What’s TMAO, and What Does It Have to Do With My Health?
With the last few weeks’ definitive guide and follow-up on fish, a reader asked me about trimethylamine N-oxide, or TMAO. What is it? TMAO is the latest justification given for why eating meat just has to be bad for you. Saturated fat didn’t take . Animal protein didn’t work . Iron was a dud . IGF-1 hasn’t panned out . Methionine isn’t enough . So now they’re using TMAO to convince you not to eat that steak. How’s it supposed to work? How TMAO Happens When certain gut bacteria encounter choline (found in eggs and liver) or carnitine (found in meat, especially red meat), some of it is converted to trimethylamine, or TMA. TMA is the compound that gives fish its “fishy odor.” Fish is actually extremely high in TMA, which I’ll discuss later on. Then, the liver converts a portion of the TMA to TMAO. Studies have shown that elevated serum levels of TMAO are linked to heart disease , type 2 diabetes, kidney disease, and even all-cause mortality. There’s definitely some heterogeneity a