The carotenoid beta-carotene enhances facial colour, attractiveness and perceived health, but not actual health, in humans

Carotenoid-based coloration plays an important role in mate choice in many animal species. It is argued to be an honest signal of health because carotenoids function as antioxidants and only healthy individuals can afford to use available carotenoids for signaling. Here, we tested the effect of dietary supplementation of the carotenoid beta-carotene on facial appearance and health in human males. Beta-carotene supplementation altered skin color to increase facial attractiveness and perceived health. However, we found no effect of beta-carotene on measures of actual health, including oxidative stress, innate immune function, and semen quality. We conclude that although carotenoid-based skin color may be sexually selected in human males, it may not be an honest signal of health.