When people ingest certain nutrients like choline (abundant in red meat, egg yolks, and dairy products) and L-carnitine (found in red meat as well as some energy drinks and supplements), gut bacteria digest them and produce a compound called trimethylamine (TMA). The liver then converts TMA into the compound, trimethylamine N-oxide (TMAO).
Turns out, elevated levels of TMAO contribute to a heightened risk for blood clot-related events such as heart attack and stroke. This holds true even after accounting for the presence of conventional risk factors (like high blood pressure, cholesterol and diabetes) and even after accounting for markers of inflammation.
So TMAO looks to be a powerful, independent risk factor for cardiovascular events. In fact, in an analysis of over 2000 people with heart disease, those found to have higher blood levels of TMAO had a four-fold greater risk of dying from any cause over the subsequent five years.
A sobering reminder of the intimate relationship between gut flora and heart health – and how what we eat has tremendous downstream effects on outcomes.
So how do we lower TMAO levels?
By minimizing the consumption of full-fat dairy products (including whole milk, egg yolk, cream cheese, and butter); both processed and unprocessed red meat (beef, pork, lamb, and veal), as well as nutritional supplements and energy drinks containing choline, phosphatidylcholine, and/or L-carnitine.
And by increasing intake of whole-food fiber and plant-based foods in general, which has been found to significantly reduce TMAO levels.
But here’s a really interesting observation - people who change over to a completely plant-based diet reduce their ability to make TMAO. Some may not make any TMAO at all—even if they try. Feeding a steak - which contains choline and carnitine – to a committed vegan has little effect on TMAO levels. Why? Because over time, vegetarians and vegans develop different gut microbial communities.
Yet another reason why eating plant-based Step One Foods on a regular basis is good for you.