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Is The Mediterranean Diet Healthy For Women?

May 28, 2024 by Dr. Steve Chaney

What Does This Study Mean For You?

Author: Dr. Stephen Chaney

There is a well-known health disparity in clinical studies related to health. For years most of the studies have been done by men for men. Women have been assumed to experience the same benefits and risks from diet choices as men. But that hasn’t always proven to be true.

The Mediterranean diet is no exception. For example, it has garnered a reputation of reducing heart disease risk for both men and women.

However, most studies on the Mediterranean diet have included primarily male participants or did not report sex specific differences in outcomes.

And the few studies that reported sex specific outcomes have been inconsistent.

Some studies have found that men and women benefitted equally from the Mediterranean diet.

Other studies have reported that men benefitted more than women.

However, these were all small studies. No meta-analyses have been reported that focused on the heart benefits of the Mediterranean diet for women.

The study (A Pant et al., Heart; 109: 1208-1215, 2023) I will describe today was designed to fill that gap.

How Was The Study Done?

The investigators started by screening the literature to find studies that:

Measured adherence to the Mediterranean diet using the original MDS (Mediterranean Diet Score) or more recent modifications of the MDS.

Included women ≥18 years without previous diagnosis of clinical or subclinical heart disease.

Performed the study with only women participants or organized their data so that the data pertaining to women could be extracted from the study.

The investigators then performed a meta-analysis on data from 722,495 women in 16 studies published between 2006 and 2021 that met these criteria. These studies followed the women for an average of 12.5 years. The studies were primarily conducted in the United States and Europe.

The individual studies divided participants into either quintiles or quartiles and compared participants with the highest adherence to the Mediterranean diet to those with the lowest adherence.

The primary outcomes measured were total mortality and the incidence of CVD, cardiovascular disease (defined as including CHD (coronary heart disease), myocardial infarction (heart attack), stroke, heart failure, and cardiovascular death).

The secondary outcomes measured were stroke and CHD, coronary heart disease (heart disease caused by atherosclerotic plaque build up in the coronary arteries).

Is The Mediterranean Diet Healthy For Women?

When comparing the highest to the lowest adherence to the Mediterranean diet:

The incidence of CVD (cardiovascular disease) was reduced by 24%.

Total mortality during the ~12.5-year follow-up was reduced by 23%.

The incidence of CHD (coronary heart disease) was reduced by 25%.

The risk of stroke was reduced by 13%, but that risk reduction was not statistically significant.

- The risk reduction for both CVD and total mortality was similar to that previously reported for men.

- Risk reduction for CVD was slightly higher for women of European descent (24%) than for women of non-European descent (21%). The later category included women of Asian, Native-Hawaiian, and African – American descent.

The authors concluded, “This study supports a beneficial effect of the Mediterranean diet on the primary prevention of CVD and death in women and is an important step in enabling sex-specific guidelines.”

I would add that the data from women of non-European decent suggests that genetic background and/or ethnicity may influence the effectiveness of the Mediterranean diet at reducing heart disease risk, but this effect appears to be small.

What Does This Mean For You?

The results of this study are not unexpected. But that doesn’t mean that studies with women are not valuable. There have been several examples in recent years where health or medical advice based on studies with men needed to be modified for females once the studies were repeated with women.

Before covering what this study means for you, I should point out that while women often fear breast cancer most, heart disease is their number one killer, as the graph on the left shows. In fact, a woman’s risk of dying from coronary heart disease is 6 times greater than her risk of dying from breast cancer.

This study shows that following a Mediterranean–style diet lowers their risk of developing and dying from heart disease. But the Mediterranean diet is not alone in providing these health benefits. It is simply a whole food, primarily plant-based diet that reflects the food preferences of the Mediterranean region.

The DASH diet, which reflects the food preferences of Americans, and the Nordic diet, which reflects the food preferences of the Scandinavian countries, are equally heart healthy. In fact, any whole food, primarily plant-based diet will reduce the risk of heart disease. You should choose the one that best fits your food preferences and lifestyle.

