Should We Increase Our Protein Intake After Age 65?

A study that purported to show that diets high in meat, eggs, and dairy could be as harmful to health as smoking supposedly suggested that “[p]eople under 65 who eat a lot of meat, eggs, and dairy are four times as likely to die from cancer or diabetes.” But if you look at the actual study, you’ll see that’s simply not true: Those eating a lot of animal protein didn’t have four times more risk of dying from diabetes—they had 73 times the risk. Even those in the moderate protein group, who got 10 to 19 percent of calories from protein, had about 23 times the risk of dying of diabetes compared to those consuming the recommended amount of protein, which comes out to be about 6 to 10 percent of calories from protein, around 50 grams a day.

So, the so-called low protein intake is actually the recommended protein intake, associated with a major reduction in cancer and overall mortality in middle age, under age 65, but not necessarily in older populations. When it comes to diabetes deaths, lower overall protein intake is associated with a longer life at all ages. However, for cancer, it seems to flip around age 65. I discuss this in my video Increasing Protein Intake After Age 65.

“These results suggest that low protein intake during middle age followed by moderate to high protein consumption in old adults may optimize healthspan and longevity.” Some have suggested that the standard daily allowance for protein, which is 0.8 grams of daily protein for every healthy kilogram of body weight, may be fine for most, but perhaps older people require more. The study upon which the recommended daily allowance (RDA) was based indicated that, though there was a suggestion that the “elderly may have a somewhat higher requirement, there is not enough evidence to make different recommendations.” The definitive study was published in 2008 and found no difference in protein requirements between young and old. The same RDA should be adequate for the elderly. However, adequate intake is not necessarily optimal intake. The protein requirement “studies have not addressed the possibility that protein intake well above the RDA could prove beneficial,” or so suggests a member of the Whey Protein Advisory Panel for the National Dairy Council and a consultant for the National Cattlemen’s Beef Association.

A study followed sedentary individuals over the age of 65 for 12 years and found they lose about one percent of their muscle mass every year. If you force people to lie in bed for days at a time, anyone would lose muscle mass, but older adults on bedrest may lose muscle mass six times faster than young people also on bedrest. So, it’s use it or lose it for everyone, but the elderly appear to lose muscle mass faster, so they better use it. The good news is that in contrast to the 12-year U.S. study, a similar study in Japan found that the “[a]ge-related decreases in muscle mass were trivial.” Why the difference? It turns out that in the Japanese study, “the participants were informed about the results of their muscle strength, [so] they often tried to improve it by training before the next examination.” This was especially true among the men , who got so competitive their muscle mass increased with age, which shows that the loss of muscle mass with age is not inevitable—you just have to put in some effort. And, research reveals that adding protein doesn’t seem to help. Indeed, adding more egg whites to the diet didn’t influence the muscle responses to resistance training, and that was based on studies funded by the American Egg Board itself. Even the National Dairy Council couldn’t spin it: Evidently, strength “training-induced improvements in body composition, muscle strength and size, and physical functioning are not enhanced when older people…increase their protein intake by either increasing the ingestion of higher-protein foods or consuming protein-enriched nutritional supplements.”

Is there anything we can do diet-wise to protect our aging muscles? Eat vegetables. Consuming recommended levels of vegetables was associated with basically cutting in half the odds of low muscle mass. Why? “[T]he alkalizing effects of vegetables may neutralize the mild metabolic acidosis” that occurs with age, when that little extra acid in our body facilitates the breakdown of muscle. I’ve discussed before how “[m]uscle wasting appears to be an adaptive response to acidosis.” (See my video Testing Your Diet with Pee and Purple Cabbage for more on this.) We appear to get a chronic low-grade acidosis with advancing age because our kidney function starts to decline and because we may be eating an acid-promoting diet, which means a diet high in fish, pork, chicken, and cheese, and low in fruits and vegetables. Beans and other legumes are the only major sources of protein that are alkaline instead of acid-forming. And indeed, a more plant-based diet—that is, a more alkaline diet—was found to be positively associated with muscle mass in women aged 18 to 79.

So, if we are going to increase our protein consumption after age 65, it would preferably be plant-based proteins to protect us from frailty. No matter how old we are, a diet that emphasizes plant-based nutrition “is likely to maximize health benefits in all age groups.”


What was that about a study that purported to show that diets high in meat, eggs, and dairy could be as harmful to health as smoking? See my video Animal Protein Compared to Cigarette Smoking.

