eli5: what are tannins and what is the effect they have on the body?


I read about tannins (found in wine, tea, coffee, chocolate, beans, nuts, etc.) being ‘antinutrients’, but also being healthy. (Antioxidants?)
Also read they might cause digestive problems for iron and other minerals. And they bind to protein? What does that mean?
Should I stop consuming foods/drinks high in tannins close to big meals?

In: 10

Tannins are a group of chemicals that are extremely common in plants, appearing to have evolved as a natural pesticide. This includes most plant-based foods, such as most berries, legumes (beans), chocolate, tea, and coffee. Beer and wine also contains tannins, though mostly from aging in oak barrels – oak has one of the highest concentrations of tannis.

While they appear to interfere with the absorbance of some important nutrients, with a normal and balanced diet, the effect will be too minimal to matter. Additionally, the health benefits of many of the tannin-containing food are vastly greater than the negative effects.

Basically, unless you have a specific health issue indicating otherwise, it really does not matter, and complete avoidance would be nearly impossible. I would strongly suggest not consuming concentrated tannins, however – I’m not even sure where you’d buy them.


As a bit of trivia, leather production uses tannins heavily, which were historically extracted primarily from oak tress, among a few others types of tree – the term tanning leather comes from tannins, or visa versa. Today, tannins are mostly produced synthetically, and are used in a bunch of industrial processes.