Of course, diet is just part of a holistic approach for reducing heart disease risk. Other important risk reduction strategies include:

Don’t smoke.

Exercise and maintain a healthy weight.

Manage stress.

Avoid or limit alcohol.

Know your numbers (cholesterol, triglycerides, and blood pressure, for example).

Manage other health conditions that increase the risk of heart disease (high blood pressure, diabetes, and high cholesterol, for example).

The Bottom Line

Most studies on the heart health benefits of the Mediterranean diet have been done with men or have not analyzed the data from men and women separately. A recent meta-analysis combining data from 16 studies with 722,495 women showed that the Mediterranean diet was just as heart healthy for women as it was for men.

For more details on this study and information on other diets that are heart healthy, read the article above.

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

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

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

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

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

_____________________________________________________________________

About The Author

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

How Much Protein Do Post-Menopausal Women Need?

March 19, 2024 by Dr. Steve Chaney

Does The Design Of The Protein Supplement Matter?

Author: Dr. Stephen Chaney

You’ve probably heard the saying, “It’s all downhill after 30”. That’s a particularly gloomy way of looking at it, but Father Time does take a toll on our body. I’m going to focus on age-related loss of muscle mass today, a physiological process called sarcopenia.

There are three factors that influence the rate at which we lose muscle mass as we age:

1) Our physiology changes. Our bodies break down our protein stores more rapidly and we have a harder time utilizing the protein in our diet to replenish those protein stores.

2) We become less active. In some cases, this reflects physical disabilities, but all too often it is because we are not giving weight-bearing exercises the proper priority in our busy lives.

3) Our diets become inadequate. The major driver of this phenomenon is loss of appetite which results in decreased caloric intake. However, physical disability, isolation, and insufficient income also contribute.

Sarcopenia in turn results in:

Loss of muscle strength. Even the simple act of picking up a grandchild or a bag of groceries can become problematic.

Increased risk of falls and fractures.

Lower quality of life.

Obviously, sarcopenia is a major health issue for those of us in our golden years. If you are younger, it is a concern for your parents or grandparents. Sarcopenia is a health issue that affects everyone.

But what can be done to prevent sarcopenia? We can’t change our physiology, but we can change our activity level and our diet. Weight-bearing exercise tugs on our muscle fibers. That stimulates those fibers to incorporate protein into new muscle cells. It is no wonder that weight-bearing exercise is recommended for preventing sarcopenia.

What about diet? Are older adults getting enough protein in their diet to benefit from weight-bearing exercise? I have shared studies showing that older adults need more protein and higher levels of the amino acid leucine to benefit from their workouts.

But those studies were done with men. There have been no studies comparing younger and older women until now.

In this article, I discuss a recent study (CF McKenna et al, Journal of Applied Physiology, Feb 22, 2024 doi.org/10.1152/applphysiol.00886.2023) that asks how much protein is needed to stimulate muscle protein synthesis following a workout in post-menopausal women and compares it to the protein needs of younger women.

How Was The Study Done?

The investigators enrolled 16 post-menopausal women who were part of a much larger study investigating exercise and nutritional regimens that preserve and/or enhance muscle mass in women.

The women in this study were on average 60 years old with a BMI of 26 (overweight). They had no heart disease, dietary restrictions, and did not take any supplements that could affect protein metabolism.

They were compared to a cohort of pre-menopausal women (average age = 24, BMI = 25 (borderline overweight)) recruited from the same large study. The experimental protocol was the same for the pre-menopausal and post-menopausal cohorts.

The study design was what is called a parallel-group design. Simply put, one leg was exercised using a leg extension machine, while the other leg was rested. The rested leg served as the control for each participant in the study.

Participants were tested ahead of time to determine the “one-repetition maximum” (1RM) weight for complete leg extension for each participant.

On the day of the experiment participants arrived in the laboratory after an overnight fast. One iv line was inserted, and a labeled amino acid was infused into the bloodstream, so the investigators could measure new protein synthesis at any time during the 4-hour experiment. Another iv line was inserted, so the investigators could withdraw blood samples.

