Written by Joyce Smith, BS. A two-week supplementation of flavonoids significantly increased plasma levels of circulating gut-derived polyphenols in exercising participants.
Only small amounts of dietary flavonoids are absorbed in the small intestine. 1 The majority remain unabsorbed and undergo microbial degradation to form diverse phenolic compounds which can then be absorbed to provide a variety of bioactive effects before elimination in the urine. A previous study by the authors demonstrated how a polyphenol-enriched protein powder significantly increased the translocation of gut-derived phenolics into the blood of athletes to mitigate the effects if exercise-induced inflammation and oxidative stress. 2 Other studies have suggested that exercise may induce a transient increase in gut permeability which accelerates the transport of gut-derived phenolics from the lower intestine to the blood. 3 Collectively, the existing limited data suggest that acute and chronic exercise may influence plasma levels of gut-derived phenolics.
Researchers, 4 investigating the existing date, hypothesized that 45-minutes of brisk walking (60% VO2max) following two weeks of increased polyphenol intake would be a sufficient exercise stimulus to increase gut permeability and the movement of gut-derived phenolics into the blood circulation. If the hypothesis was confirmed, data would demonstrate that the combination of brisk walking and increased polyphenol intake increases circulating levels of health-restoring small phenolic molecules derived from bacterial breakdown in the colon.
Seventy-seven healthy regular walkers were randomized to either sit or walk briskly on treadmills for 45 min (62.2 ± 0.9% VO2max), comprising four groups: placebo–sit, placebo–walk, flavonoid–sit, flavonoid–walk). The 329mg daily flavonoid capsules contained vitamin C, wild bilberry fruit extract, green tea leaf extract, quercetin, caffeine, and omega-3 fatty acids. A comparator group of runners (n = 19) ingested a double flavonoid dose for two weeks (658 mg/day) and ran for 2.5 h (69.2 ± 1.2% VO2max).
The primary goal was to investigate whether the combination of a 2-week supplementation of polyphenols and a 45-minute brisk walk would increase the translocation of gut-derived phenolics into the circulation. Additional analysis, extending the data from the previous 12-week community trial, would be done to determine if 2 weeks of flavonoid supplementation would be adequate time to increase circulating levels of gut-derived phenolics.
Data revealed that for both the 77 walkers and the 19 runners, the combination of 2-week flavonoid supplementation and exercise (45 minutes of brisk walking and 2.5 hours of running) increased the translocation of gut-derived phenolics into the circulation. The baseline plasma concentration of the 76 detected gut-derived phenolic metabolites was 40% higher in the runners than in the walkers (p<0.001), revealing an association between elevated fitness status and elevated plasma levels of gut-derived phenolics.
A study limitation was the rigorous hours of running which is difficult to translate to general populations. However, diet-relevant doses of flavonoids were used and showed that gut-derived phenolics circulate at higher levels throughout the body following flavonoid supplementation and exercise, potentially improving long-term health and reducing the risk for chronic disease. 1,5
Source: Nieman, David, Colin Kay, Atul Rathore, Mary Grace, Renee Strauch, Ella Stephan, Camila Sakaguchi, and Mary Lila. “Increased Plasma Levels of Gut-Derived Phenolics Linked to Walking and Running Following Two Weeks of Flavonoid Supplementation.” Nutrients 10, no. 11 (2018): 1718.
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
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Posted April 29, 2019.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
References:
- Williamson G, Kay CD, Crozier A. The bioavailability, transport, and bioactivity of dietary flavonoids: A review from a historical perspective. Comprehensive Reviews in Food Science and Food Safety. 2018;17(5):1054-1112.
- Nieman DC, Gillitt ND, Knab AM, et al. Influence of a polyphenol-enriched protein powder on exercise-induced inflammation and oxidative stress in athletes: a randomized trial using a metabolomics approach. PLoS One. 2013;8(8):e72215.
- Medina S, Dominguez-Perles R, Garcia-Viguera C, et al. Physical activity increases the bioavailability of flavanones after dietary aronia-citrus juice intake in triathletes. Food Chem. 2012;135(4):2133-2137.
- Nieman DC, Kay CD, Rathore AS, et al. Increased Plasma Levels of Gut-Derived Phenolics Linked to Walking and Running Following Two Weeks of Flavonoid Supplementation. Nutrients. 2018;10(11).
- Warner EF, Smith MJ, Zhang Q, et al. Signatures of anthocyanin metabolites identified in humans inhibit biomarkers of vascular inflammation in human endothelial cells. Molecular nutrition & food research. 2017;61(9).
