Effect of beta-carotene supplementation on the human sunburn reaction.

Beta-carotene, a quencher of excited species such as singlet oxygen and free radicals, has been reported to protect against cutaneous photodamage, including sunburn acutely and photocarcinogenesis chronically. The present double blind placebo-controlled study examines the effect of beta-carotene supplementation on the human sunburn response and specifically on the induction of sunburn cells at the time of peak reaction intensity (24 h) after a single solar simulated light exposure 3 times the individually determined minimal erythema dose (MED). Administered orally either as a single 120 mg dose to dietarily restricted subjects or for 23 d as a daily 90 mg supplement to subjects on standard diets, beta-carotene increased plasma and skin levels of beta-carotene compared to both pretreatment levels and placebo-treated controls, but provided no clinically or histologically detectable protection against a 3 MED sunburn reaction. Thus, these data suggest that oral beta-carotene supplementation is unlikely to modify the severity of cutaneous photodamage in normal individuals to a clinically meaningful degree.