Metabolic fate of strawberry polyphenols after chronic intake in healthy older adults

Food Funct. 2018 Jan 24;9(1):96-106. doi: 10.1039/c7fo01843f.

Abstract

Strawberries contain a wide array of nutrients and phytochemicals including polyphenols such as anthocyanins, proanthocyanidins and ellagitannins. These polyphenols are absorbed and metabolized to various phenolic metabolites/conjugates in the body, which may play a role in disease risk reduction. In the present study, we investigated the metabolic fate of strawberry polyphenols after chronic (90 days) supplementation of freeze-dried strawberry (24 g d-1, equivalent to 2 cups of fresh strawberries) vs. control powder in 19 healthy older adults. Blood samples were collected at two time-points i.e., fasting (t = 0 h) and 2 h after the breakfast meal. On days 45 and 90 breakfast also included a control or strawberry drink consistent with their treatment randomization. A total of 21 polyphenolic metabolites were quantified in plasma consisting of 3 anthocyanins/metabolites, 3 urolithin metabolites and 15 phenolic acid metabolites. Among anthocyanins/metabolite, pelargonidin glucuronide (85.7 ± 9.0 nmol L-1, t = 2 h, day 90) was present in the highest concentration. Persistent concentrations of anthocyanins/metabolites, urolithins and some phenolic acids were observed in fasting (t = 0 h) plasma samples on day 45 and 90 after strawberry drink consumption suggesting a role of enteric, enterohepatic recycling or upregulation of gut microbial and/or human metabolism of these compounds. Our results suggest that strawberry polyphenols are absorbed and extensively metabolized, and can persist in the circulation.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Fasting / blood
  • Female
  • Fragaria / chemistry
  • Fragaria / metabolism*
  • Fruit / chemistry
  • Fruit / metabolism
  • Humans
  • Male
  • Middle Aged
  • Plant Extracts / blood
  • Plant Extracts / metabolism*
  • Polyphenols / blood
  • Polyphenols / metabolism*

Substances

  • Plant Extracts
  • Polyphenols