Antioxidants: All About Antioxidants

Wednesday, October 4, 2006 - 2:09pm

By Erin Dummert RD, CD

You have undoubtedly heard that a diet rich in antioxidants can help prevent cancer. But what does that really mean? What foods have antioxidants? Is there such a thing as an antioxidant supplement? And what if you already have cancer? Are antioxidants a cure?

How antioxidants work

To answer these questions, we must first understand how antioxidants work in the body. Every cell in the human body runs on oxygen. However, as important as oxygen is, it also causes damage to the very cells that rely on it to live. This damage is called oxidation. You have seen the effects of oxidation when an apple that has been cut turns brown when exposed to air. However, if you put lemon juice on the apple it stays white. The lemon juice acts as an antioxidant, preventing the damage to the flesh. The process is similar in your body. Oxygen damages cells, which over time can lead to mutations such as cancer. The antioxidants in your diet work like lemon juice on the flesh of an apple, protecting cells from damage and actually reversing some damage that may have already occurred.

Best sources of antioxidants

Thousands of antioxidants naturally occur in plant foods. The most well known are vitamin E, vitamin C, beta carotene, and selenium. While they all work to prevent oxidative damage, they each have their own method of getting the job done. They also work best as a team, each doing its part to provide well-rounded protection against cancer.

The best sources of antioxidants are brightly colored fruits and vegetables. Particularly good sources are:

  • Prunes
  • Berries
  • Raisins
  • Oranges
  • Red grapes
  • Cherries
  • Kale
  • Beets
  • Red bell peppers
  • Spinach
  • Broccoli.

Ideal daily intake of antioxidant-rich foods

Studies show that people who eat 9 servings of fruits and vegetables daily are at much lower risks of developing cancer. You may be thinking that 9 servings a day is an impossible feat. While it is indeed a lot of food, it is possible to achieve! One thing to consider is serving size. A typical serving size is smaller than you may think:

  • 1 medium piece of fruit or ½ a large banana
  • ½ cup chopped fruit or vegetable
  • 1 cup green leafy vegetable
  • ¾ cup fruit or vegetable juice
  • ¼ cup dried fruit.

Studies show that antioxidant supplements do not provide the same cancer protection as the actual foods. In some cases, antioxidant supplements increase the risk of some types of cancers. No pill can provide the same balance of vitamins, minerals, and enzymes that are found in a single fruit or vegetable.

Sample antioxidant-rich menu

With a little creativity and planning, you can eat an antioxidant-rich diet everyday. Take a look at this sample menu to see how easy it can be:

½ cup oatmeal with ¼ cup raisins (1 serving fruit)
¾ cup V8 juice (1 serving vegetable)

Morning Snack
¾ cup yogurt with ½ cup blueberries (1 serving fruit)

Chicken salad sandwich with ½ cup pineapple and red grapes (1 serving fruit)
1 cup spinach salad with ½ cup chopped mixed veggies (2 servings vegetable)

Beef stir fry with 1 cup red bell peppers, asparagus, mushrooms (2 servings vegetable)
½ cup applesauce (1 serving fruit)

Total: 9 servings

Cancer and antioxidants

People who are living with cancer have a special interest in the ability of antioxidants to fight disease. While antioxidants can repair some existing oxidative damage, they have not been shown to cure cancer, and very high doses of antioxidants in supplement form may actually work against certain cancer treatments. If you are receiving chemotherapy or radiation therapy for cancer, it is recommended that you eat as many fruits and vegetables as you are able, and take a multivitamin that provides no more than 100% of the daily recommended value for vitamins and minerals, especially vitamins C and E, selenium, and beta carotene.

Studies have also shown that cancer survivors can reduce the risk of a secondary cancer or a cancer recurrence by following a plant based diet. Therefore, once cancer treatment has been completed, cancer survivors should strive to eat at least 9 servings of brightly colored fruits and vegetables daily, and may wish to continue supplementation with a multivitamin.

By incorporating antioxidant-rich foods into your diet everyday, you can take control of your health and dramatically reduce your risk of developing cancer and other age-related diseases. Start today by adding a serving of fruit to breakfast, or vegetable juice between meals. Your body will thank you with good health for a lifetime!

For further information on antioxidants and cancer see the following articles from TheDietChannel: Prevent Cancer & Heart Disease with Phytochemicals and Top 10 Cancer Fighting Foods.

For further information on the health benefits of antioxidants in your diet see the following article from TheDietChannel: The Benefits of Antioxidants.