We can only do so much to keep our body healthy, as it unavoidably ages and deteriorates toward death. As far as our mental health is concerned, it is affected by both our spiritual outlook and our physical health. When we develop some form of dementia, we become quite helpless. But the great news is that we can attain maximum spiritual health by becoming holy and one with God. I'd say, let the body and mind go and take care of you spirit foremost and you won't have anything to worry about for all eternity!