After ingested, bacteria in the gut breaks down carnitine. The carnitine turns into a compound that can harden arteries.
So, the more red meat a person eats, the more carnitine is converted to a compound, increasing its effects.
Carnitine is also found in poultry, fish, certain vegetables, and wheat, but its main source is red meat, especially lamb.
Vegans and vegetarians eat fewer foods that contain carnitine, so their gut bacteria does not process it as easily, which is one of the benefits of a meatless diet.