Just yesterday, a new study came out saying eating meat makes people fat; and we looked in to whether that’s true for fit guys (short answer: it’s not). So, when a different study from the Massachusetts General Hospital came out just a day later claiming that high animal protein consumption is linked to a higher mortality rate, we dug a bit deeper.
In the largest meta-analysis of its kind, researchers analyzed over 30 years-worth of data and more than 3.5 million people. Participants completed all-encompassing health questionnaires every two years and gave information on their dietary intake—specifically how often they consumed portions of certain types of food during the preceding year—every four years.
During the timeframe, more than 36,000 deaths were documented among study participants, about 9,000 of which stemmed from cardiovascular disease, 13,000 from cancer, and about 14,000 from other causes. Once the researchers factored out lifestyle and other dietary risk factors, they found a high consumption of protein from animal sources, including meat, eggs, and dairy was "weakly" associated with an increased rate of death, while a high consumption of protein from plant sources, including breads, cereals, pasta, beans, nuts, and legumes correlated with a lower mortality rate.
The research, published in JAMA Internal Medicine, concluded the main culprit is processed and unprocessed red meat (including both beef and pork products—and excluding fish and poultry). But, more careful analysis revealed the link between animal protein intake and elevated mortality risk only applies to people who have at least one risk factor associated with an unhealthy lifestyle. You have to be obese or underweight, have a heavy alcohol consumption, a history of smoking, or consistent physical inactivity and pack your meals with meat and animal byproducts to be at risk.
In fact, the association disappeared in participants with a healthy lifestyle. "While we expected we might find the associations to be weaker in the healthy lifestyle group, we did not expect them to completely disappear," co-author Mingyang Song, MD, said in a press release.
But, the reason why isn't that fit guys are immune to the negative effects of red meat (#bummer). "...when we looked deeper into the data, we found that—at similar levels of animal protein intake—those in the unhealthy lifestyle group consumed more red meats, eggs and high-fat dairy, while the healthy lifestyle group consumed more fish and poultry. So we suspect the different sources of animal protein between the two groups may contribute to the stronger results in the unhealthy lifestyle group," she adds.
So, it's a fair conclusion that the reason fit guys aren't suffering an early death from eating animal protein is because they're probably eating the "right" kind of animal protein. While a steak and a burger every now and again aren't going to kill you, necessarily, you should consider eating more plant-based proteins (like beans, nuts, and seeds), fish, and chicken that aren't nearly as high in saturated fat and calories as red meat.