Older women who drank tea and ate other foods high in flavonoids had a lower risk of earlier mortality from cancer and cardiovascular disease, as well as any cause, found a recent study from Australia. The study was published in The American Journal of Clinical Nutrition.
This study adds to the research on how flavonoids impact cancer risk and morality, many of which have previously found no link. The study included approximately 1,000 randomly selected women over the age of 75. The women were part of a study related to fractures and at the start of the study in 2003, they had filled out questionnaires on what they ate.
Researchers used flavonoid content from the USDA and the Phenol-Explorer (PE) databases. Over the next five years, 129 of the women had died. Participants with highest total flavonoid intake were at approximately 40 percent lower risk of dying during the five years than those with the lowest levels. This was after adjusting for key risk factors for premature death, including obesity, inactivity, smoking and low fruit and vegetable intake.
The lower mortality with high flavonoid intake was also seen for cardiovascular disease and cancer. The majority of flavonoids came from drinking black tea, which supplied a class of flavonoids called flavonols. When focusing on the types of flavonoids, the tea-containing flavanols also showed lower risk when comparing those with the highest versus lowest intake.
Other types of flavonoids — from such foods as oranges and fruit juice — did not show a lower link. This lack of association between the other classes of flavonoids could be due to their low intake, the authors note. Although there were differences in flavonoid estimates between the databases, the links with mortality were generally similar.
Study authors were supported by Kidney Health Australia, Healthway Health Promotion Foundation of Western Australia, and Sir Charles Gairdner Hospital Research Advisory Committee and by the National Health and Medical Research Council of Australia.
Published on June 10, 2015