2013-09-05 08:39:38 - NC Research Campus scientists are the first to find in a human trial that after exercise there is a 14-hour spike in polyphenolic metabolism and polyphenol absorption into the blood is enhanced through the colon not the small intestine.
The paper, Influence of a Polyphenol-Enriched Protein Powder on Exercise-Induced Inflammation and Oxidative Stress in Athletes: A Randomized Trial Using a Metabolomics Approach, was published in PlosOne on August 15, 2013. The lead author is David Nieman, DrPH, FACSM, director of the Appalachian State University (ASU) Human Performance Laboratory and co-authors are Mary Ann Lila, PhD, director of the North Carolina State University Plants for Human Health Institute (PHHI) and Nicholas Gillitt, PhD, director of nutrition research for Dole Food Company.
Polyphenols are a class of bioactive compounds in fruits and vegetables that are linked to numerous health benefits such as lowering blood pressure and blood glucose, reducing inflammation and fighting off the damaging effects of free radicals.
The study tested polyphenol
supplementation as a countermeasure to inflammation and oxidative stress. Long-distance runners were given either a soy protein complex infused with polyphenols from blueberries and green tea or just the protein complex. The runners ingested the soy protein complex for two weeks and during three days of running for two-and-a-half hours each day. Each dose was the equivalent of consuming three cups of blueberries and just over a cup of brewed green tea.
One finding of the study was that the runners in the treatment group had a polyphenolic signature in their blood that was characteristic of gut microbial metabolism of berry and green tea polyphenols.
The finding is relevant, Nieman said, because combining polyphenol intake with exercise not only increases gut permeability and allows more polyphenols into the body, the specific polyphenols that were found are known to have anti-oxidant and anti-inflammatory effects.
An equally significant finding was that the runners in the treatment group showed a longer spike in their metabolism after exercise. They basically burned fat in their sleep, Lila explained, which was evidenced by the level of fatty acid oxidation and ketogenesis with more ketones at 14 hours post exercise in the treatment group. The placebo group went back to normal levels.
Ketogenesis is the production of biochemicals called ketones from the breakdown of fatty acids in the liver that provide energy to the body, especially the heart and brain.
The findings support the consumption of fruits and vegetables before and after exercise and will lead to additional collaborative studies between the study authors.