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Natural Miracles:
What Functional Foods Can Do for You?

(Released October 2007)

 
  by Leila Kiani  

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Phytochemicals

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Research and development in food science is helping to identify many functional foods, because they can provide health benefits by reducing risk and enhancing the body's ability to manage chronic disease; so quality of life will be improved with the help of science (3).

There are many forms of functional food, but they are usually categorized in these two sections:

  1. Conventional foods: They have bioactive components linked to positive health promotion and are mostly used by consumers. For instance, soy proteins or cranberries are powerful, health-enhancing conventional foods.
  2. Fortified foods: They are used for specific reduction of disease or increasing health benefits by adding to a daily diet. Examples include calcium-fortified orange juice or eggs with increased levels of omega-3 fatty acids.
So depending on the vitamin or mineral range necessary for each day, foods (conventional or fortified) can be selected for maximum value. As you see in table 1, foods and isolated food components can reduce the risk of disease (3).

Table 1: Example of Functional food components currently marketed (3).
Functional Component Health Benefits US Regulatory Status of Claim
Soluble Oat Fiber
Coronary Heart Disease FDA Approved Health Claim
Soy Protein
Coronary Heart Disease FDA Approved Health Claim
Calcium Osteoperosis FDA Approved Health Claim
Folate-Enriched Foods Neural tube defects FDA Approved Health Claim

Cardiovascular disease and cancer are the first and second causes of death in the United States and in most industrialized countries. People who regularly eat fruit and vegetables are at low risk of cancer, cardiovascular disease, stroke, Alzheimer's, and some of the functional declines associated with aging. Prevention is a more effective strategy than treatment of chronic diseases (4).

Table 2: Examples of Functional Components (5)
Functional Components: Short Version
Beta-carotene
Lutein, Zeaxanthin
Lycopene
carrots, kale, tomatos maintain healthy cells
Anthocyanins
Flavanols
Flavanones
Flavonols
Proanthocyanidins
berries, tea, citrus fruits antioxidants, may help brain and heart, maintain cells
Sulforaphane broccoli detoxification; antioxidants
Calcium
Magnesium
Potassium
spinach, potatoes may reduce osteoporosis and high blood pressure and help muscle & nerve function
Caffeic acid, Ferulic acid apples, pears, coffee antioxidant; may help vision & heart
Free Stanols/
  Sterols
Stanol/Sterol esters
corn, wheat, fortified food may reduce coronary heart disease
for the complete chart click on the appropriate section or click here

In addition to vitamins and minerals, fruits and vegetables contain a variety of biological metabolites that are named "phytochemicals". These compounds have various biological effects, such as reducing the risk of some diseases (6).

Table 3 shows some major components in fruits and vegetables that may enhance some food (as fortification). These active ingredients (as listed below) may control or prevent some diseases (5, 7, 12, 13 and 14):

I. Carotenoids
II. Isothiocyanates
III. Antioxidants (Phenolic acids)
IV. Flavonoids

I. Carotenoids

These ingredients are found in tomatoes and tomato products, chili sauce, seafood cocktail sauce, watermelon, pink grapefruit and other sources. Several studies have linked the consumption of tomatoes and tomato products with a decreased risk of these diseases:

  1. lung, bladder, cervix, skin, breast and colorectal cancers because of their anti-oxidant and anti-proliferative properties.
  2. Cardiovascular disease, because they may inhibit cholesterol synthesis and en-hance LDL (bad cholesterol) degradation.
Studies have also shown that the processing of tomatoes and of tomato products, such as sauces, soups and juices, increases the bioavailability of lycopene (7).

Isothiocyanates

asparagus
asparagus
The consumption of cruciferous vegetables has been associated with a reduced risk of cancer of the lung, stomach, colon and rectum and also reduced risk of coronary heart disease. These vegetables include broccoli, cauliflower, kale, turnips, collards, brussel sprouts, cabbage, radish, turnip, and watercress.

These effects have been attributed to their high concentration of glucosinolates. When chewing raw vegetables an enzyme (myrosinase) hydrolyses glucosinolates to isothiocyanates, (glucosinolates are precursors of isothiocyanates).

broccoli
broccoli
Isothiocyanates can reduce poisonous effects of carcinogens and act by inhibition of cell proliferation and induction of apoptosis. Researchers at the Johns Hopkins University School of Medicine in Baltimore studied the metabolism of isothiocyanates and found that they were about six times more bioavailable than glucosinolates.

Broccoli is a "super" food. A compound found in broccoli and broccoli sprouts (sulforaphane) has been shown to be more effective than modern antibiotics against the bacteria Helicobacter pylori, which causes peptic ulcers. Moreover, tests in mice show that the compound offers tremendous protection against stomach cancer (15).

Antioxidant vitamins
squash
squash
Vitamin A, beta-carotene (a vitamin A derivative), vitamin C, and vitamin E are types of antioxidants which can help reduce oxidative damage done by free radicals in the body. Antioxidant vitamins may prevent or protect against cancer, cardiovascular disease, asthma, pulmonary function problems, diabetes and weight loss. They may also protect eyesight, help protect the brain, and promote gastrointestinal health.

For instance there are many types of antioxidants in:

Fruits

  • oranges
  • grapefruits
  • tangerines
  • lemons
  • limes
  • papaya
  • strawberries
  • cantaloupe
  • Mango
  • Kiwi
  • Apple
  • Apricot
  • Avocado
lettuce
lettuce
Vegetables
  • tomatoes
  • broccoli
  • green peppers
  • red bell peppers
  • raw lettuce
  • other leafy greens
  • spinach
Large scale studies have shown low blood levels of carotenoids correspond with greater cancer risk. Researchers have found that carotenoids in dark green leafy vegetables can inhibit the growth of certain types of breast cancer cells, skin cancer cells, lung cancer and stomach cancer (16).

bowl of spinach
Spinach
Finally, beta-carotene's anti-inflammatory effects may reduce the severity of conditions like asthma, osteoarthritis, and rheumatoid arthritis, which all involve inflammation.

The consumption of apples corresponds with reduced risk of some cancers, cardiovascular disease, asthma, and diabetes. Apples have been found to have very strong antioxidant activity, inhibit cancer cell proliferation, decrease lipid oxidation, and lower cholesterol. Apples contain a variety of strong antioxidants (17).

The total antioxidant activity of 100 grams of whole apples (with the peel) was found to be equivalent to the antioxidant effect of about 1500 mg of vitamin C. However, the amount of vitamin C in 100 g of apples is only about 5.7 mg. Nearly all of the antioxidant activity from apples comes from a variety of other compounds (18).

XI. Flavonoids

These occur in all groups of fruits and vegetables, such as berries, cherries, cranberries, red grapes, apples, citrus, broccoli, and some spices such as cinnamon. The phytochemical called anthocyanidins that exists specially in blueberries can neutralize free radical damages to the collagen matrix of cells and tissues that can induce glaucoma, peptic ulcers, varicose veins, hemorrhoids, cataracts , heart disease and cancer. Anthocyanins, the blue-red pigments, can improve the wholeness of support structures in the veins and the entire vascular system (19).

These are some benefits of Flavonoids:

  • bolsters cellular antioxidant defenses
  • may contribute to maintenance of brain function
  • may contribute to maintenance of heart health
  • neutralizes free radicals
  • may contribute to maintenance of urinary tract health

Go To The Colors of a Healthy Diet

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