Researchers reveal conditions that can increase risk of dementia

Developing conditions like heart disease or diabetes before age 55 could significantly raise the risk of dementia in later life, researchers have found.

Strokes or mental health conditions such as anxiety and depression between the ages of 55 and 70 were also linked to a two-fold increase in risk.

The research identified key time windows in which certain long-term health conditions may have the greatest impact on cognitive decline.

Oxford researchers analysed data from 282,712 people in the UK Biobank, examining patterns across 46 chronic health conditions.

They found that cardiovascular diseases including heart disease and atrial fibrillation – an irregular heartbeat – as well as diabetes were most strongly associated with dementia when they developed before age 55.

From 55 to 70, stroke and mental health conditions became more prominent risk factors.

Sana Suri, associate professor and senior fellow at Oxford Brain Sciences, said: “Although we knew that multimorbidity increased the risk of dementia, it was unclear which combinations of health conditions had the most impact and in what sequence.

“This study has identified how specific illnesses tend to co-exist with each other, and also the critical time windows in which they could pose the greatest risk.”

The study also suggests that individuals who develop cardiovascular and metabolic conditions in midlife, followed later by stroke or mental health disorders, face the highest overall dementia risk.

Up to 80 per cent of people with dementia have two or more chronic health conditions, but there has been limited understanding of how illness type, timing and combinations influence that risk.

Dr Suri said the presence and timing of other illnesses should be considered when estimating dementia risk and could help guide targeted prevention strategies.

She added: “This study identified associations between multimorbidity and dementia risk but we need to understand more about why this happens.

“We also need to try to replicate the study in more diverse groups of people to ensure the results are representative of the population.

“Future studies could examine whether efforts to manage or prevent cardiovascular problems in early-to-midlife, followed by mental health and neurological disorders when people are in their 50s and 60s, might reduce the risk of dementia.”