At the beginning of the experiment, each participant was given either a whey protein drink (whey protein isolate fortified with vitamins C, B1, B2, B3, folate, B6, and B12 and minerals calcium, magnesium, iron, zinc, and potassium) or water. They then performed a bout of single-leg extensions starting with a warm-up of 2 sets of repetitions at 30% 1RM followed by 3 sets of 12 repetitions at 65% 1RM with 90 seconds of rest provided between sets.

Immediately following exercise, muscle biopsies were collected from both legs (t=0). Muscles biopsies were also collected at 120 and 240 minutes after exercise. Blood samples were collected continually during the experiment.

Muscle tissue was isolated from each biopsy, and something called myofibrillar protein synthesis (protein synthesis in muscle fibers) was determined based on the amount of labeled amino acid incorporated into muscle protein. The amount of protein synthesis due to exercise was determined by subtracting the incorporation of labeled amino acid in muscle fibers in the rested leg from that in the exercised leg.

What Is Leucine?

Leucine is an essential amino acid. It is present in all dietary proteins, but it is more abundant in whey and soy protein than in some vegetable proteins.

Leucine is also one of three branched-chain amino acids (valine and isoleucine are the other two). If you are familiar with the weightlifting and body-building world, you will know that branched-chain amino acids are thought to be important for muscle gain. However:

It turns out that leucine is the only branched chain amino acid that stimulates muscle protein synthesis (Am J Physiol Endocrinol Metab 291: E381-E387, 2006). And protein is what gives muscles their strength and their bulk.

The other branched chain amino acids appear to play a supporting role in the quantities that occur naturally in most proteins. And adding extra valine and isoleucine to a protein supplement appears to reduce the effectiveness of leucine at stimulating muscle gain (Am J Physiol Endocrinol Metab 291: E381-E387, 2006).

What Have Previous Studies Shown?

With respect the amount of protein needed to optimize muscle gain after workouts, previous studies have shown that:

The optimal protein intake for maximizing muscle gain post workout is 15-20 gm for young men (Katsanos et al, Am J Clin Nutr 82: 1065-1073, 2005; Moore et al, Am J Clin Nutr, 89: 161-168, 2009) and 20-25 gm for older men (Symons et al, Am J Clin Nutr 86: 451-456, 2007).

More protein isn’t necessarily better. The effect of protein intake on post workout muscle gain maxes out at around 25 gm for young men and 30 gm for older men (Symons et al, J Am Diet Assoc 109: 1582-1586, 2009).

Whey protein is the best choice for enhancing muscle gain immediately after a workout. Other protein sources (soy, casein, chicken) are better choices for sustaining muscle gain over the next few hours.

A previous study by the authors of the present study showed that 15 gm of whey protein was sufficient to stimulate muscle protein synthesis in young women (average age 20). Thus, young women and young men both appear to benefit from 15 gm of protein after a workout.

How Much Protein Do Post-Menopausal Women Need?

This is a complex study, so let’s just start with the big takeaway from the study:

The same whey protein supplement that increased muscle mass in younger women failed to stimulate “cumulative muscle protein synthesis” [net increase in muscle mass] in post-menopausal women. (This was measured by determining net accumulation of labeled amino acids into the muscle fibers of the exercised leg compared to the rested leg.)

With that out of the way, we can focus on some less important findings:

There was a short-term (0-2h) transient increase in muscle protein synthesis following exercise with and without the whey protein supplement, but the result was not cumulative. In other words, the transient protein synthesis did not result in an increase in muscle mass.

There was a long-term (2-4h) transient increase in muscle protein synthesis following exercise for the group taking the whey protein supplement, but, again, the result was not cumulative. It did not result in a net increase in muscle mass.

In the group taking the whey protein supplement there was a transient increase in both insulin and leucine in the blood between 2 and 4 hours. Either or both could have driven the transient increase in protein synthesis observed during that same times.

