New study links untreated hearing loss to dementia

Mid-life hearing loss tops nine risk factors that contribute to the risk of dementia. Other factors include failing to complete secondary education, smoking, failing to seek early treatment for depression, physical inactivity and social isolation. Researchers say hearing loss can deny people a cognitively rich environment and lead to social isolation and depression, which are among the other potentially modifiable risk factors for dementia. The Lancet study is the latest in a growing body of evidence that links hearing loss and cognitive decline.

Lead author Professor Gill Livingston from University College London said: “Although dementia is diagnosed in later life, the brain changes usually begin to develop years before. Acting now will vastly improve life for people with dementia and their families and, in doing so, will transform the future of society.”

The Lancet Commission brings together 24 international experts to consolidate the huge strides that have been made in knowledge and understanding of dementia risk factors, treatment and care, and the emerging knowledge as to what we should do to prevent and manage dementia. The Commission conducted a new review and meta-analysis; based on which they extended current models of risk by including hearing loss and social isolation. Incorporating potentially modifiable risk factors from across the life-span, they proposed a novel life-course model of risk, highlighting the opportunity for prevention.

One of their key recommendations is to be ambitious about prevention. Interventions for established risk factors, such as the management of hearing loss, may have the potential to delay or prevent one third of dementias.

Reacting to the new study, the British Society of Hearing Aid Audiologist’s Chief Executive Professor David Welbourn, said: “For far too long, hearing loss has been considered unimportant by too many in the medical community. It has often been passed off as an inevitable consequence of ageing. Neither of these are true. The Lancet commission on dementia is the latest, and perhaps the most definitive, of a growing body of evidence pointing to an important truth. The risk of dementia can be significantly reduced if people take good care of their hearing.”The Lancet report shows that a quarter of the risk that individuals can manage for themselves is linked to hearing, and for the first time they raise the importance of addressing this in mid-life between 45 and 65, not simply when it has been left untreated to later life and the damage has already been done.

“This is a real wake-up call to people who can, and should, do something for themselves by getting their hearing tested and taking advice. This is such an easy way in which people can invest in their long-term health, just as they do by joining a gym or taking other steps towards a healthier lifestyle.”

According to the Commission’s report, worldwide dementia prevalence could be reduced by more than 1 million cases with a 10 percent reduction in the prevalence of seven principal health and lifestyle factors. An intervention that delayed dementia by a year might decrease the number of people living with dementia globally by 9 million in 2050.

“Overall, there is good potential for prevention and, once someone develops dementia, for care to be high-quality, accessible, and give value to an underserved, growing population. Effective dementia prevention and care could transform the future for society and vastly improve living and dying for individuals with dementia and their families. Acting now on what we already know can make this difference happen,” said Lon Schneider, MD, from the University of Southern California and co-author of the Commission.

“Today’s findings are extremely hopeful,” said Maria Carrillo, PhD, chief science officer at the Alzheimer’s Association. “At an individual level, many people have the potential to reduce their risk of cognitive decline, and perhaps dementia, through simple, healthful behaviour changes. At a public health level, interventions based on this evidence could be extremely powerful in managing the global human and economic costs of Alzheimer’s disease and other dementias.”

Source: The Alzheimer’s Society and BSHAA.