New link between red meat and heart disease revealed in study
A natural nutrient that is found in red meat called l-carnitine, has been linked to increasing heart risk according to a recent study by Cleveland Clinic, that was published in the journal of Nature Medicine.
Everyone is aware that consumption of red meat due to its high content of saturated fat and cholesterol increases the risk of heart disease, but this new study links it even further.
The study shows that the bacteria living in the digestive tract metabolizes the nutrient l-carnitine turning it another chemical, known as trimethylamine-N-oxide, or TMAO increasing its levels.
TMAO has already been thought to contribute towards the hardening of the arteries (atherosclerosis) – as major risk factor for heart disease, and the study noted that the increase in levels of TMAO slowed down the way the body processes cholesterol, enhancing the risk of cardiac problems.
"Carnitine metabolism suggests a new way to help explain why a diet rich in red meat promotes atherosclerosis,” said Dr. Stanley Hazen, one of the study’s authors.
The study team conducted a series of experiments in people and in mice, - both omnivores and vegetarians - and found that high L-carnitine consumption led to an increase of TMAO production — but only in people with certain gut bacteria.
Vegans and vegetarians did not produce as much TMAO as meat eaters after ingesting carnitine because they didn’t have as many of the harmful bacteria in their guts as meat eaters do,” Hazen said.
"The bacteria living in our digestive tracts are dictated by our long-term dietary patterns. Vegans and vegetarians have a significantly reduced capacity to synthesize TMAO from carnitine, which may explain the cardiovascular health benefits of these diets.”
L-carnitine is not only found in red meats, but is an additive in energy drinks and is a popular dietary supplement used to boast energy, and Hazen cautioned against taking carnitine supplements.
"Carnitine is not an essential nutrient; our body naturally produces all we need," Hazen said. "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."