Revealing the Connection: Hearing Aids and Dementia
Hearing aids might reduce cognitive decline in older adults, but only in people who are at higher risk of dementia, research has suggested.
In a bid to reduce the global burden of dementia, new research has unveiled a surprising and potentially powerful tool – hearing aids. The studies have found a direct link between the use of hearing aids and a reduction in cognitive decline, particularly amongst those at a higher risk of developing dementia.
Age-related hearing loss is a pervasive issue affecting two-thirds of adults over 60 worldwide. However, the use of hearing aids remains remarkably low, with fewer than three in ten people in high-income countries, and less than 10% in low and middle-income countries, using these devices. Yet, the implications of untreated hearing loss are severe, contributing to approximately 8% of dementia cases worldwide, which equates to 800,000 of the nearly 10 million new cases diagnosed each year.
The global concern for dementia prevention has led to a series of research trials exploring the impact of hearing aids on cognitive decline. The Achieve trial, published in The Lancet, included 977 adults aged 70–84 in the United States, all of whom had untreated hearing loss but were free from substantial cognitive impairment. The trial spanned over three years and consisted of two groups: one group received hearing aids and audiological counselling while the other received more general counselling on healthy ageing.
While the study found that hearing aids did not reduce cognitive decline across the entire sample, a significant reduction in cognitive decline was observed in the higher-risk group, known as the ARIC group, which comprised older adults with more risk factors for cognitive decline. This group experienced a 48% reduction in cognitive change over the three years when given hearing aids compared to the group without.
Professor Frank Lin, of Johns Hopkins University School of Medicine and Bloomberg School of Public Health, who led the study, said: “These results provide compelling evidence that treating hearing loss is a powerful tool to protect cognitive function in later life, and possibly, over the long term, delay a dementia diagnosis.”
However, the relationship between hearing loss and dementia is complex. Experts propose several theories explaining how untreated hearing loss may contribute to cognitive decline. One suggests that hearing loss causes the brain to work harder, diverting resources away from other mental functions such as thinking and memory. Another theory posits that hearing loss accelerates brain shrinkage with age, while a third possibility suggests that hearing loss leads to reduced social engagement, potentially resulting in brain atrophy.
In spite of the promising results, the studies do not definitively prove that hearing aids prevent dementia, but instead indicate they can help reduce cognitive decline and improve people’s ability to perform cognitive testing. These findings are a significant step towards understanding and potentially mitigating the risk of dementia.
Dr. Charles Marshall, a clinical senior lecturer at Queen Mary University of London, said: “These findings show us that there might be a small benefit of hearing aid use in reducing cognitive decline in an otherwise healthy population with hearing loss, but they don’t yet tell us whether hearing aids are actually preventing dementia or just improving people’s ability to perform cognitive testing.”
Furthermore, Gill Livingston, professor of psychiatry of older people at University College London, highlighted the hope these results bring. She said: “Overall, the findings from this study are huge and hopeful results. Hearing aid treatment could really make a difference for populations at risk of dementia.”
This discovery encourages greater public awareness of the importance of hearing health and potentially opens new avenues in dementia research and prevention. As with many scientific advancements, time and further research will provide more conclusive answers, but for now, the message is clear - look after your hearing health; it may just protect your future cognitive wellbeing.