NEW YORK (AP) -- Having a big belly in your 40s can boost your risk of getting Alzheimer's disease or other dementia decades later, a new study suggests.

It's not just about your weight. While previous research has found evidence that obesity in middle age raises the chances of developing dementia later, the new work found a separate risk from storing a lot of fat in the abdomen. Even people who weren't overweight were susceptible.

• Participants with normal body weight and high belly measurements were 89 percent more likely to have dementia.

• Overweight people were 82 percent more likely if they had a low belly measurement, but more than twice as likely if they had a high belly measurement.

• Obese people were 81 percent more likely if they had a low belly measurement, but more than three times as likely if they had a high measurement.