ALCOHOL tastes sweeter to rats whose mothers imbibed before birth, which might explain why fetal alcohol exposure in humans ups the risk of alcohol abuse and lowers the age at which someone has their first drink.
The taste of alcohol is a mix of sweet and bitter. To test whether prenatal exposure affects perception of these components, at the State University of New York in Syracuse and colleagues watched young rats consume ethanol and sweet and bitter water.
Those whose mothers had consumed alcohol during pregnancy lapped up ethanol and bitter water more avidly than those whose mothers didn鈥檛, although both groups lapped up sweet water. They also seemed more attracted to the smell of the ethanol (Proceedings of the National Academy of Sciences, ). Exposure before birth may familiarise rats with the bitter taste of alcohol, blunting their perception of its bitterness, which in turn drives up its sweetness.
Advertisement
These perceptions seemed set for life, except in prenatally exposed rats that hadn鈥檛 tasted ethanol during their youth: their preference for alcohol faded once they were adults. Youngentob says the take-home message is to 鈥渒eep kids away from alcohol for as long as possible鈥�.
The ability to transfer dietary flavours in the womb may have evolutionary benefits. 鈥淥ne of the ways that animals learn what鈥檚 good to eat in the world is on the basis of what mom ate during pregnancy,鈥� Youngentob says.