Being overweight increases the risk of several chronic diseases including heart disease, stroke, diabetes, and some cancers. More recently, new research indicates a possible link between being overweight and developing dementia later in life. Swedish investigators examined this connection and published their findings in Archives of Internal Medicine.

Nearly 400 men and women (70 years and older), who were healthy and free of dementia, participated in an extensive evaluation that included a detailed medical history, a review of health and lifestyle habits, a physical exam, and a mental assessment. These tests were repeated every few years, throughout the 18-year study. The investigators noted the development of dementia, which was defined as the point when mental abilities were impaired enough that day-to-day functioning was affected. The type of dementia, including whether or not it was Alzheimer's disease, was also categorized.

Women, not men, influenced by weight

Dementia occurred in 93 volunteers after 18 years. The women who developed dementia and Alzheimer were more likely to be overweight at the various evaluation points than the women who remained dementia free. This was the case even after considering other health problems associated with extra weight - high blood pressure, heart disease - and other factors such as medications, smoking habits, economic status, and education. In contrast, for men, being overweight did not influence whether or not they developed dementia or Alzheimer's disease.

How weight weighs in

How overweight may increase the risk of dementia is not fully understood, but some research supports the theory that poor vascular health - such as having high blood pressure, high cholesterol levels, and diabetes - may play a role in dementia. Keep in mind that being overweight increases risk for developing these conditions.

The researchers don't know why the link between mental functioning and weight was found only in woman. The differences in fat distribution between men and women may come into play. Note, too, that the volunteers were quite elderly, some over age 90 by the study's end.

Don't underestimate the power of overweight

For consumers, this does not alter the advice offered by health professional for years. That is, achieve and maintain a healthy body weight. The evidence that a healthy body weight lowers the risk of certain diseases is already strong. This study adds support to the notion that dementia can be added to the list.