Collagen supplements: what effects on the skin and joints?

Collagen, a key protein in the body

Collagen is a large protein found in many tissues, including skin, tendons, cartilage and bones. It represents approximately 25% to 30% of all proteins present in the human body and fulfills multiple functions in the body: it promotes the formation of skin cells, giving strength and elasticity to the skin, it protects organs and plays an essential role in blood clotting.

Collagen production that decreases with age

There collagen production by the body slows over time, decreasing by 1% per year from the start of adulthood. Studies show that women’s skin loses around 30% of its collagen during the first five years of menopause! This loss of collagen can have harmful effects:

• skin aging, which results in reduced elasticity, dryness and thinning of the skin;
• degradation of cartilage, thereby contributing to joint pain and potentially osteoarthritis;
• muscle weakness;
• bone loss, with an increased risk of fractures;
• blood circulation disorders and poor wound healing;
• a deterioration in the quality of the hair, which can become more fragile and less dense.

This is why the general public is interested in collagen products to improve these aspects of health.

Read: Collagen peptides: what the science says (subscribers)

Hydrolyzed collagen supplements: a better assimilated form

Collagen present in food, being a large protein, is not necessarily the most suitable for improving the body’s collagen content. This is why there are hydrolyzed collagen supplements, composed of smaller molecules that are more easily assimilated. “These hydrolyzed forms – in which the protein has been broken down into shorter chains called peptides – are thought to pass more easily into the bloodstream, making it easier for the body to transport these fragments to tissues where they can exert biological effects, potentially contributing to healthy skin, joints and muscles.”explains on the site The Conversation Dr. Heba Ghazal, who teaches pharmacy at Kingston University (1). But do these supplements live up to expectations?

Hydrolyzed forms of collagen pass more easily into the bloodstream

What the science says about how collagen supplements work

A review of meta-analyses takes stock of the benefits that can be expected from supplementation with collagen hydrolyzed (2). It was carried out by an international team of researchers, including several French (Marseille).

A review of 16 meta-analyses

The authors selected 16 meta-analyses covering nearly 8,000 participants, corresponding to 113 clinical trials in total. Collagen supplementation has been linked to improvements in muscle, joint and skin health.

Real results but studies that could be improved

However, these benefits appeared gradually, suggesting that it is more important to take collagen regularly over a long period of time than to follow a short, intensive course. The quality of the studies is uneven and the protocols heterogeneous, which does not make it possible to clearly determine the dosages and types of collagen the most effective. “Fifteen of the sixteen included reviews were rated as low or very low quality – not necessarily because the dietary supplements do not work, but due to methodological issues such as lack of prior registration of studies and poor communication of potential bias, explains Dr. Ghazal. Many trials were also short-lived and had few participants, limiting reliable conclusions that can be drawn about long-term effects. »

Modest effects on muscle health

Regarding musculoskeletal health, it has been shown that collagen supplementation exerted beneficial effects on various muscular parameters. In particular, it resulted in a moderate increase in lean mass and a modest gain in maximal strength.

Osteoarthritis: relief confirmed by studies

In people with osteoarthritis, taking collagen supplements has been consistently associated with symptom relief, including significant reductions in self-reported pain. This is because collagen is a major component of articular cartilage.

THE collagen peptides are part of the food supplements recommended by Angélique Houlbert in her guide Nutri-Arthrosis. She recommends pairing them with:

• MSM, glucosamine and chondroitin to reduce the intensity of pain and improve mobility (3);
• chondroitin and vitamin C, to reduce joint stiffness and range of movement (walking, stair climbing, squats) as well as quality of life (4).

Collagen, an ally for aging skin

Finally, in the field of dermatological health, collagen supplementation has consistently shown favorable results. Significant improvements were observed in skin elasticity and hydration, with high statistical certainty. However, Dr. Ghazal points out that individual differences may explain why supplements do not provide the same results for everyone. “Factors such as sun exposure, smoking, sleep quality, environment and hormone levels all influence skin aging and how the skin might respond to supplementation. »

Marine collagen, vegan… A wide variety of supplements

There was a great diversity of collagen supplements in the studies analyzed, making it difficult to recommend dosages and formulations for a given product. “Some are of animal origin, such as those from cows, pigs or chickens, while others come from marine sources, including fish, jellyfish and shellfish, explains Heba Ghazal. There are even so-called “vegan” alternatives to collagen. Some studies used dietary supplements taken orally, while others tested collagen dressings applied to the skin. »

In Nutri-ArthrosisAngélique Houlbert recommends 5 to 10 g of collagen peptides for at least 3 to 6 months, if possible choosing “French origin” and Friend of the Sea certified.

Conclusion

In conclusion, the food supplements based collagen appear to have real, if modest, benefits, particularly in terms of skin hydration, joint pain and muscle health. “The scientific database still has significant gaps, concludes Heba Ghazal. Studies must clearly specify the type of collagen used, the dose, the method of administration and the characteristics of the people taking it. »

To go further: Nutri-Arthrosis