Loneliness does not accelerate dementia, study suggests
Loneliness may harm memory at first, but a major European study tracking more than 10,000 people over seven years suggests it does not speed dementia decline over time.
Study participants who reported high levels of loneliness performed worse on memory tests at the start of the research period.
However, their ability to recall information declined at a similar rate to that of participants who did not feel alone.
Lead author Dr Luis Carlos Venegas-Sanabria, from Universidad del Rosario, said: “The finding that loneliness significantly impacted memory, but not the speed of decline in memory over time, was a surprising outcome.
“It suggests that loneliness may play a more prominent role in the initial state of memory than in its progressive decline.”
The findings were based on the Survey of Health, Ageing and Retirement in Europe study, which surveyed 10,217 people aged 65 to 94 from 12 countries grouped into four geographic regions: central, south, north and eastern.
Anyone with a history of dementia, including Alzheimer’s disease, was excluded from the study and researchers also factored physical activity, engagement in social activities, depression scores and diabetes into the results.
Memory was assessed by how well participants could recall information immediately and after a time delay. Researchers also asked participants questions, such as whether they felt a lack of companionship, to measure loneliness.
Results showed southern European countries reported the highest levels of loneliness at 12 per cent, followed by the eastern region at 9 per cent, the central region at 6 per cent and the northern region at 9 per cent.
The majority of participants, 92 per cent, reported either average or low levels of loneliness at the start of the research.
The group with high levels, 8 per cent, was older, mostly female and self-reported worse health issues. They also had a higher prevalence of depression, high blood pressure and diabetes.
Those in the high category had worse memory scores at the beginning of the study compared with those with lower loneliness levels.
However, they experienced memory decline at a similar rate to participants in the low and average loneliness categories.
Previous studies have also linked childhood loneliness with an increased risk of cognitive decline. Research showed that people who felt lonely or lacked close friendships before the age of 17 were more likely to develop dementia, even if they no longer felt lonely in adulthood.
“The 2024 Lancet Commission, part-funded by Alzheimer’s Society, found that 45 per cent of dementia cases globally could potentially be reduced by addressing 14 modifiable risk factors, on a personal or societal level,” said Dr Richard Oakley, associate director of research and innovation at Alzheimer’s Society.
“These factors include quitting smoking, drinking less alcohol, keeping physically active and avoiding social isolation, particularly in later life.
“This is important as wider research suggests that social contact and social activities may help to build up the brain’s ability to cope with disease, stress and improve mood.”
