Red Meat Linked to Heart Disease—Again

Delicious for some, but also bad for your heart. Photo via Shutterstock

If you’ve been toying with the idea of vegetarianism, a new study from the Cleveland Clinic may cement your decision. The study, published in the journal Nature Medicine, shows eating red meat may increase the risk of heart disease.

Red meat has long gotten a bad rap for its high fat content and tendency to boost cholesterol, but the research suggests those issues may actually not be as dangerous as an obscure substance called TMAO. After an individual eats red meat, bacteria in his or her intestines produces a chemical that is converted by the liver into TMAO, a chemical that, when in the blood, puts people at risk for heart disease and heart attacks. Carnatine, another substance found it red meat, is also metabolized as TMAO by the intestines, raising levels further.

In the study, the researchers had participants eat a steak, and shortly afterward observed their blood to see if a burst of TMAO had occurred. Not only did TMAO levels spike in the short-term, the researchers found that meat eaters had a higher constant level of TMAO in the blood than vegetarians, likely because frequent meat eating alters the consumer’s gut bacteria. A New York Times article about the study points out that an association between TMAO levels and heart disease does not necessarily mean the chemical causes heart problems, they may simply be related. But, the article says, the theory is that TMAO makes it easier for cholesterol to adhere to artery walls and prevents unnecessary cholesterol from leaving the body, thus leading to heart problems down the road.

The solution isn’t as simple, however, as simply cutting red meat out of the diet entirely, since lean meat is a valuable source of protein and B vitamins. (Even the study’s lead author, Dr. Stanley Hazen of the Cleveland Clinic, says in the Times report, “I am not a vegan. I like a good steak.”) Nonetheless, maybe it wouldn’t be a bad thing for all of us to a few more salads and few less burgers, just to be safe.