Finnish researchers have found that berries are a rich source of the flavonoid quercetin, a plant antioxidant that may help to prevent cancer and heart disease. Dr Iris Erlund and colleagues at the country’s National Public Health Institute discovered that eating 100 grams a day of blackcurrants, lingonberries, and bilberries for eight weeks caused blood levels of quercetin to rise between 32% and 51%. The best source of quercetin is yellow or red onion, berries contain a little less, although many have higher levels than tea and red wine, which are often marketed as good sources of the health-boosting compound. However, not all berries are rich sources of quercetin, good sources include cranberries, lingonberries, bilberries, and blackcurrant – of these cranberries contain the highest levels and blackcurrant the lowest.
SOURCE/REFERENCE: European Journal of Clinical Nutrition 2003;57:37-42