Dietary intake of 20 polyphenol subclasses in a cohort of UK women

Background: Establishing and linking the proposed health benefits of dietary polyphenols to their consumption requires measurement of polyphenol intake in appropriate samples and an understanding of factors that influence their intake in the general population. Methods: This study examined polyphenol intake estimated from 3- and 7-day food diaries in a sample of 246 UK women aged 18–50 years. Estimation of the intake of 20 polyphenol subclasses commonly present in foods consumed by the sample studied was done using Phenol-Explorer^® and USDA polyphenol databases. Women were participants in the Leeds Women’s Wellbeing Study (LWW) (n = 143), a dietary intervention study aimed at overweight women (mean age 37.2 ± 9.4 years; mean BMI 30.8 ± 3.1 kg/m²), and the Diet and Health Study (DH) (n = 103) which aimed to examine the relationship between polyphenol intake and cognitive function (mean age 25.0 ± 9.0 years; mean BMI 24.5 ± 4.6 kg/m²). Results: The estimated intake of polyphenol subclasses was significantly different between the two samples (p < 0.01) with consumption of 1292 ± 844 and 808 ± 680 mg/day for the LWW and DH groups, respectively. Flavanols and hydroxycinnamic acids were the most important contributors to the polyphenols consumed by both groups, owing to tea and coffee consumption. Other major polyphenol food sources included fruits, vegetables and processed foods. Conclusion: Older women consumed more polyphenol-containing foods and beverages, which was due to the higher coffee and tea consumption amongst the LWW participants.