High Animal Protein Diets Could Cause Early Death

While some people are concerned about not getting enough protein, a new study shows that we may have too much. The study, published in Cell Metabolism on March 4, shows that middle-aged people who eat a diet high in animal proteins from milk, meat and cheese are four times more likely to die of cancer than someone who eats a low-protein diet — a mortality risk factor comparable to smoking.

Researchers looked at 6,318 adults over the age of 50, over a span of 18 years. On average, about 16 percent of their total daily calories came from protein. Two-thirds of that amount was from animal protein. The percent of calorie intake from protein was used to categorize subjects into a high protein group (20% or more of calories from proteins), a moderate protein group (10%-19% of calories from proteins), and a low protein group (less than 10% of calories from proteins).

The study showed that those consuming high protein diets were 74 percent more likely to die of any cause within the 18-year study period than their low-protein counterparts. They were also several times more likely to die of diabetes. This risk was higher in those who got their protein from animal sources such as meat, eggs and cheese.

“There’s a misconception that because we all eat, understanding nutrition is simple. But the question is not whether a certain diet allows you to do well for three days, but can it help you survive to be 100?” study co-author Valter Longo, Edna M. Jones professor of biogerontology at the USC Davis School of Gerontology and director of the USC Longevity Institute in Los Angeles, said in a press release. “Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: Does it progress?” Longo said. “Turns out one of the major factors in determining if it does is protein intake.”

In the study, Longo and his colleagues found that foods derived from plants, such as beans and nuts, did not have the same effect on mortality as did high-protein foods from animals. The results indicate that respondents ages 50-65 consuming moderate to high levels of animal protein display a major increase in the risks for overall and cancer mortality; however, the risks may be somewhat decreased if protein does not come from an animal source. When the study controlled for the effect of plant-based protein, there was no change in the association between protein intake and mortality, indicating that high levels of animal proteins promote mortality.

“The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality,” wrote co-author Eileen Crimmins, the AARP Chair in Gerontology at the University of Southern California, in a release about the paper.

Older subjects in the study, however, saw a different outcome from eating a high-protein diet. The researchers found that older subjects (65 years and older) benefited from a moderate to high amount of protein. In this age group in the study, higher levels of protein protected against cancer, disease and premature death.

The RDA for protein is .8 grams per kilogram or 2.2 pounds of body weight. That means if you weigh 140 pounds, the suggested protein intake is 50.9 grams daily. According to myplate.gov a non-active female aged 31-50 requires 1800 calories daily, or 203.6 calories (9%) from protein, which qualifies as low protein.

Ready to reduce or give up the animal products? Here’s a great list of plant based protein sources. I’d add to that my favorite protein source hemp seeds, which provide 10 grams of protein in 3 tablespoons.

For more plant based nutrition and recipes, tune into my other posts here on Care2.com, or join my mailing list to receive recipes.


Carrie-Anne Brown

thanks for sharing

june t.
june t.2 years ago

moderation and locally raised, grass fed beef if you can find it

Tammy D.
Tammy D.2 years ago

nice to see a proper discussion here. The middle ground is that people (the world, animals, everything) would benefit from a decrease in the amount of meat they consume. I firmly believe, as a vegan, that this is the message we should be promoting. Eat less meat, eat better meat. Know where it comes from, and support better, more responsible husbandry and ag. Regardless of your personal philosophy, eating less meat will improve your health. How much less is up to you.

Chazz York
Chazz York2 years ago

I just finished an OMG Conversation. An old friend just contacted me on Skype. He said he had been told by his doctor that he needed to cut dairy, eggs, and meat from his diet. She told him that he needed to check into a vegan diet. She even suggested he try it for a couple of weeks to see if he found it doable, but she told him it would be much more beneficial to his health and longevity. He contacted me because I am the only vegan he knows, and he asked me to help him with it. I agreed to teach him about the nutritional needs on it and to teach him how to cook to make the best food possible, and he starts tomorrow on his new dietary path. After all the times I was called a liar when I said my diet was very healthy for me, and after all the times I was told I had to eat meat and dairy to be healthy enough, this man's doctor told him to drop meat, eggs, and dairy and to go vegan because she said it was the healthiest diet for him!!! I just can't stop smiling right now. He is nervous about trying it but I promised him I would help him make it a fun experience. It may make me seem weird but Helping Jon get healthy and improve his life excites me and makes me feel good. I love helping others.

Tanya W.
Tanya W.2 years ago


Tanya W.
Tanya W.2 years ago


Chazz York
Chazz York2 years ago

That is very true Gerald

Gerald L.
Gerald L.2 years ago

@ Pego R; Not to argue, but grass fed/finished beef doesn't cost more to produce, but less.

So true Pego, I had c/p his statement. Any study of Feedlot practices while easily show that.

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Chazz York
Chazz York2 years ago

You are quite right Pego R. Though I am vegan, I do see where generations ago, before mechanization of livestock farms, and the addition of the chemicals, hormones, and antibiotics the meat was not as bad for humans to eat. I am admittedly more comfortable not eating meat for a multitude of reasons, but among them are the things you pointed out in your comment. In all fairness it is necessary for us to see that the way things are done in today's society are anything but beneficial to our health. I try to circumvent that in any way I can. I do it by not using anything that is or is derived from animals and insects. I opt for the consumption of Organic, and Non GMO foods, and I work to make sure my dietary and protein intake are as healthy as possible. I wish we could all stand to force factory farming to stand accountable for what they do to the livestock prior to, during, and after slaughtering it. It kind of lets you know just how much they are getting by with wrongfully when you consider all the countries refusing to allow it into their countries.

Pego R.
Pego R.2 years ago

Not to argue, but grass fed/finished beef doesn't cost more to produce, but less. The difference is from subsidies to the beef and grain industries. The difference is schlepped out of our back pockets via taxes. I am not particularly pro vegan but it is ridiculous to have them and all of us to subsidize the process that makes our beef the most unhealthy to eat. These studies that keep pronouncing meat evil for diets are all produced on post-industrial Ag animal products which have accumulated all the pesticides and herbicides and chemical fertilizers we put on grains, PLUS everything we inject or feed the livestock to grow with stupifying speed and survive their confinement. All these researchers are well aware of the nutritional studies from regions that did not use those chems and who all had completly the oposite results from meat-based diets, so they are just following the money. Chemicalizing our Agriculture and killing off all the wildlife and soils to produce it is not doing any of us any favors. It certainly reduces the amount that can be produced per acre. It just makes consentrating the profits and subsidies to a narrow few easier