Stay smart: exercise!
There has been quite a bit of research in the last few years pointing to the mental benefits of exercise, both generally for people of all age, and specifically for older adults related to the risk of dementia. Carolyn’s Tai Chi class forwarded this nicely designed study from Kings College London that followed a couple of hundred women twins for a period of ten years, and found greater cognitive decline at the end in the twin whose leg strength was lesser at the start. The authors conclude:
This leaves two remaining explanations: LEP and cognitive ageing may be associated due to a shared mechanism which is independent of genetic and many developmental factors and specific to lower limb and/or speed and coordination of muscle function, and which affects lower limb power before cognition. … The alternative hypothesis is that leg power is a sensitive marker of the kind of PA [physical activity] that can influence cognitive ageing. The principle of parsimony would favour this latter explanation.