Older people who hold positive beliefs about old age from their culture are less likely to develop dementia. Further, people with APOE4 (associated with a genetic increased risk of Alzheimer's) with positive age beliefs are 49.8% less likely to develop dementia than those with negative cultural beliefs.
Therefore, positive age beliefs (a modifiable thing) reduces stress and can be neuro-protective.
PLoS One. 2018 Feb 7;13(2):e0191004