Recommendation
14 Background
|
| Phytochemicals are substances naturally
found in plant foods like fruits, vegetables and grains.
They are also known as phytoprotectants or bioactive
compounds. Phyto is Greek for plant.
Phytochemicals are not considered essential yet, in the
way vitamins and minerals are. Until the 1980's vitamins and minerals were considered important because they protected us against diseases caused by a deficiency of a given vitamin or mineral. The deficiency was clinically observable. A new concept began to emerge then: intakes above minimum recommended levels might be protective against chronic deficiencies. This was followed by the realization that substances, other than vitamins and minerals, and which are present naturally in foods may also be protective. These substances are the phytochemicals. The exciting news about phytochemicals is their ability to inhibit carcinogenesis. Phytochemicals are capable of halting that process at one or more of the stages. They play a variety of roles such as antioxidants, suppressors of tumor growth, antimutagens, enzyme modulators, chemical inactivators, and free radical scavengers. Most of the evidence on the beneficial effects of phytochemicals comes from laboratory studies. (Cancer was induced in animals by various chemical carcinogens and specific amounts of phytochemicals were fed to them.) This evidence suggests it may be possible that phytochemicals protect against human cancer but is not yet conclusive. In addition, under certain circumstances phytochemicals show the potential to promote cancer. More research needs to be done to confirm laboratory findings. Phytochemicals may also be significant in the prevention of other diseases such as heart disease. |
| In the view of the AICR/WCRF panel allium compounds possibly decrease the risk of stomach cancer; there is at present insufficient evidence that isoflavones decrease the risk of breast cancer. |
| Phytochemicals | Food sources |
| Allium
compounds Dithiolthiones & isothiocyanates Terpenoids: D-limonene, geraniol, menthol,and carvone Phytoestrogens: lignans & isoflavones Phenolic compounds: ellagic caffeic acids, curcumin, flavonoids (catechins) and flavonols (quercetin) Alpha-tocopherol Protease inhibitors Phytic acid (inositol hexaphosphate) Glucosinolates: indole-3-carbinol Plant sterols Saponins Coumarins |
Allium
vegetables: onions, garlic, scallions, chives Cruciferous vegetables: broccoli, cabbage, cauliflower, brussel sprouts Oil of citrus fruit peel (used as flavoring agent in ice cream, sweets, baked goods, gelatins, puddings, chewing gum) Cereals, legumes (lentils, beans, split peas, etc.), sorghum, millet, soybeans, wholegrain products, seeds, fruits and berries Berries, tomatoes, potatoes, broad
beans, broccoli, Italian squash, onions radishes,
horseradish, kale, endive, and many other fruits and
vegetables, teas walnuts, pecans Vegetable oils, whole grains, nuts and seeds Cereals: barley, wheat, oats and rye; legumes: soy beans, kidney beans, chickpeas, lentils and others Cereals, nuts, seeds and legumes Cruciferous vegetables: broccoli, cabbage, cauliflower, brussel sprouts Vegetables Soy beans Vegetables, particularly cassava, citrus fruits and some herbs |
For more information on phytochemicals visit the web site of the Center for Alternative Medicine at http://chprd.sph.uth.tmc.edu/utcam/research.htm#list
For more information on carcingenesis, please see the Extoxnet TIB on Carcinogenesis.
For other details see Recommendation 14 Vitamins, Recommendation 14 Minerals. For practical advice, see Recommendation 14 How to
Back to Fourteen Recommendations
Prepared 1998 by Bernadene Magnuson, Ph.D.
University of Idaho, Dept. of Food Science and Toxicology - EXTOXNET FAQ Team.