Abstract

High protein intake is common in western societies and is often promoted as part of a healthy lifestyle; however, amino-acid-mediated mammalian target of rapamycin (mTOR) signalling in macrophages has been implicated in the pathogenesis of ischaemic cardiovascular disease. In a series of clinical studies on male and female participants (NCT03946774 and NCT03994367) that involved graded amounts of protein ingestion together with detailed plasma amino acid analysis and human monocyte/macrophage experiments, we identify leucine as the key activator of mTOR signalling in macrophages. We describe a threshold effect of high protein intake and circulating leucine on monocytes/macrophages wherein only protein in excess of ∼25 g per meal induces mTOR activation and functional effects. By designing specific diets modified in protein and leucine content representative of the intake in the general population, we confirm this threshold effect in mouse models and find ingestion of protein in excess of ∼22% of dietary energy requirements drives atherosclerosis in male mice. These data demonstrate a mechanistic basis for the adverse impact of excessive dietary protein on cardiovascular risk.

I’m used to seeing a small and hard to see Manage Preferences link in that banner that provides a button to reject optional cookies, but we might see different things based on region

However you are incredibly closely related to one… Like the closest non-primate group to you

That’s why they use mice and guinea pigs over dogs or whatever else, they’re not too different to us and most things that are true in mice are true in humans

Actual nutritionists and dieticians have known that a balanced diet (ie enough calories and vitamins with good variation) has been the best diet we know all along, but every so often some upstart sees “X in excess is bad” and so tries to stop everyone eating X, when X in moderation is best

Ah Instagram, the best place to read news

I mean dietary requirements do differ between ethnicities due to different levels of fat and muscle gain per “neutral” calorie, and it just so happens that Northern & Eastern European people (ie people traditionally considered White) have about a 20% lower tendancy to convert calories to fat over other things (bone, muscle etc.) when compared to the average human - South Asian people have about a 20% higher tendancy towards fat whereas most other ethnicities are very close to the average.

So excess protein being a greater issue in Western society (where thre are more White people) actually kind of tracks, as there’s going to be too much protein/amino acid availability as their bodies are more proactive about producing them from other food types anyway.