Do collagen supplements work?

Collagen supplements might make your skin more elastic – but the evidence is weak.

Collagen is hugely hyped. This protein, which is important to the structure of skin and joints, has been presented as a miracle cure for everything from wrinkles to poor sleep.

Production of collagen, the most abundant protein in the body, naturally slows with age – whether you protect your skin from the Sun or not. To compensate, collagen supplementation has become a booming business. One aficionado is Bryan Johnson, the tech entrepreneur who has become a one-man experiment for how to prolong your life, who says he takes 25g (0.9 ounces) of collagen peptides every day.

But collagen is not always well understood. While there is some evidence that supplementing with this molecule has health benefits, research is limited. The main risk of taking it as a supplement may be of wasting money – there are few known side effects – but is the scientific evidence keeping pace with the marketing claims?

To start with the basics, "collagen is only found in animal connective tissue", notes Andrea Soares, a registered dietitian in Georgia, US, who is part of the Top Nutrition Coaching network, a company which helps to connect people with dietitians in their area.

Collagen products come from a variety of animals: cows, pigs, chickens and fish. Gelatine, which is used to make sweets, jelly and the capsules for pharmaceuticals, is a form of collagen. "Some plant-based supplements claim to be 'vegan collagen', but what they actually contain are collagen-boosting ingredients like vitamin C, amino acids and minerals that help your body make its own collagen," says Soares. "If you're vegan, you might want to spend your money on a well-rounded diet instead of plant-based 'collagen' supplements that don't actually contain collagen."

Different types of collagen appear to work differently. Hydrolysed collagen (collagen hydrolysate) is collagen which has been broken down into short chains of amino acids known as peptides. These get broken down further as they move through the digestive system. On the other hand, undenatured (raw) type II collagen is a component of cartilage surrounding joints. In theory it can help replenish collagen around the joints, says David Hunter, a rheumatology clinician researcher at the University of Sydney, focusing on osteoarthritis. Type II collagen is also broken down into amino acids in the stomach, though hydrolysed collagen tends to be better absorbed by the body.

In addition to the wide variety of sources and types of collagen, the substance is packaged into many different forms, from bars to drinks. Compared to powders and liquids, "tablets and gummies often have less collagen per serving and may contain added sugars or fillers," Soares says. And while consuming food rich in protein and vitamin C generally helps our bodies to make collagen, the amount of collagen present in food like bone broth varies. She advises those taking collagen as a supplement to opt for a powder or liquid, with at least 5-10g (0.2-0.4 ounces) of collagen per dose.

Overall, many marketing claims made about oral collagen products don't stand up to scrutiny. In the European Union, "no health claims for collagen supplements have got the green light," explains Leng Heng, a senior scientific officer for human nutrition at the European Food Safety Authority (EFSA).

EFSA is the EU agency that assesses risks related to novel foods. When they took a look at collagen, they concluded that the health claims submitted about it so far were not supported by enough high-quality evidence. They were "not sufficiently defined, lacked supporting human studies, or relied on evidence from animal and laboratory research, which cannot predict effects in humans," says Heng. She points out that claims such as the idea that collagen helps to maintain skin elasticity, or that it improves joint functioning, have not yet been demonstrated sufficiently by scientific research.

Potential industry bias is a key concern for determining rigour, Hunter says. Many collagen studies are funded by supplement companies or authored by employees of these companies. Conflicts of interest are supposed to be declared in academic papers, but this does not always happen. For example, one published paper includes five of seven authors who stated an affiliation to supplement companies, though no further information was given in the conflicts of interest section. (In response to a BBC query, the publisher of this paper, Elsevier, stated that the paper is now under investigation.) 

"The reality for many of these studies is that it's hard to find any that are completely independent of industry," Hunter says. Influencers sometimes tout poor-quality research and may promote higher dosages of supplements than is recommended by health authorities. Even systematic reviews and meta-analyses – large-scale reviews of the evidence, which pull together the results of multiple studies – can be compromised by the quality of the underlying studies. Hunter and his coauthors assess the risk of bias from such studies, including industry involvement. But he says that it can be hard to account fully for the bias when there simply aren't enough independent trials, as is the case with collagen.

While individual health risks of collagen supplementation appear low, there are some larger potential consequences of the growing appetite for collagen. For example, collagen supplements from cattle have been linked to deforestation in Brazil.

Meanwhile, the European Commission commissioned research into the possibility that collagen or gelatine could lead to new cases of transmissible spongiform encephalopathy (TSE, or prion disease). EFSA estimated humans' oral exposure to infected gelatine under hypothetical worst-case scenarios, and found that there was a vanishingly small to no risk.

