Currently, the terms "phytonutrient" and "phytochemical" are being used interchangeably to describe those plant compounds which are thought to have health-protecting qualities. The antioxidant, immune boosting and other health promoting properties of active compounds in plants are being investigated.
However, in common usage, they have a more limited definition. They are usually used to refer to compounds found in plants that are not required for normal functioning of the body but that nonetheless have a beneficial effect on health or an active role in the amelioration of disease. Thus, they differ from what are traditionally termed nutrients in that they are not a necessity for normal metabolism, and their absence will not result in a deficiency disease. What is beyond dispute is that phytonutrients have many and various beneficial health effects. For example, they may promote the function of the immune system, act directly against bacteria and viruses, reduce inflammation, and may also be associated with the treatment and/or prevention of cancer (the focus of this article), cardiovascular disease and any other malady affecting the health or well-being of an individual.
Allyl Sulfides are found in garlic, onions, and shallots. They suppress growth of tumor cells and bring about apoptosis, or natural cell death (cancer cells find ways to stop this process); allyl sulfides also promote excretion of cancer causing
chemicals. They lessen stomach and colon cancer, and help to treat colds, blood circulation, inflammations, arteriosclerosis and diabetes. Quercetin is a flavonoid found in medicinal plants which works to prevent inflammations and inhibits the release of histamines. In a recent study in the British Journal of Cancer, quercetin and ultrasound were used to treat skin and prostate cancers, with a 90% death of the cancer cells within 48 hours, and no visible deaths of the normal cells! This phytonutrient is used to treat cancer, prostatitis, heart disease, cataracts, and respiratory diseases like bronchitis and asthma. It is found in capers, apples, tea, onions, grapes, citrus, broccoli, leafy green vegetables, cherries, turmeric, and cranberries. Limonene is a hydrocarbon, taking its name from lemons, and is found in lemons and in noni. It helps the liver clear carcinogens from the body and promotes cell differentiation. Lutein (from Latin “Lutea” meaning yellow) is one of 600 known carotenoids. Found in leafies like spinach and kale, it is used as an antioxidant. It is also found in mango and winter squash. Early studies have shown high intakes reduced risk of breast, colon, endometrial (uterine) and prostate cancers. It is found in concentrated areas of the macula, the small area of the retina responsible for central vision. Catechin is found primarily in green tea and is an anti-oxidant that helps keep tumors from taking hold and growing. According to Norman Hollenberg, Professor at Harvard Medical School, epicatechin, a metabolic form of catechin, can reduce the risk of all four of these major human health problems: stroke, heart failure, cancer, and diabetes. His studies were based on the Kuna people in Panama who drink up to 40 cups of cocoa a week, with only 10% being struck by the big four diseases! Chlorophyll is the prime biochemical for all respiration and life in the plant world. It is strikingly similar in form to hemoglobin, differing primarily in that chlorophyll has magnesium in the center and hemoglobin has iron. This would explain partly why wheat grass juice is so instantly beneficial for those with “tired blood” and anemia. It is found in spirulina, chlorella, barley grass, and in leafy greens. It is a potent detoxification agent and protects genes against the biochemical damage that leads to cancer cell development. Sulphoraphane is the phytonutrient that activates enzymes that detoxify carcinogens; it interferes with cancer cell growth and promotes cancer cell death. It is found in broccoli & especially in broccoli sprouts. Lycopene is best known for providing protection against prostate cancer, and may also help defend the physiochemistry of humans against lunch and stomach cancer malignancies. It is found in tomatoes, watermelon, pink grapefruit, guava, papaya, and in rosehips. It is the most powerful quencher of singlet oxygen, 100 times more so than Vitamin E. It is helpful for cardiovascular disease, cancer, diabetes, osteoporosis, and male infertility. Recently the United States Food and Drug Administration concluded that tomatoes reduce no risk for lung, colorectal, breast, or cervical cancer, and only limited evidence for reduced risk of prostate, ovarian, and pancreatic cancers, all derived from 145 studies after a coalition of tomato growers and tomato product producers asked to list anti cancer benefits in nutritional labels on their products. We rarely agree with the FDA, so keep eating lots of tomatoes for their carcinogenic properties, which the FDA may or may not ever get around to formally endorsing…. Ellagic acid appears to defend cells lining the digestive tract against carcinogenic substances, and has prevented colon and esophageal cancer in animals. It is found in pomegranates, grapes, raspberries, and strawberries. Apparently, it also may help the liver to break down and remove cancer causing substances from the blood. One study in Clinical Nutrition in 2004 showed clearing of plaque in the carotid artery after three years of pomegranate juice as a supplement. Italian researchers have also found ellagic acid reducing the side effects of chemotherapy in advanced prostate cancer treatment in men, and the Hollings Cancer Institute at the University of South Carolina conducted a double blind study on 500 cervical cancer patients that showed ellagic acid caused G-arrest within 48 hours and apoptosis within 72 hours, for breast, pancreas, esophageal, skin, colon, and prostate cancers. Researchers speculate that this results when ellagic acid forms adduct (from Latin, “drawn toward”) with DNA, thus masking binding sites to be occupied by the carcinogens. Resveratrol causes apoptosis or cancer cell death. Resveratrol is a phytoalexin and is sold as a nutritional supplement. A number of beneficial health effects, such as anti-cancer, antiviral, neuroprotective, anti-aging, anti-inflammatory and life-prolonging effects have been reported, although these studies used animal subjects. Resveratrol is found in the skin of red grapes and as a constituent of red wine. David Sinclair of the HarvardMedical School and cofounder of Sirtris Pharmaceuticals has found that resveratrol increases the activity of a protein called SIRT1. Resveratrol significantly increases the lifespan of yeast and mice. Resveratrol is produced by several plants, apparently due to its antifungal properties. It is found in widely varying amounts in grapes (primarily the skins), raspberries, mulberries, in peanuts, berries of Vaccinium species, including blueberries, bilberries, and cranberries. In grapes, resveratrol is found primarily in the skin and seeds. This is particularly true for Muscatine grapes, whose skin and seeds have about 100 times the concentration as the pulp. Resveratrol interferes with all three stages of carcinogenesis - initiation, promotion and progression.