In the words of the authors, “Ingestion of 15 gm whey protein failed to stimulate [net] myofibrillar (muscle) protein synthesis in post-menopausal women. While resistance exercise with and without feeding stimulate late (2-4 h) and early (0-2h) increases in myofibrillar protein synthesis, further exercise and nutritional manipulations may be necessary to robustly stimulate the skeletal muscle adaptive response to exercise.”

They went on to say that increased exercise intensity and/or increased protein intake may be necessary for post-menopausal women to maintain or increase muscle mass.

What Does This Study Mean For Post-Menopausal Women?

I should start by acknowledging that this was a small study, as are most studies in this field of research. In part this reflects the expense of these experiments and the lack of major government support. But it also reflects the difficulty in recruiting subjects for this kind of experiment. They are hooked up to two iv’s for over four hours and have three muscle biopsies removed from each leg during that time. That’s a pretty invasive experimental protocol.

With this limitation in mind, the biggest takeaway from this study is that post-menopausal women need more protein to build muscle mass than younger women. Young women, just like young men, can build muscle mass with as little as 15 gm of protein post-workout.

Unfortunately, this study did not determine how much protein post-menopausal women need to build muscle mass post-workout. And that is a critical question, because women typically have less muscle mass than men when sarcopenia starts to set in. Resistance (weight-bearing) exercise and adequate protein intake are key to preventing the debilitating effects of sarcopenia in post-menopausal women.

In their conclusion, the authors said that “…further exercise and nutritional manipulations may be necessary [to optimize the post-workout gain in muscle mass for post-menopausal women].”

From an exercise standpoint, the authors speculated that higher intensity exercise may be needed to increase muscle mass in post-menopausal women. However, the exercise protocol they used was based on public health recommendations for resistance training for older adults. A more rigorous exercise protocol might not be suitable for many post-menopausal women.

From a nutritional standpoint, they noted that a previous study had shown that 35 gm of protein post-workout was sufficient to build muscle mass in post-menopausal women. However, they considered 35 gm of protein to be a dangerously high intake for a single serving of protein for post-menopausal women. I concur.

In summary, we know that 15 gm of protein post-workout is too little for postmenopausal women, and while 35 gm of protein is sufficient, it is probably too much. Until further studies are performed in post-menopausal women, I would recommend the 20-25 gm of protein shown to support post-workout muscle gain in older men.

But it is not just the amount of protein that is important. The design of the protein supplement also matters.

Does The Design Of The Protein Supplement Matter?

While the amount of protein in a post-workout supplement is important, the design of the protein supplement also matters. While there are lots of crazy claims on the internet, there are two natural ways to maximize the effect of a protein supplement on muscle mass. Insulin and the amino acid leucine both drive muscle protein synthesis and help maximize post-workout muscle gain.

Recent research has shown that 2-3 gm of leucine (2 gm for young men; 3 gm for older men) is sufficient to maximize post workout muscle gain if protein levels are adequate (Am J Physiol Endocrinol Metab 291: E381-E387, 2006). We don’t know the corresponding leucine requirements for women, so we will need to assume they are similar.

- A 15-gram serving of whey protein isolate only provides 1.4 gm of leucine, far below what is likely to be needed to drive post-workout muscle gain in post-menopausal women.

- If you are a man over 50 or a post-menopausal woman, you should look for a post-workout protein supplement containing added leucine. And even younger adults will get “more bang for your buck” by choosing protein supplements with added leucine.

The insulin response is maximized when the carbohydrate to protein ratio is around 2.5 to 1. The manuscript did not list carbohydrates among the ingredients used in the whey protein supplement used in this study. But if it is like many whey protein supplements nowadays, it probably contained little or no carbohydrate.

- Although less popular in today’s low carbohydrate world, post-workout supplements with a high carbohydrate to protein ratio are also effective in maximizing post-workout muscle gain.

The Bottom Line

Sarcopenia (age-related muscle loss) is a major concern for older Americans. Sarcopenia can result in:

Loss of muscle strength. Even the simple act of picking up a grandchild or a bag of groceries can become problematic.

Increased risk of falls and fractures.

Lower quality of life.

Sarcopenia can be prevented by a combination of resistance exercise and adequate amounts of protein following the workout.

