A hormone called ghrelin enhances the nose's ability to sniff out food, researchers report.
It was already known that ghrelin promotes hunger and fat storage. The new study suggests that the hormone may increase the ability to use smell to detect food and link that input with the body's natural regulation of metabolism and body weight, said University of Cincinnati scientists.
The study, which included experiments with humans and rats, appears in the Journal of Neuroscience. It was led by Dr. Jenny Tong and Dr Matthias Tschop, both of the university's endocrinology, diabetes and metabolism division.
Sniffing out hunger
"Smell is an integral part of feeding, and mammals frequently rely on smell to locate food and discriminate among food sources. Sniffing is the first stage of the smell process and can enhance odour detection and discrimination," Tong said.
"Other studies have shown that hunger can enhance odour detection and sniffing in animals," Tschop added. "Since ghrelin is a hunger-inducing stomach hormone that is secreted when the stomach is empty, this hormone pathway may also be responsible for the hunger-induced enhancement of sniffing and odour detection."
The researchers plan further research to identify the exact molecular pathways through which ghrelin affects sniff behaviour.
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