There are 20.8 million people in the United States living with diabetes, and they should all be doing one thing to prevent onset of the disease: exercise.

People should think of exercise as medicine. If you exercise and you don’t have diabetes, it can help prevent the disease. If you have diabetes and exercise regularly, it will lower your blood pressure, lower blood sugars and can even prevent the need for medication for a long period of time.

Exercise also helps control weight and prevents heart disease, which are common effects of diabetes.

When a person is diagnosed with diabetes, they generally fall into one of two camps. One group of patients is very motivated to control the disease and minimize the need for oral medication or insulin. They control their weight and their blood sugar with diet and exercise.

While they may eventually find there is a need for oral medication or insulin, delaying that need also means delaying the ravaging

effects of diabetes on the heart and vascular system.

Those in the other camp sometimes get the diagnosis and wait months or longer before seeking treatment and taking action.

The reason to work hard — to eat properly and exercise — is it can mean having diabetes for 30 years as opposed to 40 or 50 years. The longer you have the disease, the greater the likelihood you will develop retinopathy, nephropathy or heart disease.

Of the 20.8 million people who have diabetes, 6.2 million have the disease but have not been diagnosed. If you are overweight, have a family history of the disease or had gestational diabetes (diabetes that develops during pregnancy but goes away after the baby is delivered), you should be screened for diabetes. Gestational diabetics have a 50-percent chance of developing diabetes later in life.

The benefits of exercise can be reaped without doing a triathlon or running a marathon. In fact, even jogging isn’t necessary: Most people can walk and enjoy it. Walking between 6,000 and 10,000 steps daily is an attainable goal for most people, and it’s the best type of exercise because it’s available to everyone. For people with mobility problems, water aerobics is a great alternative.

In addition to the diabetes connection, exercise also helps patients with mild and moderate depression. One study showed that exercise competes on par with medication as effective treatment for depression.

A healthful diet is also part of the equation. I advise patients to shop the perimeter of the grocery store and avoid the packaged and processed goods often found in the middle aisles. Patients will guess that it takes a half-hour to walk off

the calories from a glazed doughnut, but in reality, it would take one to two hours of walking to burn those calories.

Medicine only works so well for so long. The more weight a person gains, the less the medicine will work over time. Getting daily exercise is a health strategy for everyone, but especially for people with diabetes.

DR. SONJA MADDOX is a boardcertified family medicine physician at Pacific Medical Centers (www.PacMed.org).