Do Collagen Supplements Really Make a Difference to The Skin?
Collagen is a protein found in the dermis layer of your skin. It's very important for the structure of your skin and is responsible for its firmness and bounce. As we age, collagen production slows down. The sun’s UV rays also damage collagen. One of the main causes of thinning skin, wrinkles and a rougher texture is collagen loss. So, it's no big surprise that one of the most hyped-up supplements in skincare is collagen.
While trying to push collagen into your skin from the top down via skincare products will be a wasted effort (collagen is just too big to penetrate to the dermal layer), you might be surprised to learn that there is some evidence that dietary collagen supplements can potentially improve your skin. Peer-reviewed clinical trials have found that collagen can improve skin hydration, elasticity and wrinkles (albeit to a modest extent).
It isn't entirely clear how collagen supplements work to produce these observed effects, but there has been some work towards finding a mechanism of action. Collagen is a protein, which means it's a long chain made up of amino acids. But it isn't just like any other protein we eat. Collagen contains a large amount of an amino acid called hydroxyproline, which is rarely found in any other dietary sources.
During digestion, your stomach breaks down proteins into small fragments of one to three amino acids long, which can then be absorbed into your blood. If you've taken a collagen supplement, these fragments will contain hydroxyproline. While it's unlikely that the collagen fragments will travel to your skin and reassemble into collagen there, these fragments could potentially signal to your skin to produce more collagen (it's thought to trick your body into believing that collagen has broken down, so it needs to make more). It's also possible that they can send these collagen-boosting signals while still in your digestive system.
But while the evidence seems promising for collagen supplements, there are a few big problems. Firstly, a lot of the studies on collagen are published by collagen supplement manufacturers. While there are quite a few peer-reviewed studies, they're often conducted or funded by people who profit from collagen supplements. A conflict of interest doesn't mean the data is automatically biased but it does mean that the evidence as a whole is likely to be more biased than usual.
There is also a huge variety of collagen supplements on the market made with varying sources of collagen - cows, pigs, fish - that won't all have the same structures. Additionally, collagen supplements are usually hydrolysed, which means the protein chain is broken up into smaller pieces. Like breaking up a giant Lego sculpture, there are lots of different ways of breaking up collagen. The size of the fragments and the relative amounts of the varying sized fragments will probably have an impact on how they work. This means that unfortunately, you can't assume all collagen supplements have the same level of evidence behind them.
Collagen supplements are relatively low risk and if your skincare budget stretches that far, it's probably one of the more evidence-based supplement options. But as far as skincare goes, it's a lot more cost-effective and reliable to make sure you're using tried-and-true collagen-preserving products like sunscreen, retinoids, chemical exfoliants and antioxidants first.
Qualifications - Chemistry PhD
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