Is Dairy Bad For Your Heart?

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.

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

The Fine Print Behind The Misleading Headline

 Author: Dr. Stephen Chaney

 Human NeuronsI 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?

“Exercise” Versus “Lifestyle Activity”: 

How Active Are You—Really?

Author: Dr. Pierre DuBois

canotThe 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.

Health Tips From The Professor