We know that older men require more protein than young men in a post-workout supplement designed to help them maximize the muscle gain associated with resistance exercise. But similar experiments had not been performed with women until now.

In the article above I share a study that shows that post-menopausal women need more protein than young women in a post-workout supplement. But the study did not determine how much protein they need.

I also discuss the amount of protein post-menopausal women likely need in a post-workout supplement, and how that protein supplement could be designed to maximize muscle gain and prevent sarcopenia.

For more information on this study and my recommendations read the article above.

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

______________________________________________________________________________

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

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

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

_______________________________________________________________________

About The Author

What Kind Of Protein Is Best For Strength?

February 13, 2024 by Dr. Steve Chaney

What Kind Of Protein Is Best For You?

Author: Dr. Stephen Chaney

Every bodybuilder “knows” that whey is the best protein for building strong muscles. After all, it:

Is absorbed more rapidly than some other proteins.
Contains all nine essential amino acids.
Is naturally rich in leucine, a branched chain amino acid that stimulates increased muscle mass.

However, as someone who is not a vegan but who follows the vegan literature, I frequently come across testimonials from bodybuilders and elite athletes who say they get all the strength and muscle mass they need from plant proteins.

I’ve always assumed they must have dietitians designing the perfect plant protein diet for them. But a recent study surprised me. It challenged that assumption.

Before I talk about this study, let me change our focus. Most of us will never be bodybuilders or elite athletes, but all of us face a common challenge. We all tend to lose muscle mass as we age, something referred to as sarcopenia. I have discussed this in a previous issue of “Health Tips From the Professor”.

Simply put, sarcopenia results in:

Loss of muscle strength. Even the simple act of picking up a grandchild or a bag of groceries can become problematic.
Increased risk of falls and fractures.
Lower quality of life.

Sarcopenia is a major health issue for those of us in our golden years. If you are younger, it is a concern for your parents or grandparents. Sarcopenia is a health issue that affects everyone.

In my previous article I discussed the role of adequate protein intake and exercise in preventing age-related sarcopenia. But I did not discuss what kind of protein was best for preventing muscle loss, and the frailty that comes with it, as we age.

The article (EA Struijk et al, Journal of Cachexia, Sarcopenia and Muscle, 13: 1752-1761, 2022) I will discuss today suggests that plant protein is best for preventing frailty in women as they age. It’s a surprising conclusion, so join me as I evaluate this study.

How Was This Study Done?

The data for this study came from the Nurses Health Study which started in 1976 with 121,700 women nurses and is still ongoing. This study followed 85, 871 female nurses for an average of 22 years starting when they were 60.

Food frequency questionnaires were administered to the participants in the study every four years starting in 1980. The questionnaires were used to calculate:

Total calories consumed.
Percent of calories from protein, carbohydrate, and fat.
Percent of calories from different kinds of protein.
The overall quality of the diet.
Saturated fat, polyunsaturated fat, cholesterol, and alcohol intake.

For this study the investigators used the cumulative average values from all questionnaires completed by participants in the study from age 60 until the onset of frailty.

Frailty was assessed every four years starting in 1992 using something called the FRAIL scale. The FRAIL scale defines frailty based on five self-reported criteria: fatigue, low strength, reduced aerobic capacity, having 5 or more chronic illnesses, and recent significant unintentional weight loss.

It is important to note that strength is only one of the five criteria used to identify frailty, although decreased muscle mass can contribute to lack of energy and reduced aerobic activity.

It is also worth pointing out that multiple studies have shown that primarily plant-based diets are associated with a decrease in chronic diseases.

I will come back to both of these points when I discuss the results of this study.

What Kind Of Protein Is Best For Strength?

I will start with the “big picture” results from this study and then cover some of the important details.

Average intake of:

Total protein was 18.3% of calories consumed.
Animal protein was 13.3% of calories consumed.
Plant protein was 5.0% of calories consumed.
Dairy protein was 3.8% of calories consumed.

