L carnitine: Heart Disease's Chemical Culprit? KQED New study links L carnitine in red meat to heart disease Harvard Health Red Meat and Heart Disease: The Hidden Role of microbial L Carnitine & Choline Prof Luigi Fontana Everything You Need to Know About L Carnitine If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy.