More than a third of all cancers could be prevented by changes in diet and exercise. One of the most important things you can do to reduce your risk is lose excess weight - and one of the best ways to lose weight is through a filling, fiber-rich diet including plenty of fruits and vegetables.

But that's not the reason why the National Cancer Institute recently approved the dietary guidance: "Diets rich in fruits and vegetables may reduce the risk of some types of cancer and other chronic diseases." These foods are packed with antioxidants and other compounds that protect your DNA and fight free radical damage.

Since these substances work synergistically, it's best to eat a variety of fruits and vegetables rather than relying on one particular produce item to serve as a magic bullet against disease. That said, recent studies have uncovered specific benefits in the following foods that would recommend making them a part of any healthy diet.

1. Tomatoes: Lycopene, also found in watermelon and pink grapefruit, has been linked to lower risk of prostate, ovarian and cervical cancer. It also targets the free radical that is implicated in lung and digestive cancers.

2. Broccoli sprouts: One forkful triggers a cascade of antioxidant activity that lasts for days.

3. Berries: Blueberries, cranberries, cherries, raspberries, strawberries, grapes - all rich in anthocyanins that repair and protect DNA.

4. Soybeans: Isoflavones such as genistein may help prevent and treat prostate cancer and may reduce breast cancer risk

5. Tea: Both black and green contain powerful compounds shown in countless studies to lower the risk of several types of cancer.

6. Pumpkin: This unsung super-food is a super-rich source of both beta-carotene and alpha-carotene, two hard-working carotenoids that combat lung and ovarian cancer.

7. Spinach: Popeye's favorite may help ward off cancers of the liver, ovaries, colon and prostate. The active antioxidant lutein is also found in kale and other leafy greens.

8. Garlic: Allium veggies (which also include onions and scallions) work to get your body's own antioxidant defense systems in gear. This process provides protective benefits against stomach, esophageal and breast cancers.

9. Pineapple: The enzyme bromelain may inhibit the growth of malignant cells in both lung and breast cancer, while the phenolic compounds also provide a protective benefit.

10. Apples: Can one a day help keep cancer at bay? Studies show quercetin may reduce the risk of lung cancer and impede growth of prostate cancer cells. Other antioxidants together with pectin help halt colon and liver cancer cell replication.