What are antioxidants and how do they act in my body?
Think of antioxidants in foods as the army against the damaging force of free radicals. Free radicals are compounds that interfere with normal cells and cell division with a non-stop, chain-reaction mechanism. It is this damage, called oxidative stress, which can play a role in the development of certain conditions like heart disease and cancer. This unwelcome change in cells can also play a part in the aging process inside and outside the body. Antioxidants are able to arrest some of this chain reaction and effectively neutralize free radicals.
Consuming antioxidant-rich foods is thought to provide protection and contribute to positive health benefits. The Dietary Guidelines for Americans state that “increased intakes of fruits, vegetables and whole grains and fat-free or low-fat milk and milk products are likely to have important health benefits for most Americans.”
Can’t I just buy some supplements in a bottle and then I don’t have to worry about what I eat?
Don’t let supplements become substitutes for a healthy, well-balanced diet!
Research grows and emerges as new beneficial components of foods are discovered. Chemicals in plants (phytochemicals) seem to enhance each other’s usefulness! This is called synergy, which comes from a Greek word meaning “working together.” Antioxidants in plants, along with other plant chemicals, act together to create an effect greater than could be expected by any of them alone! In a bottle of supplements, you only get what’s in the bottle, without the benefit of what is in a similar food item.
Note: The antioxidant Vitamins A and E are fat-soluble, meaning that excess amounts are stored in the liver and fatty tissues instead of being quickly excreted, creating a risk of toxicity.
Are all antioxidants alike?
No, there are different classifications of antioxidants, and some foods have more than one type. Research shows only potential benefits. Some of the most common are shown in the chart below.
 |
| Class/Components |
Food Sources |
| Carotenoids |
|
| Beta-carotene |
Carrots, various yellow-orange fruits |
| Leutin, Zeaxanthin |
Kale, collards, spinach, corn, eggs, citrus |
| Lycopene |
Tomatoes, spaghetti sauces, cooked tomato products |
| Flavonoids |
|
| Anthocyanidins |
Berries, cherries, red grapes |
| Flavanols |
Tea, cocoa, chocolate, apples, grapes |
| Flavanones |
Citrus foods |
| Proanthocyanidins |
Cranberries, cocoa, apples, strawberries, grapes, wine, peanuts, cinnamon |
| Isothiocyanates |
|
| Sulforaphane |
Cauliflower, broccoli, broccoli sprouts, cabbage, kale, horseradish |
| Phenols |
|
Caffeic acid Ferulic acid |
Apples, pears, citrus fruits, some vegetables |
| Sulfides/Thiols |
|
Diallyl sulfide Allyl methyl trisulfide |
Garlic, onions, leeks, scallions |
| Dithiolthiones |
Cruciferous vegetables – broccoli, cauliflower, cabbage, bok choy, collards |
| WHOLE GRAINS |
|
| Wheat, corn, oats, etc |
In cereals, pasta, breads and bread products.
Note: “refined or enriched” grain ingredients are NOT whole grains! |
Examples of Antioxidant Vitamins and Minerals
Vitamin/Mineral |
Daily Reference Intakes* |
Antioxidant Activity |
Sources |
Vitamin A |
300-900 micrograms |
Protects cells from free radicals |
Liver, dairy products, fish |
Vitamin C |
15-90 mg |
Protects cells from free radicals |
Bell peppers, citrus fruits |
Vitamin E |
6-15 mg |
Protects cells from free radicals, helps with immune function and DNA repair |
Oils, fortified cereals, sunflower seeds mixed nuts |
Selenium |
20-55 micrograms |
Helps prevent cellular damage from free radicals |
Brazil nuts, meats, tuna, plant foods |
Chart adapted from Food and Nutrition Board Institute of Medicine DRI reports and National Institutes of Health Office of Dietary Supplements
* DRI’s provided are a range for Americans 2–70. |
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