Trimethylamine N-Oxide (TMAO), Diet and Cardiovascular Disease


Purpose of Review

The association between plasma Trimethylamine N-Oxide (TMAO), diet and risk for cardiovascular disease (CVD) is still not fully understood. While epidemiologic research shows a causal relationship between plasma TMAO concentrations and CVD risk, the role of dietary precursors in determining plasma concentrations of TMAO and biomarkers for CVD is inconclusive.

Recent Findings

Studies in diverse populations show that plasma TMAO concentrations are positively associated with inflammation, endothelial dysfunction, type-2 diabetes, central adiposity and hypertension. Most recent studies utilizing challenges of dietary choline have not shown increases in plasma chronic TMAO concentrations while studies with carnitine have shown increases in plasma TMAO but in some cases, no alterations in plasma lipids or biomarkers of oxidative stress were observed.


TMAO is an important plasma metabolite that through several mechanisms can increase the risk of CVD. The correlations between dietary choline and carnitine on chronic plasma TMAO levels and risk for CVD requires further investigation.

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Fig. 1


Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

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Correspondence to Maria Luz Fernandez.

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Dr. Fernandez reports to have been funded by The Egg Nutrition Center; Ms. Thomas has nothing to disclose.

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Thomas, M.S., Fernandez, M.L. Trimethylamine N-Oxide (TMAO), Diet and Cardiovascular Disease. Curr Atheroscler Rep 23, 12 (2021).

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  • Trimethylamine-N-oxide
  • Carnitine
  • Choline
  • Cardiovascular disease
  • Microbiota
  • FMO3