Protein is so misunderstood. For more on the optimal amount of protein, see Do Vegetarians Get Enough Protein? and The Great Protein Fiasco.

Interested in learning more about the optimal source of protein? See:

What about the rumors that plant protein is incomplete? See The Protein Combining Myth.

For information on buffering the acid in our blood, see Testing Your Diet with Pee and Purple Cabbage.

And, for more on acid/base balance, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

How to Lower Phthalate Exposure Through Diet

Phthalates are hormone-disrupting plastics chemicals linked to a number of adverse health effects, such as disturbing infant and child development, and, in adults, may affect reproductive health in men and endometriosis in women, and is associated with increased abdominal fat in both. “Given the increasing scientific evidence base linking phthalate exposure with harmful health outcomes, it is important to understand major sources of exposure,” which I discuss in my video What Diet Best Lowers Phthalate Exposure?.

What is the most major exposure source? Diet. If you have people stop eating for a few days, you get a significant drop in the amount of phthalates spilling out in their urine. One can only fast for so long, though. Thankfully, we can see similar drops just from eating a plant-based diet for a few days, which gives us a clue as to where most phthalates are found.

The highest levels are found in meats, fats, and dairy. Poultry consistently comes out as being the most contaminated across the board with some of the highest levels ever reported, though there are geographic exceptions. In the United Kingdom, for example, fish came out worse than poultry, and, in Belgium, nothing appears to beat out reindeer meat in terms of contamination. In the United States, though, it is poultry, and the finding that egg consumption is also significantly associated with phthalate levels “suggests that chickens themselves may be contaminated” and not just arise from the plastic they’re wrapped in at the store.

The same might not be true with dairy, however. Realizing that these chemicals may be harmful, researchers in Seattle took ten families and randomized them into a five-day complete dietary replacement with fresh organic foods without any packaging. Nothing touched plastic. Organic milk was delivered in glass, and even the crates used to carry the food were wooden instead of plastic. This was like a fasting study to see what role eliminating processed foods would have on lowering phthalate levels because not everyone wants to switch to a plant-based diet—or stop eating completely. In my video, I show a chart depicting where the families started at baseline before changing their diet and where they were a week after the experiment, once again back on their baseline diet. What happened in the middle? When eating fresh and organic food, their phthalate levels went up, “a dramatic and unexpected increase in one of the most toxic phthalates—and not just by a little: It was like a 2000 percent increase. So the researchers tested all the foods. One of the spices was off the chart, and so was the dairy. Most of the phthalates apparently don’t come from the cow, however; they come from the tubing. If you milk cows by hand (which even the Amish don’t do anymore) the levels of phthalates in the milk are low, but if the same cows are milked by machine, the milk picks up phthalates from the tubing. As such, the final levels may depend more on the tubing than on what the cows are fed.

We’re not sure where the chickens are getting contaminated with phthalates, though. While that study was done on adults, we learned more recently where our kids may be getting it. Researchers found pretty much the same thing: mostly meat, including poultry and fish. Again, poultry appeared to be the worst, while soy consumption was associated with significantly lower levels. But what kind of exposure are we talking about? Researchers calculated what may be typical exposures for infants, teens, and women. How do these data compare with current guidelines? The U.S. Environmental Protection Agency’s reference dose, which is like the maximum acceptable threshold, is 20 µg/kg-day, based on liver risk. Europe places their maximum daily intake for testicular toxicity at 50 µg/kg-day. So a typical infant diet exceeds the EPA’s safety level, “while a diet high in meat and dairy was over this threshold by approximately four times. For adolescents, a diet high in meat and dairy also exceeded the EPA’s reference dose.” Indeed, diets high in meat and dairy consumption resulted in a two-fold increase in exposure. And “[a]ll diets for all groups exceeded the allowable daily intakes (ADI) derived by the US Consumer Product Safety Commission” for problems with sperm production, while diets high in meat and dairy consumption may exceed the allowable intake for risk of reproductive birth defects as well.


For more information on dietary sources of phthalates, I encourage you to watch both Chicken Consumption and the Feminization of Male Genitalia and Lowering Dietary Antibiotic Intake. Diet isn’t the only way one can be exposed internally, though. See my video Avoiding Adult Exposure to Phthalates, which discusses the risk in both children’s and adult toys.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

How to Avoid Fatty Liver Disease

In the documentary Supersize Me, Morgan Spurlock eats exclusively at McDonald’s for a month and predictably his weight, blood pressure, and cholesterol go up, but so do his liver enzymes, a sign his liver cells are dying and spilling their contents into the bloodstream. His one-man experiment was actually formally replicated. A group of men and women agreed to eat two fast food meals a day for a month. Most of their liver values started out normal, but, within just one week, most were out of whack, a profound pathological elevation in liver damage.

