Wearing hearing aids ‘can delay dementia and slow ageing’

WEARING a hearing aid may delay the onset of dementia by slowing brain ageing by eight years, scientists believe.

In recent years, several studies have shown a link between hearing loss and neurodegenerative diseases such as Alzheimer’s, but it was unclear whether deafness was a symptom of the illness or one of the causes.

Now a study of thousands of over50s has found that wearing a hearing aid appears to protect against the longterm brain decline, suggesting that becoming deaf can actually bring on, or speed up dementia.

Scientists now think that hearing loss may trigger brain damage elsewhere, and also stop people from socially interacting, which is known to protect against cognitive decline.

“The mechanism for a connection between hearing loss is still uncertain. It could be biological or more social,” said Prof Clive Ballard, of the University of Exeter Medical School, who carried out the research with colleagues at King’s College London.

“One hypothesis is that when the sensory nerve cells involved in hearing become dysfunctional, it leads to dysfunction in the other nerves they interact with in the brain and that this may then slowly spread in a cascade effect.

“Another suggestion is that hearing loss contributes to social isolation or depression, which we know are risk factors for dementia.”

In the study, people were asked to take cognitive tests to assess their working memory and concentration. After two years, the 1,557 partially deaf people who used an aid were able to focus better than the 2,815 who reported hearing loss but did not use one. Those without an aid had the concentration ability of someone eight years older.

Dr Anne Corbett, from the University of Exeter, said: “Previous research has shown that hearing loss is linked to a loss of brain function, memory and an increased risk of dementia. Our work is one of the largest studies to look at the impact of wearing a hearing aid, and suggests that wearing a hearing aid could actually protect the brain.”

Experts said making sure people had hearing aids in later life could have a huge impact on delaying dementia. Dr Jana Voigt, head of research at Alzheimer’s Research UK, said: “This is an exciting result that will need to be further tested in clinical trials, and if shown to work, encouraging people to wear hearing aids could be a simple but effective way of reducing dementia risk.”

However, Dr Llwyd Orton, lecturer in neurophysiology at Manchester Metropolitan University, said: “A reason hearing aids may work in this patient group is that losing hearing function later in life is socially isolating.”

The research was presented at the Alzheimer’s Association International Conference in Los Angeles.