Scientists identify two key factors that increase the risk of developing dementia

Scientists have identified two key factors that increase the risk of developing dementia more than any other – and one of them is frighteningly difficult to avoid. Early treatment of hearing loss and efforts to maintain social connections may delay the onset of dementia later in life, a promising new study suggests.

Research has long shown that about four in 10 cases of memory loss are preventable, writes the Daily Mail. Coping with vision loss, treating depression and getting plenty of exercise are all ways to reduce the risk. Now, Swiss scientists who followed more than 30,000 adults have found a significant link between hearing loss, loneliness and memory impairment.

In a paper published in the journal Communications Psychology, scientists from the University of Geneva said: "Addressing hearing loss along with loneliness - even in socially integrated individuals - may be critical to promoting cognitive health in later life. With life expectancy increasing, understanding the relationship between hearing loss and cognitive functioning is of paramount importance for ageing societies."

For the study, researchers analyzed 33,741 adults aged 50 and over who participated in the Study of Health, Ageing and Retirement in Europe (SHARE). Over a 17-year period, the researchers found that older adults who said they felt lonely, even if they were not socially isolated, showed a steeper decline in cognitive ability as their hearing deteriorated compared to those who were socially integrated.

Participants who were isolated and lonely consistently performed worse on all cognitive tasks, including immediate and delayed memory and verbal fluency. The researchers suggest this may be because memory processes such as retrieval are more often used by people who interact regularly with others.

Additionally, the Daily Mail notes, researchers found that lonely people experience hearing loss more severely than their peers who do not suffer from loneliness, highlighting the psychological burden of the condition, which can contribute to memory loss.

The researchers concluded that their findings support the theory that both objective and subjective social isolation are associated with the risk of developing dementia.

"Our project revealed a significant role for loneliness in shaping the extent to which reduced sensitivity is associated with cognitive processes," the researchers added.

However, the scientists acknowledged that it was impossible to establish a cause and effect relationship: "Our results suggest that both hearing impairment and psychosocial factors such as loneliness and social isolation may be related to cognitive functioning in later life. This highlights the importance of a holistic approach combining hearing health with psychosocial support to maintain cognitive health in later life."

In response to such research, experts from Alzheimer's Research UK are now calling on the UK government to include hearing testing as part of the NHS health check for people over 40.

Dr Isolde Radford said: "We don't yet know whether hearing loss directly causes dementia or whether it triggers other conditions that in turn increase the risk of developing the disease. What we do know is that hearing loss, like dementia, is not an inevitable part of ageing. This simple step could help millions of people identify hearing loss earlier and take appropriate action, such as wearing hearing aids, which could reduce their risk of developing dementia."

Last year, a landmark study also showed that almost half of all cases of Alzheimer’s could be prevented by addressing 14 lifestyle factors. To reduce the risk of dementia throughout life, the commission also made 13 recommendations for both the public and governments. These include making hearing aids available to everyone who needs them, reducing harmful noise exposure, and increasing the ability to detect and treat high cholesterol in people over 40.

Experts said the study, published in the medical journal The Lancet, gave more hope than "ever before" that the disorder which robs memory and blights the lives of millions of people could be prevented.

Alzheimer's disease is the most common form of dementia and affects 982,000 people in the UK, the Daily Mail reports. The disease is thought to be caused by a build-up of amyloid and tau proteins in the brain, which clump together, forming plaques and tangles that make it difficult for the brain to function properly. Eventually, the brain struggles to repair this damage and symptoms of dementia develop.

Problems with memory, thinking and reasoning, as well as language problems, are common early symptoms of the disease, which worsen over time, the Daily Mail notes.

Alzheimer's Research UK has found that 74,261 people will die from dementia in 2022, up from 69,178 the year before, making it the most common cause of death in the country.