Diseases & Conditions


Overview & Description

Antioxidants are a certain type of vitamins, minerals, and enzymes. They help protect your body from some health problems, such as:

  • cancer
  • artery and heart disease
  • arthritis
  • cataracts
  • Beta-carotene, vitamins C and E, and selenium are the antioxidants that have been studied the most.


    Researchers are now studying whether taking higher amounts of antioxidant supplements can help reduce the risk of chronic diseases. They continue to study how much would be needed, how long they would need to be taken, and what would be the long-term side effects. The results will not be known for a few more years.

    In the meantime, experts recommend that people eat a balanced diet low in fat with at least 5 servings per day of fresh fruits and vegetables, and plenty of whole grains. This provides good sources of the nutrients that help promote health and fight disease. These nutrients include antioxidants, dietary fiber, and other vitamins and minerals.

    Functions and Sources

    What food source is the nutrient found in?

    Foods high in beta-carotene include most red, dark orange, and deep yellow fruits, such as:

  • carrots
  • sweet potatoes
  • pumpkins
  • apricots
  • cantaloupe
  • peaches
  • broccoli
  • Foods high in vitamin C include:

  • citrus fruits, such as grapefruit, oranges, and tangerines
  • asparagus
  • broccoli
  • Brussels sprouts
  • bell peppers
  • kiwi
  • strawberries
  • tomatoes
  • potatoes with skin
  • Foods high in vitamin E include:

  • nuts
  • seeds
  • almonds
  • wheat germ
  • vegetable oils
  • whole grains
  • Foods high in selenium include:

  • seafood
  • organ meats
  • lean meats
  • poultry
  • low-fat dairy products
  • whole grains
  • How does the nutrient affect the body?

    Oxidation is the reason why a cut-up apple turns brown, or why vegetable oil turns rancid. Oxidation is caused by chemicals called free radicals. Just as in the apple and oil, when oxidation occurs in the body can lead to the onset of problems. The following events can lead to the creation of free radicals in your body or expose you to them in the environment.

  • breathing
  • the break down of protein that you've eaten
  • inhaling cigarette smoke
  • exposure to air pollution
  • UV radiation
  • A healthy body can usually break down free radicals before they become harmful. If free radicals form faster than the body can break them down, damage to cells and tissues can occur.

    Antioxidants help counteract the damage caused by free radicals in two ways.

  • They help the body prevent the formation of free radicals in the first place.
  • They can reduce the effect that free radicals have on the body.
  • Then the free radicals cannot damage cells and tissues or cause health problems.


    Author:Kelly Streit, MS, RD, LD
    Date Written:
    Editor:Crist, Gayle P., MS, BA
    Edit Date:09/30/02
    Reviewer:Kathleen A. MacNaughton, RN, BSN
    Date Reviewed:09/30/02