One key problem with any claims about the benefits of collagen is what happens when the molecule is ingested. As the London dermatologist Anjali Mahto told the BBC in 2019 , there is "little solid proof it will survive digestion, travel into the blood stream and make it to your skin". In fact, when any protein arrives in the stomach – including collagen – it is usually swiftly broken down into amino acids, which are then reassembled into the proteins that the body needs at that moment. So, if the body needs collagen, it might reassemble those amino acids into collagen, but there are no guarantees.      

Another issue is the formulation of collagen supplements. In many dermatology studies of collagen products, those products also contain other ingredients that may benefit skin health, making it hard to isolate the effects of the collagen.

However, many consumers swear by the effects of collagen on the look and feel of their skin. One systematic review and meta-analysis found that hydrolysed collagen can have beneficial effects on the skin, such as improving hydration and elasticity. However, the authors concluded that further research was needed to confirm this.

Other (industry-funded) studies have suggested that oral products with high amounts of the collagen peptides prolylhydroxyproline and hydroxyprolylglycine can improve the moisture and appearance of the skin. "What's key is consistent use," Soares says.

There are certain strategies to boost the potential benefits of collagen supplements, for instance for the tendons. Robert Erskine, a reader in neuromuscular physiology at Liverpool John Moores University, suggests that exercise might be able to stimulate the body's tissues to regenerate collagen more than usual. In turn, this can strengthen tendons, allowing someone to move more quickly and be less likely to fall.

In one study, Erskine and colleagues from universities across the UK tested whether taking hydrolysed collagen could boost the amount of collagen made by the body after high-intensity resistance exercise. The research, on a small sample of young, healthy men, found that the men produced significantly more new collagen when they drank a mixture of vitamin C and 30g (1 ounce) of hydrolysed collagen before exercise. This was a higher dosage than what had previously been studied or is typically packaged for consumers.

In another study Erskine was involved in, the team tested the same effect in healthy middle-aged men. They found that there was still an effect of collagen supplementation, but a smaller one. So, age is a factor in collagen production, as is sex. There are links between oestrogen and collagen synthesis, for example.

"I'm really interested in trying to investigate how we can improve well-being and performance of athletes, female athletes in particular," Erskine says. "I think collagen will have a big part to play in that," not only to improve performance, but also to reduce injury risk. While such research is relatively new and small-scale, it is already being integrated into the nutritional habits of elite athletes. "I think the evidence is strong enough to make these suggestions," he says.

In fact, though collagen supplements are often associated with the young and athletic or image-conscious, it is increasingly being investigated as a possible treatment for chronic conditions associated with old age. For example, there is mixed evidence of whether collagen helps with the symptoms of rheumatoid arthritis. One recent meta-analysis found that the overall quality of the research in this area is poor, so it was not possible to decide if collagen supplements can help. However, the authors noted that some studies reported adverse effects.

As for osteoarthritis, Hunter and colleagues conducted a systematic review of studies, finding that collagen supplements appeared to reduce osteoarthritis-related pain in the short term.

However, Hunter stresses that the evidence base is limited. The collagen studies the team drew on were limited in both quantity and quality (such as having small sample sizes). This is why he and colleagues didn't include collagen in a new clinical trial of complementary medicines that appear to be more promising for osteoarthritis: pine bark extract, Boswellia serrata extract and curcumin.

With any supplement, there is a risk of interactions with other medicines people are taking, so Hunter advises anyone considering taking a supplement to talk to a health professional first. Increased intake of a protein like collagen could be a concern for people with kidney or liver conditions that affect protein metabolism, Erskine says.

Many of Hunter's patients are interested in supplements, after hearing about them from adverts, media or people they know, he says. "It's really important people, particularly health professionals, be open to having those conversations," he says. "If you're dismissive, I think it's very likely that a lot of these patients will go off and just take it anyway."

In his own practice, Hunter tells patients who express interest in supplements that some are worth trying for three or four weeks. As with skin appearance, some studies suggest that the joint benefits of supplements don't kick in for two or three months, if at all. However, Hunter notes that many people living with osteoarthritis will find it hard to keep going with a supplement if they don't see effects within a month or so.

Overall, given the many reasons someone might be seeking out collagen, there's no single answer to whether a collagen supplement is worthwhile. It will depend on why you want to take it, how long you can keep taking it, how affordable it is, whether the collagen is combined with other ingredients, and how it might affect other aspects of your health. "Not everybody will respond to a collagen supplement in the same way," Erskine notes.

Ultimately, scientists point out that the hundreds of pounds per year spent on collagen supplements could be spent instead on more balanced diets, which would improve health in a number of ways. In addition to nutritious and varied food, exercise, sleep and sunscreen all have well-known benefits for skin appearance and health, for instance. It may seem boring, but it could also save you some serious cash in the long term.

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Source: BBC