Everyone who has ever tried to lose weight or build muscle has been told to be on a high-protein diet. After all, protein is the build block for muscle and it's weight benefits have been highlighted by a wide range of medical research papers—if not local fitness trainers.
But whether you're shedding kilos with the help of eggs, meat, and other sources of lean protein or are bulking up with the aid of protein powders: here's some news. According to a research paper, a high-protein diet puts you at a greater risk of heart attack.
Here is what the researchers are saying
A study conducted at the Washington University School of Medicine in St. Louis, Missouri (USA) claims that high-protein diets boost artery-clogging plaque.
The research, which conducted on mice, showed that high-protein diets spur unstable plaque—the kind most prone to rupturing and causing blocked arteries. This is dangerous because it increases the risk of heart disease and can induce a heart attack.
"There are clear weight-loss benefits to high-protein diets, which has boosted their popularity in recent years," said senior author Babak Razani, associate professor at the University.
"But animal studies and some large epidemiological studies in people have linked high dietary protein to cardiovascular problems. We decided to take a look at whether there is truly a causal link between high dietary protein and poorer cardiovascular health," he added.
The researchers studied mice who were fed a high-fat diet to deliberately induce atherosclerosis or plaque buildup in the arteries. Some of the mice received a high-fat diet that was also high in protein. And others were fed a high-fat, low-protein diet for comparison.
The mice on the high-fat, high-protein diet developed worse atherosclerosis—about 30% more plaque in the arteries—than mice on the high-fat, normal-protein diet, despite the fact that the mice eating more protein did not gain weight, unlike the mice on the high-fat, normal-protein diet.
Razani also said, "A couple of scoops of protein powder in a milkshake or smoothie adds something like 40 grams of protein—almost equivalent to the daily recommended intake."
To see if protein has an effect on cardiovascular health, we tripled the amount of protein that the mice receive in the high-fat, high-protein diet—keeping the fat constant. Protein went from 15% to 46% of calories for these mice".
Plaque contains a mix of fat, cholesterol, calcium deposits, and dead cells. Past work by Razani's team and other groups has shown that immune cells called macrophages work to clean up plaque in the arteries.
But the environment inside plaque can overwhelm these cells, and when such cells die, they make the problem worse, contributing to plaque buildup and increasing plaque complexity.
"In mice on the high-protein diet, their plaques were a macrophage graveyard," Razani informed.
"This study is not the first to show a telltale increase in plaque with high-protein diets, but it offers a deeper understanding of the impact of high protein with the detailed analysis of the plaques," said Razani.
Going easy on the protein is imperative
Eating too much protein also has many other health consequences like constipation and increased kidney damage risk. And while toning your body is important, it shouldn't come at the cost of your health. So remember to keep your protein intake to 46 grams a day (that's what experts recommend) and stay heart-disease-free.