Your zip code could increase your risk of deadly disease... and millions are at risk

People living in disadvantaged neighborhoods may be more likely to develop dementia, a government-funded study suggests.

Using US Census data, researchers in Chicago found people in economically disadvantaged neighborhoods were more than twice as likely to develop Alzheimer's disease than people in the most well-off areas.

Additionally, cognitive test scores among people in poorer areas dropped 25 percent faster with age than those from people in wealthier neighborhoods.

The researchers noted this difference was likely due to racial disparities, as Black participants were more likely to live in disadvantaged neighborhoods and are at a greater risk of Alzheimer's disease.

Experts believe this is due to a higher likelihood of developing conditions like heart disease and diabetes, which damage blood vessels in the brain and lead to dementia.

Dr Pankaja Desai, study author and director of RUSH Biostatistics Core at Rush University in Chicago, said: 'Our findings show that the community in which you live influences your risk of developing dementia. Most studies of risk factors for Alzheimer’s disease focus on the individual level, not the community level.

'Of course, intervening at the community level is challenging, but prioritizing disadvantaged communities may be an effective way to mobilize resources for older adults and provide avenues for reducing the risk of dementia for the overall community.'

However, the researchers note the study only shows an association between neighborhood and dementia and cannot prove location directly causes the memory-robbing disease.

The sample size was also small, focused solely on four neighborhoods in Chicago.

But given the findings, they encouraged experts to focus more on poor areas to help lower rising rates of dementia.

Alzheimer's disease is the most common form of dementia, a group of neurological disorders that impact memory, language, problem-solving, and other cognitive abilities.

According to the Alzheimer's Association, an estimated 6.7 million Americans were living with Alzheimer's disease in 2023. That number is expected to double by 2060.

The new study, published Wednesday in the journal Neurology, looked at Census data from 6,781 people living in four communities in Chicago.

The average participant age was 72.

The researchers tested participants on thinking and memory skills at the beginning of the study and every three years for at least six years of follow-up.

Of the participants, 2,534 were evaluated for dementia. Two out of three participants were Black while the remainder were white.

The team determined which neighborhoods were more 'disadvantaged' by looking at income, employment, education, and disability status.

By the end of the six years, 11 percent of people living in the least disadvantaged of the four communities had developed Alzheimer's disease compared to 14 percent in the second-best area.

In the second-worst area, 17 percent of participants had Alzheimer's. The most disadvantaged neighborhood, meanwhile, had a 22 percent Alzheimer's rate.

After adjusting for other factors that could increase dementia risk - like age, sex, and education level- the study showed people in the most disadvantaged neighborhoods were more than twice as likely to develop dementia than those in the most well-off areas.

The researchers noted race could be a factor in these findings.

Dr Desai said: 'More Black participants lived in areas with greater disadvantage and more white participants lived in areas with lesser disadvantage.

'Once we took neighborhood disadvantage factors into account, there was no longer a significant difference between Black and white people in their risk of developing Alzheimer’s.'

Black Americans are thought to be at an increased risk of dementia due to higher rates of risk factors like heart disease, diabetes, and high blood pressure.

They are also statistically more likely to face diagnostic challenges like discrimination from healthcare providers.

Older Black Americans have been shown to be twice as likely to have Alzheimer's or other forms of dementia than their white counterparts.

One in five Black Americans over age 70 have Alzheimer's, according to the Alzheimer's Association, compared to one in 10 non-Hispanic white Americans around the same age.

Additionally, the researchers looked at how much participants' memory and thinking test scores declined over time.

The scores of people in the most disadvantaged areas declined 25 percent faster than those of people living in neighborhoods with the lowest levels of disadvantage.

However, the team noted the study only shows association rather than causation.

The main limitation was the study's inclusion only of people living in Chicago neighborhoods, so the sample size was not diverse.

The study was funded by the National Institute on Aging, an arm of the National Institutes of Health (NIH).