The World Health Organization’s updated dementia prevention guidance — its most significant revision since 2019 — estimates that addressing untreated hearing loss could prevent approximately 7% of dementia cases globally, and now explicitly recommends hearing aid use for those with documented hearing loss.

The World Health Organization (WHO) has released updated dementia prevention guidelines that place hearing loss squarely at the center of a public health strategy for brain health. The revised guidance expands the list of modifiable risk factors, with untreated hearing loss identified as one of the largest preventable contributors to cognitive decline — accounting for an estimated 7% of dementia cases at the population level.

The update is the WHO’s most substantial revision to its dementia risk-reduction framework since 2019, and it signals a meaningful shift in how the agency frames hearing care: no longer a quality-of-life consideration alone, but a core brain health intervention.

A notable change from the previous guidelines is the shift in emphasis from screening to treatment. Where earlier guidance focused on identifying hearing loss, the updated document stresses the importance of acting on that identification — specifically, wearing hearing aids when clinically recommended.

“It highlights the importance of using hearing aids if they’re recommended, rather than simply identifying hearing loss,” says Sophie Hennessy, spokesperson for Dementia Australia, in a release.

For hearing care professionals, the distinction is clinically significant. Research published previously in The Hearing Review has linked hearing aid use to a 23% lower dementia risk in adults with hearing loss and epilepsy, and multiple studies have explored the mechanisms by which amplification may slow cognitive decline. The WHO’s formal endorsement of treatment — not just detection — lends additional institutional weight to those findings.

The Cognitive Burden of Untreated Hearing Loss

The guidelines reinforce the neurological rationale for early intervention. When hearing diminishes, the brain must allocate greater cognitive resources to decode auditory information, taxing processing capacity that might otherwise support memory, attention, and executive function. Untreated hearing loss also increases social withdrawal — a pathway that, according to the WHO, can independently accelerate cognitive decline.

The updated guidance now includes sufficient evidence to formally recommend social engagement as a protective factor against cognitive decline — a position the WHO previously held back from endorsing. “Previously, people thought social engagement was probably beneficial, but there wasn’t enough evidence,” says Kaarin Anstey, associate professor at the University of New South Wales and a member of the WHO guidelines committee. “There’s also now enough evidence to recommend social engagement to reduce the risk of cognitive decline.”

Up to 45% of Dementia Cases Linked to Modifiable Factors

The WHO estimates that up to 45% of dementia cases are associated with modifiable risk factors — a figure that encompasses hearing loss alongside smoking, excessive alcohol consumption, physical inactivity, social isolation, high blood pressure, diabetes, stroke, obesity, and depression.

“For some risk factors, the evidence is still insufficient, but for others the evidence has strengthened since 2019,” says Anstey. “More research has been published, and we’re now more confident that interventions can reduce dementia risk.”

“Physical activity is one of the risk factors with the strongest evidence supporting it,” she adds.

Air Pollution Added as a New Risk Factor

The updated guidelines also introduce air pollution as a dementia risk factor — the first time an environmental exposure of this type has been included. Fine particulate matter, known as PM2.5, from vehicle emissions, wildfires, industry, and indoor cooking fuels can bypass lung defenses and trigger inflammation and oxidative stress associated with brain aging. WHO modeling suggests that eliminating exposure to air pollution could prevent approximately 3% of dementia cases at the population level.

“The guidelines talk about pollution both inside and outside the home,” says Hennessy. “Air pollution was one of the most significant additions because it is the first time environmental risk factors have been included in the guidelines.”

The WHO also cautions against routine supplementation for cognitive protection in the general population. The updated guidance advises against taking vitamin B or E supplements, omega-3 fatty acids, or multivitamins solely to prevent dementia unless a deficiency has been clinically diagnosed, noting insufficient evidence that benefits outweigh potential harms.

Implications for Hearing Care Professionals

For audiologists and hearing instrument specialists, the updated WHO guidance reinforces an expanding body of evidence supporting the role of hearing healthcare in healthy aging. It also provides clinicians with a global health authority’s backing when communicating the cognitive stakes of untreated hearing loss to patients and referring providers alike.

The connection between hearing and cognition has increasingly been framed not as a scare tactic but as a legitimate and actionable clinical concern — one that the WHO’s revised guidelines now formally validate on a global scale.

Featured image: WHO headquarters. Photo: © Elena Duvernay | Dreamstime.com