The trouble with carnitine, according to this study, is that it becomes something perhaps more insidious once the bacteria in our guts take hold of it. Our intestinal flora quickly convert carnitine into another little-studied chemical called TMAO, which stands for Trimethylamine N-oxide. Additional studies by the same researchers found that people (and mice) with high blood carnitine or TMAO levels were at increased heart disease risk.
The studies give yet more meat to the argument that heart disease is more complex than most of us ever supposed. Saturated fat, cholesterol, sugar, and inflammation are major culprits - and now carnitine and TMAO may take their place on that infamous list.
But suspend your judgements: Additional research is sure to come, and contradictory studies about carnitine/TMAO (one published in Mayo Clinic Proceedings) have already emerged. For now, a little healthy skepticism about red meat - and more Meatless Mondays - can only be a good thing.