Researchers at the London School of Hygiene and Tropical Medicine have found that people who are underweight or even on the low side of normal weight in their middle ages run a higher risk of dementia as they age.
Study authors investigated the health records of two million people in the United Kingdom. Their findings contradicted what has normally been said about dementia: obese people are at a higher risk. In fact, a higher weight seems to be more protective, authors said.
"Our results suggest that doctors, public health scientists, and policymakers need to rethink how to best identify who is at high risk of dementia," Professor Stuart Pocock told The Guardian. "We also need to pay attention to the causes and public health consequences of the link between underweight and increased dementia risk which our research has established."
People who run the highest dementia risk are those with a body mass index (BMI) lower than 20. This group has a 34 percent higher chance of dementia than people with BMIs of 20 to just below 25, the study reports.