Sunday, July 20, 2008

The Protective Power Of Plants

The New Frontier

In China, they've been used for centuries to halt high blood pressure; in Europe, they've been linked with preventing lung cancer; in Japan, they're used as health-enhancers; in America, scientists are exploring their ability to prevent common health problems, ranging from cancer and heart disease to high blood pressure and arthritis.

Phytochemicals. These naturally occurring substances in plants are being lauded as "natural pharmacy," empowered with the ability to protect our health. Indeed, as research illuminates their potential health benefits, phytochemicals are emerging as the ultimate gift of health from a beneficient Mother Nature.

Pioneering Research

Since the 1960s, the scientific community has been working to pin down the healing properties of the phytochemicals in the plant-based whole food groups of fruits, vegetables, beans and peas (legumes), and to a lesser extent, whole grains. Then in 1989, the National Cancer Institute (NCI) sponsored still more research to target the cancer-fighting phytochemical compounds in plant-based foods, especially fruits and vegetables.

Called the "Designer Food Program," phytochemicals' link to preventing various ailments has been explored with NCI funds. To date, polyacetylenes from parsley have been found to deactivate the synthesis of prostaglandins, potent carcinogens and isoflavones from legumes seem to neutralize cancer-gene enzymes. In addition, researchers have identified sulvoraphane, one of the substances in a class of phytochemicals called indoles. Found mostly in cruciferous vegetables such as broccoli, cauliflower and Brussels sprouts, sulforaphane lowers the risk of breast cancer by deactivating excess estrogen, a female hormone associated with breast cancer.

International research has shown that phytochemical-rich diets may help to prevent high blood pressure, control cholesterol and be useful in treating a plethora of ailments ranging from cataracts to gallstones. But teasing out the phytochemical health factor in various plant-based foods isn't easy. One reason is that there are thousands, probably hundreds of thousands, of phytochemicals; another is that single phytochemicals, isolated from their relatives, may not bring anticipated health benefits.

Vegetable Power

"Eat your vegetables," admonished our mothers. Now, research is substantiating what many moms knew all along: fruits and vegetables are good for you. In fact, colored fruits and vegetables, such as dark-green spinach, chard, collard, and kale; yellow-orange carrots, sweet potato, squash and cantaloupe; and deep red tomatoes and red peppers, may be especially helpful in warding off disease," suggests The New York Times health writer Jane Brody in a recent article.

Researchers in Japan, who have been studying the health benefits of fruits and vegetables for 30 years, agree. Based on a large-scale prospective study, led by Takeshi Hirayama, M.D., and colleagues at the Institute of Preventive Oncology in Tokyo, it's likely that a lifestyle that includes lots of colored fruits and vegetables is the key to health and longevity.

This conclusion was reached after Dr. Hirayama and his research team followed more than 265,000 adults for 17 years, in six areas throughout Japan. The results linked the aging process and mortality with the lifestyle risk factors of: a diet low in colored fruits and vegetables, meat and alcohol consumption, smoking and stress management. Specifically, those whose lifestyle included lots of colored fruits and vegetables and who didn't consume meat or alcohol and didn't smoke had the lowest risk of death. Based on 44 causes of death, those with the highest mortality risk had an entirely opposite lifestyle, which included meat and alcohol consumption, smoking, and the intake of little or no fruits and vegetables. Interestingly, study participants who smoked, ate meat, and drank alcohol but who also ate colored fruits and vegetables had a death risk factor that fell between the highest and lowers risk groups.

Concludes Dr. Hirayama: "Speed of aging is likely to be controlled by lifestyle modification. Smoking cessation, avoiding or limiting alcohol and meat consumption, and increased consumption of colored fruits and vegetables must be the wisest and healthiest way to live."

Another study, the China Diet Health Project, conducted by T. Colin Campbell, Ph.D., a nutritionist at Cornell University, Ithaca, NY, supports Dr. Hirayama's findings. Dr. Campbell's project, based on data from 6,500 people, examined the link between diet, lifestyle and 45 different diseases. His conclusion: a diet consisting mostly of fruits, vegetables and grains seems to protect against many common Western diseases.

