Gelatin + vitamin C + exercise = joint benefits?

The collagen-rich extracellular matrix^[1] may be among the most underappreciated parts of the musculoskeletal system. It is required for proper functioning of the tendons, ligaments, cartilage, skin, and bone. For this matrix to function, an adequate amount of collagen and collagen crosslinking, along with water and minerals inside the tissue, is needed. Nutritional inadequacy^[2] and disease^[3] states can weaken connective tissue and leave it prone to breaking down from normal mechanical demands such as walking and even moderate exercise. In contrast, adequate nutrition^[4] and exercise^[5] are able to improve the functioning of the extracellular matrix, and collagen synthesis can be increased by an acute bout of exercise^[6]. The purpose for increasing collagen synthesis is to create denser and stiffer^[7] tissue, which can withstand higher loads^[8].

In vitro studies from engineered models of tendons and ligaments have shown that the presence of vitamin C and the amino acid proline can increase collagen production^[9] (shown in Figure 1), while increasing the amino acid glycine can improve tendon recovery from inflammation and make tendons more resistant to rupture. Up until this point, the combination of nutritional intervention and acute exercise bouts have not been studied with regard to their synergistic effects on collagen synthesis. With this in mind, researchers set up a study in humans to determine if consuming gelatin (a food derived from collagen and rich in proline and glycine) and vitamin C combined with exercise could increase collagen synthesis in healthy adult males.

Figure 1: Vitamin C's role in collagen structure and function

Reference: Shoulders et al. Annu Rev Biochem. 2009.

A collagen-rich extracellular matrix is a critical part of a healthy musculoskeletal system. In addition to exercise, nutritional components such as vitamin C and the amino acids proline and glycine also play a role in collagen synthesis. This study was setup to determine whether gelatin supplementation (rich in proline and glycine) with vitamin C could increase collagen synthesis when taken before an acute bout of exercise.