At each stage in our lives, we dwell in a certain corner of social media – and the 40-plus mums around the table at my Friday morning coffee club are no exception.
Our feeds, once filled with parenting hacks and recipe boxes, are now awash with anti-bloat capsules and menopause supplements.
Perhaps most pervasive are the collagen ads. We’ve all been invited to enjoy “radiant skin” and nurture our age-weary joints, courtesy of the ever-growing number of collagen brands and their celebrity endorsers.
And it’s not just us: the global market for collagen – valued at $5.5bn (approx. £4.1bn) in 2023 – also captures middle-aged men and fitness fanatics of all ages searching for protein supplements to support strength and recovery.
Once better recognised as lip filler, collagen – the most abundant protein in the human body and a fiendishly complex molecule that comes in 28 different varieties – has now entered common parlance as a broader health and beauty supplement. And the coffee morning crew wants to know: does it live up to the hype?
So I set out on everyone’s behalf to get the answer: what is collagen, and should we really be stirring it into our cappuccinos? Regardless of your hormone status, you may want to sit down for this one.
Caffeine-fuelled collagen
As I learn from Prof Stuart Phillips, a skeletal muscle protein expert at McMaster University in Canada, dissolving collagen powder into your coffee is nothing new.
It’s a trend that “gained a lot of traction” in the 2010s, partly thanks to self-proclaimed biohacker and Bulletproof Coffee creator, David Asprey.
Remember when we were being told to defile our morning brews with butter? That was Asprey’s genius. The Bulletproof recipe blended coffee with ghee (butter with its water and milk solids removed) and a type of oil that Asprey said stimulated the brain.
But Asprey also recommended adding collagen to this oily concoction, to “[counteract] the degenerative effects of ageing.”
“And it really took off from there,” Phillips says, noting that he prefers his own coffee straight up.
The endorsements of Asprey, who has 1.3 million followers on Instagram, and other influencers offering ‘science-backed’ advice, helped the collagen industry get off the ground.
Meanwhile, a steady stream of studies mentioning collagen supplements was already percolating from scientific journals.
One major journal platform, for example, brings up 115 studies for 2010, which rises to 642 by 2024. Supplement brands lent legitimacy to their claims by citing from this growing body of work.
Phillips now spends a lot of time on social media critiquing the science, and the claims. This is something the rest of us find difficult, because we don’t know much about how scientific studies work, or about collagen.
It’s easy, though, to get advice from armchair experts on Instagram and Facebook. One query I find on a group with over a million members, for example, has more than 250 responses recommending 16 different brands of collagen for skin, joints, energy and mood, and, in one case, “perkier” boobs.
Hey, I’m not here to judge. Given the perfect storm of childcare, plummeting hormones and ailing parents that my own peer group is facing right now, it’s hardly surprising we haven’t conducted a thorough review of the scientific literature. We can barely sit down to pee.
Support structures in our faces
Hoping to get better acquainted with collagen, I call on biophysicist and collagen expert Prof Nancy Forde at Simon Fraser University in Canada.
Forde is only too happy to indulge my interest, starting with her favourite collagen fact. As she loves to tell people, collagen – the main structural building block in our tissues – is not stable at body temperature.
It “falls apart”, she says, before it even gets that warm. “So then what holds it together in the body?” I ask, incredulously.
Forde explains how, in animals, long threads of collagen proteins are twisted together in threes and woven into the fabric of our tissues.
“Most of them are fibrils, these rope-like structures that collagens make. These are the basis for tendons and stress-bearing components of cartilage and so on,” she says.
“The key is that once they’re stuck to their neighbours and assembled into these [tissues], they get much more stabilised... That’s why we’re not just puddles on the ground.”
Collagens in our bodies are so stable, in fact, they form the scaffold for everything sitting outside of our cells, often accounting for the majority of the tissue.
Collagens make up over 90 per cent of human tendons (by dry weight) and roughly three quarters of our skin and bones. But, when processing meat products, we often regard tissues like skin and bone as the ‘waste’ parts of the animals we eat and use them instead for extracting collagen.
Interestingly, collagens in tissues have different turnover rates, so while you might have the same collagen in your cartilage for much of your life, your skin will replenish its collagen supplies several times over.
