ANTIOXIDANTS AND PHYTOCHEMICALS

Antioxidants and Phytochemicals Important in Disease Prevention

Over half of the top 25 most prescribed medicines are plant-derived.  Plants make non-nutritive substances such as phytochemicals for their own defense.  These phytochemicals help ensure the survival of the plant. In 1982, the National Academy of Sciences stated that “cancers of most major sites are influenced by dietary patterns…”  This was the first time that a non-nutrition, science-based organization emphasized the consumption of fruits and vegetables (especially cruciferous vegetables).
To date, hundreds, if not thousands of studies have been done showing a decreased risk of heart disease, diabetic complications, cataracts, cancer, Alzheimer’s and Parkinson’s related to intake of fruits and vegetables.

Three Dozen Plant Foods that have Cancer Protective Properties

Highest anti-cancer activity:
garlic, soybeans, cabbage, ginger, licorice, umbelliferous vegetables (carrots, celery, cilantro, parsley, parsnips).

Modest anti-cancer activity:
onions, flax, citrus, turmeric, cruciferous vegetables (broccoli, Brussels sprouts, cabbage, cauliflower) solanaceous vegetables (tomatoes and peppers), brown rice, whole wheat.

Some anti-cancer activity:
oats, barley, mints, rosemary, thyme, oregano, sage, basil, cucumber, cantaloupe and berries.

NUTRIENTS WHICH FUNCTION AS ANTIOXIDANTS - VITAMINS A, C, AND E

Carrots, Tomatoes, Yellow and Red Fruits and Vegetables
Beta-carotene (vitamin A) and other Carotenoids
400-600 carotenoids present in foods. Absorption of carotenoids decreases as dose increases. Other carotenoids of recent interest include lycopene (tomatoes), lutein and zeaxanthin (kale, collard greens, spinach).  Lycopene is found in abundance in tomatoes and tomato products.  Lutein is found in broccoli, spinach, greens, corn, green beans and green peas.   Good sources: dark green leafy vegetables, yellow-orange vegetables and fruits
Citrus Fruit, Peppers, Strawberries, Mangos, Papaya
Vitamin C
Vitamin C  enhances the immune system. Aids in the regeneration/recycling of vitamin E.  Good sources: citrus fruits, potatoes, cabbage, green peppers, strawberries, tomatoes
Nuts, Seeds, Vegetable Oil
Vitamin E
Vitamin E is an antioxidant.  Good sources: nuts and seeds, wheat germ, vegetable oils.

PHYTOCHEMICALS

Plant chemicals that have protective effects.  Examples include allyl sulfides, indoles, genistein, limonoids, ellagic acid, isoflavones, saponins, etc.
For several decades, evidence has been accumulating that groups of people eating a lot of fruits and vegetables had a lower incidence of many types of cancer.  There are probably thousands of chemical compounds in plant foods that are protective against cancer, heart disease, and other chronic degenerative diseases.  The term phytochemical includes a number of classes and subclasses that  exhibit a wide variety of protective mechanisms.

Phytochemicals Found in Different Plant Foods

Flavonoids

Large group of compounds occurring  naturally in fruits, vegetables, wine and tea. May act as antioxidants or interfere with the binding of hormones to cells.  Flavonoids extend the activity of vitamin C, protect LDL (bad cholesterol) from oxidation, inhibit platelet aggregation, show anti-inflammatory action, and exhibit anti-tumor action.  The most important flavonoids are anthocyanins, flavonols, and flavones.  Quercetin is a flavonoid found in red and yellow onions, kale, broccoli, red grapes, cherries, French beans, apples and cereals.
Are grapes good for you?  Grape juice contains phenolic flavonoids and red anthocyanin pigments.  Three to four ounces of raisins daily also lowers cholesterol in one study (10 gm fiber, 4 gm tartaric acid).

Phytoestrogens

Group of phytochemicals that have weak estrogen properties (one one-thousandth as strong as the hormone estrogen).  These chemicals  compete with estrogen for binding sites in breast tissue, reducing the level of estrogen in breast tissue.
The isoflavonoid genistein has the ability to protect breasts in women and the prostate in men.  Genistein is found in soy protein.  In Asian countries where soy consumption is greater than in the U.S., serum levels of isoflavones are 100 to 1000 times higher.
One to two ounces of soy protein, half a cup of soybeans, 1 cup soy beverage, or four ounces of tofu per day provide about 30-40 gm genistein.

Protease inhibitors

Widely distributed in plants, particularly in seeds and legumes.  Soybeans contain five types of protease inhibitors.  The most studied protease inhibitors in foods are trypsin inhibitors, which are found in spinach, broccoli, cucumbers, Brussels sprouts and radishes, with the highest levels detected in potatoes and corn.

Phenolic Compounds

Typically found in fruits and vegetables.  Highest levels in freshly harvested crops.  Coumarins are derived from vegetables and citrus fruit.  Phenolic compounds, catechins, flavonols, anthocyanins and tannins, found in grape juice  are able to prevent lipid oxidation.  Green tea which contains catechins and theaflavins prevent oxidation of LDL.

Allium Compounds

Found in Allium plant family, which includes onions, garlic, leeks, and shallots.

Terpenes/Limonene

In the peel of citrus fruits; may act by interfering with the action of carcinogens; aids in tumor regression. Perillyl alcohol, found in cherries, also in the class of compounds associated with tumor regression.  Citrus also contains vitamin C, folic acid, potassium and pectin.  Citrus fruit contains over 150 phytochemicals (60 flavonoids, 40 limonoids, 20 carotenoids, terpenoids, glucarates (white part).

