Residing in less affluent areas is associated with both quicker brain ageing and a heightened risk of developing dementia early in life, irrespective of an individual’s income or educational background, according to a study led by Duke University. This research, published on March 14 in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, points to the potential benefits of implementing dementia prevention initiatives in economically disadvantaged neighbourhoods and suggests that healthcare professionals should take into account a patient’s living environment as a factor in dementia risk assessment.
The study underscores the importance of considering an individual’s residential area in the broader context of dementia prevention. Aaron Reuben, PhD, the lead researcher and clinical neuropsychologist, highlighted the significance of addressing the topic of one’s living environment when assessing dementia risk. This research aligns with the growing concern over Alzheimer’s disease, the most prevalent type of dementia that significantly impairs memory and cognitive abilities. Currently affecting an estimated 58 million people worldwide, the number of dementia cases is expected to surge to 150 million by 2050. Given the absence of curative treatments or highly effective medications, the focus has shifted towards prevention through lifestyle adjustments such as diet and exercise.
Reuben was motivated by geographic patterns in dementia risk, analogous to “blue zones” where people tend to live longer. The study examined the living conditions and medical records of 1.41 million individuals in New Zealand, evaluating the socioeconomic status of neighbourhoods based on national census data, including average income, employment rates, and access to transportation. Findings revealed that individuals in the most disadvantaged neighbourhoods faced a 43% higher risk of developing dementia over two decades.
The research further delved into early indicators of neurodegeneration associated with living in economically disadvantaged areas. Utilizing data from the Dunedin Study, tracking nearly 1,000 New Zealanders from birth through adulthood, the team observed signs of poorer brain health by age 45 in individuals from poorer neighbourhoods, regardless of their income or education. That was evidenced through various measures, including the density and size of nerve cells in key brain areas and the efficiency of neural communication.
These individuals also exhibited brain characteristics typically associated with older age in MRI scans, appearing approximately three years older than their actual age. They faced more challenges with memory and daily cognitive tasks. The study suggests that the environment one lives in plays a critical role in brain health and dementia risk, potentially due to factors like air quality, social interaction levels, stress, and neighbourhood walkability.
Reuben advocates for targeted community interventions and early consideration of a person’s living environment as strategies to address and mitigate the risk of dementia. This approach highlights the necessity of starting dementia prevention efforts early, acknowledging that signs of the condition can manifest decades before a formal diagnosis. Through community-focused initiatives and considering environmental factors in dementia risk assessments, there may be a path forward in combating the increasing challenge of dementia globally.
More information: Aaron Reuben, Leah S. Richmond-Rakerd, Barry Milne, Devesh Shah, Amber Pearson et al, Dementia, dementia’s risk factors and premorbid brain structure are concentrated in disadvantaged areas: National register and birth-cohort geographic analyses, Alzheimer’s & Dementia. DOI: 10.1002/alz.13727
Journal information: Alzheimer’s & Dementia Provided by Duke University
