Estimated intake and major food sources of flavonoids among Australian adolescents

Purpose: The consumption of dietary favonoids from plant-based foods has been related to the prevention of multiple chronic diseases. However, intake data from adolescents are lacking. We aimed to characterise the intake and major sources of dietary favonoids among Australian adolescents and investigate changes during adolescence. Methods: The Raine Study Gen 2 participants completed a 212-item food frequency questionnaire at age 14 years and 17 years, with repeated measures for n=883. Items were assigned a content for six favonoid subclasses using the PhenolExplorer database, which were summed for total favonoid intake. Daily intakes and sources of favonoids and flavonoid-subclasses were determined, and change assessed between 14 and 17 years, for males and females. Results: Major food sources of favonoids and each subclass were similar at 14 and 17 years, with fruit juice the major contributor to total favonoid intake at both time points (providing 44% and 38%, respectively). Citrus favanones (predominantly hesperitin) were the major subclass at 14 years, while tea favan-3-ols were a major subclass (predominantly procyanidin dimers) at 17 years. The mean intake of total favonoids at 14 years was 210±133 mg/day, reducing by 5% (10 mg/day) by 17 years. Females consumed a more favonoid-dense diet compared to males (104.5±71.5 mg/1000 kcal vs 80.4±50.3 mg/1000 kcal per day; p<0.001). Conclusion: This study provides a comprehensive estimation of favonoid intake and their major food sources in a sample of Australian adolescents, which may be useful in the development of practical dietary recommendations.