Phytosterols

Plant sterols that are associated with a lower risk of cancer. Nuts and whole grains contain plant sterols, phytates, phytoestrogens, tocotrienols, liganans, ellagic acid, and saponins.  Refining wheat causes a 200 to 300 fold loss in phytochemicals.  Nuts also contain selenium.  Flax seed is anti-inflammatory.

Organosulphur Compounds

These chemicals increase the activity of enzymes in the detoxification of carcinogens.  Cruciferous vegetables are the best sources of these compounds.  Cruciferous vegetables include cabbage, broccoli, Brussel sprouts, and cauliflower.  High intake of cruciferous vegetables has been associated with a reduced risk of breast cancer.

Phytates

Found in the husks of grains, seeds and legumes also show cancer protective activity.

PRINCIPLES OF HEALTHFUL DIETS

1.    Consume a variety and abundance of plant foods (high F/V intake, 5-9 serv or 400 gm/d).
2.    Emphasize unrefined and minimally processed foods (high fiber, 25-35 mg/day).
3.    Limited/optional use of red meat/animal fat (<30% fat, <10% SFA, <300 mg cholesterol).
4.    Lifestyle factors such as exercise, relaxation, sleep, dietary patterns, sunshine, etc.

Recommendations by the American Cancer Society to prevent cancer (2006)

1. Maintain a healthy weight throughout life.
2. Balance caloric intake with physical activity.
3. Avoid excessive weight gain throughout life.
4. Achieve and maintain a healthy weight if currently overweight or obese.
5. Adopt a physically active lifestyle.
-Adults: Engage in at least 30 minutes of moderate to vigorous physical activity, above usual activities, on 5 or more days of the week; 45 to 60 minutes of intentional physical activity are preferable.
-Children and adolescents: Engage in at least 60 minutes per day of moderate to vigorous physical activity at least 5 days per week.
6. Eat a healthy diet, with an emphasis on plant sources.
7. Choose food or beverages in amounts that help achieve and maintain a healthy weight.
8. Eat 5 or more servings of a variety of vegetables and fruits every day.
9. Choose whole grains in preference to processed (refined) grains.
10.Limit consumption of processed and red meats.
11.If you drink alcoholic beverages, limit consumption.
-Drink no more than 1 drink per day for women or 2 per day for men.

In addition, Walter Willett, MD, DrPH, Harvard University, recommends “eating one or more servings of leafy vegetables each day” and “consuming no more than one serving of red meat a week.”

BEST “SUPPLEMENTS”ARE VEGETABLES, FRUITS, WHOLE GRAINS, SOY, LEGUMES,  NUTS AND SEEDS!

Conclusions

Establishing more precisely which foods, nutrients, or other substances in food have what effects on the development of cancer, diabetes, heart disease, cataracts, Alzheimer’s and Parkinson’s is still the subject of much research.  Although there are many questions still to be answered, we already have much valuable information on how to reduce risk of chronic diseases.
No convincing evidence exists at this time that consuming specific nutrients apart from what is found in nourishing foods is helpful. People are lulled into thinking a pill can make up for the hundreds of known and unknown compounds which make up our food supply.  And while they may have some value, they mostly produce expensive urine. Additionally, the potential for either adverse or beneficial effects depends on the intake (dose) of each nutrient and its interaction with other food components.
It is the synergistic effect of multiple variables (high fiber, low fat, high in fruits/veg, and other lifestyle factors) which are protective.
In the meantime, the Mypyramid.gov gives a good foundation on which to start evaluating and planning your diet!
Compiled by Crystal Whitten, Nutrition & Dietetics, LLU

Harvard Beets

2     bunches medium beets
2     Tbs.    butter
1    Tbs.    cornstarch
1    Tbs.    sugar
1    Tbs.    lemon juice
1     Tbs.    salt

1. Clean the beets well and remove the greens. Place in a large saucepan and cover with cold water. Bring the water to a boil, then reduce the heat and simmer until tender. The time varies drastically depending on the age and size of the beets, but they should take between 30 and 50 minutes to cook. (You may also use canned beets and avoid this first step.)
2. Drain the beets and reserve 1 cup of the liquid. Let the beets sit until they are cool enough to handle easily. Slide off the skins and slice the beets into 1/4-inch slices.
3. In a medium saucepan melt the butter. Once the butter has melted, blend in the cornstarch and mix until smooth. Slowly pour in the beet liquid and stir until the mixture thickens. Add the sugar and lemon juice. Mix well.
4. Add the beets and heat over low heat for 10-15 minutes or until heated through.

Candied Yams

6    medium yams or sweet potatoes
½    cup    brown sugar
1/3    cup    water
3    Tbs.    butter or margarine
½    t.    salt

1.  Steam potatoes or boil until tender.  Peel.  Cut in ½ lengthwise.  (Or you can use canned yams and avoid this first step. Arrange in shallow pan.
2.  Combine syrup.  Heat to boiling and pour over potatoes.  Cap with butter, if desired.  Bake at 350 for 30 minutes.

Szechuan Broccoli

2    Tbs.    soy sauce
1    Tbs.    lemon juice
1    tsp.    sugar
2    Tbs.    sesame seeds
1    Tbs.    oil
1    tsp.    fresh ginger, peeled, minced
4    cloves    garlic, minced
1    bunch    broccoli (8 cups), chopped

1. Combine soy sauce, vinegar and sugar in a small bowl; set aside.
2. Heat a large skillet or wok over medium heat.  Add sesame seeds, toast and remove—set aside.
3. Add oil, ginger and garlic to skillet or wok and stir-fry for 30 seconds.  Add broccoli and stir fry 1 minute.  Add soy sauce mixture—stir well.  Cover and let steam about 2 minutes or until broccoli is crisp-tender.  Sprinkle with sesame seeds