Patients may ask about a new study that could explain how red meat consumption might contribute to heart disease. The study, published in Nature Medicine, found that the metabolism of carnitine (a trimethylamine abundant in red meat) by gut bacteria leads to the formation of a compound associated with cholesterol transport and atherogenesis.
The compound, trimethylamine-N-oxide, or TMAO, was found to be plentiful in the blood of meat eaters, but not vegans. When meat eaters had their gut bacteria suppressed with antibiotics, their levels of TMAO did not rise after eating carnitine.
The researchers noted that increasing plasma carnitine levels were associated with increased risks for prevalent and incident cardiovascular disease, but only among those who also had high TMAO levels.
In a New York Times account, the study's senior author raised concern over the amount of carnitine in some energy drinks and bodybuilding supplements, calling the implications "scary, especially for our kids."
Nature Medicine article