A new study has shown that high-protein diets can cause plaque formation in blood vessels and lead to sclerotic arterial disease. The research results are published in the journal Nature Metabolism.
High protein diets can help you lose weight and build muscle. It is often recommended for people with high blood pressure.
However, a new study in mice by researchers at the University of Washington School of Medicine in St. Louis showed that high-protein diets increase the risk of vascular sclerosis. Moreover, we are talking about the formation of unstable plaques, the separation of which leads to blockage of the arteries, which can provoke a heart attack.
"Diets high in protein have been shown to promote weight loss, which has boosted their popularity in recent years," the school said in a press release, MD Babak Razani, head of the study. “But animal experiments and some large human studies point to a link between a high-protein diet and cardiovascular problems. We decided to check it out."
Since fat is required for plaque formation, the researchers compared vascular health in mice from the two experimental groups. One group received a diet high in fat and protein, the other a high-fat diet with normal protein content.
"A couple of scoops of protein powder in a milkshake or smoothie adds about 40 grams of protein, which is equivalent to the recommended daily intake," Razani says. high in fat and high in protein. These mice were getting 46 percent of their calories with protein, instead of fifteen."
As a result, mice on a high-fat-high-protein diet had 30 percent more plaque in their arteries than mice on a high-fat, normal-protein diet. But at the same time, they did not gain weight, and the mice from the second group got fat.
This is not the first study to demonstrate an increase in the amount of plaque in blood vessels with a protein diet, but in this case, scientists were able to understand the mechanism of the process leading to such results.
Arterial plaques are made up of a mixture of fat, cholesterol, calcium deposits, and dead cells. Immune cells called macrophages are called upon to cleanse the vessels from deposits. The authors found that excess amino acids in a high-protein diet activates a protein in macrophages called mTOR, which causes these cells to grow rather than do their job. Signals from mTOR block the ability of cells to clear the vessels of plaque and set off a chain of events leading to the death of macrophages.
As a result, accumulations of dead macophages are formed around the plaques, which only aggravates the situation with poor vascular patency.
"In mice on a high-protein diet, the plaques were just a graveyard of macrophages," Razani says.
Researchers have found that certain amino acids, especially leucine and arginine, are most conducive to mTOR activation and macrophage destruction. Red meat is especially rich in leucine, less of it is found in proteins from fish or plants.
"Future research may look at diets high in protein and varying amino acid levels to see if this can affect plaque complexity. Cell death is a key sign of plaque instability."By manipulating proteins, you can reduce this instability "- the scientist notes.