Introduction:

The TMAO Mystery Unveiled: A Diet’s Dark Secret

In the realm of heart disease and stroke risk factors, a relatively new player has emerged on the scene: Trimethylamine-N-oxide or TMAO. This enigmatic compound, found in elevated levels in blood and urine, has been closely linked to major adverse cardiovascular events (MACE), including heart attacks and strokes. But how does our diet, particularly one high in fats, contribute to the rise of TMAO levels in our bodies? Recent research, published in the journal Science in August 2021, has shed light on this intriguing connection.

High-Fat Diet: Unveiling the Culprit

A diet rich in fats, especially saturated and trans fats, has long been recognized as a risk factor for heart disease. What’s new is the revelation that such diets disrupt the intestinal lining and gut microbiota, triggering a chain reaction that culminates in elevated TMAO levels. The high-fat diet impairs the functioning of intestinal epithelial cells, which line the gut, causing them to produce excess oxygen and nitrate. Concurrently, it alters the composition of gut bacteria, promoting the growth of less friendly inhabitants, including E. Coli and other Enterobacteriaceae microbes. These unfriendly bacteria metabolize compounds found in certain foods we consume, such as carnitine, choline, and betaine, into Trimethylamine (TMA). TMA then enters the bloodstream and heads to the liver, where it undergoes transformation into TMAO before being released into circulation.

TMAO: The Silent Saboteur

But how does TMAO wreak havoc on our cardiovascular system? Experimental studies have highlighted its role in accelerating the narrowing of arteries (atherosclerosis), increasing the risk of abnormal clots (thrombosis), and igniting inflammation within blood vessels. These mechanisms are key contributors to heart attacks and strokes. In essence, the high-fat diet sets off a domino effect: it damages intestinal cells, fosters the growth of unfriendly gut bacteria, and ultimately leads to elevated TMAO levels, increasing the risk of cardiovascular events.

Double Trouble: A Warning for High-Fat Diets

Interestingly, many of the high-fat foods notorious for elevating blood cholesterol levels also drive up TMAO levels. It’s a double whammy effect on the risk of heart attacks and strokes. Having a TMAO blood level above 5.1 umol/L is now considered a significant risk factor for major adverse cardiovascular events, while levels below 3.9 umol/L are deemed safe. The catch? Most doctors don’t routinely order TMAO blood tests; you often need to request it.

The Road to Heart Health: Diet and Probiotics

So, what can you do to protect your cardiovascular health? One crucial step is to steer clear of unhealthy fats, especially those found in beef, pork, high-fat dairy products, coconut oil, deep-fried and battered foods, and pastries. Additionally, consider taking a daily probiotic supplement containing a variety of gut-friendly bacteria. These beneficial microbes help crowd out the unfriendly gut bacteria responsible for TMA synthesis, aiding in the maintenance of desirable TMAO blood levels. Don’t forget to explore fermented foods as well, as they are rich sources of probiotics. By adopting these two strategies—a lower-fat diet and probiotic supplementation, along with incorporating probiotic-rich foods—you can actively manage your TMAO levels and reduce your risk of heart attacks and strokes.

In Conclusion

TMAO, the newly discovered player in heart health, emphasizes the profound impact our diet choices can have on our cardiovascular well-being. By understanding the intricate connections between diet, gut health, and TMAO levels, we can take proactive steps to safeguard our hearts.

References:

1. Woongjae Yoo, Jacob K. Zieba, Nora J. Foegeding, Teresa P. Torres, Catherine D. Shelton, Nicolas G. Shealy, Austin J. Byndloss, Stephanie A. Cevallos, Erik Gertz, Connor R. Tiffany, Julia D. Thomas, Yael Litvak, Henry Nguyen, Erin E. Olsan, Brian J. Bennett, Jeffrey C. Rathmell, Amy S. Major, Andreas J. Bäumler, Mariana X. Byndloss. High-fat diet–induced colonocyte dysfunction escalates microbiota-derived trimethylamine N-oxide. Science, 2021. [Link to the study](https://www.science.org/lookup/doi/10.1126/science.aba3683)
2. Journal American College Cardiology: 2020. [Link to the study](https://www.jacc.org/doi/abs/10.1016/j.jacc.2019.11.060)
3. BMC Cardiology: 2020. [Link to the study](https://bmccardiovascdisord.biomedcentral.com/articles/10.1186/s12872-019-01310-5)
4. Journal American Heart Association: 2019. [Link to the study](https://www.ahajournals.org/doi/full/10.1161/JAHA.118.010606)
5. Uremic Toxicology: 2016. [Link to the study](https://www.mdpi.com/2072-6651/8/11/326)

Dr. Meschino