Slide show: Add antioxidants to your diet

Antioxidants are substances that may protect your cells against the effects of free radicals. Free radicals are molecules produced when your body breaks down food, or by environmental exposures like tobacco smoke and radiation. Free radicals can damage cells, and may play a role in heart disease, cancer and other diseases. Studies suggest that a diet high in antioxidants from fruits and vegetables is associated with a lower risk of cancer, cardiovascular disease, Parkinson's disease and Alzheimer's disease.

As a bonus, foods high in antioxidants are high in fiber, low in saturated fat and cholesterol, and are good sources of other vitamins and minerals. So which foods have the most antioxidants?

Blueberries, blackberries, raspberries, strawberries and cranberries are among the top fruit sources of antioxidants.

Pears, plums and many apple varieties (with peel) are high in antioxidants. Other fruits, such as cherries and oranges, also are good sources.

Artichokes, red cabbage and red leaf lettuce top the list of vegetables high in antioxidants. Other options include asparagus and broccoli.

Sweet potatoes and russet potatoes — with the skin on — are good sources of antioxidants. Red and white potatoes have less, but are fair sources too.

Walnuts, pistachios, pecans, hazelnuts and almonds are some of the top nuts for antioxidant content. Not crazy about nuts? Try beans and legumes, such as kidney beans, edamame and lentils, which also pack an antioxidant punch.

Toast your health with antioxidant-rich fruit juices, such as pomegranate juice. And while you're celebrating, enjoy a nibble of chocolate for another antioxidant boost.

Remember when it comes to adding antioxidants to your diet, no one food or food group should be your sole focus. Instead, be sure to incorporate a variety of fruits, vegetables, nuts, beans and legumes into your healthy diet.