At the start of the study, smokers scored lower on average than people who never had smoked on all tested aspects of cognition, except memory; those scores were about the same. During a five-year span. smokers’ scores in all areas, including memory, declined about twice as fast as non-smokers’ did. The more cigarettes smokes, the greater the decline.

Who may be affected? People who smoke. Smoking causes lung cancer and several oterh types of cancer and is associated with heart disease, stroke, chronic obstructive lung disease, cataracts and an array of reproductive and early childhood problem. In the US, one of every five deaths each year has been linked to smoking.

Cautions: Smoking status was determined by participants’ responses on a questionnaire.