Can moisturisers contribute to keeping us healthy? Doctor of medicinal chemistry Michelle Wong says there's growing evidence they aren't just for vanity and more people should be using them.
Dr Wong is a cosmetic chemist and science communicator who runs the popular Lab Muffin Beauty Science blog where she tests skin products, turning her into a global beauty influencer.
She talked with RNZ Sunday Morning's Jim Mora about the latest and greatest - or not so great - of the beauty world.
Among them, findings from US university studies that the condition of people's skin could drive damage to other parts of the body, including bone-loss, inflammation and cognitive abilities.
Wong says she's not surprised.
"Our skin is living, so for a long time people just assumed our skin was mostly dead - but it is connected - even the top so-called 'dead' layers you can put things on them that will impact the lower layers.
"All parts of our body are connected, there are lots of influences. Our skin isn't just protection from the environment it also mediates communication between the insides of our body and the environment."
Skin that is healthy can protect better against external elements, and could influence inflammation, Wong says, while skin that is not healthy can put the body under stress, affecting a person's well-being.
While the body produces natural moisturisers and not everyone needs to put moisturiser on their skin, she says as we get older some of the elements in the skin - like hyaluronic acid - that hold onto moisture also decrease, and it's more likely that our skin will be dry or damaged.
"There are lots of studies showing that the quality of life is really bad if you have untreated skin conditions. It's uncomfortable, you can't sleep properly... As we get older we do tend to get less moisturised skin, we produce less of those lipids, it becomes less comfortable.
"So I think there are a lot of people that should be using moisturiser who aren't, especially... men."
Wong says moisturiser has the added benefit that it can also double as sun protection if it has sunscreen in it, which many do.
Luxury spending patterns in tough times
The global beauty market is growing by 6 percent a year, with people still willing to spend big bucks on beauty items even in a tough economy. It's due to what's called "the lipstick effect", Wong says.
"Basically in hard times people tend to spend more money on small indulgences because something like a single luxury lipstick is so much affordable than a luxury car, and you still get that little boost of making yourself feel better - kind of like taking care of yourself and just feeling better, in a more affordable way.
"Now, are more expensive products actually better? - Generally no," she says.
"Most of the time the stuff inside, you can get similar ingredients and similar performance with much cheaper products."
Spotlight on a key moisturising ingredient
Recent research from the University of California suggests the benefits of hyaluronic acid for skincare have been oversold.
Wong says a widespread myth about hyaluronic acid is that it can hold 1000 times its weight in water: "It's really widespread, but if you think about it it's not super-believable."
However, while hyaluronic acid "is probably oversold - it's still good," Wong said.
The ingredient is "an effective humectant" - something that grabs onto water, and some forms of it could perhaps penetrate deeper into the skin and have some longer term anti-ageing effects."
Sugar in our diet has an effect on our skin
Research about how sugar effects skin and appearance is a good reminder about the widespread benefits of a balanced diet. A study from the French National Centre for Scientific Research found that eating white bread, white rice, potato chips and sweets could negatively affect the attractiveness of faces.
"If you eat better, your face will look better," Wong says.
"There's actually quite a lot of research on glycemic load - how quickly the sugar from the food you eat hits your bloodstream.
"Essentially what's happening is if you have high blood sugar then you have more sugar going around your body, and these sugars can attract to various things inside your body like proteins - and this process is called glycation.
"Having these sugar molecules on these things that means they are changing the structure of the things and also how they function, this happens all over the body, [including to our] skin. Its also happening to proteins in our skin like collagen, which is impacting both how our skin looks - how wrinkly, how plump it looks - and there's a lot of evidence that the level of glycation increases in our skin throughout our lives.
"It's just part of ageing."
Wong says a balanced diet with less processed food will include less refined carbohydrates, which means less glycemic load - less sugar molecules travelling through our blood and affecting the rest of our molecules.
RNZ
