The unmapped chemical complexity of our diet.
Albert-László Barabási, Giulia Menichetti & Joseph Loscalzo
Nature Food volume 1, pages 33–37(2020)
Our understanding of how diet affects health is limited to 150 key nutritional components that are tracked and catalogued by the United States Department of Agriculture and other national databases. Although this knowledge has been transformative for health sciences, helping unveil the role of calories, sugar, fat, vitamins and other nutritional factors in the emergence of common diseases, these nutritional components represent only a small fraction of the more than 26,000 distinct, definable biochemicals present in our food—many of which have documented effects on health but remain unquantified in any systematic fashion across different individual foods. Using new advances such as machine learning, a high-resolution library of these biochemicals could enable the systematic study of the full biochemical spectrum of our diets, opening new avenues for understanding the composition of what we eat, and how it affects health and disease.
An interesting assertion regarding TMAO:
Consider, for example, trimethylamine N-oxide (TMAO). Recent studies have found that patients with stable coronary heart disease had a fourfold greater risk of dying from any cause over the subsequent five years if they had high blood levels of TMAO.
While TMAO and its precursor trimethylamine (TMA) naturally occur in fish and milk, important sources of TMAO in the Western diet are L-carnitine and choline, both of which are found in red meat. These molecules are metabolized by gut bacteria into TMA, which is then converted in the liver to TMAO (Fig. 1). The Mediterranean diet, which regularly pairs red meat with fresh garlic, derives some of its known health benefits from allicin, which blocks TMA production in the gut, ultimately lowering the TMAO concentration in plasma. Taken together, there are at least six distinct biochemicals in our diet involved in the TMAO pathway: L-carnitine, choline, TMA, TMAO, allicin and 3,3-dimethylbutan-1-ol (DMB). Yet, only one of them, choline, is tracked and quantified in nutritional databases. The remaining five, despite the key roles they play in health, are effectively nutritional dark matter
The paper then notes that extra-virgin olive oil and red wine similarly block TMAO production.