Matilda Whitworth is a doctor, chemist, and outreach worker based in Perth, Western Australia. This week, she takes on the some of the myths around moisturisers.
My mum bought a moisturiser the other day. This is what was written on the packaging:
A light non-greasy formula based on actives extracted from Beech Tree Buds and stabilised using Ultra High Frequencies. Tests have shown that these actives smooth the cutaneous microrelief leading to a 10 percent wrinkle reduction being observed after only 4 weeks. Additional tests have shown that skin moisturisation improved by 30 percent.
After I finished laughing, I tried to find the studies proving the "10 percent wrinkle reduction" and couldn't. In fact, there was nothing I could find online to support these claims. Even the website on the jar didn't exist! But really, I was far from surprised.
There are very few academic papers about over-the-counter moisturisers, and many of those that do exist are small and/or funded by the manufacturer. One of the reasons is that for cosmetics manufacturers, rigorous peer-reviewed research can be a disadvantage. As bad science-debunker Dr. Ben Goldacre explained for The Guardian: "If [studies] show no effect, then your business is trash; but if they do show an effect, then busybodies wade in to regulate your pharmaceutically-active product."
This lack of evidence and transparency wouldn't fly for medicines or medical products; the Therapeutic Goods Administration (TGA) just wouldn't allow it. But as long as cosmetic companies use soft, meaningless words "revitalise" and "refresh" and avoid any therapeutic claims (i.e. saying they can prevent, diagnose, cure. or alleviate a disease, ailment, or defect) they escape TGA assessment and don't have to prove anything.
What's interesting is that cosmetic companies aren't technically allowed to use this language. According to the Trade Practises Act 1974, "scientific and technical terms and symbols should not be used unless they are accompanied by a clear and accurate statement of their meaning." But it's not hard to find a moisturiser that flagrantly ignores these instructions.
So what do moisturisers actually do? Can they make us look younger (as many of them claim), or is appearance mostly up to our genes, age. and environment? I decided put the question to Dr. Alexandra Stedman, a GP and cosmetic medicine specialist working in Perth.
The first thing Alex highlights is there's no single way to define what "younger" skin looks like. When cosmetic companies use this vague term on their moisturisers, it's impossible to know whether they are referring to lines and wrinkles, dryness, pigmentation, turgor, resilience, pliability, glow, or all of the above.
"If we assume that looking younger means having healthier looking skin, then moisturisers do definitely work," Alex explains. "I see clients who use products versus those that don't, and the users certainly look healthier. But do they look younger? I don't know. Their skin has a better texture and feels healthy to touch and treat. But unless I had a comparison with them without moisturiser, how could I say they looked younger, and how could I measure that?"
"Just look at the skin of the eczematous and aged patients we see. So much healthier when moisturised! But again I ask, is it younger?"
When we use moisturisers our skin looks healthier because it's less dry. But according to Alex, no one needs fancy or expensive moisturisers to achieve this. "A simple Sorbolene will work," she says.
But what about moisturisers that contain some sort of "active ingredient?" Do any of those may skin look younger?
"Sunscreen definitely works" says Alex, and highlights that there's enough agreement on sunscreen's ability to slow the effects of ageing that the TGA treats moisturisers with sunscreen as medicines. What's pleasing is that this claim, unlike many others on cosmetics, is backed up by good science. For example, in a large randomised control trial published in the Annals of Internal Medicine in 2013, there was no detectable increase in skin ageing over four-and-a-half years in the daily sunscreen group.
There's also evidence to show that vitamin A derivatives can improve skin appearance by increasing cell turnover, thickening deep skin layers, and slowing collagen breakdown. However, because active retinoids like retinoic acid can cause redness and burning it is only available on prescription. While some moisturisers contain weaker retinoids such as retinol, their slow metabolism to retinoic acid and the small quantities used mean these creams are far less effective. Many don't even indicate the concentration of retinol present, relying on the hype around vitamin A to sell the product.
Then there is hyaluronic acid (HA), which is the skin's key moisture retention molecule—one gram of HA can hold almost six litres of water. When injected into the skin, HA also has a remarkable affect on collagen, the molecule that keeps skin firm and supple.
"Hyaluronic acid injected into the skin definitely works to stimulate collagen and improve elasticity," explains Alex, who regularly uses the hyaluronic acid fillers Juvederm and Restylane in her patients. "But does it work if used topically? I don't know." The traditional thinking about topical HA is that the molecule is too large to penetrate the skin. This means that while it can sit on the skin surface and bind water, it cannot stimulate collagen production like the injectable form.
A recent study has reported the benefits of smaller, more penetrating HA-like molecules (low molecular weight HA and nano-HA) on skin hydration and elasticity, although neither paper directly commented on the impact on collagen synthesis.
So aside from moisturisers, is there anything else that can make us look younger? Botox and fillers like Juvederm and Restylane can certainly go some way to reducing wrinkles. Eliminating dry skin and dead cells with a chemical or physical exfoliant can also improve the appearance of fine lines and wrinkles. But if you are seriously worried about having old-looking skin, then, like anything in medicine, prevention is better than cure.
"The main preventable causes of skin ageing are sun exposure and smoking," stated British Association of Dermatologists spokeswoman Nina Goad in a 2009 piece for The Guardian . "So if you're worried about wrinkles, limiting these factors is sensible."
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