DUSSELDORF, GERMANY. Sunlight and ultraviolet radiation cause the formation of reactive oxygen species in the skin resulting in photooxidative damage such as sunburn (erythema), premature aging of the skin, and skin cancer. Since beta-carotene and tocopherols (vitamin-E) are effective scavengers of reactive oxygen species one might speculate that supplementation with these antioxidants would decrease the risk of photooxidative damage.
Researchers at the Heinrich Heine University now report that this is indeed the case. Their experiment involved 20 healthy subjects with white skin and significant sensitivity to sunlight. The participants were randomly assigned to one of two groups. Group 1 supplemented with 25 mg of a natural beta-carotene extract from Dunaliella salina while group 2 supplemented with the beta- carotene plus 335 mg of synthetic vitamin E. The supplements were taken daily for 12 weeks with the main meal. The beta-carotene content of the blood and underarm skin increased by over 400 per cent (from 0.54 to 2.92 micromol/L) and 166 per cent (from 0.12 to 0.32 nanomol/gram) respectively after 12 weeks of supplementation. During the same period vitamin E content in blood serum samples from group 2 rose by about 80 per cent (from 42.0 to 75.6 micromol/L).
An evaluation of the extent of sunburn after being exposed to ultraviolet radiation at various strengths clearly showed that the resistance to sunburn increased significantly in both groups after 12 weeks of supplementation. The protective effect was greatest in group 2 and was equivalent to the protection afforded by a sunscreen with a sun-protection factor (SPF) of 3.0. The equivalent SPF obtained in group 1 was 2.4. The researchers conclude that oral supplementation with beta-carotene and vitamin E is useful for diminishing sensitivity to ultraviolet light.
Stahl, Wilhelm, et al. Carotenoids and carotenoids plus vitamin E protect against ultraviolet light-induced erythema in humans. American Journal of Clinical Nutrition, Vol. 71, March 2000, pp. 795-98