Diet and exercise can influence the risk of cognitive decline (CD) and dementia by potentially influencing hippocampal neurogenesis long before their onset, according to new research from King’s College London.
The study, published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, suggests that altered neurogenesis in the brain could potentially represent an early biomarker for both CD and dementia.
Using an in vitro neurogenesis assay, researchers investigated how the blood serum from a longitudinal cohort aged over 65 years (n=418) with and without CD and dementia could influence hippocampal neurogenesis in laboratory settings and whether diet and exercise were important factors.
Serum blood samples were collected 12 years prior to CD and dementia diagnosis and tested on human hippocampal stems cells. Additionally, information on each participant’s sociodemographic, lifestyle and clinical data was collected and incidence cognition status and dementia were measured over a 12-year period.
Over the course of the study, the researchers established that 12 years prior to diagnosis, both CD and Alzheimer’s were associated with levels of neural stem cell death.
The team also found that exercise, nutrition, vitamin D levels, carotenoid and lipid levels were all associated with the rate at which cells die off.
Furthermore, physical activity and nutrition were key factors that also determined CD status. Specifically, researchers found that reduced physical activity and increased malnutrition both increased cell death which in turn increased the risk for future CD.
Study lead investigator Dr Sandrine Thuret said: “Our study has demonstrated not only that there are individual markers of hippocampal neurogenesis associated with CD and dementia 12 years later, but also that there is some degree of specificity with respect to diagnoses of dementia subtypes."
Dr Andrea du Preez, the study’s first author, said: “While more work is undoubtedly needed to fully understand how diet and exercise might modulate hippocampal neurogenesis, our findings may represent an effective early preventative strategy against CD and dementia.”
