Health Buzz: How Smelling Food Could Lead to Weight Gain

Could this experiment be applied to humans in the first place? (GETTY IMAGES)
That alluring smell of a juicy hamburger is practically as good as biting into one itself. But can smelling food, in fact, affect how our bodies process food?

A new study done on mice at the University of California–Berkeley suggests that, yes: How food smells could be a key factor in whether the body decides to burn calories or store them. The study was published July 5 in Cell Metabolism.

Researchers divided the mice into three groups: normal mice, super-smellers (those with a boosted sense of smell) and those who didn't have a sense of smell, SF Gate reports. All mice consumed the same amount of high-fat food, but those dubbed super-smellers put on the most weight. The normal mice still gained weight as well – twice their typical weight. The mice without a sense of smell gained the least weight.

Researchers say these results show a connection between the smell system and metabolism-regulating areas of the brain – though how they interact isn't yet clear.

Through gene therapy, researchers knocked out the sense of smell in adult mice temporarily by eliminating olfactory neurons but keeping stem cells. The mice who lost their sense of smell burned calories quickly, though they did see an uptick in the hormone noradrenaline. This is a stress response hormone that, in humans, could result in a heart attack if sustained at high levels.

Could this experiment be applied to humans in the first place? Study author Céline Riera told SF Gate that perhaps people's brains could be tricked into doing something similar, taught to burn, not store calories when eating.

"If we can validate this in humans, perhaps we can actually make a drug that doesn't interfere with smell but still blocks that metabolic circuitry," study author Andrew Dillin said in a statement. "That would be amazing."

It might be a bit of a leap to rid people looking to lose weight of their sense of smell, but for the morbidly obese it could be an option other than stomach stapling or bariatric surgery.

"Maybe once a year you block your sense of smell for a while and then you lose the weight from the year and do it all over again," Dillin told SF Gate. "We don't know yet. There's a lot we still need to do."