August 28, 2013
Want to keep the memory working well into old age? It may be worth paying more attention to your hearing. A new study reports that poor hearing may contribute to memory and thinking problems in old age.
The findings, published in the American Medical Association journal JAMA Internal Medicine, add to growing evidence that hearing loss may be linked to memory problems, including an increased risk for dementia. With about two thirds of people over 70 suffering from some degree of hearing loss, which often goes untreated, the repercussions could be significant.
For the study, researchers followed 1,984 older men and women in their 70s over six years. None had serious memory or thinking problems at the start of the study.
All got hearing exams during the trial, as well as regular tests of memory and cognitive function. Compared to seniors with normal hearing, those with hearing impairment were 24 percent more likely to have memory and thinking deficits. The more severe the hearing loss, the more likely they were to have cognitive problems. But even those with mild hearing loss had a greater rate of cognitive decline.
The researchers found that those with poor hearing took, on average, 7.7 years to show a 5-point drop on a standard test of memory function. Those with normal hearing, on the other hand, would take 10.9 years to show such a decline.
Scientists aren’t sure why hearing loss may contribute to brain problems. One theory is that people with hearing problems are less likely to go out and engage socially, forgoing outings with friends and no longer attending concerts and other events. Social isolation and feelings of loneliness are associated with an increased risk of Alzheimer’s and other forms of dementia. Having a wide social network, on the other hand, may reduce dementia risk.
The researchers also speculate that because additional energy is needed to process sound in the hearing impaired, it may make it harder for them to process memories.
In the current study, those who wore hearing aids to correct their hearing showed lower rates of cognitive decline, though most seniors did not wear them. Medicare typically does not pay for hearing aids, and many older people cannot afford them or do not get regular audiology checkups. More research is needed to determine whether proper correction of hearing loss can help to stem cognitive losses.
Frank R. Lin, MD, PhD; Kristine Yaffe, MD; Jin Xia, MS; et al: “Hearing Loss and Cognitive Decline in Older Adults.” JAMA Internal Medicine, published online January 21, 2013.