Gums have even faster turnover times; the rapid losses were clear to see in 17th century sailors suffering from scurvy. As Forde explains, scurvy is linked to low vitamin C levels, but it’s a collagen disease.
“If you don’t get enough vitamin C, you can’t make collagen properly,” she says. “And one of the first symptoms is your gums getting kind of gooey and losing their rigidity.”
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Problems digesting collagen
From what Forde tells me, then, there’s no question about whether we need collagen. Just as the collagen brands claim, it’s essential to whole body health.
And, just as they claim, we lose it as we age – although how rapidly, and why, are slightly mysterious. (The rate of decline varies and has to do with factors like sun exposure and hormone levels.) But these are just facts about the collagen in our bodies.
When used by collagen brands, such facts constitute what Phillips calls “soft claims”. They insinuate that bovine or marine collagen in a jar or sachet is directly transported into your tissues to “replace what you’ve lost” (also a phrase often used by brands). This is not the case.
Collagen is a giant of a molecule – over 1,600 times bulkier than vitamin C or a simple sugar – so you can’t eat it and get it past your stomach to your skin, or joints, in one piece.
Even collagen brands usually acknowledge their collagens are hydrolysed (broken up) into short chunks called ‘peptides’, then digested further in our guts to release amino acids – the pearls on the string of the collagen thread. (Vegan ‘collagens’ are actually plant extracts with a matching amino acid profile.)
But where do these collagen fragments go? Well, animal studies using radioactive collagen (to track it through the body) show components of collagen supplements end up in tissues, mainly cartilage, though it’s not clear what they do there.
And in 2005, Japanese scientists found that when humans eat hydrolysed collagen from pig skin and chicken feet, pairs and triplets of the amino acids in collagen are transferred into our blood.
Some researchers argue that certain amino acid pairs abundant in collagens drive new collagen production in our tissues, but their theories aren’t proven.
As Phillips explains, most of the amino acids strung onto collagen threads in our bodies don’t even come from food. Our cells can make them on their own.
And we don’t need to eat collagen specifically to get the other ‘essential’ amino acids, because other proteins contain them too.
Collagen, in fact, sucks as an all-round protein source, because it lacks one essential amino acid: tryptophan.
“If we were stuck on a desert island and you had collagen and I had milk protein, you’d die,” Phillips says.
In his own research, he uses collagen as a low-quality control protein to measure the benefits of staples like whey protein (from milk) for building muscle, alongside weightlifting.
He’s also shown, in a small study in older women, that collagen supplements are no better than whey for promoting collagen production in muscles.
Problems with collagen studies
So, if you want to boost your collagen, is there any point supplementing with collagen over another protein?
Plenty of studies support the benefits of collagen for skin, nails, joints, strength and recovery, and more. “[Collagen] reduces the wrinkling and roughness of the skin,” states one. “[Collagen] is most beneficial in improving joint functionality and reducing joint pain,” asserts another.
But, when it comes to comparing collagen to other proteins, most studies actually use carbohydrates, like maltodextrin, as controls – rather than proteins.
If we want to know whether it’s collagen we need to plop into our coffee or any old protein powder, this doesn’t make any sense – does it?
I put the question to dermatologist Dr Christina Weng, from the Massachusetts General Hospital in the US. After all, it doesn’t set much of a benchmark to use something containing no amino acids whatsoever.
“Great point,” Weng says. “And there’s a reason for that, which is that these trials aren’t meant to develop an approved drug and so the standard… is lower than what you would expect for a pharmaceutical company developing a medication for arthritis, for example.
"So they can pick whatever control they want. And they’re going to keep the barrier as low as possible.”
By setting such a low bar, these studies tell us nothing about whether the amino acid profile specific to collagens (high proline, high glycine) could be more beneficial than other proteins.
And this isn’t the only problem with the collagen literature. To pick another one: guess who funds most of the studies?
In a recent review of 12 studies on collagen’s effects on “delaying the ageing process”, nine of them were funded or conducted by collagen, or health and beauty, companies. (Another was authored by consultants to skincare companies.) Phillips and Weng are sceptical too.
“Someone the other day said ‘Here are three systematic reviews in the beauty area’,” says Phillips. “I said, ‘Go back and find the source of the funding,’ like you did. And it’s hard work, right?”
