Vitamin E supplements make male European green lizards smell more sexy. New research published online in the journal PLoS One, led by Gábor Herczeg, shows that vitamin E in the lizards’ diet can get into the secretions left by male lizards. When males eat more vitamin E, females will spend more time near their secretions, apparently hoping for a little high antioxidant loving.
Why might females prefer males with higher levels of vitamin E? The scientists think it might be because vitamin E is hard to come by, and it has to come from the diet. (See the post on parasitoid wasps…it’s a similar story for linoleic acid in male wasp pheromones). And vitamin E is important for a lot of other things besides making sexy-smelling secretions. If a male is going to boost his scent with vitamin E, he better have a surplus of it.
Basically, the harder it is to get that much vitamin E, the healthier a male has to be to make secretions with tons of it. By choosing males with the most vitamin E in their diet, females are picking those males that probably have better health and a better ability to get food.
We don’t yet know whether lizards that eat more vitamin E are more fertile, or wether they are even better at getting females to mate with them. All we know so far is that females think they smell better.
But why do females like the smell of vitamin E?
It could just be that vitamin E is an easy way to judge the overall health of a male. One other possibility is that this antioxidant might be important for sperm health. In humans, studies have shown that seminal fluid is high in reactive oxygen species (ROS) that can cause DNA damage in sperm. It’s also high in antioxidants that presumably protect the sperm from ROS. Whether eating more vitamin E, or other antioxidants, can help protect sperm hasn’t yet been shown, but it is an interesting possibility.