Press Releases

1999 Releases

Walking Reduces Risk of Type 2 Diabetes in Women

For immediate release: October 19, 1999 

Boston, MA--Previous research has suggested that an increasing level of physical activity is associated with reduced risk of type 2 diabetes. This new study finds that both moderate forms of exercise, such as walking, as well as more vigorous forms of activity, prevent type 2 diabetes. The research is the latest finding of the Brigham and Women's Hospital-based Nurses' Health Study and is published in the October 20, 1999 issue of the Journal of the American Medical Association.

This is encouraging news for the estimated 60 percent of Americans who do not exercise. The study finds that moderate exercise, such as walking, can be spread throughout the day and can extend the same benefits as vigorous activity.

"Our research suggests that people can cut their risk of type 2 diabetes nearly in half by attaining a total of an hour of moderate-intensity activity each day," said lead author Frank Hu, assistant professor of nutrition at the Harvard School of Public Health. "The activity can come from a variety of sources throughout the day: walking to the bus stop in the morning, taking the stairs at work, or running errands. It doesn't have to mean going to the gym and exercising furiously. It doesn't matter how you get your exercise, just that you get it."

Type 2 diabetes has been characterized as the epidemic of our time. It is a metabolic disorder resulting from the body's inability to make enough, or properly use, insulin. It strikes in adulthood and is responsible for more than 14 million cases of diabetes in the US and is the leading cause of new blindness and kidney disease. Diabetes also causes nerve disease, heart disease, and stroke. Each year, at least 190,000 people die from diabetes and its complications.

"People with higher than average risk for type 2 diabetes are those who are overweight and people who are not physically active," said Hu. Increasing age is also related to risk, with half of all cases found in Americans aged at least 55 years.

With demographic trends in America showing an aging population that is increasingly overweight and sedentary, it is expected that rates of diabetes will continue to rise.

Type 1 diabetes accounts for five to 10 percent of all diabetes cases and typically strikes in childhood.

Researchers analyzed the physical activity of 70,102 women, ages 40 to 65 at the beginning of the study, over a period of eight years. Women were asked questions about walking time and pace, as well as the type and degree of other forms of exercise. During the eight years of follow-up, a total of 1,419 cases of Type 2 Diabetes were diagnosed.

"Physical activity helps to reduce risk of Type 2 Diabetes two different ways," said Hu. "Physical activity often reduces bodyweight. We know that being overweight is related to a higher risk of diabetes, so losing weight cuts risk. Secondly, physical activity improves insulin sensitivity, allowing the body to make better use of its own insulin," said Hu.

The Nurses Health Study was initiated in 1976 at Brigham and Women's Hospital. It is the longest major women's health study ever undertaken and has resulted in hundreds of journal articles, many containing groundbreaking findings on how to prevent some of the major causes of disease and death in women.

"While we performed this research among women," said Hu. "We would expect similar results for men."

For further information, please contact:

Robin Herman
Director of Communications
Harvard School of Public Health
677 Huntington Avenue
Boston, Massachusetts 02115
Phone: 617-432-4752
Email: rherman@hsph.harvard.edu

Christine Baratta, Brigham and Women's Hospital, (617) 732-5008
Tricia Oliver, Brigham and Women's Hospital, (617) 732-5008
Robert Hutchison, Brigham and Women's Hospital, (617) 732-5008