What’s happening is non-alcoholic fatty liver disease (NAFLD), the next global epidemic, as I discuss in my video How to Prevent Non-Alcoholic Fatty Liver Disease. Fatty deposits in the liver result in a disease spectrum from asymptomatic fat buildup to non-alcoholic steatohepatitis (NASH), which can lead to liver scarring and cirrhosis, and may result in liver cancer, liver failure, and death.

NAFLD is now the most common cause of chronic liver disease in the United States, affecting 70 million Americans, nearly one in three adults. Fast food consumption is a great way to bring it on, since it’s associated with the intake of soft drinks and meat. Drinking one can of soda a day may raise the odds of NAFLD by 45 percent, and those eating the equivalent of 14 chicken nuggets’ worth of meat a day have nearly triple the rates of fatty liver compared to those eating 7 nuggets or less.

It’s been characterized as a tale of fat and sugar, but evidently not all types of fat are culpable. Those with fatty hepatitis were found to have eaten more animal fat and cholesterol, and less plant fat, fiber, and antioxidants. This may explain why adherence to a Mediterranean-style diet, characterized by high consumption of foods such as fruits, vegetables, whole grains, and beans, is associated with less severe non-alcoholic fatty liver disease. It could also be related to the presence of specific phytonutrients, like the purple, red, and blue anthocyanin pigments found in berries, grapes, plums, red cabbage, red onions, and radicchio. These anthocyanin-rich foods may be promising for the prevention of fatty liver, but that’s mostly based on petri dish experiments. There was one clinical trial that found that drinking a purple sweet potato beverage seemed to successfully dampen liver inflammation.

A more plant-based diet may also improve our microbiome, the good bacteria in our gut. “‘We are what we eat’ is the old adage but the modern version might be ‘we are what our bacteria eat.’” When we eat fat, we may facilitate the growth of bad bacteria, which can release inflammatory molecules that increase the leakiness of our gut and contribute to fatty liver disease.

Fatty liver disease can also be caused by cholesterol overload. The thought is that dietary cholesterol found in eggs, meat, and dairy oxidizes and then upregulates liver X receptor alpha, which can upregulate something else called SREBP, which can increase the level of fat in the liver. Cholesterol crystals alone cause human white blood cells to spill out inflammatory compounds, just like uric acid crystals in gout. That’s what may be triggering the progression of fatty liver into serious hepatitis: “the accumulation of sufficient concentrations of free cholesterol within steatotic hepatocytes [fatty liver cells] to cause crystallization of the cholesterol.” This is one of several recent lines of evidence suggesting that dietary cholesterol plays an important role in the development of fatty hepatitis—that is, fatty liver inflammation.

In a study of 9,000 American adults followed for 13 years, researchers found a strong association between dietary cholesterol intake and hospitalization and death from cirrhosis and liver cancer, as dietary cholesterol can oxidize and cause toxic and carcinogenic effects. To limit the toxicity of excess cholesterol derived from the diet, the liver tries to rid itself of cholesterol by dumping it into the bloodstream. So, by measuring the non-HDL cholesterol in the blood, one can predict the onset of fatty liver disease. If we subtract HDL from total cholesterol, none of the hundreds of subjects followed with a value under 130 developed the disease. Drug companies view non-alcoholic fatty liver disease as a bonanza, “as is the case of any disease of affluence…considering its already high and rising prevalence and…[its] needing continuous pharmacologic treatment,” but maybe avoiding it is as easy as changing our diet, avoiding sugary and cholesterol-laden foods.

“The unpalatable truth is that NAFLD could almost be considered the human equivalent of foie gras (loosely translated from French as ‘fat liver’). As we overeat and ‘force-feed’ ourselves foods that can result in serious health implications, however, having such a buttery texture in human livers is not a delicacy to be enjoyed by hepatologists [liver doctors] in clinical practice!”


Like my video Preventing Gout Attacks with Diet, How to Prevent Non-Alcoholic Fatty Liver Disease covers an important topic worth the extensive coverage the video provides.

For more on how bad added sugars are for us, see:

For more on how bad cholesterol can be, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: