The Red Meat Question: Will Eating Meat Shorten Our Lifespans? Or Help Us Live Longer?
by Nils Osmar. July 9, 2022. Medical disclaimer
Red meat is a puzzler.
On the one hand, it’s a highly nutritious food, rich in bio-available nutrients. When those nutrients are available from our diets, we thrive.
According to this 2022 study, which contradicts many of the messages coming from other health authorities, as consumption of red meat increases, so does life expectancy. See study: Total Meat Intake is Associated with Life Expectancy: A Cross-Sectional Data Analysis of 175 Contemporary Populations
From the study:
Worldwide, bivariate correlation analyses revealed that meat intake is positively correlated with life expectancies. This relationship remained significant when influences of caloric intake, urbanization, obesity, education and carbohydrate crops were statistically controlled. Stepwise linear regression selected meat intake, not carbohydrate crops, as one of the significant predictors of life expectancy. In contrast, carbohydrate crops showed weak and negative correlation with life expectancy.
This suggests that we may be better off eating (some) red meat than avoiding it entirely.
If this is the case, why do so many health authorities — including some folks in the anti-aging community — recommend avoiding it? It turns out that there are some problems with red meat from a longevity perspective. They have to do with two amino acids, leucine and methionine.
The methionine issue
.One of the amino acids meat is rich in is methionine. Methionine is is a double-edged sword from a health perspective. It’s an essential amino acid, required for normal growth and repair of body tissues. We literally can’t live without it. But in excess, it becomes pro-aging, not only in human beings, but in all species
According to a Science Direct article called “Amino acids in the regulation of aging and aging-related diseases“, “methionine restriction appears to be an evolutionary conserved mechanism to delay aging.
So eating diets low in methionine (or low in meat) is one obvious approach to living longer. But it creates a danger that our intake of methionine may go too low, if we don’t find another food source of it. But whatever the source, the pro-aging effect is ready to kick in if we eat too much of it.
Glycine detoxifies methionine
For those who would like to include red meat in their diets, it turns out that we can prevent the pro-aging effects of methionine by taking glycine (or eating foods high in it). From an article by Dr. Chris Masterjohn:
“A diet providing 150 grams of animal protein from steak and 22.5 grams of collagen would provide about 16.5 grams of glycine. This is within the estimated requirement of 10-60 grams per day. You would also have around 4 grams of excess methionine in your diet, which would demand an extra 2-4 grams of glycine over and above what you need without considering the methionine.
Your glycine intake, at 16.5 grams, would provide 12.5 grams of glycine after fully compensating for the methionine, still within the range of 10-60 grams per day. You might consume more glycine, pushing your intake further up within this range, if you use it at the recommended doses for specific purposes like managing your blood sugar, promoting sleep, or boosting your joint health.”
Those who’d like to increase their glycine can do so by taking supplements, or by eating foods such as collagen peptides which are naturally high in glycine.
The leucine problem
Another problem with red meat from a longevity perspective is the high leucine content. Like methionine, leucine is essential. We need leucine some in our diets, or we’ll die. But like methionine, it’s associated with some problems. A key one is that it activates mTOR.
mTOR isn’t bad; it’s a key enzymatic process which is essential to maintaining strong muscles and to a strong immune response. But too much mTOR activation is clearly associated with shorter lifespans.
The problem is that when mTOR (the growth pathway) is activated, AMPK (the longevity pathway) is switched off. We may be healthier and have stronger muscles and immune systems, yet die younger, if we don’t find opportunities to activate AMPK.
What I’m doing
I’ve tried a number of approaches over the years, including:
- Eating a diet rich in both plant and animal products
- Eating a vegan diet
- Eating an omnivorous diet, but with zero meat
With each change, I made notes about my state of health.
I was vegan for three years; during that stretch I ate no animal-based foods. As I’ve written elsewhere, this approach did not work well for me. I’m not writing this to put down vegans, but in my case, eating a totally plant-based diet resulted in my getting sick more often, losing muscle, losing my sex drive, and developing mood and memory problems. Going vegan may work for some people, but it did not work for me.
I’ve tried Dr. Valter Longo’s approach, which is to eat an “essentially vegan” diet, but one which does include small amounts of meat and other foods from animal sources. I have deep respect for Dr. Longo’s thinking and his research into the benefits of fasting. But his approach also did not work in the long term for me. When I followed his low-protein, low-leucine, low-methionine recommendations, I started (again) losing muscle, gaining body fat, and developing health problems that were similar to those I went through when I was vegan.
The same thing happened when I tried following Dr. David Sinclair’s recommendations, which are similar in some respects to Dr. Longo’s (though Sinclair eats one meal a day, which Longo had condemned as a practice that he believes will shorten our lives).
At the present time, I’ve gone back to eating a high-nutrient omnivorous diet. It includes some red meat, along with other animal=based foods such as fish and poultry. I also eat lots of big green salads, steamed cruciferous vegetables, and many other foods from the plant kingdom, and eat mushrooms (from the fungal food kingdom). (Fungi are, interestingly, closer to animals, biologically speaking, than to plants.) When I eat red meat, I follow Chris Masterjohn’s recommendation of balancing it by also eating more collagen and taking glycine.
Fasting for AMPK
I am concerned about excess mTOR activation and underactivating AMPK. So I balance my omnivorous diet by doing a lot of fasting (which activates AMPK even more strongly than a plant-bsased diet). I usually skip eating entirely two days a week.
For me, alternating between mTOR-activation days and AMPK activation days has turned out to be ideal for building health. I’m actively building muscle at the age of 69; I have good energy for working out; my mind and memory are sharp and clear. I’m “supporting” my body with ample nutrients on my workout days, and “challenging” it with lower leucine and methionine, and/or fasting, on my recovery days. To me, this is the best balance I’ve found (so far).
Feel free to post information about your approach in the comments section below.