Scientists from the Leibniz Research Institute for Environmental Medicine, Germany, and Amway Corporation report that 12 weeks of supplementation with the Nutrilite Multi Carotene product led to significant increases in skin carotenoid levels after four, eight and 12 weeks, compared to placebo, and this was correlated with protection against UVA and UVB irradiation.
“Our results are in line with a previous study [Grether‐Beck et al. Br. J. Dermatol. 2017;176:1231‐1240] in which oral intake of carotenoids was found to decrease UVA radiation sensitivity of human skin at a molecular level,” wrote the researchers in the journal Photodermatology, Photoimmunology & Photomedicine.
“The current study corroborates and extends these observations and provides the first clinical evidence that oral intake of carotenoids can protect against UVA radiation.”
Study details
The randomized, double-blind, placebo-controlled study included 60 volunteers with Fitzpatrick skin types II‐IV, which meant the skin types varied from fair/ burns easily (Type II) to light brown/ burns minimally, tans easily (Type IV). Participants were randomly assigned to receive the Nutrilite Multi Carotene product providing 4.25 mg of beta-carotene and 1.10 mg alpha-carotene (EVTene by Malaysia’s ExcelVite), plus 1.12 mg of lutein and 0.053 mg of zeaxanthin, or placebo three times a day for 12 weeks.
Results showed that, after 12 weeks of supplementation, daily oral intake of the carotenoids-complex, but not placebo, increased UVA-induced minimal persistent pigmentation dose (MPPD) values and hence protects human skin against UVA-induced pigmentation and UVA radiation.
The researchers also measured the minimal erythema dose (MED), which is a measure of the minimal amount of energy required to induce visible reddening of the skin (erythema). The data indicated that carotenoid supplementation increased the UVB-induced MED, meaning it required more UVB to redden the skin. In other words, the carotenoids offered protection against UVB-induced erythema.
Commenting on the potential mechanism(s) of action, the researchers noted that the carotenoids offered protection via their antioxidant effects.
“We here provide the first clinical evidence that oral intake of carotenoids can protect human skin against UVA radiation,” they wrote.
“Notably, this effect was observed in healthy subjects who were not following an extensive dietary restriction, but instead were allowed to keep their normal dietary habits. We, therefore, believe that the carotenoid‐based intervention described in this study might be of relevance for the general population. Also, increased skin pigmentation due to solar radiation exposure is a cosmetic concern to a large part of the world's population.20
“Future clinical work is needed to further address if and to what extent nutritional supplementation with carotenoids can mitigate or prevent clinical consequences of UVA irradiation beyond skin pigmentation, such as photoaging and photocarcinogenesis,” they concluded.
Source: Photodermatology, Photoimmunology & Photomedicine
Published online ahead of print, doi: 10.1111/phpp.12541
“Orally administered mixed carotenoids protect human skin against ultraviolet A‐induced skin pigmentation: A double‐blind, placebo‐controlled, randomized clinical trial”
Authors: S.M. Baswan et al.