High dietary intake of polyphenols linked with longevity
For the first time a high intake of natural polyphenols in whole foods has been associated with a substantial reduction in mortality in older adults. The new research from scientists in Italy and the US measured a 30 per cent reduction in mortality.
The study, published in June 2013 in the Journal of Nutrition, is the first to evaluate the total dietary polyphenol intake by using a nutritional biomarker and not only a food frequency questionnaire.
Dietary polyphenols improve health
Polyphenols are naturally occurring compounds found largely in fruits, vegetables, coffee, tea, nuts, legumes and cereals. More than 8,000 different phenolic compounds have been identified in plants. Polyphenols have antioxidant, anti-inflammatory, anticarcinogenic effects, as well as other health benefits.
The research is based on a 12-year follow-up of a population sample composed of 807 men and women aged 65 or over from Greve and Bagno in Tuscany, Italy, within the InCHIANTI study. The researchers analysed the effect of polyphenol-rich diets by means of a nutritional biomarker – the total urinary polyphenol (TUP) concentration – as a proxy measure of intake.
The study found that overall mortality was reduced by 30 per cent in participants who had rich-polyphenol diets (greater than 650mg per day) compared with the participants who had low-polyphenol intakes (less than 500mg per day).
“Results corroborate scientific evidence suggesting that people consuming diets rich in fruit and vegetable lower the risk of several chronic diseases and overall mortality,” said Raul Zamora Ros, first author of the study.
New biomarkers for nutritional studies
Moreover, researchers said the study stressed the importance of evaluating food intake by using nutritional biomarkers, not only food frequency questionnaires. The researchers said the development of new nutritional biomarkers enables a more precise and objective estimation of intake than food frequency questionnaires.
“Nutritional biomarkers take into account bioavailability and individual differences,” said Professor Cristina Andrews Lacueva, Head of the Biomarkers and Nutritional and Food Metabolics Research Group of the University of Barcelona and co-ordinator of the study. “This methodology makes a more reliable and accurate evaluation of the association between food intake and mortality or disease risk,” she said.
The Biomarkers and Nutritional and Food Metabolics Research Group, which participates in the project Fun-C-Food (Consolider Ingenion), collaborates actively with several international research groups. It focuses its activity on the analysis of new more effective and sensitive nutritional biomarkers based on the bioavailability of bioactive compounds in food and their activity in order o associate the intake of certain foods with their potential effects on people’s health.
The research was undertaken by Cristina Andrés Lacueva, Montserrat Rabassa and Mireia Urpí Sardà, from the Department of Nutrition and Bromatology of the UB; Raúl Zamora Ros (ICO-IDIBELL), and experts Antonio Cherubini (Italian National Research Centre on Aging), Stefania Bandinelli (Azienda Sanitaria di Firenze, Italy) and Luigi Ferrucci (National Institute on Ageing, United States).