Produce for Better Health Foundation: Health Benefits of Phytochemicals
The Produce for Better Health Foundation (PBH) is a non-profit education foundation whose mission is to be the catalyst for creating a healthier America through increased consumption of a variety of fruits and vegetables. PBH is chair of the National 5 a Day Partnership, consisting of government agencies, non-profit organizations, and industries working in collaboration to expand the efforts to increase consumption of fruits and vegetables for improved public health. The 5 A Day for Better Health Program is the nation's largest public-private nutrition education initiative with 5 A Day coordinators in each state, and territory, and the military as well.
In May 1991, PBH was formed to serve as co-sponsor, along with the National Cancer Institute (NCI), of the 5 A Day for Better Health program with the primary purpose of overseeing industry participation. What began with the support of 60 produce industry companies and commodity boards has today grown to serve 700 members representing growers, shippers, packers, merchandisers, commodity boards, trade associations, food industry organizations, health insurers, health professionals, and retailers reaching consumers in 30,000 supermarkets nationwide. This and its over 90-member board of directors speaks to the industry's confidence in PBH's efforts to increase fruit and vegetable consumption.
Produce for Better Health Foundation has also been recognized by Health and Human Services Secretary as a winner of the second annual Innovation in Prevention Awards, which highlight businesses and organizations which demonstrate leading efforts to promote health lifestyles in their community. The programs which PBH was recognized for is "Changing How Kids Eat." This innovative campaign encourages school foodservice operators and chain restaurants to promote consumption of five or more servings of fruits and vegetables a day to school-age children and their families.
Health Benefits of Phytochemicals
Modern medicine is confirming the ancient wisdom and healthy inspirations of the traditional diets from the Mediterranean, Asia, and Latin America. The intriguing question is what foods from these cuisines contributed most to their extremely low incidence of chronic diseases, many of which affect Americans today—heart disease, certain cancers, obesity, and type II diabetes. Although these cuisines have dramatic differences in their flavors, they do have something in common. These healthy dietary traditions are plant-based, that is, they are based on a wide variety of grains, seasonal vegetables and fruits, beans, legumes, nuts, and plant oils, and modest amounts of meats and saturated fat. These healthy cuisines provide a rich combination of vitamins, minerals, phytochemicals, fiber, antioxidants, and other healthy nutrients which have a synergistic effect in providing protective health benefits. The seasonal use and freshness of these plant foods maximizes the protective effect of these nutrients. Scientists have been better able at identifying the type of overall dietary patterns that are associated with reduced disease risk, rather than identifying individual nutrients or phytochemicals. The major differences between these traditional diets and the typical American diet is related to the amount of dietary proteins regularly consumed (animal versus plant sources) and dietary fats (saturated versus plant oils). Although these cuisines have low to moderate intakes of animal protein, their major source of dietary protein is plant-based (legumes, beans, nuts, and soybeans).
Background Information and Health Recommendations
The scientific literature has opened new doors for a better understanding of the medicinal value of plants, which extends beyond the information we already know concerning vitamins and minerals. Current medical evidence collectively demonstrates that fruit and vegetable intake is associated with improved health and reduced risk of major disease, and may promote a delayed onset of age-related medical risks. The American Cancer Society recently published that diet, lifestyle, and environment play a strong role in the development of cancer. It is estimated that up to 70 percent of all preventable cancers and 33 percent of cancer deaths are attributable to diet. In a prospective study, researchers followed 39,876 female health professionals who were part of the Womens Health Study for an average of five years. The study concluded that a high intake of fruits and vegetables was associated with less cardiovascular disease. The study also concluded that these protective benefits of fruits and vegetables may be a result of the combinations of micronutrients, antioxidants, phytochemicals, and fiber in fruits and vegetables. Additional research from the Nurses Health Study and the Health Professionals follow-up cohort study found that people consuming four or more servings of fruits and vegetables a day had a decreased risk for coronary heart disease. An intake of at least eight servings per day produced the most decrease in heart disease risk. Today, these scientific findings can be translated into nutrition messages which emphasize eating more foods which are good for us, such as fruits and vegetables, rather than not eating certain foods—a far more positive message than what many consumers or food professionals have encountered in the past.
