Carlos Solis
One sense can pull you back in time faster than any other. Catch the smell of modeling clay and you might suddenly recall your first days of school, or a whiff of someone else’s perfume can revive a memory of an old love. That link between smell and memory feels familiar to many people.
Neurologists long ago found that the olfactory system connects directly to brain regions that handle memory and emotion, such as the hippocampus and the amygdala. When we inhale, scent receptors in the nose bind to odor molecules, and olfactory sensory neurons send electrical signals to different parts of the brain. All of this happens in milliseconds.
“These are very direct connections between the olfactory system and brain areas tied to memory and emotion,” says Professor Thomas Hummel of the Technical University of Dresden, who has studied the sense of smell for decades.
Clinicians often view loss of smell as an early warning sign of broader cognitive decline. Loss of smell correlates with neurodegenerative diseases, including Alzheimer’s, and it also occurs with normal aging.
Can You Train Your Sense of Smell to Protect Your Brain?
But what if you go the other way? If you strengthen your sense of smell, will you improve not only your ability to detect odors but also your memory and thinking?
A number of studies, many with small sample sizes, have shown measurable changes in cognitive scores and even in brain structure after olfactory training. A 2023 review that pooled 18 papers concluded that olfactory training can improve specific aspects of cognition, such as problem-solving and learning.
Study participants also showed increases in the volume of certain brain regions, including the hippocampus and the olfactory bulb, along with strengthened neural connections. Improvements appeared not only in people with existing cognitive decline but also in the general population.
Hummel says it’s not a cure-all — improving smell won’t instantly make you smarter. But it can support certain cognitive functions, and a simple, side-effect-free exercise can produce those changes.
How to Train Your Sense of Smell at Home
You don’t need expensive equipment for at-home training. Here’s a basic protocol used in studies:
- Gather about four familiar but distinct scents.
- Choose strong aromas; they work better than weak ones. Researchers often use clove, lemon, coffee, and eucalyptus.
- Spend about five minutes, twice a day, sniffing each scent in turn.
- Smell each aroma for at least 20 seconds while focusing on it. Ask yourself how it presents, which notes you detect, and whether it feels stronger than you expected.
- Replace the scents with new ones every two months.
Hummel emphasizes that researchers need larger, more robust studies because the effects may be subtle in some people. Still, the exercise is simple and safe, and it causes no harm, so it’s worth trying.
Based on BBC Science Focus
