Approximately two-thirds of all adults over the age of 70 have some degree of hearing loss. Few people seek out treatment, however. A recent study found that even mild hearing loss – when hearing is still considered normal by most people – is linked to cognitive decline.
The participants in the cross-sectional study, which included more than 6,000 men and women who were 50 years or older (average age, 59 years) and living in the United States, were part of the Hispanic Community Health Study and the National Health and Nutrition Examination Study (NHANES). Each of the participants completed a series of tests to gauge neurocognitive function. They also underwent audiometry tests to assess their hearing.
The association between cognitive decline and hearing loss first appears with mild hearing loss and progresses in a dose-dependent manner as hearing worsens. The authors of the study used statistical models to identify associations between hearing loss and cognitive decline. They found that for every 10 dB decrease in hearing, cognitive function decreased as well, especially among those who were in the earliest stage of hearing loss.
Interestingly, a related study found that the risk of developing mild hearing loss was nearly 30 percent lower among people who adhered to healthy dietary patterns such as the DASH diet or the Mediterranean diet, suggesting that diet may play a role in preventing mild hearing loss.