The biggest study ever on collagen was just released - here are the benefits it actually found

Collagen has quickly become one of the most talked-about and sought-after supplements for women, along with creatine. Brands that sell it promise everything from improved skin and hair to muscle mass.

While collagen is an essential protein in the body, acting like glue for the skin, muscles, tendons, bones, and ligaments, giving them elasticity and resilience, up until recently, the evidence on taking collagen supplements has been limited.

A new umbrella review, published in the Aesthetic Surgery Journal Open Forum, has brought together evidence from 16 systematic reviews, 113 randomised controlled trials and almost 8,000 people to try and change this.

What are the benefits of collagen?

The team from Anglia Ruskin University (ARU) in Cambridge examined how collagen intake affects all of our major health areas, taking into account dose and duration of supplementation among participants. The two areas they found the greatest improvements in were skin health and osteoarthritis outcomes, with few reliable results in other areas.

Skin health

Many women take collagen to help improve their skin health as they age. The good news is that the ARU team found that those who took collagen for longer periods experienced greater improvements in skin hydration and elasticity.

However, it didn’t find collagen to be beneficial for improving skin roughness or texture.

Osteoarthritis symptoms

The other area where the most benefits were observed was in the joint health of people with osteoarthritis.

The review found that longer supplementation was associated with reduced pain and stiffness, and the authors say collagen offers a strong alternative to more medicalised joint disease treatments.

There were also improvements in the muscle mass, muscle structure, and tendon structure of participants who took collagen, although these were not dramatic.

Healthy ageing

While the benefits of collagen for skin health and osteoarthritis were most obvious, together, they make a case for collagen as a good supplement for boosting longevity.

Lee Smith, Professor of Public Health at ARU and co-author of the study, says: "This study brings together the strongest evidence to date on collagen supplementation.

"Collagen is not a cure-all, but it does have credible benefits when used consistently over time, particularly for skin and osteoarthritis. Our findings show clear benefits in key areas of healthy ageing, while also dispelling some of the myths surrounding its use," he said.

"This study marks an important step towards more informed public guidance and better-designed future research. We need more high-quality clinical trials, including research examining long-term health outcomes, optimal dosing and differences between collagen sources."

What doesn't collagen help with?

Oral health

Some people believe taking collagen is beneficial for oral health as it acts as structural support for the jawbone, gums, and ligaments in the mouth. However, the team did not find any convincing evidence that collagen lowers the risk of gum disease or boosts the chance of a positive outcome after cosmetic dentistry.

Metabolic health

Collagen is a source of protein, so some people point to supplementation as a way to manage blood sugar levels and insulin sensitivity and improve satiety. However, the team also looked at markers for this, such as cholesterol, blood pressure, and blood sugar levels, and found very mixed results.

Exercise performance

Sports nutrition brands have added collagen into their supplement line-up in recent years. It makes sense, given the reported benefits for musculoskeletal health. However, “despite widespread marketing claims aimed at athletes and fitness enthusiasts”, the study found “little evidence that collagen improves exercise performance or recovery”.

The researchers found “no meaningful benefits for post-exercise muscle recovery, muscle soreness, or the mechanical properties of tendons”.

Collagen production starts to slow down in our mid-20s. We can start to see the impact from our 30s onwards, as the decrease in oestrogen during perimenopause contributes to further collagen loss in our late 40s and 50s. This is why collagen supplements are popular.

Signs of collagen loss include brittle hair and nails, fine lines on your face and sagging skin. It can also impact your flexibility and cause pain in your joints and tendons.

The review didn’t go into detail on the specifics of bovine, vegan, or marine collagen supplements, but it’s one of the most comprehensive studies of collagen so far.