Scientists from Appalachian State University and the University of North Carolina at Greensboro also reported that two weeks of supplementation with a morning and mid-day serving led to significant decreases in some proteins involved in inflammation.
“Beet supplementation did not counter exercise-induced increases in pro-inflammatory oxylipins but did increase post-exercise levels of two anti-inflammatory EPA- and DHA-derived oxylipins,” they wrote in Frontiers in Nutrition.
“The strongest effect of beet supplementation was related to a significant decrease in a cluster of proteins involved in complement activation and inflammation. These data support that 2-weeks intake of a mixed beet-based supplement with morning and midday doses moderates protein biomarkers of exercise-induced inflammation in athletes.”
Growing interest
There has been increasing levels of interest in the potential benefits of beetroot juice for boosting athletic performance, particularly following a report in the Wall Street Journal that stated that the Auburn University football team drinks the juice before its games.
The majority of the science has supported the potential sports nutrition benefits of beetroot, linked to the nitrate concentration in the vegetable. Recent studies have reported significant benefits for a range of athletes, including swimmers and cyclists.
Nitrate is one of the dietary ingredients endorsed by World Athletics as being generally regarded as boosting performance, and there have been reports of sports teams around the world adopting beetroot juice as part of their nutrition strategies.
The beet supplements used in the new study were provided by Wisconsin-based Standard Process, which also funded the study. They were composed of powder from beets and fermented beets providing 106 mg of nitrates per serving, plus 100 mg of a green tea extract with caffeine, Camu Camu to provide 22 mg vitamin C, B vitamins from quinoa sprouts (thiamin, riboflavin, niacin and vitamin B6) and a mushroom blend of caterpillar fungus, lion’s mane and chaga.
Study details
Twenty middle-aged male and female cyclists were recruited to participate in the randomized, placebo-controlled, double-blind, crossover study. The cyclists were randomly assigned to consume the beet supplement or placebo for two weeks and then underwent a 2 hour and 15 mins cycling bout at about 70% VO2max. This was followed by a two-week washout period before they crossed over to the other group for a further two weeks and another cycling bout.
“This is the first exercise-based human clinical trial to investigate the influence of beet supplementation on inflammation using a human systems biology approach,” the researchers stated.
Data from multi-omics analysis that included untargeted proteomics and a targeted oxylipin panel showed that while the beet supplement did not impact pro-inflammatory oxylipins, a significant reduction in anti-inflammatory oxylipins was observed. Specifically, EPA-derived oxylipin 18-hydroxyeicosapentaenoic acid (18-HEPE) and the DHA-derived oxylipin 4-hydroxydocosahexaenoic acid (4-HDoHE) were significantly reduced compared to placebo.
In addition, the proteomic analysis revealed increases in 21 proteins and decreases in 45 proteins following beet supplementation compared to placebo.
“[The data] supported a linkage of beet supplementation with reduced complement activation and inflammatory responses, metabolic process and negative regulation of biological processes, and responses to stimulus, and an increased regulation of insulin-like growth factors (IGF) and uptake of IGF binding proteins, and symbiotic interactions,” the researchers reported.
Commenting on the need for additional studies to support these findings and advance the science, they noted that this study did not investigate the impact of different formulations or dosing approaches. They also called for future studies to evaluate if higher beet-nitrate intake over a longer time period will enhance these anti-inflammatory effects and impact pro-inflammatory oxylipins.
Source: Frontiers in Nutrition
Volume 11 - 2024 | doi: 10.3389/fnut.2024.1408804
“Beet supplementation mitigates post-exercise inflammation”
Authors: D.C. Nieman et al.