An international study in which UB experts participate highlights that resveratrol does not confer health benefits

Resveratrol is a polyphenol substance mainly found in grape-derived products like red wine. Photo: Lourdes Cardenal/Wikimedia Commons
Resveratrol is a polyphenol substance mainly found in grape-derived products like red wine. Photo: Lourdes Cardenal/Wikimedia Commons
Research
(22/05/2014)

An international study shows diets rich in resveratrol —a polyphenol substance found in red wine, dark chocolate and berries— do not reduce deaths, cardiovascular disease or cancer in older people. Cristina Andrés Lacueva and Mireia Urpí Sardà, lecturers from the Department of Nutrition and Bromatology of the University of Barcelona (UB) participated in the study. The paper, published in the journal JAMA Internal Medicine, underlines that polyphenol-rich food intake does not reduce mortality, unlike previous studies associated resveratrol with antioxidant, antiinflammatory and anticarcinogenic effects.

Resveratrol is a polyphenol substance mainly found in grape-derived products like red wine. Photo: Lourdes Cardenal/Wikimedia Commons
Resveratrol is a polyphenol substance mainly found in grape-derived products like red wine. Photo: Lourdes Cardenal/Wikimedia Commons
Research
22/05/2014

An international study shows diets rich in resveratrol —a polyphenol substance found in red wine, dark chocolate and berries— do not reduce deaths, cardiovascular disease or cancer in older people. Cristina Andrés Lacueva and Mireia Urpí Sardà, lecturers from the Department of Nutrition and Bromatology of the University of Barcelona (UB) participated in the study. The paper, published in the journal JAMA Internal Medicine, underlines that polyphenol-rich food intake does not reduce mortality, unlike previous studies associated resveratrol with antioxidant, antiinflammatory and anticarcinogenic effects.

Polyphenols are naturally occurring compounds found largely in fruits, vegetables, coffee, tea, nuts, legumes and cereals. The new study is observational and is part of the project InChianti. It is based on a 12-year follow-up of a population sample composed by 783 men and women aged 65 or over from Greve and Bagno (Tuscany, Italy). Participants were not assigned a particular diet, but red wine consumption is common in the area.

Researchers analysed 24 hours of urine samples to detect the levels of metabolites of resveratrol. “It is the first time that we can assess unequivocally diet resveratrol by measuring it in urine samples by means of mass spectrometric methods”, explains Cristina Andrés Lacueva, head of the Biomarkers and Nutritional & Food Metabolomics Research Group of UB. This methodology is more precise than eating habits surveys as it is not based on participantsʼ memory and it considers bioavailability and individual differences. The benefits of polyphenol-rich food intake —for example wine, chocolate or fruit— are not only due to the consumption of one of these food items, but to total consumption.

After taking into account other factors such as age and gender, people with higher urinary resveratrol metabolite concentrations presented the same mortality rates than those with lower urinary resveratrol levels. Resveratrol concentration was not either associated with markers of inflammation or a reduction of cardiovascular disease or cancer.

Despite results, previous studies proved that polyphenol-rich foods —for instance, red wine, dark chocolate and berries— reduce inflammation in some people and still appears to protect the heart. Richard D. Semaba, professor from the Johns Hopkins University School of Medicine (Unites States) and leader of the study, points out that “itʼs just that the benefits, if they are there, must come from other polyphenols or substances found in those foodstuffs”. “These —he adds— are complex foods, and all we really know from our study is that the benefits are probably not due to resveratrol”.

In fact, a previous study developed by the former UB research group associated high polyphenols intake with a 30% reduction in mortality in older adults.