A new study, which combined the results of various Italian studies, has reported that high consumption of foods containing flavones and flavonols is associated with reduced risk of breast cancer. Flavones and flavonols are micronutrients found primarily in vegetables and fruits. The analysis was designed to investigate the relationships between dietary intake of flavonoids and proanthocyanidins and risks of various types of cancer. The authors analyzed data from multiple Italian case-control studies including approximately 10,000 confirmed cases of certain cancers and more than 16,000 cancer-free controls. The level of intake of the various micronutrients was divided into five groups and the risk of cancer for the highest intake group was compared to the lowest level of consumption.

Total intakes of flavonoids, flavanones, and flavonols were found to be inversely related to oral and laryngeal cancers. Intake of flavanols was also found to be inversely related to laryngeal cancer, whereas intake of flavanones was inversely related to esophageal cancer. Reduced risk of colorectal cancer was associated with high intake of anthocyanidins, flavonols, flavones, and isoflavones. Inverse associations were also found between proanthocyanidins and colorectal cancer. Flavonols and isoflavones were found to be inversely associated with risk of ovarian cancer, whereas flavonols and flavones were inversely associated with renal cancer. No association between flavonoids and prostate cancer was found. An approximate 20% reduction in risk of breast cancer was found for high dietary intake of flavones and for high dietary intake of flavonols.