Aug. 21, 2001 -- People may be able to greatly reduce their risk of an often fatal form of cancer simply by exercising moderately and eating a healthy diet, according to a new study.
The study, published in this week's Journal of the American Medical Association, says obese people with sedentary lifestyles have twice the risk of developing pancreatic cancer as those who are active and not obese. Harvard School of Public Health researchers say that by walking or hiking as little as 1.5 hours a week, people can reduce their risk of this cancer by 50 percent.
"Even if you are obese you can reduce your risk," says the study's lead author, Dr. Dominique Michaud. "Moderate exercise makes a difference."
Proper Diet and Exercise
This study suggests that an additional 15 percent of pancreatic cancer cases could be avoided with proper diet and physical activity.
Because of studies like this one linking cancer to poor diet and lack of exercise, the American Cancer Society has decided to change its nutritional guidelines this fall to include an increased emphasis on physical activity and maintaining a healthy body weight.
"Because there are no tests to detect pancreatic cancer early there is a great need for better ways to prevent the disease, and also for improvement in early detection," said Dr. Michael Thun, an epidemiologist with the American Cancer Society.
The study, which looked at data from two large trials of 46,648 men, and 117,041 women, showed that tall height and high body mass index (BMI) were associated with pancreatic cancer. Moderate physical activity, on the other hand, was associated with a lower risk of cancer. BMI is figured by dividing your weight in kilograms by thesquare of your height in meters.
The study said that people with a BMI of 30 or more have a 72 percent increased risk of pancreatic cancer compared with those with a BMI of less than 23. Someone with a BMI of more than 25 is classified as overweight; a BMI of 30 or more is considered obese.
Pancreatic Cancer Kills 95 Percent of Patients
This link between activity level and BMI and pancreatic cancer may be a clue as to how pancreatic cancer develops. Inactivity and obesity, as well as diabetes impair the body's ability to metabolize glucose. These factors lead to high levels of insulin in the pancreas, which may trigger cancer. However, researchers say that further studies need to be done before a direct link between insulin levels, blood glucose levels, and cancer can be established.
Until recently, the only avoidable risk factor known to affect pancreatic cancer was smoking. Now it appears that moderate activity and maintaining a healthy body weight can lower the risk.
Breast and colon cancer have been linked to activity levels and obesity. But unlike pancreatic cancer, other types of cancers tend to have several contributing factors.
Pancreatic cancer is the fifth leading cause of cancer deaths in the United States. It is especially difficult to treat because of its rapid growth, proximity to other important organs, and inaccessible location. The result is a cancer that kills 95 percent of its victims within five years of diagnosis.