Phytochemicals are compounds in foods found in plants that are thought to be beneficial to health. More than 5000 different types have been identified, and several studies have linked their intake to reduced risk for cardiovascular disease, cancer, diabetes, Alzheimer’s, cataracts, and age-related decline. While they may be beneficial, they are not considered nutrients
(substances necessary to sustain life), thus no daily recommended intakes have been established.
A list of five popular phytochemical families are listed below, along with their
health claims and
food source.
Carotenoids:Includes: Alpha-carotene, beta-carotene, lutein, lycopene, zeaxanthin, etc.
Health Claims: Diets with foods rich in these phytochemicals may reduce the risk of
cardiovascular disease, certain cancers (e.g., prostate), and age-related eye diseases (
cataracts,
macular degeneration).
Food Source: Red, orange, and deep-green vegetables and fruits, such as carrots, cantaloupe, sweet potatoes, apricots, kale, spinach, pumpkin, and tomatoes.
Flavonoids: 1Includes: Flavones, flavonols (e.g., quercetin), catechins (e.g., epigallocartechin gallate or EGCG), anthocyanidins, isoflavonoids, etc.
Health Claims: Diets with foods rich in these phyotochemicals are associated with lower risk for cardiovascular disease and cancer, possibly because of reduced inflammation, blood clotting, and blood pressure and increased detoxification of carcinogens or reduction in replication of cancerous cells.
Food Source: Berries, black and green tea, chocolate, purple grapes and juice, citrus fruits, olives, soybeans and soy products (soy milk, tofu, soy flour, textured vegetable protein), flax seed, whole wheat.
Phenolic acids: 1Includes: Ellagic acid, ferulic acid, caffeic acid, curcumin, etc.
Health Claims: Similar benefits as flavonoids.
Food Source: Coffee beans, fruits (apples, pears, berries, grapes, oranges, prunes, strawberries), potatoes, mustard, oats, soy.
Phytoestrogens: 2Includes: Genistein, daidzein, lignans.
Health Claims: Foods rich in these phytochemicals may provide benefits to bones and reduce the risk of cardiovascular disease and cancers of reproductive tissues (e.g., breast and prostate).
Food Source: Soybeans and soy products (soy milk, tofu, soy flour, textured vegetable protein), flax seed, whole grains
Organosulfur compounds:Includes: Allylic sulfur compounds, indoles, isothiocyanates, etc.
Health Claims: Foods rich in these phytochemicals may protect against a wide variety of cancers.
Food Source: Garlic, leeks, onions, chives, cruciferous vegetables (broccoli, cabbage, cauliflower), horseradish, mustard, greens.
1 Flavonoids, phenolic acids, and stilbenes are three groups of phytochemicals called phenolics. The phytochemical Resveratrol is a stilbene. Flavonoids and phenolic acids are the most abundant phenolics in our diet.
2 Phytoestrogens include phytochemicals that have mild or anti-estrogenic action in our body. They are grouped together based on these similarities in biological function, but they also can be classified into other phytochemical groups, such as isoflavonoids.
