Stroke is a leading cause of disability and death in the United States and other industrialized countries. High cholesterol is among several known risk factors, but the influence of obesity is less well understood. Stroke is very difficult to treat once it occurs, so prevention is key. If obesity is a reliable risk factor, weight loss in middle age could help stave off strokes later in life.

What the researchers wanted to know: Does obesity during middle age increase the risk of having a first stroke in later years?

What they did: A Swedish research team collected information on body mass index (BMI) from 7,402 men between 47 and 55 years old and then followed the group's hospital treatments and causes of death for 28 years. BMI is a measure of obesity that incorporates body height and weight. Obesity is generally defined as a BMI of 30 or more.

What they found: The study group had a total of 873 first strokes, which on average occurred when patients were around 74 or 75 years old. Strokes were 93 percent more common in men with BMIs of 30 or more than they were in men with low BMIs—between 20 and 22.5. When other risk factors like age, hypertension, high cholesterol, and diabetes were taken into account, the heaviest men had nearly nearly four times the risk of stroke. Researchers also found that every 1-point increase in BMI boosted the risk of a later stroke by 5 percent. Factoring in other risk factors lessened the influence of BMI, but it remained significant: a 3 percent increase in risk for every 1-point rise in BMI.

What the study means to you: If you're overweight, the study suggests that one more reason to trim down is that it appears to reduce the chance of a debilitating or potentially fatal stroke later in life.

Caveats: The study looked only at strokes treated in hospitals, so episodes treated elsewhere or not treated at all were not taken into account.

Find out more: The Internet Stroke Center at Washington University in St. Louis has information on stroke risk factors. The National Institute of Neurological Disorders and Stroke has information on preventing stroke.

Figure out your body mass index.

Read the article: Jood, K. et al. "Body Mass Index in Mid-Life Is Associated with First Stroke in Men." Stroke. December 2004, Vol. 35, pp. 2764-2769.

Abstract online: http://stroke.ahajournals.org