Even lean beef should be avoided
Poor, much-maligned beef. High in saturated fat, beef has been linked to a number of health problems, including heart disease and high cholesterol. But beef lovers could find solace in lean cuts.
Now a new study suggests even lean beef should be avoided. All beef (even lean cuts) contain carnitine, a substance that, when mixed with the naturally occurring bacteria in our intestines, forms a dangerous compound called TMAO. That compound is associated with atherosclerosis, or plaque build-up in our arteries, which can lead to heart attacks.
“The bacteria living in our digestive tracts are dictated by our long-term dietary patterns,” said study co-author Stanley Hazen, of the Cleveland Clinic, in a statement. “A diet high in carnitine actually shifts our gut microbe composition to those that like carnitine, making meat eaters even more susceptible.”
The study followed 2,595 students and measured carnitine levels, as well as those of its byproduct, TMAO. Meat eaters produced more TMAO after eating carnitine.
Carnitine is also found in fish, poultry and wheat—though in much smaller amounts—and some people take carnitine as a supplement. Researchers say these supplements will need further study to make sure they aren’t forming TMAO or, subsequently, heart disease.