And in Europe, Dr. H. K. Bisalski, a professor at the Institute fur Biologische Chemi in Stuttgart, Germany, has linked specific antioxidant properties for phytochemicals to preventing heart disease. A biochemist specializing in this field of research, Dr. Bisalski has studied what he calls "preventive plasma levels," the concentrations of phytochemicals and antioxidants needed in the blood to prevent heart disease.

To reap the preventive effects of certain phytochemicals, he recommends at least 200 grams of fruits and vegetables daily, in order to achieve optimal plasma levels of the antioxidants beta carotene and vitamins E and C.

"I've studied the preventive effects of phytochemicals and antioxidants," he explained during a recent interview, "and 200 grams daily of fruits and vegetables is enough to bring plasma levels to 2-5 mg. beta carotene daily; 15-30 mg. vitamin E (alpha-tocophorol); and 150 mg. vitamin C," the amounts he believes are adequate to prevent heart disease. "These aren't low doses," he says. "They're higher than the Recommended Daily (Dietary) Allowance (RDA) in the United States."

For those of us who can't always achieve this goal, Dr. Bisalski suggests "ritualizing" your intake of fruits and vegetables. "The most effective way to increase your intake of phytochemicals is by drinking mixed vegetable juice and fruit juice. For instance, in the morning you don't decide if you're going to brush your teeth. You just do it. It has become a ritual. In the same way, try to establish a ritual of drinking orange juice or fruit juice in the morning. In the afternoon, have two glasses of mixed-vegetable juice. If you do this every day, it will become a ritual, and you'll be certain you're getting the necessary level of phytochemicals."

Disease Prevention

There has been a lot of talk about changing our health-care system from one that emphasizes treatment of disease with drugs and surgery to one that emphasizes prevention. More than ever, we're beginning to realize the importance of assuming responsibility for our own health. Nowhere is this more apparent than in choosing the foods we eat. Nutrition is being "re-discovered" as scientific research will attest, as a major preventive as well as a curative treatment tool for certain diseases. In the future, phytochemicals may play a large part in our efforts to maintain good health and prevent the diseases that plague our society.


Perhaps some of the most exciting and credible research is being done in the field of cancer prevention and treatment. When the American Cancer Institute (ACI) began a reported $6 million study of phytochemicals to identify and assess cancer preventive properties and safety, phytochemicals moved into the mainstream of scientific research. There was another important breakthrough when the NCI earmarked $20 million for research led by Dr. Herbert Pierson, to study five foods found to be high in various phytochemicals: soybeans, garlic, licorice, citrus and vegetable juices. (See our article on "Designed Foods," page )

Just how do phytochemicals offer protection? Numerous mechanisms exist by which natural phytochemicals (and antioxidants) are believed to protect against carcinogenesis. Phytochemicals seem to work their magic by interfering with the development of cancer at the cellular level. Some prevent potential cancer cells from forming; others protect cells from damage by blocking, suppressing or inhibiting duplication of cancer cells; or they may help to boost the immune system. For instance, Brassica vegetables (including broccoli, cauliflower, cabbage, and Brussels sprouts) contain the phytochemical sulforaphane, which seems to stimulate the production of anti-cancer enzymes and bolster the body's natural ability to ward off cancer. Indoles, found in the same vegetables, seem to stimulate enzymes that make the hormone, estrogen, less effective, possibly reducing breast cancer risk.

There have been at least 150 human studies done to compare the eating habits of people with and without lung, esophageal, breast and other cancers. Those who ate the most fruits and vegetables were about half as likely to have cancer as those who ate the least. Research into anti-carcinogenic factors of chemicals in plants was boosted by discoveries such as those by University of Minnesota Professor Lee Wattenberg, who observed that members of the cabbage (cruciferous) family, such as broccoli, protected mice from carcinogens. Since Wattenberg's work, many similar studies have identified other cancer-fighting phytochemicals.

In Japan, observations of very low lung cancer rates in a society of heavy smokers, as well as extremely low levels of breast and intestinal cancer, led investigators to research the high levels of phytochemicals found in the traditional Japanese diet of soy-based foods, vegetables and green tea. Green tea was found to be high in catechins as well as certain other phytochemicals and antioxidants and seemed to play a role in strengthening the immune system and combating cancer.


