HISTORY
Over two thousand years ago Hippocrates said, "Let food be thy medicine." Although the concept of functional foods is not entirely new, it has evolved considerably over the years. In the early 1900s food manufacturers in the
Other twentieth-century examples include vitamin A and D fortification of milk and niacin and folic acid fortification of grains. These early fortification examples, however, focused on reducing the risk of diseases of deficiency. In the latter part of the twentieth century, consumers began to focus on wellness and the reduction of chronic disease. Research now focuses frequently on the promotion of health through many lifestyle factors, including the consumption of an optimal diet. As of 2002, researchers have identified hundreds of food components with functional qualities, and they continue to make new discoveries surrounding the complex benefits of phytochemicals in foods.
FUNCTIONAL FOODS
The term "functional foods" refers to foods and their components that may provide a health benefit beyond basic nutrition. Functional foods do more than meet minimum daily nutrient requirements—they also can play a role in reducing the risk of disease and promoting good health. Biologically active components in functional foods impart health benefits or desirable physiological effects.
All foods have a function when consumed in proper balance as part of an overall healthy diet. Functional foods may include whole foods, such as fruits and vegetables, which represent the simplest example. Those foods that have been fortified, enriched, or enhanced with nutrients, phytochemicals, or botanicals, as well as dietary supplements, also fall within the realm of functional foods.
The functional attributes of many traditional foods are only now being discovered. Examples include phytoestrogens in soy foods and a variety of antioxidants in fruits and vegetables, such as lycopene in tomatoes. Still, new food products are being developed with beneficial components, with a focus on wellness and the reduced risk of chronic disease (i.e., foods and beverages containing pre-and probiotics to maintain gastrointestinal health, calcium-fortified beverages to maintain bone health, and dressings and spreads containing plant stanol and sterol esters, which may decrease the risk of heart disease).
"Functional Foods" are foods or dietary components that may provide a health benefit beyond basic nutrition. You can take greater control of your health through the food choices you make, knowing that some foods provide specific health benefits. Examples include everything from fruits and vegetables to fortified or enhanced foods. Biologically active components in functional foods impart health benefits or desirable physiological effects. Functional attributes of many traditional foods are being discovered, while new food products are being developed with beneficial components.
What are functional foods: A functional food is any food that exerts health properties beyond the traditional nutrients it contains. There are two categories of functional foods.
1. Foods that naturally contain biologically active, non-nutrient compounds that provide health benefits. These compounds are phytochemicals, which are also sometimes called nutraceuticals. Based on this definition, all plant foods could be considered functional foods since they are all rich in phytochemicals or nutraceuticals
2. Food products specifically formulated to have higher amounts of nutrients or phytochemicals than would naturally occur in that food. These are also called “designer foods.”
Functional foods can be defined as foods that contain components that impart health benefits beyond basic nutrition. The functional attributes of many traditional foods and food components are being discovered. In addition, new food products are being developed to enhance or incorporate the beneficial compounds.
Many common foods, along with specially-modified new food products, are included as being "functional foods." A few examples of functional foods are licorice, green tea, soy, flaxseed, garlic, wine, fish, fruits, vegetables, grains, legumes and seeds.
Many times the terms functional foods, nutraceuticals and phytochemicals are used interchangeably. Phytochemicals are plant chemicals, usually referring to those compounds which seem to have biological effects on the body. Again, technically this would include vitamins and minerals, but usually means non-traditional compounds that do not cause a deficiency condition if not present. Examples are lycopene and isoflavones. Many of the foods listed as functional foods are functional foods because they contain a certain phytochemical.
Defining Nutraceuticals or Phytochemicals: Phytochemicals are plant chemicals that differ from nutrients in some important ways. Essential nutrients—which include protein, fats, minerals, and vitamins—are essential for life. Without them, people develop acute deficiency disease symptoms that can eventually cause death. Nutrients are found in all of the food groups.
Phytochemicals are not necessary for life but they help to promote optimal health by lowering risk for chronic diseases, such as cancer and heart disease. They are found only in plant foods. Fruits and vegetables are among the best sources of these compounds. Phytochemicals are believed to have many health benefits.
Some groups of phytochemicals that have been linked to decreased cancer risk include:
· Allyl sulfides, which may stimulate activity of enzymes that help to eliminate toxic compounds and are found in onions, scallions, and leeks.
· Dithiolthiones and isothiocyanates, which may increase activity of enzymes that help to detoxify carcinogens and are found in the cruciferous family of vegetables—broccoli, cauliflower, Brussels sprouts, cabbage, turnips, and others.
· Indoles, which may interfere with estrogen metabolism and therefore could reduce risk for some estrogen-related cancers such as breast cancer. They are also found in cruciferous vegetables.
· Isoflavones, which are found in soy foods and have a number of effects that may affect cancer risk.
· Lignans, which are found in rye and flaxseed and may reduce breast cancer risk because they act as anti-estrogens.
· Flavonoids are a special class of phytochemicals that includes hundreds of different compounds. Most are excellent antioxidants and some have hormonal properties. Among some of the most studied flavonoids are quercetin, which is found in tomatoes, potatoes, broccoli, and onions and kaempferol, which is found in kale and endive.
· Carotenoids are a group of phytochemicals that act as pigments, giving plants their bright green, orange, yellow, red, and blue colors.
