The research

The research

THEORY: People who delay retirement have less risk of developing Alzheimer’s disease or other types of dementia, a study of nearly half a million people in France found.

THE REASONS: Researchers say the conclusion makes sense. Working tends to keep people physically active, socially connected and mentally challenged — all things known to help prevent mental decline.

ABOUT DEMENTIA: About 35 million people worldwide have dementia, and Alzheimer’s is the most common type. In the U.S., about 5 million have Alzheimer’s — 1 in 9 people aged 65 and over.