Exercising Your Sense of Smell to Support Your Cognitive Health

by SHANNON DAHLUM, FDN-P 

As you age, it’s expected that you’ll eventually begin to experience a decline in the quality of your senses. You may have your vision checked annually and have prescriptions for eyeglasses or contacts adjusted to ensure you continue to see well. At some point you’ll likely notice you have trouble understanding the conversations going on around you, and may rely on hearing aids to improve your sense of hearing. One sense that you may not expect to diminish, but that may have even greater implications in your wellness, is your sense of smell.

The brain circuitry involved in your olfactory sense (your sense of smell) is directly connected to your brain’s memory circuitry. You’ve probably experienced the effect of this many times yourself; you’re exposed to a smell that’s associated to a memory and are immediately transported back to that memory before you even have a moment to think about it. For me, every time I smell roses, I immediately feel the loving presence of my grandmother, who always wore the scent of roses.

Because olfaction and memory share the same circuitry, the loss of smell can be predictive of the development of neurological and psychiatric diseases. Some estimates have associated the loss of olfactory capacity with 70 different neurological disorders including Alzheimer’s, Parkinson’s and schizophrenia. Perhaps supporting your sense of smell as you age is even more important than supporting your vision and hearing. This isn’t something your doctor checks at your wellness visits, though, so how can you work on maintaining a healthy olfactory sense, and possibly, healthy neurological function?

Research has shown that using aromatherapy improves memory, language skills and depression symptoms in patients with moderate dementia. One recent study found significant improvements in the cognitive function of older adults who didn’t even have previous signs of cognitive impairment. In this study, performed at the University of California, 60-85 year olds were exposed to the scent of essential oils in a diffuser for 2 hours per night while they slept.

Seven different pure essential oils were rotated in an essential diffuser each night for six months. Results after the six months showed a whopping 226% increase in memory performance compared to controls. The study participants also reported improved sleep, which may have played a role in the improved memory, as well.

The researchers who conducted the study say that this finding transforms the long known tie of olfaction and memory into an easy to apply, non-invasive technique for strengthening memory and potentially deterring dementia. Not only did the participants experience memory improvements, but imaging revealed better integrity in the brain pathway called the left uncinate fasciculus. This pathway, which connects the medial temporal lobe in the brain (which is crucial for memory) to the decision- making prefrontal cortex, typically diminishes with age.

While your doctor may not have much to offer you for improving a declining sense of smell, you now have a simple tool you can apply yourself for improving and maintaining your olfaction and cognitive function. Another great perk is how it may also improve your sleep! All you need is an essential oil diffuser that will run for 2 hours and some pure essential oils. The study utilized oils of rose, orange, eucalyptus, lemon, peppermint, rosemary and lavender, but it may not be necessary to use all seven in a rotating fashion as they did in the study. Of those, choose what you like and just start with that! You can add more scents to your rotation over time.

There don’t appear to be any studies to determine if smelling artificial fragrances provide the same beneficial effect, but it has been shown that many of the chemicals in them negatively impact other aspects of health, especially hormonal health. Shopping for pure essential oils can be tricky because the labeling can be misleading; the word “pure” can be used on a bottle of oil that only contains a few drops of pure essential oil in a bottle mostly full of artificially fragranced oil. It’s best to do your research on the the brand of oil you find in stores and find out where they’re sourced from before you purchase them. I personally trust all of the oils sold at Fiesta on Eighteenth, and they carry essential oil diffusers, as well.

Strength training is important as you age for maintaining your metabolic health, and now it seems as though training your sense of smell can be a simple way to support your cognitive health. Luckily, your sense of smell is one thing you can actually train while you’re asleep, so it’ll be tough to come up with an excuse to avoid it!