Brain chemical makes alcohol taste more bitter to women

Scientists at The Florey have discovered a chemical in the brain that may explain the different drinking habits of men and women. It all comes down to how our brains detect bitter tastes, and it could be harnessed to help women stop binge drinking.

Dr Leigh Walker, an expert in the neurobiology of anxiety and alcohol use disorders at The Florey, said science has so far primarily focused on examining how male brains work. Her new study, published in the journal Neuropsychopharmacology, looked at how female brains might differ from male brains and identified differences in response to taste.

“The taste of alcohol is an important and often overlooked factor that drives alcohol preference, intake and use,” Walker said.

“We have identified a chemical in the brain that makes alcohol taste bitter to females, unless the drink is sweetened.”

The research centred on ‘CART’, a neuropeptide present in all species and associated with energy balance, depression, anxiety and reward-related behaviour, including those around drinking alcohol. Working with graduate researcher Xavier Maddern and other Florey researchers, Walker studied the effect of inhibiting CART in mice that were trained to drink alcohol.

“Alcohol has an underlying bitter taste,” Walker said. “When we inhibited CART in male mice, their drinking increased. And when we knocked out the same brain chemical in female mice, they drank less. But when the alcohol was sweetened, the female mice drank more. This tells us that without CART, alcohol is unpalatable to females.”

The findings could pave the way for treatments designed to help women stop binge drinking, which is important as rates of risky drinking and alcohol use disorders are rising in women much faster than in men.

“If we can find a way in future research to target the CART neuropeptide system, we may be able to create treatments to help women curb excessive alcohol use,” Walker said. “And if we can work out how male and female brains differ it will open unprecedented opportunity to treat disorders of the brain in women, including alcohol use disorders.”

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