Feb 20: A recent report published in Nature has shed light on the potential risks associated with high protein intake, particularly in relation to cardiovascular health. While high protein consumption is often touted as a key component of a healthy lifestyle in western societies, the study’s findings suggest a more nuanced understanding of its impact.
The research, which involved a series of clinical studies on both male and female participants, focused on the role of amino acid-mediated mammalian target of rapamycin (mTOR) signaling in macrophages in the pathogenesis of ischaemic cardiovascular disease. The studies, registered under NCT03946774 and NCT03994367, incorporated varying levels of protein ingestion, detailed plasma amino acid analysis, and human monocyte/macrophage experiments.
One of the pivotal discoveries of the study was the identification of leucine as the primary activator of mTOR signaling in macrophages. The research revealed a threshold effect, indicating that high protein intake and circulating leucine levels above a certain point could trigger mTOR activation and functional effects in monocytes/macrophages. Specifically, the data suggested that only protein intake exceeding approximately 25 grams per meal induces mTOR activation and its associated effects.
Impact of High Protein Intake
Furthermore, the study delved into the impact of high protein intake on atherosclerosis in male mice. By designing specific diets that mirrored the protein and leucine content typically found in the general population, the researchers were able to confirm the threshold effect observed in human studies. The findings indicated that protein ingestion surpassing around 22% of dietary energy requirements could contribute to the development of atherosclerosis in male mice.
These results provide a mechanistic basis for understanding the potential adverse effects of excessive dietary protein on cardiovascular risk. The study’s implications may prompt a reevaluation of dietary recommendations related to protein intake, particularly in the context of cardiovascular health.
The research not only highlights the need for a more nuanced approach to understanding the impact of high protein consumption but also underscores the importance of considering individualized dietary requirements. As discussions surrounding nutrition and health continue to evolve, these findings contribute valuable insights that could inform future dietary guidelines and public health initiatives.
The research was led by Dr. Zhang and colleagues investigated the relationship between protein consumption, circulating leucine levels, and cardiovascular outcomes in two clinical trials—NCT03946774 and NCT03994367—that included graded amounts of protein and detailed plasma amino acid analyses.
