Botanical extracts as anti-aging preparations for the skin: a systematic review.

Although topical creams and other anti-aging products purport to reduce the appearance of aging and skin wrinkling, there has been no critical analysis in the scientific literature of their effectiveness. This systematic review critically evaluates the evidence for the effectiveness or efficacy of botanical treatments in reducing skin aging and wrinkling. MEDLINE, Embase, CINAHL®, CENTRAL and AMED databases were searched from their inception until October 2009. Reference lists of retrieved articles were hand-searched. Manufacturers and professional associations were contacted in order to identify further non-published studies. No language restrictions were applied. Only randomized clinical trials or controlled clinical trials assessing the effectiveness of botanical extracts in reducing wrinkling and aging of the skin were included. Data were extracted by two independent reviewers and methodological quality was assessed using the Jadad score and key aspects of the Cochrane risk of bias tool. Of 36 potentially relevant studies, 11 trials of botanical extracts for reducing skin wrinkling and the appearance of aging met all the inclusion criteria. No trials were identified following contact with anti-aging and cosmetic organizations, companies and professional bodies. A significant reduction in skin wrinkling was noted for date kernel extract, cork extract, soy extract, Rosaceae and peony extract. No significant reduction was noted for green tea, Vitaphenol® (a combination of green and white teas, mangosteen and pomegranate extract) or maca root. All trials were of poor methodological quality. Adverse effects were frequently not reported. In summary, there is some weak evidence to suggest that several botanical extracts may be effective in reducing the appearance of skin aging but no evidence that this effect is enduring. Independent replications with larger, more diverse samples, longer treatment durations and more rigorous study designs are required to validate these preliminary findings.