Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis

Abstract

Background: Musculoskeletal injuries are the most common complaint in active populations. More than 50% of all injuries in sports can be classified as sprains, strains, ruptures, or breaks of musculoskeletal tissues. Nutritional and/or exercise interventions that increase collagen synthesis and strengthen these tissues could have an important effect on injury rates.

Objective: This study was designed to determine whether gelatin supplementation could increase collagen synthesis.

Design: Eight healthy male subjects completed a randomized, double-blinded, crossover-design study in which they consumed either 5 or 15 g of vitamin C-enriched gelatin or a placebo control. After the initial drink, blood was taken every 30 min to determine amino acid content in the blood. A larger blood sample was taken before and 1 h after consumption of gelatin for treatment of engineered ligaments. One hour after the initial supplement, the subjects completed 6 min of rope-skipping to stimulate collagen synthesis. This pattern of supplementation was repeated 3 times/d with ≥6 h between exercise bouts for 3 d. Blood was drawn before and 4, 24, 48, and 72 h after the first exercise bout for determination of amino-terminal propeptide of collagen I content.

Results: Supplementation with increasing amounts of gelatin increased circulating glycine, proline, hydroxyproline, and hydroxylysine, peaking 1 h after the supplement was given. Engineered ligaments treated for 6 d with serum from samples collected before or 1 h after subjects consumed a placebo or 5 or 15 g gelatin showed increased collagen content and improved mechanics. Subjects who took 15 g gelatin 1 h before exercise showed double the amino-terminal propeptide of collagen I in their blood, indicating increased collagen synthesis.

Conclusion: These data suggest that adding gelatin to an intermittent exercise program improves collagen synthesis and could play a beneficial role in injury prevention and tissue repair. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12616001092482.

Keywords: bone; exercise; inury prevention; ligament; return to play; tendon.

FIGURE 1

Schematic timeline of the study. PINP, N-terminal peptide of pro-collagen I.

FIGURE 2

Amino acid concentration in the serum after ingestion of 5 or 15 g vitamin C–enriched gelatin or a placebo control. The amount of (A) glycine, (B) proline, (C) HyPro, (D) lysine, (E) HyLys, and (F) leucine in the blood was determined by HPLC by the University of California, Davis Proteomics Core. The data are presented as means ± SEMs for the 8 subjects who completed the crossover study. The 2-factor ANOVA (treatment and time) indicated a significant time effect for all amino acids tested (P < 0.001). The interaction effect is noted on each graph. Treatment effects are noted beside the group as part of the legend. *Significant treatment effect relative to the placebo, P < 0.05.^†Significant treatment effect relative to the 5-g group, P < 0.01. HyPro, hydroxyproline; HyLys, hydroxylysine.

FIGURE 3

Collagen concentration in engineered ligaments treated with PRE or serum isolated 1 h after ingestion of 5 or 15 g vitamin C–enriched gelatin or a placebo control. The (A) content of collagen and the (B) concentration of collagen (percentage of dry mass of the tissue) were determined after 6 d of treatment with media that were supplemented with 10% of the subject-derived serum. The data are presented as means ± SEMs for 6 constructs treated with the serum from a representative subject. These results were consistent with the use of serum from the 4 subjects who were tested by using this bioassay. *Significant difference from PRE, P < 0.05; ^ΨSignificant difference from placebo, P < 0.05. PRE, blood taken before supplementation.

FIGURE 4

Mechanics from engineered ligaments treated with PRE or serum isolated 1 h after ingestion of 5 or 15 g vitamin C–enriched gelatin or a placebo control. The (A) CSA of the engineered ligament as well as the (B) MTL, (C) modulus, and (D) UTS of the engineered ligaments were determined after 6 d of treatment with media that were supplemented with 10% of the subject-derived serum. The data are presented as means ± SEMs for 6 constructs treated with the serum from a representative subject. These results were consistent with the use of serum from the 4 subjects who were tested by using this bioassay. *Significant difference from blood before exercise, P < 0.05. CSA, cross-sectional area; MTL, maximal tensile load; PRE, blood taken before supplementation; UTS, ultimate tensile strength.

FIGURE 5

Collagen synthesis after exercise and ingestion of placebo or 5 or 15 g gelatin. (A) PINP concentration in the blood of subjects 4, 24, 48, and 72 h after the first exercise bout together with (B) the AUC for PINP concentrations from the placebo or 5- or 15-g gelatin groups. The data are presented as means ± SEMs for the 8 subjects who completed the crossover study. *Significant difference from placebo group, P < 0.05. ^†Significant treatment effect relative to the 5-g group, P < 0.01. PINP, N-terminal peptide of pro-collagen I.