Collagen is a fibrillar protein of the conjunctive and connective tissues in the human body, essentially skin, joints, and bones. Due to its abundance in our bodies, its strength and its relation with skin aging, collagen has gained great interest as an oral dietary supplement as well as an ingredient in cosmetics. Collagen fibres get damaged with the pass of time, losing thickness and strength which has been linked to skin aging phenomena. Collagen can be obtained from natural sources such as plants and animals or by recombinant protein production systems. Because of its increased use, the collagen market is worth billions. The question therefore arises: is it worth it?
This 2019 systematic review assessed all available randomized-controlled trials using collagen supplementation for treatment efficacy regarding skin quality, anti-aging benefits, and potential application in medical dermatology. Eleven studies with a total of 805 patients were included. Eight studies used collagen hydrolysate, 2.5g/d to 10g/d, for 8 to 24 weeks, for the treatment of pressure ulcers, xerosis, skin aging, and cellulite. Two studies used collagen tripeptide, 3g/d for 4 to 12 weeks, with notable improvement in skin elasticity and hydration. Lastly, one study using collagen dipeptide suggested anti-aging efficacy is proportionate to collagen dipeptide content.
The authors concluded that preliminary results are promising for the short and long-term use of oral collagen supplements for wound healing and skin aging. Oral collagen supplements also increase skin elasticity, hydration, and dermal collagen density. Collagen supplementation is generally safe with no reported adverse events. Further studies are needed to elucidate medical use in skin barrier diseases such as atopic dermatitis and to determine optimal dosing regimens.
These conclusions are similar to those of a similar but smaller review of 2015 which concluded that the oral supplementation with collagen peptides is efficacious to improve hallmarks of skin aging.
And what about the many other claims that are currently being made for oral collagen?
A 2006 review of collagen for osteoarthritis concluded that a growing body of evidence provides a rationale for the use of collagen hydrolysate for patients with OA. It is hoped that ongoing and future research will clarify how collagen hydrolysate provides its clinical effects and determine which populations are most appropriate for treatment with this supplement. For other indication, the evidence seems less conclusive.
So, what should we make of this collective evidence. My interpretation is that, of course, there are caveats. For instance, most studies are small and not as rigorous as one would hope. But the existing evidence is nevertheless intriguing (and much more compelling than that for most other supplements). Moreover, there seem to be very few adverse effects with oral usage (don’t inject the stuff for cosmetic purposes, as often recommended!). Therefore, I feel that collagen might be one of the few dietary supplements worth keeping an eye on.