Collagen supplements are advertised to make you look younger, relieve joint pain, and stimulate hair and nail growth. However, many experts doubt their efficacy due to the relative instability of collagen molecules and their size.
A substantial portion of ingested collagen is thought to be degraded in the stomach. In addition, intact collagen molecules are far too large to be effectively and efficiently absorbed in our GI tract.
Furthermore, many are skeptical of the quality of supportive studies as most of them are manufacturer-funded. Not to mention the fact that many studies have used animal models, instead of human models. The doubt is further fueled by the inability of the studies to elucidate the exact mechanisms by which these supplements might work.
Nevertheless, some scientific studies suggest oral collagen supplements can improve the skin texture and increase skin elasticity, both of which may help reduce the visible signs of aging. In addition, some studies also suggest taking oral hydrolyzed type 1 collagen daily can reduce inflammation and relieve the symptoms of osteoarthritis.
Below, we take a closer look at the scientific evidence that supports the potential benefits of oral collagen supplements.
Why Oral Collagen Supplements May (or May Not) be the Fountain of Youth
Researchers believe that the collagen supplement might stimulate the body’s natural collagen production mechanisms and hence confer the benefits. Below we discuss many of the studies that have looked at the potential benefits of collagen.
- According to a 2012 pilot open-label study, daily supplementation with BioCell Collagen® for 12 weeks resulted in a significant reduction of skin dryness. However, the study results cannot be considered conclusive because it was a preliminary study and did not include the control group.
- A 2013 study examined the effect of oral collagen supplement VERISOL® on women aged 45-65 years. After 8 weeks of investigation, the researchers concluded that VERISOL® was effective in reducing skin dryness and promoting skin elasticity.
- In 2014, another study found that the supplement Pure Gold Collagen® was effective in reducing the signs of aging. The researchers noted that collagen type 1 (present in the supplement) improved skin elasticity and helped the skin stay hydrated. However, this was an open-label study and hence we cannot jump to any conclusion due to the risk of bias.
- In the same year, a study published in the Journal of Skin Pharmacology and Physiology revealed that oral collagen hydrolysate could help improve skin elasticity and moisture content of the skin. Most notably, this was a double blind, placebo-controlled trial, which means the risk of bias, is low. However, the number of participants in the study is not enough to draw any conclusion.
The Absorption of Ingested Collagen from the Stomach
Most of ingested collagen cannot survive the harsh environment in the stomach. In addition, collagen is a large molecule that cannot be absorbed by the large intestines.
For an orally administered drug/supplement to be effective, a substantial portion of it should cross the intestinal barriers, reach the bloodstream and then the sites of action.
While collagen is far to be large to be absorbed intact, our stomach and GI tract breaks the molecule down into smaller components, which are then absorbed. However, there is a large portion of collagen that goes absorbed when simply ingesting unaltered collagen.
According to a study published in the Journal of Agricultural and Food Chemistry, the relative and absolute bioavailability of ingested collagen are 57.8% and 49.6%, respectively. This means that approximately half of the ingested collagen survives degradation in the stomach. Note that this study used rat models, not human subjects.
One way for collagen supplements to be more completely absorbed is to "hydrolyze" them. For a collagen supplement to be properly absorbed, it needs to be broken into smaller components, which is what is done with "hydrolyzed" collagen products. Hydrolyzed collagen molecules are small enough to be absorbed into the bloodstream. Hydrolyzed collagen is sometimes referred to as "collagen peptides".
Various studies have shown that hydrolyzed collagen is absorbed in clinically sufficient amounts to produce effects on the body. In fact, one animal study, showed that over 90% of hydrolyzed collagen was absorbed within 6 hours of ingesting and had measurable accumulations in both the cartilage and skin.
The Bottom Line
- Evidence points to our bodies being able to absorb hydrolyzed collagen to a significant extent.
- While more studies are needed, preliminary evidence suggests that collagen supplements can be effective for improving skin elasticity and improving moisture retention.