Moving Beyond Nutrients-Tea Flavonoids and Human Health is it Time to Consider Food-Based Bioactive Guidelines?

Abstract

Flavonoids are a diverse group of natural compounds with flavan-3-ols being a predominant subgroup within these. Tea is one of the best sources of flavonoids and flavan-3-ols including the arubigins. Whilst flavonoids are not regarded as ‘essential’ to human health their bioactive properties influence health. Given this, there has been growing interest in the movement towards the development of dietary recommendations for bioactive compounds such as flavonoids in tea made from the leaves of Camellia sinens. In the United States the Academy of Nutrition and Dietetics in 2022 convened an expert scientific panel concluding that we should be moving towards a food-based dietary recommendation for flavan-3-ols, with 400- 600 mg/d appearing to confer cardiometabolic protection. Intakes from dietary surveys indicate that habitual intakes of flavanol-3-ols are variable, ranging from 33 mg/d (non-tea drinkers) to 698 mg/d (tea drinkers) and depend on the inclusion of dietary sources providing these such as tea and citrus fruits. Given this, the inclusion of such dietary sources may help to plug gaps between habitual intakes and these benchmarks thought to offer cardiometabolic protection. Ongoing research, uniformity of sub-classes of flavonoids measured and use of biomarkers will aid future movements towards food-based guidelines for bioactives.