Smells affect us in both short- and long-term. In worms and flies, too much smell of the opposite sex can speed up the critter's ageing
process and shorten its life. Even if none actually has sex. Similar to the effect of smelling too much good food even without eating it.The explanation lies in the fact that the fruit fly sperm is toxic and every sexual encounter shortens the lives of females. If the males were actually allowed to have sex, their lifespans bounced back. Perhaps because od the trade-off between sex and longevity and, more importantly, the clash between expectations and experience. If we smell food and can’t eat any, the build-up of digestive enzymes can actually cause us harm. Likewise, male flies that smell females but can’t actually mate may suffer the consequences for their unfulfilled expectations.
References
Gendron, Kuo, Harvanek, Chung, Yew, Dierick & Pletcher. 2013. Drosophila Life Span and Physiology Are Modulated by Sexual Perception and Reward. Science http://dx.doi.org/10.1126/science.1243339
Maures, Booth, Benayoun, Izrayelit, Schroeder & Brunet. 2013. Males Shorten the Life Span of C. elegans Hermaphrodites via Secreted Compounds. Science http://dx.doi.org/10.1126/science.1244160
