Nick NorwitzMD PhD, Oxford-Harvard | Metabolic Health Educator | “Stay Curious”

Does Meat Cause Heart Disease? The Truth About Histidine and ImP

26 Jul 2025 · 1 min

Watch on YouTube

1:11

In this YouTube explainer, the presenter debunks the viral claim that the amino acid histidine—abundant in meat—is a direct cause of heart disease. The speaker clarifies that the recent paper actually identified imidazole propionate (IMP), a metabolite produced by gut bacteria from histidine, as the culprit. Two large human cohort studies showed higher IMP levels were associated with poorer blood‑sugar control, increased inflammation, and greater atherosclerotic burden. In mouse experiments, administering IMP accelerated plaque formation without altering cholesterol, primarily by disrupting insulin signaling through activation of the mTOR pathway. Crucially, IMP concentrations were unrelated to dietary histidine intake; they depended on the composition of gut microbes that convert histidine to IMP. Therefore, reducing protein intake—whether animal or plant—is not the solution. Instead, the speaker advises supporting gut health by eating whole, minimally processed foods, managing stress, and avoiding ultra‑processed products to keep IMP production low.

Chapters

The internet just saw one new paper and decided that histidine, the essential amino acid in meat, is the new dietary villain. Hot takes were everywhere: histidine causes heart disease, cut meat to save your arteries. Spoiler: they're dead wrong. What the paper actually found, which was quite interesting, is that imidazole propionate, or IMP for short, a molecule made by gut bacteria, yes, from histidine, can cause atherosclerosis. In two big human studies, more IMP meant worse blood sugar, more inflammation, and more atherosclerosis. And in mice, IMP directly caused plaque buildup without changing cholesterol levels. But it ramped up and broke insulin signaling, mostly by flipping a metabolic switch called mTOR. But here's the twist. Here's the important thing. IMP levels had nothing to do with how much dietary histidine people ate. It all came down to which gut bacteria were converting the histidine into IMP. So no, cutting protein is not the answer. Be that meat protein or actually plant protein as well, which contains essential amino acids. If you want to lower IMP, eat real food, ditch ultra-processed food, manage stress, and read the caption. Your gut doesn't need drama, it just needs support.