Picture this that you're eating an egg omelette or slurping up a protein shake, thinking that you're nourishing your body, but that may not necessarily be the case.
Protein is considered as one of the healthiest nutrients. Fitness enthusiasts chug on bottles of protein shakes daily. From common breakfast worldwide, eggs, to lunch and dinner, everything contains good amounts of protein. Here’s why protein can cause harm to heart health.
In a study published in 'Nature Metabolism', scientists have revealed a molecular mechanism suggesting that excessive consumption of protein, particularly from animal sources, could increase the risk of atherosclerosis – the hardening of arteries.
More protein, not always better?
The study consisted of small human trials with experiments made on mice and cells in a petri dish showing that consuming over 22% of calories from protein can lead to activation of immune cells that play a role in the formation of atherosclerotic plaque.
Furthermore, the researchers showed that single amino acid, leucine, appears to have a disproportionate role in driving the pathological pathways associated with atherosclerosis, or stiff, hardened arteries.
The Study
"Our study shows that dialling up your protein intake in pursuit of better metabolic health is not a panacea. You could be doing real damage to your arteries," said senior and co-corresponding author Babak Razani, M.D., Ph.D., professor of cardiology at Pitt.
"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."
"We have shown in our mechanistic studies that amino acids, which are really the building blocks of the protein, can trigger disease through specific signalling mechanisms and then also alter the metabolism of these cells," Bettina Mittendorfer, Ph.D., a metabolism expert at the University of Missouri, Columbia, said. He has collaborated with Razani.
"For instance, small immune cells in the vasculature called macrophages can trigger the development of atherosclerosis."
Based on initial experiments in healthy human subjects to determine the timeline of immune cell activation following ingestion of protein-enriched meals, the researchers simulated similar conditions in mice and in human macrophages, immune cells that are shown to be particularly sensitive to amino acids derived from protein.
The research by Razani and Bettina showed that consuming more than 22% dietary calories through protein daily can affect macrophages negatively. They are responsible for cleaning out cellular debris leading to accumulation of graveyards of those cells inside vessel walls and contributing to worsening the atherosclerotic plaques.
Conclusion
Their work showed that consuming more than 22% of daily dietary calories through protein can negatively affect macrophages that are responsible for clearing out cellular debris, leading to the accumulation of a "graveyard" of those cells inside the vessel walls and worsening of atherosclerotic plaques overtime.