Black people are more likely to develop dementia than white and South Asian people, a UK study suggests.
It confirms previous study findings but the reasons are complex, University College London (UCL) researchers said.
A mix of genes and underlying health conditions, such as high blood pressure and obesity, may play a role in dementia risk among black people.
Larger studies with more dementia cases in ethnic groups are needed to tease out the precise causes.
Experts are warning that by 2050, more than 153 million people worldwide could have dementia, up from 57 million in 2019.
The predicted rise is largely down to ageing, and growing populations.
The UCL research followed nearly 300,000 people who took part in the UK Biobank study for up to 14 years.
During that time, about 6,000 people developed dementia – most were white, 91 were black and 79 were South Asian.
Despite the small number affected in black and South Asian groups, the study found that the same factors increased the risk of dementia in all three ethnic groups,
These risk factors were hypertension, or high blood pressure, obesity, smoking, social isolation, air pollution, depression, diabetes and hearing loss.
Health checks
The study, published in PLoS One, found hypertension and obesity were more common in black people, compared to white or South Asian people.
Black people in the study were also more likely to be carriers of a gene linked to dementia.
But some risk factors were less common in black people, such as smoking, drinking more than 21 units of alcohol per week, and having high cholesterol.
Dr Naaheed Mukadam, study author and senior research fellow in psychiatry at UCL, said what lies behind a higher risk of dementia in black people was a “complex picture”.
“It could be driven by genetics or the way their risks are managed,” she said.
“The difference means we need greater awareness in that population that dementia is a concern – and more proactive management of risk factors like hypertension, and more health checks.”
