The research looked at the effects of long term exposure to traffic-related particulate matter in the air on skin aging, through an epidemiological study on 400 women between the ages of 70 and 80.
Measurements of the concentration of traffic-related particulate matter in the atmosphere for the study areas (either rural or urban locations in Germany) were compared with the signs of aging shown by the women’s facial skin including pigment spots, wrinkles and skin laxity.
According to the study, the higher the concentration of traffic related airborne particles the higher the number of age spots. In addition, there was also a significant association between levels of air pollution and the nasolabial fold (the skin folds that run either side of the nose).
Protecting the skin from air pollution
Commenting on how to protect the skin from the effects of air pollution, study author Professor Jean Krutmann said: “Traffic related particulate matter is mainly carbon particles, and these carbon particles bind to organic substances like poly aromatic hydrocarbons. So, all you need to know is how the carbon and the poly aromatic hydrocarbons affect skin ageing.”
According to Krutmann, the poly aromatic hydrocarbons’ role in skin aging is likely to be related to its binding to the aryl hydrocarbon receptor (AhR) which is found in both keratinocytes and melanocytes.
“When you stimulate the AhR receptor you could be increasing melanin production which could explain the increase in pigment spots seen in the research,” he told CosmeticsDesign.com USA.
Targeting this receptor could be a potential way for ingredients suppliers to try to tackle the problem and Krutmann said some companies may already have molecules suited to the task.
“…cosmetic supplier Symrise has developed a topically applicable molecule that can act as an antagonist to this receptor. I am confident that this molecule or others similar would be effective at stopping this poly aromatic hydrocarbon related pigment production,” he said.
‘Carbon particles can penetrate the skin’
The carbon particles themselves, especially when they are in the nano form, can penetrate into the skin, according to Krutmann and activate an inflammation related signalling cascade.
However, as the cell membrane is not homogeneous and the reactions usually start in the lipid rich domains called RAFTS, trying to stabilise these domains could be a potential for an active ingredient, he said.
“Many years ago we found a molecule that can stabilise these rafts. When using this molecule or related molecules you could probably block the nanoparticle effect. [At this point it] doesn’t matter if the nanoparticle is sitting on the keratinocyte surface the inflammation cascade cannot be stimulated,” Krutmann explained.
According to Krutmann, who is based at the Institute for Environmental Medicine at the University of Düsseldorf, the researchers are looking for a partner to help test this hypothesis.
Source: Journal of Investigative Dermatology
2010, issue 130, pages 2719 – 2726, doi:10.1038/jid.2010.204
Airborne particle exposure and extrinsic skin aging
Andrea Vierkötter, Tamara Schikowski, Ulrich Ranft, Dorothea Sugiri, Mary Matsui, Ursula Krämer and Jean Krutmann.