Sound, touch, sight and other senses travel complex pathways to reach the brain, but what makes smell special is that when scent molecules enter your nose, they travel to the olfactory bulb in your brain, which then transmits the signal directly to the limbic system, says Schwantes. This system contains structures like the amygdala and hippocampus, brain regions associated with emotion and memory.
Research on why aromatherapy promotes health is still limited, but experts cite some general scientific theories about why scents affect the body and brain.
The “pharmacological hypothesis” claims that scents act directly on the autonomic and central nervous systems, which regulate everything from heart rate and digestion to speech and memory. Studies of lavender, for example, have found that it affects the activity of cyclic andenosine monophosphate, a biochemical messenger within cells in the body that is associated with sedation.
Then there’s the “psychological hypothesis.” If you’ve ever smelled a baking pie or a roasting chicken and had that happy feeling of returning to your grandparents’ house, this hypothesis may ring a bell. This theory suggests that our responses to smells are learned. In other words, we associate smells with emotional experiences, and ultimately, those smells evoke the pleasant or unpleasant feelings associated with those experiences. For example, one study showed that people exposed to pleasant smells, like baking cookies or roasting coffee, were more likely to help strangers. Another study found that people exposed to unpleasant smells had a lower tolerance for frustration.
Aromatherapy Basics for Children
Although the empirical evidence is still limited, some scents in particular seem to promote a sense of well-being in children, says Vanessa Battista, a nurse practitioner in the Neuromuscular Program at Children’s Hospital of Philadelphia.
