Where do Australians get dietary flavonoids from?

Abstract

Introduction: Laboratory-based in vitro studies provide compelling evidence supporting the involvement of dietary flavonoid intake in risk of coronary heart disease and some cancers. Associations between intakes of individual flavonoids and disease outcomes at the population level are emerging from recent epidemiological studies. As an important step in the development of methods to assess flavonoid intakes across populations, the major sources of dietary flavonoids in the adult Australian population were identified. Methods: Data from a 24-hour diet recall questionnaire used in a national nutrition survey (NNS95- comprising a sample of 10851 subjects aged 19 years and over) were combined with USDA data on flavonoid content of foods to identify key sources. Results: Black and green teas clearly were the dominant sources of the flavonols kaempferol, myricetin and quercetin. Other significant flavonol sources included onion, broccoli, apple, grape, coffee and beans. Black and green teas also were dominant sources of flavon-3-ols, with wine, apples and pears contributing somewhat. In terms of flavanone consumption, oranges, lemon (eriodictyol), mandarin and grapefruit were the major sources. Parsley, celery and English spinach were the major flavone sources. Wine was the major anthocyanadin source with smaller amounts from cherry and blueberry. Conclusions: There is a risk that if the ubiquitous occurrence of flavonoids within vegetables and fruits is not acknowledged in nutrition promotion, then an important health promotion opportunity will be missed. Flavonoids represent an opportunity for a major shift in the way vegetables and fruits are promoted to populations with insufficient intake levels.