Experts believe that dementia is brought on by both genetic and environmental factors. The genetic factors include genes passed from the mother and father of an individual while environmental factors are lifestyle choices such as smoking, diet and exercise. Since the genes that cause dementia are not modifiable, researchers hope that positive changes in lifestyle can decrease the possibility of developing dementia. A recent study in JAMA explores the extent of each factor on dementia. The study used information from a UK based biobank. A biobank holds health information about individuals including disease history and lifestyle choices. The study looked at 20,000 individuals aged 60 or older. Using pre-set lifestyle choices the researchers gave each individual a score in which a higher score denoted a "better" or healthier lifestyle. There can be errors with this method of scoring such as only accounting for specific factors and being unable to distinguish which factors have an effect on the results. Similarly a genetic risk score was created by looking for gene variants strongly associated with patients who have Alzheimer's. Together these numbers created the polygenic risk score.
It was found that while both factors have an effect on the development of dementia, they work independently of each other. Individuals who came up with a bad score for both genetic and lifestyle factors had a risk of developing dementia two and a half times higher than those with better scores. This study does not prove that lifestyle choices are the cause of dementia but only that they may influence the development.
I believe that more studies should be conducted to look further into the relationship between lifestyle and dementia. This way high risk patients can start to make changes early in life and possibly delay the onset of the dementia. This would give them and their families more time to enjoy each others company.
Original Article: https://www.health.harvard.edu/blog/your-risk-of-dementia-do-lifestyle-and-genetics-matter-2019091317671