How can a healthy diet help prevent disease?

Healthy eating can improve your nutrition and help reduce your risk for several diseases, including:

Cancer:
Eating more fruits and vegetables is associated with a lower risk of lung, oral, esophageal, stomach, and colon cancer. Evidence is not as strong for breast cancer and prostate cancer.

A high-fat diet is associated with increased risk of colon, prostate, rectum, and endometrium cancers. There is a weaker association between breast cancer and a high-fat diet. Substantial evidence suggests that saturated fat plays an important role in increasing cancer risk.

Heart attack and stroke: One study found that men and women who closely followed the U.S. Department of Agriculture (USDA) dietary guidelines had a 28% risk reduction in heart attack and a 14% risk reduction in stroke compared with those who did not follow the guidelines as well.

High cholesterol: Reducing fat (especially saturated fat) can decrease the risk of high cholesterol levels and the subsequent risk of coronary artery disease (CAD). For more information, see the topics High Cholesterol and Coronary Artery Disease.

High blood pressure: Eating plenty of fruits and vegetables (8 to 10 servings per day), reducing salt and sodium, following a low-fat diet, and eating low-fat dairy products (3 servings per day) can reduce the risk of high blood pressure and can lower blood pressure, which may also reduce your risk for CAD. For more information, see the topic High Blood Pressure (Hypertension).

Osteoporosis: Getting enough calcium will help protect you from osteoporosis. Calcium is found in dairy products and certain leafy, green vegetables and in many products that are calcium-fortified. For more information, see the topic Osteoporosis.

Spina bifida: Eating foods that contain folate or folic acid (such as leafy, green vegetables or folic acid-enriched grains) before and during pregnancy can help protect babies from this birth defect. Women of child-bearing age should consider taking a supplement containing 400 micrograms (0.4 mg) of folic acid per day.