1. Rosenberg, Karen


According to this study:


* Both an unfavorable lifestyle and a high genetic risk are independently associated with a higher risk of dementia in older adults.


* A favorable lifestyle is associated with a lower risk of dementia, even in people who have a high genetic risk.



Article Content

Both genetic and lifestyle factors contribute to a person's risk of developing Alzheimer's disease and other types of dementia. Researchers conducted a retrospective study to determine if the genetic risk of dementia can be offset by lifestyle factors.


They used data from a population-based cohort of people ages 60 and older who had not self-reported or been diagnosed with cognitive decline or dementia at baseline. The researchers constructed a polygenic risk score based on genetic variants associated with a person's risk of Alzheimer's disease and dementia. They also created a healthy lifestyle score based on four well-established dementia risk factors: smoking status, physical activity, diet, and alcohol consumption. A total of 196,383 participants were followed for 1,545,433 person-years.


Of participants with high genetic risk, 1.23% developed dementia compared with 0.63% of those with low genetic risk. Of participants with an unfavorable lifestyle, 1.16% developed dementia compared with 0.82% of those with a favorable lifestyle. Of participants with both high genetic risk and an unfavorable lifestyle, 1.78% developed dementia compared with 0.56% of those with low genetic risk and a favorable lifestyle. A favorable lifestyle was associated with a lower risk of dementia across genetic groups. Among participants with high genetic risk, 1.13% with a favorable lifestyle developed dementia compared with 1.78% of those with an unfavorable lifestyle.


The study had several limitations, including that the lifestyle score wasn't independently validated, lifestyle factors were self-reported, and participants' mean age at the end of follow-up was 72 years, which limited the number of incident dementia cases.


Lourida I, et al JAMA 2019 Jul 14 [Epub ahead of print].