Using a randomized, crossover-design protocol, the researchers tested their hypothesis that consuming vitamin C with gelatin, a food derivative of collagen, combined with exercise could increase collagen synthesis.
In a previous study, the researchers developed a tissue-engineered model that mimics the developing tissue to better understand tendon and ligament biology. They found that the presence of ascorbic acid in these engineered tissues, together with the amino acid proline, can increase collagen production, showing improvement of mechanics in the Achilles tendons after injury.
“[This] suggests that a nutritional intervention that increases amino acid components of collagen and the co-factor vitamin C may improve collagen synthesis,” the researchers wrote in their study, published in the American Journal of Clinical Nutrition.
Study design: Supplementation, blood drawing, resting, and exercising
The study was supported by grants from the National Institute on Aging project, the University of California, Davis, and the Australian Institute of Sport. The nutritional supplements used in the study included gelatin from Ward McKenzie Pty Ltd., vitamin C concentrates from Lucozade Ribena Suntory Limited, and maltodextrin by Polyjoule as the placebo.
Eight healthy, recreationally active young men (mean age 27), arrived at the laboratory after an overnight fast for the researchers to collect baseline blood samples. Participants were then immediately provided with the isocaloric study beverage containing either the placebo, 5g, or 15g gelatin dissolved in the flavored low-calorie beverage with 48 mg vitamin C.
Participants rested one hour after ingesting the supplement. In this period, two blood samples were taken—within 30 minutes of ingestion and after the hour was over—to determine amino-terminal propeptide of collagen I content. Afterwards, participants completed six minutes of continuous rope skipping to load the musculoskeletal system.
Then, participants remained in the laboratory in a rested state for the subsequent four hours during which time four more blood samples were collected. After the last blood sample was drawn, the cannula was removed, and subjects were allowed to leave the laboratory.
On departure, they were provided with a skipping rope and instructed to complete a further three sessions per day of six minutes of continuous skipping with a minimum of six hours between each bout of exercise. The subjects ingested their supplement, which was provided in a blinded manner, one hour before each rope-skipping session. Participants returned 24 hours, 48 hours, and 72 hours after the initial visit for in lab exercises and more blood drawing.
Researchers used engineered ligaments from a male donor and treated it for six days with experimental media containing blood taken before supplementation or one hour after consuming the supplement with the varying levels of gelatin.
Observations
Researchers found that supplementation with increasing amounts of gelatin increased circulating glycine, proline, hydroxyproline, and hydroxylysine, peaking one hour after the supplement was given.
Engineered ligaments treated for six days with serum from samples collected before or one hour after subjects consumed a placebo or 5 or 15 g gelatin showed increased collagen content and improved mechanics. Subjects who took 15 g gelatin one hour before exercise showed double the amino-terminal propeptide of collagen I in their blood, indicating increased collagen synthesis.
“The current study demonstrates for the first time that consuming a gelatin and vitamin C–rich supplement increases the appearance of the amino acid components of collagen within human serum,” the researchers wrote.
A second interesting finding, according to the researchers, was that the engineered ligaments showed an “increase in mechanics in all of the supplement groups, although the collagen content of the constructs only increased in the gelatin supplemented groups.”
The Ribena drink used in this study was selected because it is naturally enriched with vitamin C. Although the researchers did not measure vitamin C concentrations in the serum, they wrote “it is possible that this component of the supplement had a positive effect on engineered ligament mechanics. Vitamin C is required for collagen synthesis.”
They added: “These data suggest that adding gelatin and vitamin C to an intermittent exercise program could play a beneficial role in injury prevention and tissue repair.”
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.116.138594.
Vitamin C–enriched gelatin supplementation before intermittent activity augments collagen synthesis
Authors: Gregory Shaw, Ann Lee-Banthel, Megan LR Ross, Bing Wang, Keith Baar