What Happens to the Cream You Put on Your Skin?
The question: ‘What happens to the cream you put on your skin?’ was put to me a month ago by Rineke Voogt, Editor at the Volkskrant. I think she was sorry she asked the question after hearing my monologue reply. As there is so much to tell about the effects of cosmetic ingredients in and on the skin! Fortunately she has managed to make an interesting (and brief) summary of this. I promise to tell the whole story soon, but for now here is the article in the Volkskrant:
What happens to the cream you put on our skin?
Rineke Voogt 13 september 2015
On holiday, we consciously apply our sun cream, maybe some aftersun in the evening and many people don’t step outside without applying a day cream. But what actually happens to that stuff when we spread it over the skin? Where does it go? And can a lotion really hydrate or get rid of wrinkles?
The skin is a shield against the outside world, says Research Physician of Cosmetic Dermatology, Jetske Ultee. It is not the intention that viruses and bacteria can just infiltrate our bodies. Normal cosmetic products such as body lotion also remain in the stratum corneum: the outermost layer of the skin which consists of layers of dead skin cells.
‘That is fine, because that is where we want the substance to work,’ says Ultee. The basic function of a lotion is to hydrate the outermost skin layer. ‘This is basically how it works. First of all, the ingredients in the lotion seal off the skin, making it more difficult for moisture to escape. This is especially useful in winter when the atmospheric humidity is low. Alongside this, a product often contains particles which soak up moisture like a sponge. These two things ensure that your skin is hydrated-from inside and out, with your own moisture. That effect lasts for just a couple of hours, until the substance is broken down.
Your skin acting as a shield doesn’t mean that some substances aren’t able to penetrate further. ‘Studies have shown that particles contained in a sun cream have been found in the bloodstream. And a painkiller such as Voltaren gel or a topical medicine also absorbs deeper, otherwise it wouldn’t work’.
There are various factors which determine whether a substances gets further than the stratum corneum. For example, the size of the particle – a molecule needs to be tiny in order to penetrate into a cell. It also depends on the substance in which the particles are dissolved: the skin is pretty waterproof because it is oily. So, fat soluble particles will penetrate more easily. The condition of the skin also plays a factor in this, because if the outermost layer is damaged due to eczema or after shaving, the shielding function of the skin is compromised. Some products have ingredients deliberately added to them in order to disturb the barrier which allows the active components to absorb more easily through.
Some cosmetic products promise more than they can deliver. Added anti-oxidants, for example, rarely work, says Ultee. That is, the molecules disintegrate under the effect of oxygen and light – and that is difficult to avoid with cream in a jar.
A product, such as an anti-wrinkle cream, would need to go deeper than the outermost layer. Collagen, the protein which is responsible for the firmness of the skin and counteracts wrinkles, is actually created deeper in the skin. The problem is: collagen is too big a molecule to penetrate very far through. An anti-wrinkle with protein sometimes seems to be effective, but it is a trick: ‘Collagen retains moisture well. Dry lines in the skin disappear and it feels soft – but the wrinkles are still there’, according to Ultee.
Regards, Jetske
(Dr. Jetske Ultee-Research Physician Cosmetic Dermatology)
You can also read:
‘ Anti-Oxidants in Cosmetic Products’ (and if they work…)
‘ A Healthy Barrier Function, a Healthy Skin’
‘The Perfect Face Cream’
‘Help with Choosing Your Sun Cream’
‘Help with Choosing Your Moisturizer’