Black people more likely to develop dementia, large study finds

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.

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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."

Diverse communities

A recent study by the same researchers, which looked at 20 years' worth of GP and hospital health records, found black people had a 22% higher incidence of dementia being recorded than white people.

They also found black and South Asian people were diagnosed at a younger average age than white people in the UK.

Katherine Gray, research communications manager at Alzheimer's Society, said 25,000 people living with dementia were from ethnically diverse communities, with the number predicted to double by 2026.

"However, current research into dementia risk factors is mostly in people from white European ancestry," she said, adding that there was a need to better understand and support diverse populations.

She called for more research into the experiences of ethnically diverse communities and a doubling of dementia research funding.