Carnitine, a compound in red meat and added as a supplement to energy drinks, has been found to promote hardening and clogging of the arteries (atherosclerosis). The findings, by researchers from The Cleveland Clinic, appear in the journal Nature Medicine.
The research shows that bacteria living in the human digestive tract metabolize the compound carnitine, turning it into trimethylamine-N-oxide (TMAO), a metabolite previously linked to the promotion of atherosclerosis in humans.
Interestingly, the research finds that a diet high in carnitine promotes the growth of the bacteria that metabolize carnitine, compounding the problem by producing even more of the artery-clogging TMAO.
"The bacteria living in our digestive tracts are dictated by our long-term dietary patterns," researcher Stanley Hazen said. "A diet high in carnitine actually shifts our gut microbe composition to those that like carnitine, making meat eaters even more susceptible to forming TMAO and its artery-clogging effects. Meanwhile, vegans and vegetarians have a significantly reduced capacity to synthesize TMAO from carnitine, which may explain the cardiovascular health benefits of these diets."
While carnitine is occurs naturally in red meats, it's also a dietary supplement available in pill form and a common ingredient in energy drinks. With this new research in mind, Hazen cautions that more research needs to be done to examine the safety of chronic carnitine supplementation.
"Carnitine is not an essential nutrient; our body naturally produces all we need," Hazen says. "We need to examine the safety of chronically consuming carnitine supplements as we've shown that, under some conditions, it can foster the growth of bacteria that produce TMAO and potentially clog arteries."
Discuss this article in our forum
Energy Drinks And Alcohol A Seductive But Dangerous Combo
Barbeque Cancer Warning
New thinking on vascular disease and Alzheimer's
Gender and sickness: women are different
Source: Cleveland Clinic