Carnitine in Red Meat, Energy Drinks Linked to Heart Disease

A new study may be shedding light on just how bad red meat can be for you, and, more importantly, how it's unhealthy. Researchers at the Cleveland Clinic have found that an intricate mixture of certain stomach microbes and a chemical found in red meat - and many fashionable energy drinks - can produce an organic compound that causes heart disease in lab mice.

Consensus has long been that eating red meat is maybe not the healthiest thing one can do. While it's a source of iron and other vitamins and minerals, red meat is high in saturated fat and cholesterol, and over the years its been linked to an increased risk for certain cancers, especially colon cancer, diabetes, obesity and, of course, cardiovascular problems. Some steakhouses, like the Heart Attack Grill, have even played off red meat's lethal reputation.

But the recent study in Nature Medicine, published April 7, makes it clearer just what, specifically, about red meat causes trouble for the old ticker. According to the New York Times, Dr. Stanley Hazen of the Cleveland Clinic lead a study proposing that a little-researched chemical byproduct of some stomach bacteria, called trimethylamine N-oxide or TMAO, could be created in the blood after people eat red meat. 

To test the theory, Hazen bought a George Foreman grill and served up 8-ounce steaks to six men and women, after which, they had their blood drawn and tested. After eating the steak, TMAO levels shot up in their blood, which didn't happen for a vegan control group. Additional studies found that meat eaters had more of the compound in their blood, and were more likely to produce higher TMAO levels when exposed to the isolated chemical, which is found in red meat, called carnitine.

It seems carnitine, when metabolized by some stomach bacteria, produces TMAO in the bloodstream. The researchers have found TMAO to cause heart disease in mice, and to correlate with heart attack risk in humans. Though there is much more to learn about this complicated interaction, Dr. Hazen is worried about carnitine found in energy drinks, and in athletic and body building diet supplements which are thought to build muscle.