Different risks of developing dementia have been identified in different nationalities: who is most susceptible

A new UK study has found that risk factors for dementia pose a greater risk for ethnic minorities. Scientists say conditions such as diabetes and obesity increase the risk of developing the disease in South Asian and black people.

A British study shows that the most common risk factors for dementia appear to have a greater impact on blacks and Asians, prompting increased efforts to tackle health inequalities.

The number of adults living with dementia worldwide is projected to nearly triple to 153 million by 2050. Experts say the disease poses a serious and rapidly growing threat to the future health and social care systems in every community, country and continent.

Researchers have long known that some of the biggest risk factors for dementia, such as high blood pressure and diabetes, are more common in ethnic minorities.

New research shows that certain risk factors are not only more common among ethnic minorities, but also have a greater impact on their risk of developing the disease compared to white people.

The study, published in the journal Plos One, did not establish why this happens. But the researchers said the impact of risk factors such as diabetes and obesity appeared to be “increased” among some ethnic groups.

The team, led by Naahid Mukadam from University College London, examined the relationship between risk factors and dementia using health data from 865,674 adults in England between 1997 and 2018. The research team found that 12.6% of study participants developed dementia. About 16% were white, 8.6% were South Asian, 12.1% were black and 9.7% were from other minority ethnic groups.

The researchers assessed risk factors associated with dementia in patients, including obesity, diabetes, sleep disorders, high blood pressure and dyslipidemia, a lipid imbalance that can cause heart disease.

High blood pressure was associated with a higher risk of dementia in black people compared to white people, while South Asian people had a higher risk associated with sleep problems, diabetes, low HDL cholesterol and high blood pressure.

Compared with white patients, high blood pressure had a 1.57 times greater impact on the risk of developing dementia in South Asians and 1.18 times more in blacks, the researchers said.

The team said their study could explain “previous findings of greater susceptibility, earlier age of onset of dementia and shorter survival after dementia diagnosis in minority ethnic groups.”

The study authors added: “We found that not only are some risk factors for dementia more prevalent in minority ethnic groups, but also that the impact of some of these risk factors is even greater than in white populations. We therefore need personalized dementia prevention based on ethnicity and risk factor profile to ensure dementia prevention is equitable.”

David Thomas, Head of Unit at Alzheimer’s Research UK, comments: “It is the shocking truth that people from minority ethnic backgrounds face an increased risk of a range of diseases and this affects their ability to lead healthy lives. Recent research has shown that dementia is no exception – people from South Asian and black communities appear to be more likely to die from dementia, and at a younger age. These latest findings point to one reason for this: the influence of risk factors such as high blood pressure in increasing a person’s risk of developing dementia appears to be greater in both South Asian and Black communities. It will be important to understand why this effect is stronger, as it would open up a huge opportunity to reduce the personal and societal impact of this heartbreaking condition. But this is not only a public health problem, it is also a political problem. We need a national cross-government prevention strategy to address health inequalities.”

Meanwhile, the results of a second study, also conducted by the University of California, show that people with early-stage Alzheimer’s disease, the most common cause of dementia, have difficulty turning when walking, writes The Guardian.

A small study of about 100 people published in the journal Current Biology found that people with early-stage Alzheimer’s disease consistently overestimated their turns and had greater variability in their sense of direction.

Sian Gregory, from the Alzheimer’s Society, said problems with navigation were thought to be one of the earliest noticeable changes in the disease, so the study provided “valuable information”.