When protein intake was divided into quintiles (5 equal parts) and women consuming the most protein were compared to those consuming the least protein for an average of 22 years:

Those consuming the most total protein had a 7% increased risk of developing frailty.

Those consuming the most animal protein had a 7% increased risk of developing frailty. (It is perhaps not surprising that the results were essentially the same for total and animal protein since animal protein was 73% of the total protein consumed by women in this study.)

Those consuming the most plant protein had a 14% decreased risk of developing frailty.

Consumption of dairy protein did not affect frailty.

Substituting as little as 5% of calories of plant protein for:

Dairy protein decreased the risk of developing frailty by 32%.

Animal protein decreased the risk of developing frailty by 38%.

Non-dairy animal protein (meat, fish, and eggs) decreased the risk of developing frailty by 42%.

In addition, substituting as little as 5% of calories of dairy protein for non-dairy animal protein decreased the risk of developing frailty by 14%.

But, as I said above, the frailty scale used in this study included the criteria of developing 5 or more chronic illnesses, and long-term consumption of plant protein is known to reduce the risk of developing chronic illnesses. So, it is important to break the study down into its component parts. When that was done the statistically significant results were:

Those consuming the most total protein had a 7% increased risk of low strength and a 25% increased risk of developing 5 or more chronic diseases.

Those consuming the most animal protein had a 9% increased risk of low strength and a 35% increased risk of developing 5 or more chronic diseases.

Those consuming the most plant protein had an 18% decreased risk of low strength. (It is interesting to note that plant protein consumption did not have a statistically significant effect on the development of chronic diseases in this study. That suggests that the “protective” effect of plant protein may simply be due to the absence of animal protein from the diet.)

Consumption of dairy protein did not affect any of the frailty criteria.

Finally, prevention of strength loss due to age-related sarcopenia is known to require exercise as well as adequate protein intake.

So, it was somewhat surprising that no difference in the association between protein intake and frailty was seen in women with high physical activity compared with those with lower physical activity levels. However, this may be because the range in activity level between the women in this study was relatively small. There didn’t appear to be a significant number of “gym rats” among the women in this study.

What Kind Of Protein Is Best For You?

One take-away from this study is clear. If you are a woman and want to minimize sarcopenia (loss of muscle mass and strength as you age), plant protein is an excellent choice.

A variety of plant proteins is best, so you get all the essential amino acids.

You don’t need to become a vegan. This study showed that replacing as little as 5% of your calories from animal protein with plant protein can have a significant benefit. Any healthy primarily plant-based diet will do.

This study enrolled only women aged 60 or above, so we don’t know whether the results apply to men or to younger women.

We don’t know why plant protein is better than animal protein at preventing age-related sarcopenia.

It could be because primarily plant-based diets are anti-inflammatory, and inflammation plays a role in sarcopenia.

Or it could be because primarily plant-based diets reduced the risk of chronic diseases, and chronic diseases can lead to loss of strength.

To be clear, this is a study that focuses on the type of protein that is best for long-term health and strength as we age. This is not a study of the best protein for increasing muscle mass following a workout.

Multiple studies show that whey protein can be a good post-workout choice.

However, other studies show that plant protein can also be a good post-workout choice if extra leucine is added to make it equivalent to whey protein in terms of leucine content.

The Bottom Line

You have probably heard that it is all downhill after age 30. But it doesn’t have to be.

One of the downhill slopes we all face is something called sarcopenia (age-related muscle loss). The resulting loss of strength and agility can severely impact our quality of life in our golden years.

We can prevent sarcopenia with the combination of a high protein diet and resistance training (weight bearing exercise).

But what kind of protein is best? In this issue of “Health Tips From the Professor” I review a large, well-designed study that suggests plant protein is the best choice for women if they wish to reduce age-related muscle loss and the weakness that comes with it.

For more details about 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.

______________________________________________________________________________

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

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

_____________________________________________________________________

About The Author

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Does Red Meat Cause Frailty In Older Women?

May 31, 2022 by Dr. Steve Chaney

Which Proteins Are Best?

Author: Dr. Stephen Chaney

The 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?

This 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?

The 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?

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. 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.