WOULD YOU pay £40 ($53) for some powder made from the ground-up, chemically processed skin, bones and connective tissues of cows or fish? Marketed that way, perhaps not. But stick it in a bottle labelled supplementary collagen, and things might start to look more appealing. Collagen supplements are in vogue, taken both by athletes (who hope for stronger, more injury-resistant joints and ligaments) and the beauty-conscious (for its alleged ability to smooth wrinkled skin and restore lustre to hair). How much good they do, though, remains unclear.
PREMIUM Illustration: Cristina Spanò
Collagen is a structural protein that provides shape and support to everything from skin and bones to muscles and tendons. One estimate is that it makes up 25-30% of all protein in the body. And since the body is constantly growing new skin and hair and remodelling its bones, it gets through quite a bit of the stuff every day.
Exactly how much it needs—and whether it can get it all from a healthy diet—is hazy. Like all proteins, collagen is built up from smaller amino acids, a set of chemical Lego bricks that can be assembled in an endless variety of ways. Nine of those amino acids are classified as “essential”, meaning humans cannot produce them internally and must get them directly from food. But glycine and proline—the two most abundant amino acids in collagen—are not among them. Both can be produced by the body from other chemicals, suggesting that supplements might not be necessary after all.
There are, appropriately enough, wrinkles. Collagen synthesis declines with age, for one thing. Sunbathing, cigarettes and too much booze also seem to slow its production. And some researchers have tried to argue, from biochemical first principles, that glycine may be “semi-essential”: although the body can produce some, it may not be enough to properly meet demand. For all these reasons, taking more might be useful.
The empirical evidence is decidedly mixed, and of uneven quality. Still, one review paper in the International Journal of Dermatology, published in 2021, examined 19 other articles to conclude that taking collagen supplements did seem to decrease skin wrinkling. Another, published earlier this year in Orthopedic Reviews, looked at 14 studies on the effects of collagen on joints and found around half reported positive effects.
But the focus on collagen may be misguided. Collagen supplements are really just a subspecies of protein powder. One possibility is that the benefits from taking collagen are really just the benefits of taking protein in disguise. If so, a complete protein like whey (or a more protein-rich diet) may well be better than a lower-quality source like collagen.
There is evidence to support this. One notably rigorous—albeit short-term—study, published in 2023 by researchers in the Netherlands, measured the effects on connective tissue of having a group of athletes take either a placebo, collagen or whey. It found that, while neither collagen nor the placebo seemed to boost tissue growth during recovery from exercise, whey protein did.
For now, those keen on collagen can take comfort from the fact that no study has suggested the stuff is harmful. In the meantime, those looking for a useful hack might consider gelatine, a processed form of collagen used to make things like jelly, sweets and marshmallows. It can be bought at a fraction of the cost of the pricey supplements.