Assessment of Phenolic Compound Intake from Plant-Derived Products in Adolescents from Ontario, Canada

Purpose: To better understand which plant-derived products contribute to the usual daily total polyphenol content (TPC) intake of Canadian adolescents. Methods: A convenience sample from 2 southwestern Ontario high schools was obtained (n = 108). Students of all gender and ethnicity were invited to participate if they were enrolled in grades 9-12 and were between the ages of 13 and 18 years. To measure the usual intake of TPC found in fruits, vegetables, fruit juices, nuts and legumes, tea, and coffee and coffee-based beverages, participants completed a food frequency questionnaire. TPC of the tea, coffee and coffee-based beverages, and fruit juices were determined spectrophotometrically, and the TPC of all other food items were calculated using the Phenol-Explorer Database. Results: Participants' median consumption of TPC was 974 mg/day (25th, 75th percentile; 559, 2161, respectively). Fruit contributed 69% to TPC intake with 24% from vegetables; 3% from juice; 2% from tea, coffee, and coffee-based beverages; and 0% from nuts and pulses. No sex differences were found. Conclusion: The results of this exploratory study suggest that fruit is the major contributor to the daily TPC intake of adolescents in Ontario, Canada; however, a larger-scale study is warranted to confirm these findings.