Sense of Smell and Dementia

Our sense of smell is closely tied with how we experience the world, how our food tastes and is one of the strongest senses associated with memory.  But many older adults have lost some degree of their sense of smell and as a result can lose interest in eating or over season food. The loss of smell in older age can also be an early indicator of Alzheimer’s Disease and because smell can alert us to dangers such as smoke or gas leaks, can be a serious deficit.

A 2015 study, published in the Journal of the American Medical Association Neurology, discovered a  decreased sense of smell in older adults was associated with an increased risk of Alzheimer’s Disease dementia.   It is believed that neurodegenerative changes in the olfactory bulb and other regions of the brain that involve smell account for this correlation.

Odor identification tests can be used for early detection of Alzheimer’s; if an individual cannot recognize three of ten familiar scents including leather, lemon, orange or smoke, they may be at an increased risk for AD.   The testing is not perfect however because the ability to smell can also be diminished by smoking, other brain diseases including Parkinson’s, head injuries or normal aging.

Our sense of smell’s connection to memory can also serve as an important tool to help older adults with dementia recover long-forgotten moments.  The scent of freshly baked cookies, the woods in the fall, a bonfire, roasted turkey, pine trees or even a particular brand of soap can help bring comfort to someone with dementia by triggering happy distant memories when short term recall may be lost.

As part of a dementia friendly initiative in Japan, projects aimed at improving the lives of people with dementia include fragrance workshops which help participants recall memories and emotions through the sense of smell.  And aromatherapy, the use of essential oils to improve physical and mental health, has also been used with some success to help reduce agitation, aid in sleep and increase alertness in patients with dementia.  Lavender oil in particular has been used to create a calming environment.

To learn more about the sense of smell and dementia, visit the Psychology Today website by following this link.