There's already pretty much nothing good to say about obesity. Now factor in Alzheimer's.

It turns out that being seriously overweight not only translates into a greater risk of heart attack, stroke, and a host of other life-threatening conditions, but recent findings indicate that it's bad for the brain as well. Especially if the weight is concentrated around the middle, because it's associated with the brain changes linked to Alzheimer's disease.

Although the waist is one of the riskiest places to gain weight -- abdominal fat has long been associated with heart disease -- the Alzheimer's connection makes an ever-expanding middle a dire double whammy. Fortunately, the news isn't all bad. One of the things that's been shown to reduce the risk of dementia also pares off pounds: your old friend, exercise. Becoming more active, step by step (check RealAge's online tools for guidance), is one of the simplest, surest ways to keep your gray matter in good working order -- and get your waist back, too.