The science of skincare
Many of us spend a great deal of time, money and energy on our skin, but are the various potions and lotions in our bathroom cabinets actually doing it any good? Chris Smith spoke to dermatologist Jane Sterling from Addenbrookes Hospital. First off, Chris asked Jane for the lowdown on skin...
Jane - Well skin, of course, is the covering to all our bodies, with a slightly modified version over the front of the eye and mouth. There are two important layers of the skin, there’s the epidermis, a wonderful self-renewing very thin surface that’s continually being made from below, and continually lost from the surface. And below that is the dermis. That’s the stretchy but sort of padding layer just beneath, and then, of course, we get down to fat and muscle. So our skin is a self-renewing surface. It protects us from the outside and keeps the inside - inside.
Chris - One statistic I read was we lose something like 40 or 50 thousand skin cells every second. Does that sound about right?
Jane - We certainly lose a lot. And most people don’t realise that household dust is mainly skin that’s being shared.
Chris - As we were walking around through our homes you’re breathing yourself and your housemates in. Isn’t that true?
Jane - That is true.
Chris - When the skin is young and youthful, like yours and mine, why is it different from someone who’s gone all craggy and needs loads of lipstick, like Katie - no I’m just kidding Katie, you’re not all wrinkly and leathery. But someone who’s gone a bit ancient, what’s the difference?
Jane - As we all get more ancient we will get more wrinkly and our skin will be soft and less vibrant looking - it’s just what happens. So we lose some thickness to our skin as we get older; we get drier because our grease glands stop working quite so well, so we look a bit duller and definitely saggier.
Chris - If you pinch the back of your hand, for example. I remember doing this on my daughter earlier you just sort of raise the skin up like a tent, it immediately pings back in her. But in me… mmm it takes the return time, the relax time is a few seconds.
Jane - That’s right.
Chris - So why is that?
Jane - That’s your dermis that hasn’t got as much collagen and elastin as it did when you were younger.
Chris - And why is that?
Jane - That’s a natural ageing process but that’s magnified by the effects of the sun. So that’s one of the major effects of having a lot of sun exposure is we get collagen damage, and as we get older both collagen and elastin aren’t produced as much.
Chris - So when I go to a supermarket or chemist or something and buy and anti-ageing cream or something to make me look a bit younger, how do those things work?
Jane - If they work.
Chris - I suppose they’re defying the eye potentially aren’t they? But is it defying the eye, is it actually doing something physically to the skin?
Jane - They’ll do certain things, like every cream they’ll keep moisture in the skin so they’ll stop your skin looking dried up, and it’ll stop it drying up so much as the day goes on. They might have a little bit of shine to them, of course, if they contain greasy things so that dull look that can make you look older, you can lose that.
But the creams that are put forward as anti-ageing creams, there’s a bit of a debate as to how well they work because they really need to get down into the dermis to do something to that collagen and elastin, and they don’t do that as well on actual skin as they do in cell culture, for instance. The only constituent of anti-ageing creams that really has good evidence behind it are the retinoids - retinol.
Chris - They’re vitamin A like chemicals, aren’t they?
Jane - That’s right, similar to vitamin A. But put on the surface they do seem to go deep enough to produce a measurable effect on wrinkles.
Chris - And what is that effect? Are they encouraging the skin to what, make more elastic tissue; make more collagen?
Jane - Make more collagen, yes.
Chris - And that irons out the wrinkles a bit.
Jane - Yes. But, of course, but it’ll really only work when you’re using it. And the tests that are used to measure wrinkles are pretty detailed so whether you would notice a huge difference - probably not. You might notice a little difference to the end of treatment period with it.
Chris - And when one does slap on lots of makeup day, after day, after day relentlessly. Is there evidence that that’s bad for you? Does that age, harm, or damage the skin or does it not make any difference?
Jane - Well, as long as you don’t react to the makeup you’re putting on - you don’t develop an allergy to it, which is always possible. And as long as it’s not a drying, dehydrating effect on the skin then there should be no long term problems. For makeup, on other thing you can sometimes do if it’s a really heavy sort of concealer makeup it can bring up acne spots but otherwise should be no long term damage.