Unhealthy habits alter thinking, memory skills

A woman smokes a cigarette in a restaurant in Munich, December 31, 2007.

NEW YORK (Reuters Health) - If you're having trouble remembering where you left your keys or recalling a word, mull over the number of times and how many years you've continued unhealthy behaviors.

Previous research has linked declining thinking and memory skills with unhealthy behaviors such as smoking, abstaining completely from alcohol, not getting enough physical activity, and not eating enough fruits and vegetables daily.

In the current study, Dr. Severine Sabia and colleagues found the more each of the 5,123 adult participants reported these behaviors the greater their "risk of cognitive deficit," Sabia told Reuters Health in an email.

Over a 17-year period, adult men and women who accumulated the most versus the least number of unhealthy behaviors were nearly three times more likely to show poor thinking skills, and about two times more likely to have declining memory, Sabia and colleagues report in the American Journal of Epidemiology.

Sabia, of Hopital Paul Brousse in Villejuif, France, and fellow researchers surveyed health behaviors of civil service office workers in London, UK, when the workers were 44 (early-midlife), 56 (midlife), and 61 (late-midlife) years old.

After allowing for the impact of age, gender, and social and economic status, the investigators found current smokers more likely to show the lowest memory, verbal, and math-related thinking and reasoning skills at each survey.

The investigators noted similar findings among non-drinkers versus those who had between 1 and 14 alcoholic drinks a week, and those who ate fewer versus more than 2 servings of fruits and vegetables each day.

Men and women who reported lower levels of physical activity during midlife and late-midlife also showed greater risk for cognitive deficit.

Considering the unhealthy behaviors assessed in the current study are modifiable, Sabia's team calls for greater promotion of healthy lifestyles to protect against later-life cognitive deficits.

SOURCE: American Journal of Epidemiology, August 15, 2009