Eating too much protein could cause heart problems, according to researchers at the University of Pittsburgh School of Medicine. In a study, published in Nature Metabolism, involving people, mice, and cells, consuming over 22% of daily calories from protein was linked to immune cell activation, contributing to the formation of plaque in the arteries, a condition called atherosclerosis. The amino acid leucine, found in animal products like beef and eggs, played a significant role in this molecular process.
Senior author Babak Razani warned against increasing protein intake blindly, saying it might harm arteries. He said that this study could encourage discussions about tweaking diets for better health.
“Our hope is that this research starts a conversation about ways of modifying diets in a precise manner that can influence body function at a molecular level and dampen disease risks,” he said in a statement.
The study also questioned the popular belief that more protein is always better. Based on a 10-year survey of average American diets, a lot of daily calories come from protein, mostly from meat.
This aligns with the idea that protein is crucial for health, but studies, including this one, suggest too much might not be good for long-term health. Razani and metabolism expert Bettina Mittendorfer collaborated for a deeper understanding. The study spanned different models, from cells to mice to humans. Initial experiments with healthy people guided the timeline for immune cell activation.
Simulations in mice and human cells showed that eating more than 22% of daily calories from protein can harm macrophages, cells that help clear debris, leading to plaque buildup in arteries.