>> But propping someone up with diabetes from 40-50 is nothing in cost compared to keeping someone healthy from age 65-75, because at 65-75 you'll still likely be treating diabetes but on top of that also tons of other ailments introduced by age.
I think this is part of the point. No one is saying age related conditions will go away or become cheaper to care for, but merely that you can reduce the costs by eliminating the additional health issues brought about by an unhealthy lifestyle.
You seem to also conflate a lot of lifestyle issues with age related issues. For example: you mention strokes, which can lead to expensive, long term care. Strokes do increase with age, but they are also tied to lifestyle choices, and can be reduced by a preventive care (http://en.wikipedia.org/wiki/Stroke#Prevention)
I think this is part of the point. No one is saying age related conditions will go away or become cheaper to care for, but merely that you can reduce the costs by eliminating the additional health issues brought about by an unhealthy lifestyle.
You seem to also conflate a lot of lifestyle issues with age related issues. For example: you mention strokes, which can lead to expensive, long term care. Strokes do increase with age, but they are also tied to lifestyle choices, and can be reduced by a preventive care (http://en.wikipedia.org/wiki/Stroke#Prevention)