Dietary intake patterns and major sources of flavonoids in a representative sample of the Australian population
Background - Flavonoids are an important category of non-nutrient food components with antioxidant and other potentially significant biological properties. Evidence from laboratory-based in vitro studies provide compelling evidence supporting the involvement of dietary flavonoid intake in human chronic disease risk. However, studies on associations between intakes of individual flavonoids and disease outcomes at the population level are scarce. Objective - To identify patterns and sources of dietary intake of individual flavonoids in the Australian population. Design - Data from the 24-hour diet recall questionnaire of the national nutrition survey (NNS95- involving a representative sample of 10851 subjects) were combined with USDA data on flavonoid content of foods to identify consumption patterns and key sources. Outcomes - Black and green teas clearly were the dominant sources of the flavonols and flavon-3-ols. The largest flavonol sources comprised onion (isorhamnetin and quercetin), broccoli (kaempferol and quercetin), apple (quercetin), grape (quercetin), coffee (myrcetin) and beans (quercetin). Oranges (hesperetin and naringenin), lemon (eriodictyol), mandarin (hesperetin) and grapefruit (naringenin) were the major flavonone sources and parsley (apigenin), celery (apigenin and luteolin) and English spinach (luteolin) were the major flavone sources. Wine was the major anthocyanadin source (delphinidin, malvidin, peonidin and petunidin), with smaller amounts from cherry (pelargonidin and peonidin) and blueberry (delphinidin, malvidin, peonidin and petunidin). Conclusion - The major dietary flavonoid sources for Australian adults are restricted to a relatively small number of key foods. Inter-age variations in flavonoid intake are particularly pronounced for naringenin and some anthocyanins. The complexity of consumption patterns for individual flavonoids indicates that the promotion of foods on the basis of antioxidant content (as a general phenomenon) oversimplifies the issue and potentially understates the contribution that vegetables and fruits make to good health.
Proceedings of the Nutrition Society of Australia Annual General Meeting