To fulfil our culture’s relentless drive for wrinkle-free skin and an eternal youthful glow, collagen supplements have been gaining more attention, fuelling a booming industry. How well do they work? The short answer: there is evidence that eating collagen may be effective, but experts say we can get what we need through a healthy diet.

There’s no doubt this protein – the most abundant in the body – is important. Collagen is derived from the Greek word kólla, meaning glue, and makes up around three quarters of the skin. More than skin-deep, collagen provides structure for bodily organs, blood vessels, teeth, bones, cartilage, tendons and ligaments (its properties have even been exploited for an assorted array of innovations including glue, musical instrument strings, fabrics and rope baskets).

As with many other biological assets that youth take for granted, collagen starts waning with age as bodies slow down and produce less of it. This manifests in wrinkles as skin becomes less supple and able to retain its tightness, potentially lowering its other vital functions such as hydration, antioxidant support and immune defence. Lower collagen production can also slow wound healing, which explains why increasing dietary protein can double the recovery rate.

Here’s the kicker: collagen is a complex protein made up of 19 different amino acids. If you eat it, the digestive tract’s job is to break down the amino acids before releasing them into the blood stream – and there’s no guarantee they will reform in the same way.

“Collagen doesn’t stay collagen,” explains Pia Winberg, a scientist exploring the benefits of seaweed for wound healing, “and [your body] only makes it if [that’s] what you need first in terms of protein and you have the right set of amino acid building blocks to make it”.

“The marketing of collagen supplements is taking people for a ride, a bit, unless they are deficient in certain dietary amino acids, in which case of course it will benefit. But they could equally get that from just increasing amounts and/or diversity of protein intake.”

Associate professor Stephen Shumack, a clinical dermatologist, agrees that while there’s little harm in taking collagen supplements, getting the building blocks of the protein from a good, rounded diet is a logical and cheaper way to go.

“Collagen supplements are a current fad based on little scientific evidence,” he says. “Fortunately, there is little downside to taking them.”

Some evidence supports supplements

However, various animal studies suggest the whole protein might be directly absorbed, so the story could be a bit more complex. Whether it’s from the whole protein or its constituents, the small body of research that has been conducted in humans does offer some support for collagen supplementation (usually derived from cows, pigs and fish, although Winberg is exploring seaweed as a vegetarian source of the key amino acids).

A 12-week placebo-controlled trial reported that a collagen supplement with nutritional cofactors including vitamins C and E, and zinc improved skin quality in women over 35 years old. Overall, a review found 11 studies that provide supporting evidence for improved skin elasticity and hydration, and wound healing.

There may also be some benefit for osteoarthritis, supported by a controlled trial with athletes that found reduced subjective joint pain in those who took the collagen supplement. Another study reports superior muscle mass and strength following supplementation combined with strength training in male volunteers.

One limiting factor to studies is inconsistent dosages, which makes it hard to determine optimal levels of supplementation.

Dominique Condo, a sports dietitian and researcher with Deakin University in Melbourne, says we are still learning about collagen, but she uses the supplements regularly with elite athletes to strengthen their joints and muscles, particularly important for injury prevention and rehab. She notes that dose is important, especially given that it could be used anywhere in the body.

“I can’t speak to the beauty products as I don’t know enough about them,” she says, “but from a muscle and joint perspective we know there is a certain dose you need to see increases in collagen production (around 15 grams per serve). This is a decent amount of collagen and so it may be that some of the products marketed for the benefits don’t actually have the amount needed.”

Supplements aside, there are several ways to protect and boost collagen levels, where healthy habits come up trumps. First, avoid collagen damaging activities like smoking, eating too much sugar and refined carbohydrates, lack of sleep and exercise, stress and ultraviolet rays from excessive sun exposure.

A healthy diet rich in diverse plant foods can deliver a suite of antioxidants that help counter skin damage. We can also derive the necessary amino acids and nutritional cofactors that help the body make collagen from dietary sources.

Amino acids come from protein-rich foods like eggs, legumes, dairy, fish, poultry and meat. Vitamin C, a critical cofactor, is found in many plant foods including red capsicum, broccoli, citrus and berries. Zinc is also important, high quantities are found in shellfish, legumes, nuts and seeds. Others include proline, found in egg whites, wheat germ, dairy products, cabbage, asparagus and mushrooms, and glycine, delivered by gelatin and protein-rich foods. Copper might also help, which can be ingested through sesame seeds, organ meats, cashews, lentils – and for chocolate lovers, it’s also found in cocoa powder.

So if you’re starting to see unwanted wrinkles or have deeper needs like wound healing and muscle repair, there’s no harm in taking a collagen supplement. However, you’re likely to get the same benefits from living and eating well and including plenty of good quality protein.