Although there are many different types and causes of arthritis, painful, swollen joints, stemming from inflammation in the joint region, is a common denominator. So far, there is no specific cause or cure for this disease, but preliminary studies show that some phytochemical-rich foods may work to reduce swelling and inflammation associated with various types of arthritis. More research is needed before the FDA will consider approving some of these substances for the treatment of rheumatoid arthritis.

Phytochemicals in the following foods have been found to help alleviate arthritic problems in many people. Bioflavonoids in citrus fruits, fruits, vegetables, whole grains, legumes, and honey help to reduce inflammation. Allylic sulfides in garlic and ginger help to block formation of inflammatory substances. Gamma-linolenic acid (GLA), found in the seeds of evening primrose and black currant have been found to reduce inflammation in some people.


Osteoporosis (loss of bone mass mainly in the vertebral spinal column, wrist, and hip) afflicts at least 15-20 million Americans (mostly women). At least one out of three people age 65 or older have some form of the disease. The primary cause of death in elderly women is complications from hip fracture, often the result of osteoporosis which began years earlier. One-third of all victims die within a year following these fractures. In a recent article on osteoporosis, soy foods expert Dr. Mark Messina, Ph.D., cites the work of William Prouix and Connie Weaver, Ph.D. and their research on soybeans and the prevention of osteoporosis: "...soybeans," he writes, "are a good source of calcium, which is absorbed about as well as the calcium found in milk. In addition, the isoflavones in soybeans have a beneficial effect on bone health, possibly by inhibiting bone resorption." Furthermore, soy protein does not seem to cause loss of calcium the way proteins in animal foods do.

PMS and Menopause

Could certain phytochemicals influence a woman's production of the hormones that promote PMS (pre-menstrual syndrome)? No one knows for sure, but there's some evidence that certain phytochemicals can minimize psychological and physical symptoms. When a woman's body stops making estrogen, and she enters into menopause, she may suffer from such side effects as hot flashes and mood disturbances. Isaflavones, found in soy products and also contained in cereals (such as corn flakes), whole grains, complex carbohydrates, legumes, and cold pressed oils (such as sesame, olive, corn and safflower) may help to control these symptoms, as well as depression, fatigue and anger.

Current research, (including studies of the Asian diet, which includes many soy-based foods) shows that soybeans help to provide relief from mood swings and hot flashes. "In Japan, where women traditionally eat a high soy diet, hot flashes are so rare that there is no word to describe them," states a recent study. Similar findings have been seen with women following strict vegetarian or vegan diets.

The reasons for these findings seem to stem from a diet lower in fat (high-fat diets increase the estrogen level in the body) and higher in phytoestrogens. Phytoestrogens are weak estrogens produced by approximately 300 different plant-based foods such as bean sprouts, sesame seeds, carrots, corn, apples, oats, etc. However, the best source is probably soy-based foods such as soybeans, tofu, soy milk, soy protein and tempeh (but not soy oil or soy sauce).

Because they are rich in the phytoestrogen, an isoflavone called genistein, as well as a host of other phytochemicals, soy foods are sparking the interest of health professionals such as Dr. Messina, and Dr. David Zava, co-director of the Cancer Research Division, California Public Health Foundation, and others affiliated with cancer research. These phytoestrogens seem to mimic the body's estrogen without its detrimental effects. It may be that soybeans, for instance, contain a natural analogue which seems to block estrogen's ability to stimulate certain hormone related carcinogens. Indeed, the NCI recently devoted an entire meeting to dietary phytoestrogens.

Researchers believe that during and after menopause, a woman's low levels of estrogen may boost the risk of heart disease and osteoporosis. Phytoestrogens can provide a source of the hormone without seeming to increase the risk of cancer.

Could Your Refrigerator be the Medicine Cabinet of the Future?
What is the future of phytochemicals and their role in healthcare and disease prevention?
As the population ages, the need to improve the quality of life in later years becomes more important. Paired with this is a concern about the quality of health care in this country. Subsequently, more people are taking responsibility for their own health. Sorting out which plant chemicals might be useful in preventing disease is still a new science; however, evidence gathered so far indicates that choosing a diet rich in fruits and vegetables can lower the risk of disease.

