even for those statin drugs that cross the blood brain barrier. That means that merely being on a statin drug did not influence the risk of developing Parkinson’s. It was only when patients were on statin drugs for a period of time and were subsequently taken off statins that the risk of developing Parkinson’s was affected – and the effect was to increase risk! In the context of the first two findings, that result is also a bit more consistent with model B.

The Bottom Line:

If I were writing one of those medical blogs, I would have probably have gone with the party line and told you that statins decrease your risk of developing Parkinson’s. And if I were one of those health bloggers who never let the facts get in the way of a good story, I’d probably be scaring you with headlines saying that statins increase your risk of Parkinson’s.

But, I’m a scientist. I actually read the article, and I tell it to you like it is. Here’s your bottom line.

1) Ignore the headlines. The study they are talking about can’t distinguish between statins increasing or decreasing the risk of Parkinson’s. Don’t let anyone tell you that reducing the risk of Parkinson’s is a side benefit of statin therapy. That simply has not been proven.

2) The study does clearly show that discontinuing the statin drugs simvastatin and atorvastatin is associated with increased risk of developing Parkinson’s. That’s a big red flag for me, because 53% of patients discontinue statin therapy because of side effects, cost or other reasons.

3) However, statin drugs do save lives, especially for people who have already had a heart attack, so talk with your doctor about the benefits and risks of statin drugs, and which statin drugs are best for you.

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.

How Much Exercise Do You Need?

October 17, 2013September 19, 2013 by Dr. Steve Chaney

“Exercise” Versus “Lifestyle Activity”:

How Active Are You—Really?

Author: Dr. Pierre DuBois

The most frequent questions I get are: “How much exercise do I need?” and “What’s the best way of getting that exercise?” If you are like most people, working out just for the sake of working out does not really appeal (although there are many dedicated gym buffs who couldn’t live without their daily workouts!).

We all know that it’s important to exercise regularly if we want to live a long and healthy life. However, if you find the idea of trotting along on a treadmill for 15 minutes and then spending half an hour of working out on Nautilus machines to be about as exciting as a trip to the dentist, then this article is for you!

What the Experts Recommend:

Experts recommend that we get at least 150 minutes of exercise each week to stay in shape. But many people find taking this much exercise at once (or in three 50-minute stretches) too daunting.

The good news is that a recent study conducted by researchers at Boston University that was published in the journal Medicine & Science in Sports & Exercise found that bouts of exercise lasting less than 10 minutes a couple of times daily, such as the kind you get when cleaning the house, were sufficient to meet your weekly exercise needs.

What the Study Showed

Over 2,000 participants were included in the study, more than half of whom were overweight. Motion detectors were attached to each of the subjects for eight days, and an average of half the participants met their weekly exercise quota of 150 minutes. The average participant met his or her quota with exercise that lasted less than 10 minutes at a time. The types of exercise ranged from moderate (heavy cleaning, walking briskly and sports such as golf and badminton) to vigorous (running, hiking, shoveling and farm work).

As long as the participants met their 150-minute per week quota, no matter the length of their exercise, they had lower body mass index, smaller waists, lower triglycerides and better cholesterol levels than those who did not meet the quota.

Assistant professor at Boston University’s School of Medicine, Nicole Glazer, says “This study really speaks to the idea that some activity is better than nothing. Parking a little bit farther away, getting off the bus one stop early—all of these little things can add up and are related to a healthier profile.”

For years, researchers have studied the effects of exercise from practicing sports or visiting the gym. However, according to Glazer, “This idea of lifestyle activity is one that is under-measured in research studies.” Activities such as taking the stairs instead of the elevator, using a push mower instead of a riding mower, etc. can add up to a significant amount of energy expenditure. Experts still stress that it’s important to also get in some traditional forms of exercise and not merely replace it with lifestyle activity. Still, any exercise is useful.

“The levels of sedentary behavior in this country are alarming. So the concern that someone’s going to stop exercising and instead just get off the bus a stop earlier, that’s not my concern,” Glazer says. “The real concern is, is this a stepping-stone? Is this the way we can get inactive people to do any sort of activity? People will come up with any excuse to not exercise. I don’t need to worry about my giving them one. They’ll be able to think of something.”

The Bottom Line:

Experts recommend 150 minutes of moderate intensity exercise a week

That doesn’t mean that you need to be a gym rat or marathoner. Ten minute exercise intervals centered around everyday lifestyle activities can be sufficient.

So you are out of excuses. You have the time. You have all the equipment you need. You don’t even need special workout clothes.

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.