Fish

Does Red Meat Cause Frailty In Older Women?

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Which Proteins Are Best?

Author: Dr. Stephen Chaney

Fatty SteakThe ads from the meat lobby say, “Red meat does a body good”. Are the ads true?

If we consider the health consequences of regularly eating red meat, the answer appears to be a clear, “No”. Multiple studies have shown a link between red meat consumption and:

  • Coronary heart disease.
  • Stroke
  • Type 2 diabetes.
  • Colon cancer, prostate cancer, and breast cancer.

And, if we consider the environmental consequences of red meat production, the answer also appears to be, “No”. I have discussed this in a recent issue of “Health Tips From the Professor”.

But what about muscle mass and strength? Red meat is a rich source of protein, and we associate meat consumption with an increase in muscle mass. Surely, red meat consumption must help us build muscle mass and strength when we are young and preserve muscle mass and strength as we age.

This is why the recent headlines claiming that red meat consumption increases the risk of frailty in older women were so confusing. I, like you, found those headlines to be counterintuitive. So, I have investigated the study (EA Struijk et al, Journal of Cachexia, Sarcopenia and Muscle, 13: 210-219, 2022) behind the headlines. Here is what I found.

How Was The Study Done?

Clinical StudyThis study utilized data acquired from the Nurses’ Health Study (NHS). The NHS began in 1976 with 121,700 female nurses aged 30 to 55. This study followed 85,871 nurses in the NHS once they reached age 60 for an average of 14 years.

Dietary intake was assessed using a food frequency questionnaire that was administered to all participants in the study every four years between 1980 and 2010. The long-term intake of red meat and other protein sources was based on a cumulative average of all available diet questionnaires for each participant.

The participants also filled out a Medical Outcomes Short Report every four years between 1992 and 2014. Data from this survey was used to calculate something called the FRAIL scale, which includes the following frailty criteria:

  • Fatigue
  • Low muscle strength.
  • Reduced aerobic capacity.
  • Having ≥5 of the following chronic diseases:
    • Cancer
    • High blood pressure
    • Type 2 diabetes
    • Angina
    • Myocardial infarction (heart attack)
    • Congestive heart failure
    • Asthma
    • COPD (chronic obstructive pulmonary disease)
    • Arthritis
    • Parkinson’s disease
    • Kidney disease
    • Depression
  • Greater than ≥5% weight loss in two consecutive assessments.

Frailty was defined as having met 3 or more criteria in the FRAIL scale. The study looked at the effect of habitual consumption of red meat or other protein sources on the development of frailty during the 14-year follow-up period.

Does Red Meat Cause Frailty In Older Women?

The investigators separated the participants into 5 quintiles based on total red meat consumption, unprocessed red meat construction, or processed red meat consumption. The range of intakes was as follows.

Total red meat: 0.4 servings per day to 1.8 servings per day.

Unprocessed red meat: 0.3 servings per day to 1.3 servings per day.

Processed red meat: 0.04 servings per day to 0.6 servings per day.

Clearly none of the women in this study were consuming either vegan or keto diets. As might be expected from a cross-section of the American public, there was a fairly narrow range of daily meat consumption.

Here are the results of the study:

  • Each serving per day of total red meat increased frailty by 13%.
  • Each serving per day of unprocessed red meat increased frailty by 8%.
  • Each serving per day of processed red meat increased frailty by 26%.
  • When each component of the frailty index was examined individually, all of them were positively associated with red meat consumption except for weight loss.

This was perhaps the most unexpected finding of the study. Not only did red meat consumption increased the risk of chronic diseases in these women, which would be expected from many previous studies. But red meat consumption also made these women more tired, weaker, and shorter of breath.

The authors concluded, “Habitual consumption of any type of red meat was associated with a higher risk of frailty.”

Which Proteins Are Best?

Red Meat Vs White MeatThe investigators then asked if replacing one serving/day of red meat with other protein sources was associated with a significantly lower risk of frailty. Here is what they found:

  • Replacing one serving per day of unprocessed red meat with a serving of:
    • Fish reduced frailty risk by 22%.
    • Nuts reduced frailty risk by 14%.
  • Replacing one serving per day of processed red meat with a serving of:
    • Fish reduced frailty risk by 33%
    • Nuts reduced frailty risk by 26%
    • Low-fat dairy reduced frailty risk by 16%
    • Legumes reduced frailty risk by 13%.

The authors concluded, “Replacing red meat with another source of protein including fish, nuts, legumes, and low-fat dairy may be encouraged to reduce the risk of developing frailty syndrome. These findings are in line with dietary guidelines promoting diets that emphasize plant-based sources of protein.” [I would note that fish and low-fat dairy are hardly plant-based protein sources.]

What Does This Study Mean For You?

Questioning WomanI am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies.

And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results. As I said earlier, increased protein intake is usually associated with an increase in muscle mass when we are young and a preservation of muscle mass as we age. There is no obvious metabolic explanation for why an increase in red meat consumption in older women would cause a decrease in muscle mass and other symptoms of frailty.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and bad for the health of the planet as I have discussed in an earlier issue of “Health Tips From the Professor”. And substituting other protein sources, especially plant proteins, is better for our health and the health of our planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. While I am not ready to say that red meat causes decreased muscle mass, I do think this study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

The Bottom Line

A recent study looked at the effect of red meat consumption on frailty in older women. It came to the unexpected conclusion that:

  • Each serving per day of total red meat increased frailty by 13%.
  • Each serving per day of unprocessed red meat increased frailty by 8%.
  • Each serving per day of processed red meat increased frailty by 26%.
  • The increase in frailty could be reduced by replacing one serving/day of red meat with a serving of fish, nuts, low-fat dairy, or legumes.

I am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies. And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and for the health of the planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. This study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

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.

Health Tips From The Professor