Researchers from the United Kingdom and the United States have looked at more than 170,000 people to examine the impact of flavonoids on ovarian cancer risk.
Aedín Cassidy, Tianyi Huang, Megan S. Rice, Eric B. Rimm and Shelley S. Tworoger drew their information from participants in the Nurses’ Health Study and Nurses’ Health Study II. These researchers are affiliated with Norwich Medical School’s Department of Nutrition (UK), Harvard School of Public Health, Brigham and Women’s Hospital of Boston, Mass. and Harvard Medical School. There were 171,940 study subjects between the ages of 25 and 55. These participants were issued “food-frequency questionnaires” every four years and that data was analyzed to calculate not only their total flavonoid intake, but also their consumption of subclasses of flavonoids like flavanones, flavonols and anthocyanins. These results were cross-referenced with the risk of developing ovarian cancer.
The study lasted for 22 years and 723 of the subjects were reported through medical records to have been diagnosed with ovarian cancer. Analyses showed no statistically significant effect of total flavonoid consumption on ovarian cancer risk. Interestingly, the participants that had the highest intake of the flavonoid subgroups of flavonols and flavanones had slightly lower risk of the cancer than those who consumed the smallest amount of these subgroups. The researchers found that consumption of black tea, with its high flavonol content, was correlated with these lower ovarian cancer rates. According to an , researcher Cassidy reported that drinking a few cups of black tea daily was linked with a 31% reduction in risk of ovarian cancer.