Agreed. Most consumers wouldn’t dig any deeper, or couldn’t – the constant barrage of collagen ads in my feeds constantly refer to brand’s own trials, which are often unpublished.
As for Weng, she describes her perspective on the collagen research as “overall sceptical”. A larger, more critical review that she recommends highlights “several biases” in how the studies were carried out.
Many of these studies introduce problems I haven’t even considered yet – so, for my own sanity, I stop short of going through all 26 of them.
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Cell centric health claims
Still, determined to get to the crux of how some researchers contend collagen might work, I arrange a call with Kyoto University’s Prof Kenji Sato, who did some of the earlier research on amino acid pairs being transferred into human blood.
Unlike most researchers, he’s compared the effects of collagen to those of another protein – casein, from milk – albeit in mice, and in a study funded by collagen producer Nitta.
His team wounded mice then fed them collagen peptides, casein or water. They saw faster healing and suppressed scarring in the collagen-fed mice and Sato puts this difference down to the proline-hydroxyproline (Pro-Hyp) amino acid doublet that is common in collagen.
In the dish, at least, Pro-Hyp seems to act as a repair signal, activating collagen-producing cells called fibroblasts, which are present in all tissues including skin. But Sato suggests it only works on very specific forms of fibroblasts – new ones that appear at wound sites.
“I see no effect on the old fibroblasts,” says Sato, referring to other fibroblasts present all the time in normal skin.
And while other researchers are starting to study Pro-Hyp too, it’s early work and there remains a huge gap between what Pro-Hyp does in mice or cells, and proving it’s relevant for humans at the low concentrations measured after taking supplements.
My impression is that the wealth of claims that collagen brands are making is massively overblown. It’s important for health claims to be properly evaluated, Sato says, in order “to send the correct information to consumers.”
In Japan, he tells me, liquid collagen peptides are recommended for treating bedsores only, based on recent evidence. Claims for skin and joints are not approved.
In the EU and UK, supplement makers aren’t allowed to make any ‘health claims’ about collagen, as former president of the Association for Nutrition in the UK, Dr Margaret Ashwell, explains via email.
Claims about collagen improving skin and joint health have been reviewed by the European Food Safety Authority (EFSA) but not authorised.
And, surprisingly, ‘beauty’ claims about collagen products, such as improving the appearance of skin, require no authorisation – provided they don’t imply a health benefit. Given what I’m seeing online, I can only assume these rules are not being well policed.
Keep your coffee clean
If dumping powdered connective tissue into your americano doesn’t appeal, there are other ways you can achieve collagen’s benefits.
After all, while browsing through a list of authorised health claims, I stumble upon other supplements with claims related to collagen.
So, first, make sure you’ve stocked up on citrus fruits. Registered health claims for vitamin C include its contributions to “normal collagen formation for the normal function of” blood vessels, bones, cartilage, gums, skin and teeth. Plus, as Forde reminds me, it will stave off scurvy, which (believe it or not) is on the rise again.
Another suggestion is to do as Weng and Phillips recommend and increase protein intake via whole foods with each meal, which should improve absorption compared to downing a supplement in one sitting.
If convenience demands you take a supplement, then you’ll get “more bang for your buck,” Phillips says, from a “complete” protein, like milk or soy, containing all the amino acids.
But if you feel collagen is a must, then Weng advises doing your research and finding one free of additional ingredients “that can cause real health issues,” such as heavy metals.
In the case of marine collagens, for example, a recent study found “alarming” levels of lead that vary considerably between brands.
For skin health, Weng has a couple of other ideas too. The UV light in sunshine damages collagen, as does sugar – having too much sugar in your blood, as in diabetes, seems to be associated with chemical modifications to collagens that are also seen with ageing. So, staying out of the sun and cutting down on cake with your coffee should help.
Also, though, a note from me to my flat white-swilling friends. Seek well-informed sources on skin and joint health, menopause and your health generally.
It’s not easy, I know – but at least be curious about who is funding the research, and who is benefiting when it’s cited on social media.
In other words: ruin your coffee with powdered skin and bones if you must, but you might do just as well to top up the milk.
Collagen, meanwhile, still makes great fertiliser, says Phillips: “Years ago, we took skin and bones from dead animals and we boiled it up. We sprayed it on farmers’ fields.” And that, he hints, is where it’s better left.
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