Orally administered mixed carotenoids protect human skin against Ultraviolet A-induced skin pigmentation: A double blind, placebo controlled, randomized clinical trial.
Photodermatol Photoimmunol Photomed. 2020 Feb 18. Epub 2020 Feb 18. PMID: 32072695
Sudhir M Baswan
BACKGROUND: Photoprotection of human skin is determined as the capacity of sunscreens to prevent Ultraviolet (UV) B radiation-induced erythema and UVA radiation-induced pigmentation. It is unequivocal that, in addition to sunscreens, oral supplementation with carotenoids can protect human skin against UVB radiation-induced erythema. It is not known if this is also the case for UVA radiation-induced pigmentation.
OBJECTIVE: To clinically evaluate the photoprotective effects of daily supplementation with carotenoids against UVA radiation-induced pigmentation.
METHODS: In this double blind, placebo-controlled trial, 60 subjects (Fitzpatrick types II-IV) were randomized to receive Nutrilite™ Multi Carotene supplement or placebo for 12-weeks. UVB-induced Minimal Erythemal dose (MED), UVA-induced Minimal Persistent Pigmentation Dose (MPPD) and skin carotenoid levels were measured at baseline, 4, 8 and 12 weeks of intervention. Skin color was evaluated by expert clinical graders and bycolorimetry . Carotenoid levels in the skin were measured by the Biozoom® device.
RESULTS: In the intervention group, a significant increase in comparison with the placebo group was observed in (i) skin carotenoid levels, (ii) UVB-induced MED and (iii) UVA-induced MPPD values obtained by colorimetry.
CONCLUSION: Daily supplementation with carotenoids protects human skin against both UVB-induced erythema and UVA-induced pigmentation.