Many people might choose to follow a diet high in protein content to lose weight and build muscle mass. But a new study in mice suggests that such a diet could put cardiovascular health at risk.
New research in animal models shows that high protein diets may directly affect cardiovascular health, potentially increasing heart attack risk.
“There are clear weight loss benefits to high protein diets, which has boosted their popularity in recent years,” says Dr. Babak Razani, an associate professor of medicine from Washington University School of Medicine in St. Louis, MO.
“But,” he adds, “animal studies and some large epidemiological studies in people have linked high dietary protein to cardiovascular problems.”
That is why Dr. Razani and his colleagues decided to try to find out whether high protein diets might actually influence cardiovascular health directly by facilitating the buildup of plaque inside the arteries.
“We decided to take a look at whether there is truly a causal link between high dietary protein and poorer cardiovascular health,” explains Dr. Razani.
30% more arterial plaque
In the study, the researchers fed mice a high-fat diet. They explain that mice require a high-fat diet in order to develop arterial plaque in the first place.
But while some of the mice received a diet that was high in fat and proteins, others received a high fat diet with a low protein content. This allowed the investigators to pinpoint any differences.
“A couple of scoops of protein powder in a milkshake or a smoothie adds something like 40 grams (g) of protein — almost equivalent to the daily recommended intake,” notes Dr. Razani.
High-protein diets are known to be beneficial for weight loss, but the cons may outweigh the pros.
— Washington University in St. Louis (@WUSTL) January 27, 2020
“To see if protein has an effect on cardiovascular health, [in our study] 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,” he explains.
Dr. Razani and his team soon found that the rodents that had fed on the high fat, high protein diet had not just developed atherosclerosis — a condition characterized by the buildup of arterial plaque — but that this was significantly worse than in the mice that had eaten the high fat, low protein diet.
A recipe for heart attack
Mammal bodies, the researchers explain, actually have a first-line defense against arterial plaque. A type of white blood cells called “macrophages” usually “pick up” on the presence of these deposits and remove them.
However, sometimes they are unequal to the task. When this happens, macrophages die, leaving arterial plaque to continue to build up.
“In mice on the high protein diet, their plaques were a macrophage graveyard,” Dr. Razani says, commenting on what he and his team found.
The researchers also looked into the mechanism through which dietary protein may contribute to the creation of unstable arterial plaque.
Further, the new research shows that high-protein diets spur unstable plaque—the kind most prone to rupturing and causing blocked arteries. More plaque buildup in the arteries, particularly if it’s unstable, increases the risk of heart attack.
“There are clear weight-loss benefits to high-protein diets, which has boosted their popularity in recent years,” says senior author Babak Razani, an associate professor of medicine at the Washington University School of Medicine in St. Louis. “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.”
The new study appears in the journal Nature Metabolism.
Online Int’l News with additional input by GVS News Desk