People with a well developed cortex find quinine less bitter, study finds

Reactions to quinine, the compound that gives tonic water its characteristic bitter taste, have been found to correlate with the size of an area of the brain known as the entorhinal cortex.

The finding, by a team of researchers led by Liang-Dar Hwang of Australia’s Queensland Brain Institute, is the first evidence that relative brain size relates to the perception of flavour.

Hwang and colleagues enrolled more than 1600 volunteers in Australia and the US in a quest to discover variations in reactions to sweet and bitter substances.{%recommended 7307%}

Participants were asked to rate their reactions to tastes along the sweet-to-bitter spectrum. Each then underwent an MRI scan to determine the size of his or her brain.

The results – published in the journal Behavioural Brain Research – were surprising.

“We found that the left side of the entorhinal cortex, an area of the brain responsible for memory, odour and visual perception, was larger in people who found quinine to be less bitter,” says Hwang.

The finding can’t be interpreted to mean that bigger cortexes indicate a fondness for tonic water, but it does support the contention that those with the enlarged area found the taste less confronting.

At first blush, the research may seem to be of little practical value, but Hwang and his colleagues disagree.

“Our study is a step towards understanding exactly how the brain perceives taste,” he explains.

“The findings have implications for improving dietary behaviour and treating eating disorders.

“By targeting specific areas in the gustatory cortex, we could treat eating disorders using methods such as transcranial magnetic stimulation, a non-invasive treatment currently used to treat mental illness.”

There is no word thus far on whether the researchers plan to extend the experiment by adding a good gin to the mix.