The term "Phytochemical" is a fairly new one in the public health and nutrition vocabulary. Phytochemicals are naturally occurring and biologically active plant compounds that provide health benefits.

• New phytochemicals are being discovered on a daily basis, and it is estimated that plants contain hundreds of thousands of different phytochemicals (1).
• Some of the health-promoting phytochemicals that have been identified are present in familiar foods, such as fruits, vegetables, nuts, grains, legumes, seeds, licorice, soy, and tea.

Researchers have long known that phytochemicals provide health benefits for plants, but it is only recently that certain phytochemicals have been recommended for the purpose of disease prevention and treatment for humans.

• Cancer, diabetes, heart disease, and hypertension are four important areas of current phytochemical research(2).
• It is believed that phytochemicals may be effective for combating or preventing disease due to their antioxidant effects. Antioxidants protect other molecules from oxidation when they are exposed to free radicals.
• When scientists began seeing the connection between antioxidant phytochemicals and cellular protection, repair and regeneration, the study of phytochemicals for human health began in earnest (3).

Commonly Studied Phytochemicals

Phytochemical	Food Source	Suggested Health Benefits*
Terpenes carotenoids liminoids	Grains, soy products, citrus fruits, green foods oranges pink grapefruit, spinach, tomatoes Citrus fruit peels	Antioxidant protection from free radicals Enhance immune response; protect skin cells Protect lung tissue; stimulate liver detoxification enzymes
Thiols Glucosinolates Sulforaphane Allylic sulfides Indoles	Plants containing sulfur-rich phytochemicals: allium and cruciferous vegetables(broccoli and broccoli sprouts, cabbage, Brussels sprouts, bok choy, kale, cauliflower, rutabaga, turnips, radishes, diakon) garlic, onions, chives, leeks Cruciferous vegetables (see above)	Antioxidant activities provide protection from free radicals; switch on liver's detoxifying enzymes; activate white blood cells; remove toxins; prevent tumor growth in esophagus, breast, lungs, stomach, liver, prostate, and colon. Promote immune responses Protect cardiovascular and immune systems; prevent cancer; thwart genetic mutation; lower cholesterol; act as natural antibiotics against viruses/ bacteria, fungi, and parasites Increase production of enzymes that inactivate food toxins and carcinogens
Phenols Flavanoids Flavonals Isoflavones Catechins and gallic acid	Berries, grapes, eggplant Grapefruit, buckwheat, citrus, soybeans, milk thistle, chamomile, artichokes, red wine, apples Pine bark; grape seeds Soybeans, chic peas Green tea, black tea, coffee	Stabilize free radicals; modify prostaglandin pathways; block enzymes that cause inflammation (allergies, autoimmune diseases, infections); prevent cancer, heart attacks and strokes Enhance effects of vitamin C; inhibit enzyme activity; block estrogen induced cancers; lower blood pressure; prevent break down of prostaglandins, reduce platelet aggregation and stickiness; protect blood vessels; strengthen capillaries; fight inflammation; improve diabetes, hemorrhoids, varicose veins, destroy hepatoxins Promote antioxidant activity; relieve fatigue; ease arthritis and allergies; lower cholesterol; strengthen capillaries; promote healthy skin Prevent tumor growth; prevent the buildup of arterial plaque; reduce the risk of heart disease and stroke; fight osteoporosis; relieve some menopausal symptoms Promote antioxidant activity; inhibit cancer, heart disease, bone loss
Physterols	Pumpkins, rice, soybeans, yams, green and yellow vegetables, vegetable oils	Block cholesterol uptake; lower risk of heart disease; reduce inflammation and block tumor growth in breast, prostate, colon
Tocopherols	Seeds, nuts, soybeans, wheatgerm, whole grains	Protect cell membranes; neutralize free radicals
Isoprenoids	Grains, nuts, and seeds	Neutralize free radicals by handing them over to antioxidants and chemically stabilizing them

* A few, if any of these effects are rigorously proven by modern science. The effects listed in this table, however, have been suggested by the preponderance of science or by a majority of health professionals and nutritionists who have assessed the evidence.

A decade ago, Dr. Paul Talalay and his research team at Johns Hopkins isolated and identified sulforaphane, the precursor of which is a glucosinolate found in cruciferous vegetables, and particularly broccoli, as a phytochemical with very promising disease prevention and treatment properties (4-8).

• They discovered that broccoli sprouts, grown for three days from seeds, contained between 20 and 50 times the concentration of sulforaphane as mature, cooked broccoli (5).
• The considerable variation in the amount of sulforaphane was based on the type of broccoli seeds and growth conditions (5).
• To ensure that consumers could purchase a safe, consistent and guaranteed amount of sulforaphane (SGS™), the Johns Hopkins University researchers developed BroccoSprouts® and Brassica® teas.

Research to date indicates that the potential of SGS is wide reaching and powerful:

• In a 2000 report presented at the American Association of Cancer Research, researchers found that sulforaphane significantly inhibited colon cancer in rats (9).
• A 2000 report in Cancer Letters by the University of Illinois showed that sulforaphane significantly reduces the capacity of a carcinogen to cause cancer through its ability to bind to DNA (10).
• A French study published in Cancer Research, March 2001, shows that sulforaphane not only activates antioxidants, but it removes carcinogens AND kills cells with potential cancer causing mutations (11).
• In 2001, Dr. Bernard Juurlink at the University of Saskatchewan demonstrated that sulforaphane retards oxidative damage leading to arterial occlusion. Sulforaphane may, therefore, interrupt the progression of plaque development leading to strokes (12).
• In September 2001, Dr. James Brooks at Stanford University reported that human prostate cancer cells responded well to treatment with sulforaphane by showing dramatic increases in their protective Phase 2 enzymes (13).
• In December 2001, Dr. Paul Talalay and his colleagues at Johns Hopkins University described new studies showing that sulforaphane protects human retinal (eye) cells against a variety of severe oxidative challenges (14).
• In May 2002, this same research team at Johns Hopkins University reported that sulforaphane kills Helicobacter pylori, the bacterium responsible for the vast majority of gastritis and stomach ulcers and for many cases of stomach cancer (15).

