Carrots, Longer Life and a Lot of Sex

Have you ever thought about the link between carrots and sexual success?

A team at the Universities of Glasgow and Exeter has found that the plant pigments called carotenoids, besides slowing down the aging rhythm of the males and thus prolonging their life, makes them more attractive to females.

Carotenoids usually give plants yellow and red hues and animals eating those plants, due to these pigments, turn themselves more colorful and more attractive to potential mates.

Carotenoids' physiological role is that of antioxidants, preventing oxidative stress (with role in aging) and enhancing the immune system.

The study revealed for the first time how males eating more carotenoids could prolong their life and the long-lived males could become more attractive to females. The research was made on stickleback fish and compared the sexual success of males that were fed with the same basic diet varying just on the carotenoid amount.

Male sticklebacks require even more carotenoids during the mating season to produce the red throat patch, a strong sexual signaling for the females.

"Males provided with fewer carotenoids still tried to produce a bright red throat patch, but could only do so by diverting carotenoids away from their role as antioxidants; so by trying to look as good as possible, these males aged faster." said Dr Thomas Pike, researcher in Environmental and Evolutionary Biology at Glasgow University.

In this species, the male builds a nest in which the female lays her eggs and then gets off.

The male remains to care for the eggs and young.

"It seems that females can tell if males haven't eaten many carotenoids, even if they do look quite red, and probably found these males less attractive because they were more likely to die before they had finished looking after the young," said Pike.

"The positive effects of a carotenoid-rich diet are likely to apply to many other animal species as well - but whether eating carrots makes humans longer-lived and more handsome remains to be seen!"

"The most brightly coloured males often get the girl, but why females prefer such show-offs hasn't been clear. Our study shows that redder males are more likely to be good fathers, because they can survive the demands of parenting." said Dr Jon Blount, Research Fellow at the University of Exeter.