Protein, that macronutrient that helps repair and regrow damaged muscles, is undoubtedly the most important nutrient in an athlete’s diet. Not only that, protein (in any form, whether it be whey, casein, or plant-based) helps keep bones, cartilage, and blood healthy.
So it’s important to eat enough protein, but eating excess amounts won’t get you any more jacked any quicker, and in fact it might be slowly killing you.
That’s according to a recent study that found a lower-protein diet, specifically a vegan one, may be the key to lowering your risk of heart disease.
Researchers at Penn State College of Medicine found that Americans typically eat two-and-a-half times more sulfur amino acids—a subcategory of amino acids that occur in protein-rich foods—than needed, and that the amino is tied to cardiovascular disease.
Sulfur amino acids include methionine and cysteine, both of which are needed for growth. Too much of them, though, can increase the rate of heart disease according to prior research.
“This study provides the first epidemiologic evidence that excessive dietary intake of sulfur amino acids may be related to chronic disease outcomes in humans,” John Richie, a professor of public health sciences at Penn State College of Medicine, said in a release.
For the study, published in The Lancet, researchers looked at the bloodwork of more than 11,000 people and found that those who ate fewer than 15 mg of sulfur amino acids per kilogram of body weight per day were less likely to contract heart disease than those who ate above the suggested amount.
Most of the people who fell under the limit ate a primarily plant-based diet.
“People who eat lots of plant-based products like fruits and vegetables will consume lower amounts of sulfur amino acids,” Zhen Dong, lead author on the study and a Penn State College of Medicine graduate, said in a release. “These results support some of the beneficial health effects observed in those who eat vegan or other plant-based diets.”
While the study isn’t suggesting you totally eliminate protein, telling bodybuilders to limit their protein intake is bound to be controversial.
Nutrition expert Dr. Gabrielle Lyons has previously criticized studies that link excess protein to diseases such as cancer, and any old-school bodybuilder will tell you the secret to gains is to pound as many whey protein shakes as your body can handle.
The study’s authors though claim the gains are not worth the risk. “Here we saw an observed association between certain dietary habits and higher levels of blood biomarkers that put a person at risk for cardiometabolic diseases,” Richie said.