A word of caution... Many phytochemicals are still being evaluated for their safety and effectiveness. Optimal levels of, and interactions between certain phytochemicals have not yet been determined. However, it is safe to consume at least the 5-9 servings a day of fruits and vegetables as recommended in the US Dietary Guildlines(16).

Researchers will continue to identify and investigate phytochemicals for prevention and treatment of disease, and there is tremendous potential in the undiscovered. We at Brassica Protection Products recommend that you stay informed about this emerging field of knowledge. A healthy diet, rich in phytochemicals, can lower health care costs and prolong and improve the quality of human life (17).

References:

1. Conn E, 1995. The world of phytochemicals. Chapter 1, 1-14. Proceedings of the Tenth Annual Penn State Symposium in Plant Physiology.
2. Polk, M, 1996. Feast on Phytochemicals. AICR newsletter. Issue 51.
3. Smith, TJ, 1998. Renewal: The Anti-Aging Revolution. Emmaus, PA: Rodale Press.
4. Fahey J and Talalay, P, 1995. The Role of Crucifers in Cancer Chemoprotection. In Phytochemicals and Health, DL Gustine, HE Flores, eds. Rockville, MD: American Society of Plant Physiologists.
5. Fahey J, Clevidence B, and Russell M, 1999. Methods for assessing the biological effects of specific plant components. Nutrition Reviews, Vol. 57, No. 9 (Part II), September.
6. Prochaska HJ, Santamaria AB, and Talalay P, 1992. Rapid detection of inducers of enzymes that protect against carcinogens. Proc Natl Acad Sci USA Mar 15;89(6):2394-8.
7. Fahey J, Zhang Y, Talalay P, 1997. Broccoli sprouts: An exceptionally rich source of inducers of enzymes that protect against chemical carcinogens. Proc. Natl. Acad. Sci. USA, Vol 94 September 16pp. 10367-10372.
8. Zhang Y, Kensler TW, Cho C, Posner GH and Talalay , 1994. Anticarcinogenic activities of sulforaphane and structurally related synthetic norbornl isothiocyanates. Proc Natl Acad Sci USA Apr 12;91(8):3147-50.
9. Chung F-L, Conaway CC, Rao CV, Reddy BS, 2000. Chemoprevention of colonic aberrant crypt foci in Fischer rats by major isothiocyanates in watercress and broccoli. Proceedings of the American Association for Cancer Research, March 2000; 41:660.
10. Singletary K, MacDonald C. Inhibition of benzo[a]pyrene- and 1,6-dinitropyrene-DNA adduct formation in human mammary epithelial cells by dibenzoylmethane and sulforaphane. Cancer Letters, July 3, 2000; 155(1):47-54.
11. Gamet-Payrastre L, Li P, Lumeau S, Cassar G, Dupont MA, Chevolleau S, Gase N, Tulliez J, Terçé F, 2000. Sulforaphane, A naturally occurring Isothiocyanate, Induces Cell Cycle Arrest and Apoptosis in HT29 Human Colon Cancer Cells. Cancer Research, March 1; 60(5):1426-1433.
12. Wu L; Juurlink BHJ, 2001. The impaired glutathione system and its up-regulation by sulforaphane in vascular smooth muscle cells from spontaneously hypertensive rats. Hypertension, 19:1819-1825.
13. Brooks JD, Paton VG, and Vidanes G, 2001. Potent induction of Phase 2 enzymes in human prostate cells by sulforaphane. Cancer Epidemiology, Biomarkers & Prevention, Sept.; 10:949-954.
14. Gao X, Dinkova-Kostova AT, and Talalay P, 2001. Powerful and prolonged protection of human retinal pigment epithelial cells, keratinocytes, and mouse leukemia cells against oxidative damage: the indirect antioxidant effects of sulforaphane. Proc. Natl. Acad. Sci. USA, December 18; 98(26): 15221-15226.
15. Fahey JW, Haristoy X, Dolan PM, Kensler TW, Scholtus I, Stephenson KK, Talalay P and Lozniewski A, 2002. Sulforaphane inhibits extracellular, intracellular, and antibiotic-resistant strains of Helicobacter pylori and prevents benzo[a]pyrene-induced stomach tumors. Proc. Natl. Acad. Sci. USA, May 28;99(11):7610-7615.
16. http://www.health.gov/dietaryguidelines/dga2000
17. Willett W, 2002. Eat, Drink and Be Healthly. New York: Simon and Shuster.

Internet Links:

• The Phytochemical Revolution
  (Renewal Research) a chapter from Renewal: The Anti-Aging Revolution by Timothy J. Smith, M.D.
• Ohio State University Extension Fact Sheet : Phytochemicals - Vitamins of the Future
• Phytochemicals and Functional Foods
  Position of The American Dietetic Association.
• USDA Nutrient Data Laboratory - provides analytical values for different compounds in found in foods.
• 5 A Day: A Rainbow of Colors makes it Easy for Kids to Eat the Fruits and Vegetables they need Every Day
• Texas A&M University : Televised course. See especially Phytochemicals in fruits and vegetables to improve health.
• Harvad Public Health NOW, August 24, 2001, Nutrition Book Author Willett Rebuilds USDA Food Pyramid
• USDA : Frequently Asked Questions About Phytonutrients