"Foods can no longer be evaluated only on the basis of their nutrition and fiber content," says Dr. Messina. "We have a new paradigm in nutrition. Foods contain phytochemicals, which are, in a sense, the vitamins and minerals of the 21st century."

Black Bean Salsa

Here's a recipe we think you'll like, not only because it tastes good but because it's also loaded with foods rich in disease-fighting phytochemicals.

15 oz. canned black beans cooked with salt
1 cup chopped tomatoes
1/2 cup yellow corn, cooked, drained
1/2 cup chopped red onion
1/4 cup fresh cilantro, chopped
1/4 cup canned jalapeno peppers, chopped
1 clove minced garlic
1/4 cup fresh lime juice

1. Drain black beans well. Jalapeno peppers should also be drained and seeds removed.

2. Combine all ingredients in a medium bowl and toss well. Let stand one hour. Serve over burritos, with main dishes or as a dip with toasted tortilla chips.

Yield: 3-1/2 cups

1/2 CUP SERVING: 84 calories, 5g protein; 16g carb; 1/2g fat; 0g saturated fat; 176mg sodium; 0mg cholesterol; 5g fiber.

Fruit Potpourri

Calvin's Own Phyto-Feasting

Making sure he has plenty of phytochemical-rich foods in his diet, Calvin Scherwitz of Waco, Texas, has been "ritualizing" his intake of phytochemicals for more than eight years. We've included two of his recipes here (modified for Nourish). Every morning, Calvin begins his day with a refreshing "Fruit Potpourri," a phytochemical-rich fruit infusion made in a Vitamixer. A blender works just fine, though, with most fruits. Although our sample for his Veggie Stir-Unfry contains seven veggies, Calvin's version often includes up to 14 vegetables: tomatoes, bell peppers, cauliflower, broccoli, onion, squash, water chestnuts, celery, mushrooms, bean sprouts, Chinese cabbage, carrots, snow peas and bamboo shoots. He especially liked to prepare it when his son, Trey, brought friends home from college, "and they just loved it," says Calvin. For a change of pace, bake a potato; slice it or mash it, then place a portion on the bottom of the dinner plate. Cover with unfried veggies of choice.

5 slices peaches, fresh or frozen
1 small banana, peeled
3 large strawberries, fresh
1 cup pineapple, fresh or canned
1/4 pineapple juice, from bottle or canned fruit
1/2 cup fruit cocktail, canned, in natural juices
1-1/2 cups water or soy milk or nonfat milk
1 Tbsp. vanilla (opt.)
1/4 nonfat, dry milk (opt.)
15 ice cubes (opt.)

Place all ingredients in a blender. Mix until well-blended. Enjoy!

Yield: 4-5, 8 oz. servings

1 serving: 93 calories; 2g protein; 21g carb; .4g fat; .08g saturated fat; 25mg sodium; .67g cholesterol; 1.6g fiber.

Veggie Stir-Unfry

3 garlic cloves, peeled and minced
4 Tbsp. lemon juice
2 Tbsp. reduced sodium soy cause
2 Tbsp. balsamic vinegar
1 Tbsp. brown sugar (opt.)
1/2 tsp. black pepper, freshly ground

1 zucchini, chopped
1 red pepper, chopped
6 large button mushrooms, sliced
1 cup corn kernels, frozen
Flowerettes from 1 stalk broccoli, chopped
30 snow peas, trimmed
1 onion, chopped
2 potatoes, baked, sliced or mashed (opt.)

1. Wash and prepare the vegetables; set aside.

2. Make the dressing by mixing the ingredients in a bowl.

3. To make the stir-unfry, heat the dressing in a wok or large saucepan. Add the veggies, then stir over high heat for 3 minutes, or until tender-crisp. Serve as is, or over potatoes, or whole grains, such as brown rice or barley.

Yield: 6, 1 cup servings

1 SERVING: 145 calories; 4.4g protein; 33.8g carb; .3g fat; .06g saturated fat; 214mg sodium; 0g cholesterol; 4.0g fiber.

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