Few words evoke as much fear and anxiety as "cancer." While there have been many medical advances in cancer research over the past several years, cancer is something that many of us continue to fear. We find ourselves wondering what we can do to prevent it. Of course there is no guarantee that we can prevent certain types of cancer, but there is evidence that shows that a healthy lifestyle helps to protect us. With April being designated as 'Cancer Control Month,' it's a good time to think about what we can do to improve our own health.
The role of antioxidants is a particularly popular nutrition topic in the media these days; in particular, their role in cancer prevention, anti-aging, and heart health. But what are antioxidants and how do they really benefit us?
Antioxidants are substances found in our foods that prevent or repair damage to our cells caused by oxidation. When certain cells come into contact with oxygen, they undergo oxidation, which causes them to lose an electron. Without a full set of electrons, these cells are unstable and are known as free radicals. If left unchecked, free radicals can build up in our bodies and cause damage. Fortunately for us, there are antioxidants. Antioxidants work by donating an electron to free radicals, making them stable once again. Research now shows that, in addition to preventing oxidation, antioxidants perform many other important roles in our bodies, such as reducing inflammation, keeping arteries flexible, and preserving the genetic material in our cells.
Some antioxidants are manufactured by our bodies and others we must obtain from food. The following chart lists the different classes of antioxidants, where they can be obtained, and what important role(s) they play in our health. While the names of these antioxidants seem intimidating and you may find yourself thinking, "I'll never remember all of this," keep in mind that the most important aspect of this chart is to understand which antioxidant-rich foods are important to include on a daily basis.
Antioxidants |
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Class/Components |
Source |
Potential Benefit |
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Carotenoids |
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Beta-carotene |
carrots, sweet potatoes, butternut squash, apricots, spinach, cantaloupe |
neutralizes free radicals which may damage cells; supports cellular antioxidant defenses |
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Lutein, Zeaxanthin |
kale, collards, spinach, corn, eggs, citrus fruits |
may contribute to maintenance of healthy vision |
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Lycopene |
tomatoes and processed tomato products |
may contribute to maintenance of prostate health |
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Flavonoids |
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Anthocyanidins |
berries, cherries, red grapes |
support cellular antioxidant defenses; may contribute to maintenance of brain function |
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Flavanols—Catechins, Epicatechins, Procyanidins |
tea, cocoa, chocolate, apples, grapes |
may contribute to maintenance of heart health |
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Flavanones |
citrus foods |
neutralize free radicals which may damage cells; support cellular antioxidant defenses |
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Flavonols |
onions, apples, tea, broccoli |
neutralize free radicals which may damage cells; support cellular antioxidant defenses |
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Proanthocyanidins |
cranberries, cocoa, apples, strawberries, grapes, wine, peanuts, cinnamon |
may contribute to maintenance of urinary tract health and heart health |
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Isothiocyanates |
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Sulforaphane |
cauliflower, broccoli, broccoli sprouts, cabbage, kale, horseradish |
may enhance detoxification of undesirable compounds and support cellular antioxidant defenses |
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Phenols |
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Caffeic acid, Ferulic acid |
apples, pears, citrus fruits, some vegetables |
may bolster cellular antioxidant defenses; may contribute to maintenance of healthy vision and heart health |
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Sulfides/Thiols |
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Diallyl sulfide, Allyl methyl trisulfide |
garlic, onions, leeks, scallions |
may enhance detoxification of undesirable compounds; may contribute to maintenance of heart health and healthy immune function |
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Dithiolthiones |
cruciferous vegetables—broccoli, cabbage, bok choy, collard |
contribute to maintenance of healthy immune function |
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Whole Grains |
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Whole grains |
cereal grains |
may reduce risk of coronary heart disease and cancer; may contribute to reduced risk of diabetes |
Examples of Antioxidant Vitamins and Minerals |
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Vitamins |
Daily Reference Intakes* |
Antioxidant Activity |
Source |
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Vitamin A |
300-900 µg/d |
Protects cells from free radicals |
Liver, dairy products, fish |
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Vitamin C |
15-90 mg/d |
Protects cells from free radicals |
Bell peppers, citrus fruits |
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Vitamin E |
6-15 mg/d |
Protects cells from free radicals, helps with immune function and DNA repair |
Oils, fortified cereals, sunflower seeds, mixed nuts |
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Selenium |
20-55 µg/d |
Helps prevent cellular damage from free radicals |
Brazil nuts, meats, tuna, plant foods |
Research shows that nutrients from foods are better absorbed and better utilized by the body than nutrients obtained from vitamin and mineral supplements. Be sure to talk to your doctor before taking any vitamin or mineral supplements.
References
1. The National Cancer Institute
(http://www.cancer.gov/newscenter/pressreleases/antioxidants/)
2. Efficacy of antioxidant supplementation in reducing primary cancer incidence and mortality: Systematic review and meta-analysis. (Jan. 2008). Mayo Clinic Proceedings, 83,1, 23-34.