Flavonoids may protect against chronic disease

In a new study from Finland, researchers have found that people who have a high intake of the plant compounds flavonoids are less likely to die from heart disease or develop some cancers or other chronic diseases.

Researchers studied the diets of more than 10,000 men and women and found that those who ate fruits and vegetables rich in different flavonoids had a lower risk of overall mortality and of several chronic diseases.

Flavonoids are antioxidants found in a variety of fruits and vegetables and also in tea and red wine. Scientists believe that they fight free radicals associated with the onset of heart disease, stroke and several other diseases. The researchers said that apples had the most positive benefits.

The study was based on a questionnaire and an interview with each participant to find out what they had eaten during the previous year. The team then estimated the flavonoid intake of each individual after looking at their diets, and followed the development of disease in the participants for up to 28 years after the initial interview.

The Finnish team conclude that the risk of several chronic diseases, including heart disease, stroke, lung and prostate cancer, type 2 diabetes and asthma, falls as the consumption of flavonoids rises.

Out of many different flavonoids available in the diet, quercetin, found in high quantities in apples, was the most powerful, although kaempferol found in onions, was also linked to a reduced risk of mortality from heart disease. The researchers said that the risk of stroke was 30 per cent lower in people who ate the most kaempferol than in those who ate the least.

High levels of quercetin were linked to lower risks of lung cancer and prostate cancer and the flavonoid also seemed to provide some protection against type 2 diabetes.

The researchers suggested that further research on people who eat different types of flavonoid-rich foods should now be carried out.