Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis.
Level 2 - randomized trial
Individual randomized double-blind crossover trial
PubMed 27852613 · doi:10.3945/ajcn.116.138594
What was done
Eight healthy male subjects completed a randomized, double-blind, crossover trial consuming 5 g or 15 g of vitamin C-enriched gelatin or a placebo. Blood was sampled every 30 minutes to assess circulating amino acids, and larger samples collected before and 1 hour post-ingestion were applied to in vitro engineered ligaments for 6 days. One hour after supplement ingestion, subjects performed 6 minutes of rope-skipping, repeating this cycle 3 times daily (≥6 hours apart) for 3 days. Circulating amino-terminal propeptide of collagen I (PINP) was measured before and at 4, 24, 48, and 72 hours after the initial exercise bout.
What was found
Gelatin intake dose-dependently elevated circulating glycine, proline, hydroxyproline, and hydroxylysine, peaking at 1 hour post-ingestion. Engineered ligaments treated with serum collected 1 hour after 5 g or 15 g gelatin consumption showed increased collagen content and improved mechanical function. Ingesting 15 g gelatin 1 hour prior to exercise doubled circulating PINP levels compared to baseline. Exact numerical values, confidence intervals, and p-values were not provided in the abstract.
Why it matters
This study provides mechanistic evidence that pairing vitamin C-enriched gelatin ingestion with intermittent mechanical loading acutely enhances systemic collagen synthesis markers and tissue mechanics in vitro.
Limits
The trial had a very small sample size (n = 8) restricted to healthy young men. The abstract reports surrogate biochemical markers (PINP) and ex vivo bioengineered tissue responses rather than direct in vivo tendon/ligament collagen synthesis rates or clinical injury prevention outcomes.