Say it you may not believe… Smell, smell fat.

Everyone knows that eating more, moving less, easy to gain weight. But a recent scientific study found that when there was no increase in eating and no decreased movement, the fat of experimental animals increased simply by smelling a certain smell. Smell smell can also grow fat?! The researchers chose nematodes as the subjects of research into fat metabolism.

Say it you may not believe... Smell, smell fat.

The work, published in Nature Communications, a unit of Nature, is led by Professor Meng Wang of Baylor College of Medicine.

On the one hand, the nematodes are transparent, and the researchers used an innovative chemical imaging technique, the simulation Raman scattering microscope, to see directly how and how the lipid molecules in the nematodes are distributed and changed. On the other hand, as a model animal, the complete neural network of nematodes has been clarified, and scientists can quickly find out which neurons may be involved in regulation through common genetic techniques.

Say it you may not believe... Smell, smell fat.

Professor Wang Meng, author of the study (Photo: Baylor College of Medicine)

In the study, the scientists found that a group of AWC olfactory neurons did not eat more or move less after a genetic mutation, but as the lipid metabolism declined, the amount of fat stored in the intestines increased – the fat of the nematodes is stored mainly in the intestines.

Given that the activity of different olfactory neurons is regulated by specific odor molecules, this phenomenon has led scientists to speculate that the odor molecules that stimulate aWC olfactory neurons may directly regulate lipid metabolism and fat reserves.

To test this hypothesis, the researchers conducted a series of odor exposure experiments: not to feed the nematodes, and to smell them differently. After a small screening of some common odor molecules, the researchers noted that when 2-butanone was present in the container, the activity of aWC olfactory neurons was inhibited, and the nematodes smelled for four hours, and the body’s fat levels quickly increased. Fortunately, the regulatory effect is dynamic ally, and when the smell of this sweet silk is removed, the fat levels will recover.

Through experimental methods such as RNA interference, the researchers clarified from the molecular mechanism how downstream neuroendocrine activity regulates lipid metabolism after odor activation of this group of olfactory neurons. The clarification of these signaling pathways also provides many clues for interfering with fat regulation.

Say it you may not believe... Smell, smell fat.

Research schematics (Image Source: Resources)

Taken together, this study sheds light on the effects of olfactory perception on fat metabolism and suggests that not all odors but specific smells may play a key role.

Of course, the sense of smell is very complex, and the different combinations of odor receptors in olfactory neurons make the sense of smell very different individuals. In daily life, we must have experienced, the same smell (such as the smell of durian), some people “real fragrance”, some people smell want to vomit. So, the study authors concluded the paper, the findings suggest that different sense of smell perception may be associated with different levels of obesity. If these associations are further studied, we will have new ways to prevent and treat obesity.