Cognitive decline and dementia can be influenced by levels of diet and exercise up to 12 years before the onset of symptoms

Older man and head shaped puzzle

Researchers have established an association between diet and exercise and the risk of cognitive decline and dementia. According to findings from King’s College London, diet and exercise can influence hippocampal neurogenesis and neural stem cell death as much as 12 years before the onset of symptoms of cognitive decline and dementia.

The study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, suggests that altered neurogenesis in the brain may be an early biomarker for both cognitive decline and dementia.

Researchers examined the effects of serum samples from a longitudinal cohort aged over 65 years (n=418) with and without cognitive decline and dementia on hippocampal neurogenesis in laboratory settings and investigated whether diet and exercise were important factors.

Sociodemographic, lifestyle, and clinical data were collected, and incidence cognition status and dementia were measured over a 12-year period. On average, participants were 76 years old at baseline and 66% were female; cognition was assessed for an average of 8.5 years and the average age of dementia onset was 85 years.

The investigators established that cognitive decline and Alzheimer’s disease were associated with levels of neural stem cell death 12 years before diagnosis. In addition, exercise, nutrition, vitamin D levels, carotenoid, and lipid levels were all associated with the rate at which cells die off. Physical activity and nutrition were key factors—reduced physical activity and increased malnutrition both increased cell death, which in turn increased the risk for future cognitive decline.

Lead investigator Dr Sandrine Thuret said: ‘Our study has demonstrated not only that there are individual markers of hippocampal neurogenesis associated with [cognitive decline] and dementia 12 years later, but also that there is some degree of specificity with respect to diagnoses of dementia subtypes.

First author Dr Andrea du Preez 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.

  • Du Preez A, Lefèvre-Arbogast S, Houghton V et al. The serum metabolome mediates the concert of diet, exercise, and neurogenesis, determining the risk for cognitive decline and dementia. Alzheimers Dement 2021; Aug 17 [Epub ahead of print]. DOI: 10.1002/alz.12428.

This article originally appeared on Univadis, part of the Medscape Professional Network.