Black and South Asian people with dementia die younger, study finds

British people from black and south Asian backgrounds who have dementia die both younger and sooner after diagnosis than white people, according to a new study.

The study by researchers from University College London (UCL) and the London School of Hygiene and Tropical Medicine found that South Asian people die 2.97 years younger and black people 2.66 years younger than their white people with dementia.

The research, led by Dr Naaheed Mukadam, senior research fellow at UCL, was based on an analysis between 1997 and 2018 of electronic health records of 662,882 UK residents aged over 65. It is the first study to look into the incidence and prevalence of dementia, as well as age of diagnosis, survival and age of death, across white, black and south Asian ethnic groups.

Other key findings include:

• Dementia rates have increased across all ethnic groups
• Black people are 22% more likely to get dementia than their white peers
• Dementia is 17% less common among those from a south Asian background

According to the paper, published in the medical journal Alzheimer’s & Dementia: “The earlier age of dementia diagnosis in people of black and south Asian [origin] … may be related to the higher prevalence of some risk factors for dementia such as, in older south Asians, fewer years of education, and in both groups hypertension [high blood pressure], diabetes and obesity.”

The paper adds: “Overall, our findings show black and south Asian patients are diagnosed with dementia at a younger age and die at a younger age with dementia than white patients, losing more years of life.”

Highest prevalence of rates of dementia to date

The study also found that 11.8% of over-65s have dementia, the highest figure for the prevalence of dementia in Britain found in any study so far. The researchers say the difference is due to rising life expectancy since the previous estimates were drawn up.

Mukadam said that the disparity between ethnic groups was “concerning”, adding that the researchers had been unable to pinpoint the reason for the difference: “We do not know if earlier death after dementia diagnosis is because dementia is picked up at a later stage in minority ethnic groups and therefore people decline faster, if underlying risk factors in these groups contribute to worse overall health or if there is a difference in post-diagnostic support that results in these differences.”

She said, however, that “targeted interventions” to raise awareness about the greater prevalence of certain risk factors in some ethnic minorities, and how they can affect brain health, such as diabetes among south Asians, could help prevent dementia developing.