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Chilli study reveals why some like it hot

Hot stuff A fondness for the burn of spicy food has less to do with tolerance and far more to do with personality, according to a new study.

Researchers from Pennsylvania State University have found a love of chilli is associated with sensation seeking and reward, but found no evidence that chilli lovers get desensitised to chilli burn over time.

"Rather than merely showing reduced response to the irritating qualities of capsaicin (the compound that gives chilli its burn) as might be expected ... these findings support the hypothesis that personality differences may drive differences in spicy food liking and intake," the authors wrote in the journal Food Quality and Preference.

"We always assumed that liking drives intake - we eat what we like and we like what we eat. But no one had actually directly bothered to connect these personality traits of sensation seeking with intake of chilli peppers," says lead author and self-confessed chilli lover Professor John Hayes.

The discovery of a relationship between fondness for chilli and sensitivity to reward was also new, says Hayes who is an assistant professor of food science at Pennsylvania State University.

Nearly one hundred volunteers were given liquid samples of capsaicin and asked to swill it in their mouth for three seconds before spitting out.

They were then asked to rate the burning sensation and, in a separate questionnaire, rate their liking of various foods.

"We used this thing called sensitivity to punishment and sensitivity to reward questionnaire," says Hayes.

"One is the idea that there are these rewarding stimuli - things you're going to go and seek out - versus the sensitivity to punishment - that's the avoidance behaviour."

The lack of a connection between desensitisation and liking spicy food had been suggested by earlier research, but this study adds further weight to that notion.

"It's pretty clear from earlier work that it can't just be desensitisation; there has to be some sort of affective shift because it's not just that it doesn't burn as badly, it's that you actually learn to like the burn."

The work is part of a bigger study looking at the genetics of oral sensation which Hayes hopes will advance our understanding of why people differ in their food preferences.

This may even have implications for future public health interventions around healthy eating, he says. For example, an individual's genetic profile around oral irritation and food preferences could help a dietician prescribe a healthy eating plan tailored to that profile.