Health effects, sources, utilization and safety of tannins: a critical review

Tannins are complex, astringent and water soluble phenolic compounds known to reduce the bioavailability of nutrients in gut. Furthermore, tannins pose some health consequences viz. antinutritional effect, reduced digestibility, mutagenic and carcinogenic effects and inducer, hepatotoxic activity and co-promoters of several diseases. However, recent studies have explored and confirmed numerous health benefits like anti-oxidant, anti-cancerous, anti-allergic, anti-inflammatory, anti-helminthic and anti-microbial activities). Owing to their astringency, the food applications are very limited; whereas, they have wide applications in pharmaceutical industries. The present review has been aimed to highlight the classification, sources, occurrence, health effects, industrial applications and the safe limits of consumption of tannins.

Automated summary

Tannins are phenolic compounds known for their complex and astringent properties, which can reduce nutrient absorption in the gut. Although they pose health risks like reduced digestibility and carcinogenic effects, recent studies have also shown their health benefits such as antioxidant and anti-cancer properties. While their food applications are limited due to astringency, tannins have wide uses in pharmaceutical industries.