Higher education and physical activity can protect against it.
Recent research conducted by the University of Copenhagen details significant connections between genetic predispositions to poor lifestyle habits, such as smoking and high body mass index (BMI), and the heightened risk of developing dementia. The study, involving over 400,000 European participants, employed advanced genetic analysis to explore modifiable risk factors, emphasizing the importance of education and physical activity as protective measures against the disease.
Dementia is a chronic and debilitating condition characterized by a progressive decline in cognitive function, and its global prevalence continues to rise. Understanding its underlying causes is vital for prevention and early detection of this disease. This study, published as a preliminary report, focused on individual-level genomic data to establish causal relationships between various poor lifestyle habits and dementia.
The researchers used a substantial genomic dataset from the UK Biobank, made up of nearly 409,000 participants in Britian of European descent. They collected comprehensive data, including genetic information, baseline measurements, and self-reported behavioral habits such as smoking and physical activity. Pre-existing medical conditions were categorized using International Classification of Diseases (ICD) codes.
Among the study cohort, which consisted of 53.7% women with a median age of 59, dementia was found to be more prevalent in men than women. The initial observations indicated that 13.2% of participants reported ischemic heart disease, with 1.7% diagnosed with all-cause dementia, 0.9% with Alzheimer’s disease, and 0.4% with vascular dementia.
The team calculated polygenic risk scores (PRS) for each participant to assess genetic predispositions to these risk factors, and they found that genetically predicted smoking, a high BMI, high blood pressure, type 2 diabetes, high low-density lipoprotein (LDL) cholesterol, and high triglycerides all significantly increased the risk of developing various forms of dementia.
The researchers also revealed that both extended education and physical activity provided protective factors against both vascular dementia and Alzheimer’s disease. The findings suggested that higher genetically predicted levels of physical activity could reduce the risk of developing this form of dementia by as much as 42%.
Despite significant advancements in dementia research, causal associations between lifestyle factors and dementia outcomes often remain controversial. Many studies have attempted to clarify these connections but are limited by the lack of age-specific data, leading to conflicting results. As a result, much of the existing literature to date has relied on observational evidence with limited clinical validation. However, the new study’s use of Mendelian Randomization strengthens the evidence base by establishing clearer causal links between lifestyle choices and dementia risk, more accurately predicting associations between the two.
By focusing on modifiable factors, the study advocates for behavioral interventions to lower the risk of dementia, particularly emphasizing higher education and increased physical activity. As understanding of dementia and Alzheimer’s diseases’ connection with genes advances, these insights can inform effective public health strategies to minimize the number of new cases each year.
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