Just on the day Ireland confirms its unpopular decision to put health alerts on wine labels, an American study throws water on the fire. More: the survey indicates a series of foods and beverages containing a reasonable amount of flavonoids, a class of polyphenols with significantly positive effects on health.

The research, called "Change in habitual intakes of flavonoid-rich foods and mortality in US males and females - PubMed" includes in its group of authors, international scientists of great prestige, first of all Walter Willett, an epidemiologist at the Harvard School of Public Health of Boston, one of the most important researchers in the world on nutrition and health. The research examines a very large sample of US subjects (55,786 women and 29,800 men), middle-aged and without chronic diseases as a starting point. We evaluated the associations between changes in intake of highly flavonoid-rich foods and mortality. A score, called "flavodiet", was also defined, based on the global intake share of foods and beverages that are known to be major contributors to flavonoid intake. Flavonoids are a class of polyphenols important for their very positive biological effects on health. Although nearly all plant-based foods contain flavonoids, some contain exceptionally high concentrations.

For red wine, this study shows a 4% lower risk of mortality for each increase in intake of 3.5 glasses per week. The increase of 3.5 portions per week also demonstrates a significant reduction in mortality for blueberries and peppers (5%, 9% respectively). Furthermore, increasing one cup of tea per day leads to a 3% reduction in mortality. On the other hand, equally positive effects were not observed with other foods rich in polyphenols such as apples, dark chocolate and citrus fruits. When instead the "flavodiet" score is considered, it has been shown that an increase of three portions per day in the intake of foods rich in flavonoids (for example a cup of tea, a serving of blueberries and a glass of red wine) leads to a 8% reduction in mortality risk.

The study authors therefore conclude that encouraging increased intake of specific flavonoid-rich foods and beverages in middle-aged males and females may reduce the risk of early mortality.