Like so many supplements today, collagen is touted as something to improve hair, skin, and nails. Many of this products are a combination of the various types of collagen including Types I, II, and III. These supplements are recommended at about 20 grams of collagen per day to be taken orally. They exist in pill and powder form. Many remark about the very fishy or horrible aftertaste. Some cannot even get the 20 grams of collagen down.
For those who do, there are anecdotal reports of improvement in the hair, skin, and nails. The real question is does ingesting collagen into the GI tract translate into the fully synthesized collagen fibrils within the human body – within the skin, within the muscles, etc. Collagen is digested down into much smaller subunits in the GI tract. The body must then take those smaller units and then synthesize collagen. Some will provide the collagen with Vitamin C as that is essential to the process as well.
However, there is nothing special about the amino acids in collagen and your body already gets those amino acids through the diet or can be synthesized in other ways. Where are the studies that illustrate that ingestion of collagen orally results in the creation of increased collagen throughout the body to restore skin, connective tissues, and muscle? There are a few small participant studies that link collagen ingestion to increased muscle potentiation of one sort or another as well as improvements in skin. However, these are small samples and certainly do not address all of the claims made by supplement companies and manufacturers.
One recent study reviewed fifteen randomized controlled trials were selected after screening 856 articles. The study populations included 12 studies in recreational athletes, 2 studies in elderly participants and 1 in untrained pre-menopausal women. Study outcomes were categorized into four topics: (i) joint pain and recovery from joint injuries, (ii) body composition, (iii) muscle soreness and recovery from exercise, and (iv) muscle protein synthesis (MPS) and collagen synthesis. The results indicated that COL is most beneficial in improving joint functionality and reducing joint pain. Certain improvements in body composition, strength and muscle recovery were present. Collagen synthesis rates were elevated with 15 g/day COL but did not have a significant impact on MPS when compared to higher quality protein sources.
Another study gave the experimental group 2.5 g of collagen peptides, acerola fruit extract, vitamin C, zinc, biotin, and a native vitamin E complex. This controlled trial was performed on 72 healthy women aged 35 years or older. They received either the food supplement (n = 36) or a placebo (n = 36) for twelve weeks. A skin assessment was carried out and based on objective validated methods, including corneometry (skin hydration), cutometry (elasticity), the use of silicon skin replicas with optical 3D phase-shift rapid in-vivo measurements (PRIMOS) (roughness), and skin sonography (density). The test product significantly improved skin hydration, elasticity, roughness, and density.