High intakes of polyphenols may reduce mortality risk

According to a new study from Italy, a diet rich in polyphenols – found largely in fruits and vegetables – can decrease the long term risk of mortality by 30%.

In the observational study, the polyphenol intakes of 807 men and women aged 65 or over were analyzed by means of a nutritional biomarker – the total urinary polyphenol (TUP) concentration – and death cases were documented during 12 years (1). The study results showed that overall mortality was reduced by 30% in participants who had rich-polyphenol diets (more than 650 mg/day) in comparison with the participants who had low-polyphenol diets (less than 500 mg/day).

The researchers commented that these observations corroborate scientific findings suggesting that people consuming diets rich in fruit and vegetables are at lower risk of several chronic diseases and overall mor- tality. Moreover, the research stresses the importance of evaluating – if possible – food intake by using nutri- tional biomarkers, and not only by answering food frequency questionnaires, which are prone to bias as they are based on participants’ memory. The use of nutritional biomarkers takes into account bioavailability and individual differences, and allows a more reliable and accurate evaluation of the association between food intake and mortality or disease risk.

More than 8,000 different phenolic compounds have been identified in plant food sources, such as fruits, vegetables, coffee, tea, nuts, legumes and cereals. In in-vitro studies, polyphenols have been shown to have antioxidant, anti-inflammatory, anti-cancer and other potential health-promoting properties. The health effects of polyphenols depend on their quantity consumed and bioavailability, which varies greatly from one molecule to another (2) and among individuals (3).

1. Zamora-Ros R. et al. High Concentrations of a Urinary Biomarker of Polyphenol Intake Are Associated with Decreased Mortality in Older Adults. Journal of Nutrition. 2013; 143(9):1445–1450.
2. Manach C. et al. Bioavailability and bioefficacy of polyphenols in humans. I. Review of 97 bioavailability studies. Am J Clin Nutr. 2005; 81:230–242.
3. Urpi-Sarda M. et al. HPLC-tandem mass spectrometric method to characterize resveratrol metabolism in humans. Clin Chem. 2007; 53:292–299.