The cost of smoking:

Bruce Graham writes: Re. "Richard Farmer's chunky bits" (yesterday, item 11). Richard Farmer: actually, smokers have higher rates of vascular dementia than non smokers, so it would not be a straightforward calculation. It is incorrect to think that smoking will help you escape this fate. Arguably, smoking would be beneficial for cerebral function if people started using nicotine only after they reached an advanced age (say, 80), thus gaining the stimulant effects, and avoiding the atherosclerosis.