A new Mayo Clinic study, Exercise and Computer Use May Prevent Mild Cognitive Impairment, found that physical exercise and computer use may help protect against mild cognitive impairment, a disorder of the brain that affects nerve cells involved in thinking abilities. So if you are stuck trying to solve a programming problem, get up and move!
In the area of Cognitive Impairment is something I also want to mention: Pernicious Anemia.
Pernicious Anemia comes about due to the lack of the Vitamin B12. Mostly in the Elderly whom can no longer absorbed it, and have used up their store of B12. Strict Vegetarians or Vegans are also prone to not getting proper amounts of B12. Programmers living on Junk Food come to mind here as well. In a paper I read some years ago, it said that fifty percent of people diagnosed with at least mild Alzheimer's Disease were in fact suffering from B12 deficiency. Give them a B12 shot or two and they became 'normal'. Who defines 'normal' is a debate for different blog...
Also I've covered a couple of other Computer/Health related items in the past: