Hey kids, did you know smoking was bad for you? You did? Well, how about this: A new study has found that heavy smoking in middle age more than doubles your risk of Alzheimer’s. The study, one of the first to examine smoking’s effect on the brain, surveyed 21,123 middle-aged people between 1978 and 1985, then followed them for an average of 23 years. Those who smoked two packs a day or more were 114% more likely to develop dementia.
Those who smoked one or more packs a day saw a 44% increased risk, while those who smoked half a pack had a 37% increased risk. Middle-aged people who said they were ex-smokers did not exhibit a higher risk. Researchers suspect the increased risk comes because smoking narrows blood vessels in the brain—the same reason, incidentally, that smoking is known to increase the risk of stroke, the LA Times explains. (Read more smoking stories.)