Antioxidants and Your Diet


What are antioxidants?

Antioxidants are substances found naturally in food. They protect your body's cells from damage caused by harmful molecules called free radicals.

Some free radicals are formed from normal body processes when it uses oxygen. Others come from pollutants such as cigarette smoke. Antioxidants protect your cells from the damage caused by free radicals.

Just for a moment, think of your body like your car. It rusts when the metal in the car reacts with oxygen. If you cover it with a protective coating, it doesn't rust as quickly. Similarly, eating foods that contain antioxidants every day can help protect your body from free radical damage.

Antioxidants help to keep you healthy and may also help prevent some chronic diseases such as diabetes and heart disease. There are many different antioxidants that can be found in food. Some examples are vitamins and minerals like vitamin C, vitamin E, and selenium. Phytochemicals, compounds found naturally in plants, may also act as antioxidants. Some phytochemicals are flavonoids, polyphenols and carotenoids.

Steps You Can Take

Get your antioxidants from food

  • Vitamin C is found in: guava, peppers (red, yellow, green), kiwifruit, strawberries, citrus fruits, papaya, brussels sprouts, broccoli, leafy vegetables, tomatoes, and potatoes.
  • Vitamin E is found in: almonds, sunflower seeds, vegetable oils, leafy vegetables, peanuts and peanut butter, sweet potato, and avocado.
  • Selenium is a mineral that is found in: Brazil nuts, fish, shellfish, meat, poultry, grain products, wheat germ, wheat bran, beans, oat bran and eggs.
  • Carotenoids are found in: kale, tomatoes/tomato products, spinach, sweet potato, carrot, leafy vegetables, pumpkin, squash, guava, watermelon, grapefruit. A commonly known carotenoid is beta-carotene.
  • Flavonoids are found in: berries (especially dark colored berries), cherries, red grapes, onions, apples, cocoa, tea (especially green tea).

Be careful with antioxidant supplements

The best way to get antioxidants is from food. Supplements often have higher amounts than you need and may be harmful. More research needs to be done. The amounts commonly found in food and in a daily multivitamin mineral supplement are safe.

Tips to help you get more antioxidants

  • Eat more plant foods
    • Fill your plate with at least 3/4 plant foods. Think of meat as a garnish rather than the focus of the meal.
    • Eat 7-10 servings of vegetables and fruit each day. The recommended amounts depend on your age and gender.
    • Pick a variety of colourful fruit and vegetables every day. Eat at least one dark green and one orange vegetable every day.
    • Include whole grains, nuts and seeds, soy products, dried beans, peas, and lentils more often.
    • Enjoy vegetarian meals often.
  • Use small amounts of vegetable oil when you prepare your meals. "Eating Well with Canada's Food Guide" recommends that you include 30-45 mL (2-3 Tbsp) of unsaturated fat each day (such as canola, olive and soybean oils and non-hydrogenated margarines). This oil can help you absorb some antioxidants better.
  • Stir-fry, steam or microwave vegetables, using just a small amount of water. This helps prevent antioxidant losses into the water.

Additional Resources

HealthLinkBC Medically approved nonemergency health information and advice.

Eating Well with Canada's Food Guide.

Last updated: April 2009

These resources are provided as sources of additional information believed to be reliable and accurate at the time of publication and should not be considered an endorsement of any information, service, product or company.

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Dietitian Services at HealthLinkBC (formerly Dial-A-Dietitian), providing free nutrition information and resources for BC residents and health professionals. Go to Healthy Eating or call 8-1-1 (anywhere in BC). Interpreters are available in over 130 languages.

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