Tannins and human health: a review

• Published in: Critical reviews in food science and nutrition 1998-08, Vol.38 (6), p.421-464
• Main Authors: Chung, K.T. (The University of Memphis, Memphis, TN.), Wong, T.Y, Wei, C, Huang, Y.W, Lin, Y
• Format: Article
• Language: English
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; AGENTES ANTINEOPLASTICOS; Anti-Bacterial Agents; Anticarcinogenic Agents; ANTIINFECTIVE AGENTS; ANTIMICROBIAL PROPERTIES; ANTIMICROBIALS; ANTIMICROBIANOS; ANTIMICROBIEN; Antimutagenic Agents; ANTIMUTAGENS; ANTINEOPLASTIC AGENTS; ANTINUTRITIONAL FACTORS; Biological and medical sciences; CARCINOGENOS; CARCINOGENS; CHEMICAL STRUCTURE; COMPOSICION APROXIMADA; COMPOSITION GLOBALE; DANGER POUR LA SANTE; DOSAGE EFFECTS; EFECTOS DE DOSIFICACION; EFFET DOSE; ENZYMIC ACTIVITY; ESTRUCTURA QUIMICA; FACTEUR ANTINUTRITIONNEL; FACTORES ANTINUTRICIONALES; FISIOLOGIA DE LA NUTRICION; Food; FOOD COMPOSITION; Health; HEALTH HAZARDS; HUMAN NUTRITION; Human physiology applied to population studies and life conditions. Human ecophysiology; Humans; INHIBICION; INHIBITION; INVESTIGACION; LITERATURE REVIEWS; Medical sciences; MEDICAMENT CYTOSTATIQUE; MICROORGANISME; MICROORGANISMOS; MICROORGANISMS; MODE OF ACTION; Molecular Structure; NUTRICION HUMANA; NUTRITION HUMAINE; NUTRITION PHYSIOLOGY; Nutritional survey. Food supply and nutritional requirement; PELIGRO PARA LA SALUD; PHYSIOLOGIE DE LA NUTRITION; PROPIEDADES ANTIMICROBIANAS; PROPRIETE ANTIMICROBIENNE; PROXIMATE COMPOSITION; RECHERCHE; STRUCTURE ACTIVITY RELATIONSHIPS; STRUCTURE CHIMIQUE; SUBSTANCE CANCERIGENE; SUSCEPTIBILITY; TANINOS; tannic acid; TANNIN; TANNINS; Tannins - adverse effects; Tannins - analysis; Tannins - chemistry; Tannins - classification; Tannins - pharmacology; tea polyphenols; TOXICIDAD; TOXICITE; TOXICITY; water soluble polyphenols
• ISSN: 1040-8398; 1549-7852
• DOI: 10.1080/10408699891274273

Tannins (commonly referred to as tannic acid) are water-soluble polyphenols that are present in many plant foods. They have been reported to be responsible for decreases in feed intake, growth rate, feed efficiency, net metabolizable energy, and protein digestibility in experimental animals. Therefore, foods rich in tannins are considered to be of low nutritional value. However, recent findings indicate that the major effect of tannins was not due to their inhibition on food consumption or digestion but rather the decreased efficiency in converting the absorbed nutrients to new body substances. Incidences of certain cancers, such as esophageal cancer, have been reported to be related to consumption of tannins-rich foods such as betel nuts and herbal teas, suggesting that tannins might be carcinogenic. However, other reports indicated that the carcinogenic activity of tannins might be related to components associated with tannins rather than tannins themselves. Interestingly, many reports indicated negative association between tea consumption and incidences of cancers. Tea polyphenols and many tannin components were suggested to be anticarcinogenic. Many tannin molecules have also been shown to reduce the mutagenic activity of a number of mutagens. Many carcinogens and/or mutagens produce oxygen-free radicals for interaction with cellular macromolecules. The anticarcinogenic and antimutagenic potentials of tannins may be related to their antioxidative property, which is important in protecting cellular oxidative damage, including lipid peroxidaton. The generation of superoxide radicals was reported to be inhibited by tannins and related compounds. The antimicrobial activities of tannins are well documented. The growth of many fungi, yeasts, bacteria, and viruses was inhibited by tannins. We have also found that tannic and propyl gallate, but not gallic acid, were inhibitory to foodborne bacteria, aquatic bacteria, and off-flavor-producing microorganisms. Their antimi