Collagen is a structural protein in numerous tissues throughout your body and makes up about 30% of the total protein mass. There are many fibers that make up collagen and make it strong. Its key role is to make up the structure of skin and bones. Since 2014, online searches for collagen have increased steadily according to Google Trends. It has become one of the top-selling supplements on the market with claims of improving hair, skin, and nails being an attractive selling point.
Hydrolyzed collagen is what makes up the collagen supplements that you see on the market. Hydrolyzed just means the breaking down of a molecule with water. The molecules are shorter in length than undenatured proteins which allows them to be absorbed faster and more efficiently. It is also more soluble in water and that makes it more convenient to add to drinks.
There are opposing arguments against collagen supplementation that state that it has no benefit due to it being disposed of during the digestive process. Some will state that it is broken down into single amino acids and then digestion renders it unusable by the body. However, this doesn't appear to be the case. Collagen can be utilized by the body and gives credence to its usage in clinical trials.
The collagen you are getting in a supplement can be sourced from cattle, pigs, chickens, or from marine life. Small collagen peptides(short-chain amino acids) can increase fairly significantly in the bloodstream following ingestion. They are unique in that they are either 2 or 3 amino acids in length (di and tri-peptides). The three amino acids that make up collagen are glycine, proline, and hydroxyproline with vitamin C being required for the production of hydroxyproline. This is why a vitamin C deficiency can lead to skin diseases and bleeding gums. This is a manifestation of weak collagen.
Collagen peptides can be measured in the blood once they are ingested which leads us to believe that they do survive the digestive process. They are then distributed through the body particularly in the skin where, as shown in rat studies, they can stay in place for up to two weeks. Collagen peptides can also act as signaling molecules that bind to receptors on the surface of fibroblasts. Fibroblasts are skin cells that are major factories for collagen. This stimulates the production of collagen, elastin, and hyaluronic acid. Collagen peptides in the blood are a marker for collagen breakdown and act as a signal to the body that it needs to produce more collagen.
In this study in the International Journal of Dermatology, "19 studies were selected, with a total of 1,125 participants aged between 20 and 70 years (95% women). In the meta-analysis, a grouped analysis of studies showed favorable results of hydrolyzed collagen supplementation compared with placebo in terms of skin hydration, elasticity, and wrinkles. The findings of improved hydration and elasticity were also confirmed in the subgroup meta-analysis. Based on results, ingestion of hydrolyzed collagen for 90 days is effective in reducing skin aging, as it reduces wrinkles and improves skin elasticity and hydration." This is a nicely sized meta-analysis and I was actually surprised by the compelling evidence for collagen supplementation. This shows a clear benefit and there were no biases in the research and they were not funded by collagen supplement companies.
In one other study, 69 women aged 35-55 years were randomized to receive 2.5 g or 5.0 g of collagen supplement or placebo once daily for 8 weeks, with 23 subjects in each treatment group. At the conclusion of the study, skin elasticity in both collagen dosage groups showed a "statistically significant improvement in comparison to placebo. After 4 weeks of follow-up treatment, a statistically significantly higher skin elasticity level was determined in elderly women."
Research in the area of osteoarthritis and sports injury recovery is ongoing but thus far has looked promising. Some recommend them for soft tissue injury recovery. In this meta-analysis published in International Orthopaedics, the goal was to evaluate the effect of collagen-based supplements on osteoarthritis symptoms. The results indicated that collagen is effective in improving osteoarthritis symptoms which are often debilitating and the cause of disability and chronic disease.
Other areas to watch for collagen supplementation research include aiding in insulin sensitivity, lipid metabolism, and reducing high blood pressure in people with type II diabetes.
I have to admit that I have been extremely skeptical regarding the claims some health promoters have made regarding collagen. I simply needed to see solid evidence before I recommend a supplement or use one myself. In the case of collagen, the evidence is convincing and I have started adding a daily dose to my coffee in the morning as it is odorless and flavorless. I use one scoop of collagen peptides which gives me 10 grams. Have I noticed a difference in my skin and joints? I can honestly say that I do. I would expect results to vary amongst individuals but given the number of studies that are accessible and their promising results, I do recommend a collagen supplement for adults over 40.