Red Meat, Gut Bacteria and You
Yesterday I mentioned new findings that may explain why red meat can be bad for your health. Before anyone thinks I’m picking on beef, let me be clear: I’m not a militant vegetarian with an agenda. I am a Doctor of Naturopathic Medicine, though, and I’m interested in helping people achieve optimal health. I know from my training and experience that what we eat directly affects our health.
I’m not prejudiced against red meat per se, but the facts are clear: Numerous studies have shown that eating more red meat (and processed meats) is linked to a higher risk of common diseases, such as type 2 diabetes, cardiovascular disease (including stroke and atherosclerosis), and even certain types of cancer. This link is consistent, and it simply doesn’t apply to “white” meats, such as poultry or pork. And fish consumption tends to have the opposite effect, actually improving some health outcomes. So there seems to be something about red meat in particular that encourages disease.
Now scientists think they know what it is. The culprit appears to be L-carnitine, an amino acid abundant in beef. By itself, carnitine is an ordinary amino acid; one of the building blocks of protein. We can even make it in our bodies from two other amino acids. But in the gut, carnitine encourages a particular species of bacteria to thrive, to the detriment of other beneficial bacteria. Here’s the kicker: The new bacteria interact with the gut wall to produce a compound that promotes atherosclerosis.
Concentrations of this compound, trimethylamine-N-oxide (TMAO) are higher among people who consume carnitine (found not only in red meat, but in some energy drinks and dietary supplements). But because of the diversity of helpful bacteria living in their guts, vegetarians do not produce nearly as much TMAO after ingesting carnitine as meat eaters do. The takeaway message? To avoid heart disease—the number one killer—consider curtailing your consumption of red meat.
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