Hearing Loss and Dementia

In the last few years more and more attention is being paid towards the effects of hearing loss on cognitive health. After all, we hear from our brains, our ears are merely a pathway to our auditory systems (1). It stands to reason that any sensory deprivation, such as hearing loss, could lead to wider adverse effects on brain vitality. It is something that researchers have been asking themselves for decades but not until recently has there been more convincing data in support of this.

In one of many compelling studies, Lin. et al found a strong link between persons suffering from hearing loss and the incidence of dementia. The study showed a strong positive correlation between hearing loss and dementia; more specifically, the greater the severity of hearing loss the higher the chance of the subject developing dementia. Intriguingly, even with only a mild hearing loss the chance of subjects developing dementia had already doubled compared to that of a normal hearing person (2).

In a separate study of elderly subjects, it was found that hearing loss was associated with increased levels of brain atrophy (shrinkage) as seen on MRI scans. The study theorized that hearing loss increased the rate of incident dementia through altered cognitive load due to reduced social engagement (3).

These findings are consistent with a more recent body of work undertaken by a group of researchers at the University of Utah. Not only did they observe that persons with hearing loss have an increased rate of developing dementia, they also documented that these subjects had an earlier onset and increased severity of cognitive decline. The data suggest that hearing impairment may be a risk factor for cognitive dysfunction in adults aged 65 years and older (4).
Despite this, it is important to recognize that correlation does not always equal causation. In other words, just because you have hearing loss does not mean you have or will definitely develop dementia. In fact there has been a conflicting study (5) in the body of literature, so it is important to be mindful and objective.

What we do know however, through evidence-based research, is: the sharper and more active you keep your mind the better (3, 6, 7). This means taking care of all your senses – visual (eyes), auditory (ears), motor (movement), olfactory (taste/smell). See the best you can; hear the best you can; be physically active the most you can; and live a long and meaningful life.

1. Wiener, F. M. (2009). "How we hear." Physics Today 2(12): 8-14.
2. Lin, F. R., et al. (2011). "Hearing loss and incident dementia." Archives of neurology 68(2): 214-220.
3. Lin, F. R., et al. (2013). "Hearing loss and cognitive decline in older adults." JAMA internal medicine 173(4): 293-299.
4. Gurgel, R. K., et al. (2014). "Relationship of hearing loss and dementia: a prospective, population-based study." Otology & Neurotology 35(5): 775-781.
5. Gennis, V., et al. (1991). "Hearing and cognition in the elderly: new findings and a review of the literature." Archives of internal medicine 151(11): 2259-2264.
6. Crews, J. E. and V. A. Campbell (2004). "Vision impairment and hearing loss among community-dwelling older Americans: implications for health and functioning." American Journal of Public Health 94(5): 823-829.
7. Kirk-Sanchez, N. J. and E. L. McGough (2014). "Physical exercise and cognitive performance in the elderly: current perspectives." Clinical interventions in aging 9: 51