Dementia affects an estimated 50 million people worldwide and about 4 million in the U.S., about 9% of adults 65 or older.¹ In the past, several factors have been identified that reduce the risk of dementia, including educational level, high blood pressure, diabetes mellitus, obesity, smoking, sedentary lifestyle, depression, social isolation. Recent research says that in older adults, treatments for hearing and vision problems can also help reduce the risk of dementia.

Hearing and vision problems are common as people age and problems often go untreated. Hearing loss affects more than 40% of adults over 60 and about two-thirds of adults 70 and older. Yet fewer than 20% of adults with hearing loss get hearing aids or other treatment.²

About one in three individuals will have some type of vision loss by the age of 65. Cataracts are one of the common issues, affecting as many as half of all adults by age 75.

A recent study in JAMA Internal Medicine found that older adults who underwent cataract surgery had nearly a 30% lower risk of subsequently developing dementia compared with older adults who did not.³ The lower dementia risk remained even after the researchers adjusted for numerous health variables, such as smoking status, diabetes, hypertension and body weight. Adults who had glaucoma surgery—a procedure that does not restore vision loss—did not have a similar dementia benefit.

“These findings suggest timely extraction of cataracts could significantly improve the quality of life for older adults as well as their caretakers,” Cecilia S. Lee, M.D., M.S., lead author on the study and associate professor of ophthalmology at the University of Washington, told Psychiatric News.⁴ The authors suggest several possible reasons for the benefit, including reduced isolation and greater participation in activities with the improved vision post-surgery. In addition, Lee told Psychiatric News, vision impairment can create challenges for the brain and there may be a neurological link as well.

Age-related hearing loss is also associated with increased risk for dementia, according to a growing body of research. For example, the authors of a large meta-analysis conclude that age-related hearing loss is a modifiable risk factor for cognitive decline, cognitive impairment, and dementia.⁵ Hearing loss is also associated with an increased risk for social isolation, anxiety disorders and depression, and may account for as many as 9% of new dementia cases.⁶

It's not certain whether hearing loss affects cognition directly or indirectly. Some research suggests it directly causes cognitive problems.⁷ While exact mechanisms are not well understood, hearing loss results in additional cognitive challenges and may cause changes in the brain which may contribute to risk for dementia.

Hearing loss is “a compelling target in preventive strategies for dementia,” the authors of one study conclude, for a number of reasons—it is common and often under-treated, and easily diagnosed and treated relative to other dementia risk factors.² Hearing health interventions, particularly hearing aids, show promising benefits for depressive symptoms and cognitive function, but are often not used.⁶

The authors of another meta-analysis point to the multiple benefits of increased hearing screening and use of hearing aids: “Given extensive evidence that demonstrates advantages of using auditory amplification in the alleviation of hearing handicap, depression, and tinnitus, and the improvement of cognition, social communication, and quality of life, regular hearing screening programs for identification and management of midlife hearing loss and tinnitus is strongly recommended.”⁸