
But there are possible risks to consuming supplemental acetyl-l-carnitine. Low blood levels of acetyl-l-carnitine are associated with negative outcomes, including depression (according to this recent Stanford study), so we want to make sure we get enough. Can we just eat more read meat (which contains substantial amounts of l-carnitine) or take supplemental ALCAR to bolster our blood levels? There’s always a catch. In this case it’s TMAO, a dangerous chemical that promotes hardening of the arteries. Various pathogenic gut bacteria convert dietary and supplemental l-carnitine to TMAO.
Well that’s a drag.
So are there ways to kill off these bad bacteria, or inhibit their metabolic processes so that l-carnitine can be absorbed into the bloodstream, and less TMAO is created?


