Scientists from personal care manufacturer Johnson and Johnson (J&J) in conjunction with researchers at the IEC in Lyon and the Institut Gustave Roussy in Villejuif have investigated the effects of a combination of known anti-ageing ingredients on photodamaged skin.
Decrease in wrinkle number The research, published in this month's International Journal of Cosmetic Science, concluded that a combination of retinol, lactose and glycolic acid significantly decreased the number of wrinkles and the length of the wrinkled area.
Forty women with fair complexions between the ages of 35 and 50 were involved in the study, applying a formulation containing the three ingredients to one side of the face and a placebo cream to the other twice daily over a 12 week period.
A significant decrease in the number of wrinkles was seen in comparison to the placebo cream after two weeks, report the researchers led by C. Bertin, and after four weeks the total surface area with wrinkles was found to be significantly smaller.
Other parameters measured by the team included the regularity and elastic properties of the skin.
Although these properties improved during the treatment period there was no significant difference between the effects of the active and the placebo formulations, according to the team.
The team concludes that "with a well-chosen combination of active ingredients, a significantly better efficacy can be obtained with an anti-ageing cream in comparison with its placebo on photoageing signs" .
The 'well-chosen combination' in this case was 0.1 per cent retinol, 5 per cent lactose and 4 per cent glycolic acid (a commonly used Alpha Hydroxy Acid or AHA).
AHAs, retinoids and oligosaccharides AHAs and retinoids have been the fundaments of anti-ageing treatment for many years and more recent research on oligosaccharides has suggested a possible anti-ageing activity.
According to Bertin and the team, topical application of retinoid compounds such as retinol may induce collagen and fibronectin synthesis whilst inhibiting the production collagenase (an enzyme that breaks down the bonds in collagen molecules).
Meanwhile AHAs such as glycolic acid are believed to be involved in the cell's energy cycle, whilst stimulating the synthesis of dermal intercellular substances that may help in the reduction of fine wrinkles.
Furthermore the inclusion of the disaccharide lactose is hoped to decrease the synthesis and release of elastase (an enzyme that breaks down bonds in elastin molecules), explained the authors.