Phytochemicals are naturally occurring chemicals found in vegetables, fruits and grains. Phyto means plant in Greek. Phytochemicals may be used by our bodies as part of their disease-fighting mechanism. Some of the anticancer effects are only beginning to be explored. Phytochemicals are different from vitamins and minerals because they have no nutritional value. Some are antioxidants that help protect against cell damage.

PhytochemicalsFood Sources
IsochiocyanatesCruciferous vegetables (cabbage, broccoli, cauliflower and kale)
IndolesCruciferous vegetables
SaponinsBeans and legumes
Allyl sulfidesOnions, garlic, leeks, chives
IsoflavonesSoy beans (tofu, soymilk)
Phenolic acidsTomatoes, citrus fruits, strawberries, raspberries, carrots, whole grains, nuts
TerpenesCherries, citrus fruit peel
PolyphenolsGreen tea, grapes, wine


Antioxidants are phytochemicals that are believed to protect the body against harmful cell damage from oxidation. Antioxidant nutrients are in a group of vitamins and minerals and are thought to protect against cancer, heart disease and maybe normal aging. Oxidation damages cells, and if this damage accumulates, scientists believe it can result in disease. Various antioxidants do different jobs, such as deactivate free radicals or transforming them to less toxic substances. 

AntioxidantsFood Sources
SeleniumBrazil nuts, meat, seafood, eggs, whole grains, legumes
Vitamin EWheat germ, vegetable oil, nuts
Vitamin CCitrus fruit, melon, strawberries, pineapple, tomato, pepper, potatoes
CarotenoidsDark green leafy vegetables, and yellow, red, orange, vegetables and fruits
Vitamin AGreens, squash, carrots, pumpkins, red pepper, sweet potatoes, apricot, cantaloupe, mango, papaya, peaches


Carotenoids are antioxidants that are vitamin A-related substances that are being researched for their anti-cancer properties. There have been 600 carotenoids identified and hundreds of carotenoid compounds are still awaiting investigation. 

Beta-carotene is a well known carotenoid and it is believed to reverse pre-cancerous mouth sores and is essential for healthy skin and mucous membranes. It is thought that megadoses of beta-carotenes can suppress blood levels of other carotenoids that may have their own valuable anti-cancer actions. 

High doses of one nutrient can antagonize the absorption of other nutrients. Emphasis should be placed on eating a variety of foods in moderation. It is more fun to eat foods than take a pill.

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