My advice would be to use your brain for this stimulating work as much as you like, and manage any stress response separately, that is, get plenty of exercise,

My advice would be to use your brain for this stimulating work as much as you like, and manage any stress response separately, that is, get plenty of exercise, sunlight , nutrition, and as a bonus look into some kind of mindfulness routine particularly where you practice being aware of where stressful physical responses can be perceived and mental patterns that can release them, after all anything you practice doing with your mind will affect its physical formation in one way or another. Plenty of brilliant 90 year olds out there who never stopped their minds from working.