Is L-Carnitine the Link between Red Meat and Heart Disease?

摘要

A recent article in Nature Medicine (2013) suggests that the nutrient L-carnitine, found in red meat and nutritional supplements, promotes atherosclerosis as a result of enteric bacteria in the gut forming a toxin called trimethylamine (TMA), which is further metabolized to trimethylamine-N-oxide (TMAO) [1]. Two other articles by many of the same authors similarly argue that gut bacteria transform dietary choline and phosphatidylcholine to yield TMA with negative cardiovascular consequences [2,3]. Furthermore, omnivorous human subjects produce more TMAO than do vegans or vegetarians; this difference is possibly related to the higher dietary L-carnitine intake of the non-vegetarians. We argue that the conclusions from these studies relating TMO/TMAO to dietary L-carnitine, whether from food or dietary supplements, are misleading and, in fact, L-carnititne is cardioprotective.