Overall Dietary Patterns and Health
| Nutrient Pattern | Protection against Risk Factors |
|---|---|
| Plant sterols, soy, soluble fiber | Cholesterol reduction |
| Antioxidants: Vitamins C, E, isolfalvones, phytochemicals | Inhibit oxidation of low-density lipoproteins; decrease coronary heart disease risk |
| B Vitamins: folate, B6, B12 | Reduce certain amino acid levels which are thought to promote heart attacks |
| Flavonoids, Omega-3 fatty acids | Prevent stroke and heart attack |
| Whole grains | Positive effects on blood sugar control and coronary heart disease risk factors |
The National Cancer Institute and Produce for Better Health Foundation started with the "5 A day" campaign in 1991. Today the campaign is called "Fruits & Vegetables: More Matters". The campaign promotes 5 to 13 servings of fruits and vegetables a day based on gender and caloric needs, as recommended by the 2005 Dietary Guidelines, and also promotes consumption of a variety of colorful fruits and vegetables. A multicolored eating plan ensures all of the benefits of each family of produce. The more colorful the plate, the greater the health benefit. The disease-fighting nutrients are found in the pigments of these different fruits and vegetables. Nutrients found in dark green and bright orange vegetables provide nutrients which have been found to be consumed in inadequate amounts among Americans. These nutrients include vitamins A and C, and magnesium and potassium as well.
The 2005 USDA Dietary Guidelines of Americans recommend four and one half cups (nine servings) of fruits and vegetables each day for the reference 2000 calorie level. The 2005 USDA Food Guidelines (at the reference of a 2000 calorie) also recommend the following:
- Dark green vegetables 3 cups per week
- Orange vegetables 2 cups per week
- Legumes (dry beans) 3 cups per week
- Starchy vegetables 3 cups per week
- Other vegetables 6½ cups per week
For more information on the new 2005 USDA Dietary Guidelines go to:
http://www.health.gov/dietaryguidelines/dga2005/document/
Phytochemicals
The growing interest in nutrition research is in thousands of bio-active compounds produced by plants, also known as phytochemicals. Phytochemicals provide protection against cardiovascular disease, several common cancers, premature aging, and other chronic diseases. They are also responsible for many of the distinguishing characteristics of different plants, for example, the bright colors of yellow, red, orange, and green seen in tomatoes, peppers, and leafy vegetables, the particular flavors of bitter and astringent we experience in eating certain greens, olives, and persimmons. Foods are very complex in their nutritive composition; their protective benefits come from the interactions of their different nutrients such as fiber, vitamins, and different phytochemicals. This effect is referred to as food synergy. The medical research continues to emphasize that there is no one magical phytochemical, but that there is a synergistic or "team effort" to their medicinal values. It is questionable whether the protective benefits are possible when one phytochemical is isolated, such as in a supplement. What we do know is that eating whole and seasonal foods gives us hundreds of optimal phytochemicals.
Collectively, these phytochemicals have phyto-power. Their complementary and overlapping mechanisms of action are protective to us when we include them in our daily meals. Many different modes of actions have been attributed to their medicinal value. Table 1 summarizes the disease preventative mechanisms of plants which have been identified by medical studies.
Table 1: Disease Prevention Mechanisms of Plants
- Antioxidant activity
- Detoxification of carcinogens and harmful chemicals
- Stimulation of the immune system
- Altered hormone metabolism
- Blood pressure reduction
- Antibacterial and antiviral properties
- Maintain normal DNA repair
- Inhibit tumor growth
- Decreases processes which promote cardiovascular disease
The thousands of different types of phytochemicals can be categorized under various families. Table 2 provides these families as well as the specific phytochemicals, their proposed mechanism for health, and dietary sources.
Of particular importance is the action of some phytochemicals as antioxidants.
There are many phytochemicals which also have antioxidant capabilities; subgroups include the flavonoids and ellagic acid. Emerging scientific evidence has shown that the flavonoids from the polyphenol category have antioxidant powers greater than those of vitamins C and E, and beta-carotene as well.
An antioxidant helps prevent or delay the oxidative damage to the body, cells, and tissues caused by free radicals. Scientists believe that free radical damage is an important stage which contributes to diseases like heart disease, cancer, and premature aging. Free radicals are generated as a natural byproduct of our body's metabolism and also found in our environment from smoking, air pollution, and excessive exposure to sunlight. One of the most damaging free radicals is the unstable, highly reactive form of oxygen, which attacks cells, genes, and tissues in a rapid chain reaction sequence. The antioxidants stabilize the free radical and stop the damaging chain reaction effect. An antioxidant analysis called ORAC (Oxygen Radical Absorbance Capacity), developed by researchers at the USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Mass., finds early evidence that eating fruits and vegetables having high antioxidant activity may help slow the processes of aging and reduce the risk of age-related diseases such as cancer and heart attacks.
