discoveries magazine

Could Smell Impact Metabolism?

Clint Blowers

Hunger can activate your sense of smell, but is there a relationship between your nose and your weight? New research at Cedars-Sinai suggests that what we smell might affect how our bodies process food.

In one recent study, investigators uncovered a connection between olfactory neurons, which control smell, and metabolism, the body's process of converting food into energy. Celine Riera, PhD, found that mice without olfactory neurons—no sense of smell—ate the same amount and type of food as normal mice but remained leaner. In mice without functional sniffers, Riera found that the hypothalamus—the part of the brain that regulates energy, balance and appetite—perceived food differently.

We're very excited about this finding, which may give us the opportunity to better understand the pathways of obesity in humans, says Riera, an investigator in the Cedars-Sinai Center for Neural Science and Medicine.

Another study aims to discover whether the reverse relationship between smell and metabolism could exist. Shehnaz Hussain, PhD, is investigating non-alcoholic fatty liver disease, a condition linked to obesity and diabetes that can lead to cirrhosis and cancer of the liver. An upcoming study will regulate the diets of people with the disease to explore, among other functions, whether a change in food intake can affect sense of smell.

Fortunately, despite our bodies’ and brains’ complicated relationship to food, aromas still have zero calories.