Somehow they’re not getting the stuff that’s poisoning the rest of us.
If processed foods are a culprit, they don’t eat any of that. Home-cooked meals from fresh produce is a staple for them.
That, plus they are likely not going to see doctors with the same frequency as others. Being diagnosed with the listed diseases/conditions would generally involve at least several visits to “health care providers”. Just a thought.....
Chores, duties, and responsiblities, keep them busy and focused.
They are not eating the same poison/food that we are eating.