ORAC Values for Top Scoring Fruits and Vegetables
According to the researchers, the test-tube assay measures the ability of foods, blood plasma, and other substances to subdue oxygen free radicals, which can cause damage to healthy cells. Fruits and vegetables that have the highest ORAC units per 100 grams included prunes, raisins, blueberries, blackberries, kale, strawberries, raspberries, Brussels sprouts, plums, alfalfa sprouts, broccoli flowers, beets, oranges, red grapes, red bell peppers, cherries, kiwi fruit, and grapefruit.
Table 2
| Phytochemicals | ||
|---|---|---|
| Plant Food | Phytochemical | Protective Effects |
| Grains and beans | Sapponins, isoflavones |
|
| Soy beans | Genistein | Alter hormone metabolism to reduce tumor growth |
| Allium vegetables: onions, garlic, chives, leeks, scallions | Quercetin, sulfur allyl cystein, allicin |
|
| Cruciferous vegetables: broccoli, kale, Brussels sprouts, cabbage, cauliflower, cabbage | Sulforane, brassin, indoles, glucosinolates, isothiocyanate | Antioxidants |
| Citrus fruits | Terpenes, flavones |
|
| Wine, grapes, cranberries, berries | Flavonoids, ellagic, quercetin | Antioxidant: beneficial for heart disease and cancer |
| Green, black, oolong teas | Flavonoids, quercetin, polyphenols, catechins |
|
| Extra virgin olive oil | Oleuropin, hydroxytyrosol | Antioxidant, beneficial for heart disease prevention |
| Tomatoes | Lycopene | Antioxidant |
| Fiber | Phytoestrogens | Reduce risk of hormone- related cancers |
Vegetables and fruits taste their best when their flavors and colors mature naturally with the seasons. The beauty and flavors of cuisines from the Mediterranean, Asia, and Latin America have already motivated many of us to include more seasonal fruits and vegetables in our daily meals. Much of what we have learned from the healthy global cuisines has centered on the concept that the traditional diets emphasize food and the awareness of its tradition and preparations. Good food begins with quality ingredients. Local, fresh, and seasonal products are essential to this cuisine, as are the steps to capture flavor, nutrition, and the balanced use of additional ingredients.
References and Suggested Reading
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Messina, M.J., Persky, V., Setchell, K.D.R., et al. Soy intake and cancer risk: a review of the in vitro and in vivo data. Nutr Cancer. 1994;21:113-131.
Drewnoski and Carneros, Bitter taste, phytonutrients, and the consumer: a review. Am J Clin Nutr 2000;72:1424-35.
Cao, Sofic, Prior. Antioxidant capacity of tea and common vegetables. J Agric Food Chem. 1996; 44:3426-3431.
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Trichopoulou, A, et al. Nutritional composition and flavonoid content of edible wild greens and green pies: a potential rich source of antioxidant nutrients in the Mediterranean Diet. Food Chemistry 2000;70:319-323.
Wise, J.A., Morein, R.J., Sanderson, R., Blum, K. Changes in plasma carotenoid, alpha tocopherol, and lipid peroxide levels in response to supplementation with concentrated fruit and vegetable extracts; a pilot study. Curr Ther Res Clin Exp 1996; 57:445-61.
Rice-Evans, C.A., Miller, N.J., Bolwell, P.G., Bramely, P.M., Pridham, J.B. The relative antioxidant activities of plant derived polyphenolic flavonoids. Free Radic Res 1995;22:375-83.
Visioli, F., and Galli, C. The effect of minor constituents of olive oil on cardiovascular disease: New findings. Nutrition Reviews 1998; 56 (5) 142-147.
Formica, J.V., Regelson, W. Review of the biology of quercetin and related bioflavonoids. Food Chen Toxicol, 1995; 12: 1061-80.
Hayashi, A., et al. Effects of daily oral administration of quercetin chalcone and modified citrus pectin. Altern Med Rev 2000;6:546-552.
Abdalla, D.S., Terao, J. Inhibitory effect of flavonoids on low density lipoprotein peroxidation catalyzed by mammaliam 15 lipoxygenase. IUBMB Life 2000 Apr;49;4: 289-95.
Liggins, J., et al. Daidzein and Genistein content of fruits and nuts. J Nutr Biochem 2000;11:326-31.