Carotenoids include:
· Beta-carotene, found in carrots, sweet potatoes, leafy green vegetables, red peppers, and pumpkin. Beta-carotene from foods has been linked to a reduced risk for lung cancer.
· Lycopene, found in tomatoes and strongly linked to reduced risk for prostate cancer.
· Lutein, found in leafy green vegetables and linked to reduced risk for cancer and macular degeneration.
Functional foods in the marketplace: In the past, foods were commonly fortified with nutrients to help prevent specific nutritional deficiencies. Technically, any fortified food could be considered a functional food. Some examples are iron-fortified cereals, vitamin D-fortified milk, and iodized salt. Today, many functional foods are aimed at boosting intakes of phytochemicals to reduce risk for chronic disease like cancer and heart disease.
Examples of functional foods you can find at the store include:
· Cereals and breads with added isoflavones
· Fruit juices with herbs that have alleged immune-enhancing properties, such as echinacea
· Margarine with added phytosterols, which help to reduce cholesterol
DEMAND:
Consumer interest in the relationship between diet and health has increased the demand for information on functional foods. Rapid advances in science and technology, increasing health-care costs, changes in food laws affecting label and product claims, an aging population, and a rising interest in attaining wellness through diet are among the factors fueling
SCIENTIFIC CRITERIA
Many academic, scientific, and regulatory organizations are considering ways to establish the scientific basis to support claims for functional components or the foods containing them. FDA regulates food products according to their intended use and the nature of claims made on the package. Five types of health-related statements or claims are allowed on food and dietary supplement labels:
1. Nutrient content claims indicate the presence of a specific nutrient at a certain level
2. Structure and function claims describe the effect of dietary components on the normal structure or function
of the body
3. Dietary guidance claims describe the health benefits of broad categories of foods
4. Qualified health claims convey a developing relationship between components in the diet and risk
of disease, as approved by the FDA and supported by the weight of credible scientific evidence available
5. Health claims confirm a relationship between components in the diet and risk of disease or health
condition, as approved by FDA and supported by significant scientific agreement.
A large body of credible scientific research is needed to confirm the benefits of any particular food or component. For functional foods to deliver their potential public health benefits, consumers must have a clear understanding of, and a strong confidence level in, the scientific criteria that are used to document health effects and claims. The scientific community continues to increase its understanding of the potential for functional foods and their role in health.
Functional foods are an important part of wellness that includes a balanced diet and physical activity. Consumers should consume a wide variety of foods, including the examples listed on the following page. These examples are not "magic bullets." The best advice is to include foods from all of the food groups represented on the Food Guide Pyramid, which would incorporate many potentially beneficial components.
| Examples of functional components* | ||
| Class/Components | Source* | Potential benefit |
| Carotenoids | ||
| Alpha-carotene | carrots | Neutralizes free radicals that may cause damage to cells |
| Beta-carotene | various fruits, vegetables | Neutralizes free radicals |
| Lutein | green vegetables | Contributes to maintenance of vision |
| Lycopene | tomatoes and tomato products (ketchup, sauces, etc.) | May reduce risk of prostate cancer |
| Zeaxanthin | eggs, citrus, corn | Contributes to maintenance of vision |
| Collagen Hydrolysate | ||
| Collagen Hydrolysate | gelatin | May help alleviate some symptoms associated with osteoarthritis |
| Dietary Fiber | ||
| Insoluble fiber | wheat bran | May reduce risk of breast and/or colon cancer |
| Beta glucan ** | oats | Reduces risk of cardiovascular disease (CVD) |
| Soluble fiber** | psyllium | Reduces risk of CVD |
| Whole grains** | cereal grains | Reduce risk of CVD |
| Fatty Acids | ||
| Omega-3 fatty acids, DHA/EPA | tuna; fish and marine oils | May reduce risk of CVD and improve mental, visual functions |
| Conjugated linoleic acid (CLA) | cheese, meat products | May improve body composition, may decrease risk of certain cancers |
| Flavonoids | ||
| Anthocyanidins | fruits | Neutralize free radicals, may reduce risk of cancer |
| Catechins | tea | Neutralize free radicals, may reduce risk of cancer |
| Flavanones | citrus | Neutralize free radicals, may reduce risk of cancer |
| Flavones | fruits/vegetables | Neutralize free radicals, may reduce risk of cancer |
| Glucosinolates, Indoles, Isothiocyanates | ||
| Sulphoraphane | cruciferous vegetables (broccoli, kale), horseradish | Neutralizes free radicals, may reduce risk of cancer |
| Phenols | ||
| Caffeic acid | | |
| ferulic acid | fruits, vegetables, citrus | Antioxidantlike activities, may reduce risk of degenerative diseases like heart disease and eye disease |
| Plant Stanols/Sterols | ||
| Stanol/stanol ester** | corn, soy, wheat, wood oils | May reduce the risk of coronary hear disease (CHD) by lowering blood cholesterol levels |
| Prebiotic/Probiotics | ||
| Fructo-oligosaccharides (FOS) | | May improve gastrointestinal health |
| Lactobacillus | yogurt, other dairy | May improve gastrointestinal health |
| Saponins | ||
| Saponins | soybeans, soy foods, soy protein-containing foods | May lower LDL cholesterol, contains anticancer enzymes |
| Soy Protein | ||
| