Is there a link between hearing loss and Alzheimer’s?
Many wonder if there is a link between hearing loss and Alzheimer. Alzheimer’s disease is the degeneration of a person’s cognitive abilities. It is the best known form of dementia. Researchers have studied the issue to identify all the factors that cause this disease, and findings show that deafness may be linked to cognitive decline. A recent study* established that hearing-impaired seniors are more likely than seniors with normal hearing to develop dementia or Alzheimer’s disease. These studies were conducted on some 2,000 seniors aged 75 to 84. Cognitive degeneration was 30% to 40% higher in participants with hearing loss than in those with normal hearing. According to researchers, the level of cognitive decline was directly linked to the level of hearing loss.
Why is there a relationship between hearing loss and Alzheimer’s?
The researchers involved in this study developed three theories to explain the link between hearing loss and Alzheimer.
First theory: Social isolation
Social isolation is a proven risk factor for Alzheimer’s disease. Solitude is linked with increased inflammation throughout the body, and stress sensitivity. This symptom triggers several aging-related disorders, including dementia. Hearing loss that isn’t corrected can lead to isolation. Hearing-impaired persons tend to decrease their social activity little by little, and to unwillingly withdraw into themselves.
Second theory: Cognitive load
The effort required by the brain to understand and translate sounds it must strain to hear can consume the brain’s energy. It therefore dedicates less effort to other parts of the brain that also need it, like memory.
Third theory: Pathological link between hearing loss and Alzheimer
There could be a pathological link, meaning a disease-related link, between hearing loss and Alzheimer’s disease. There could also be a genetic or environmental factor that would lead to both of these conditions at once. Research results have shown that hearing loss must not be ignored since this can have long-term consequences on cognitive ability. Researchers hope that more advanced studies will prove that correcting hearing loss can help reduce cognitive degeneration.
By Sophie Waridel, audiologist, Polyclinique de l’Oreille
*Source: Hearing Loss and Cognitive Decline in Older Adults, a study by Dr Franck Lin (Johns Hopkins School of Medecine).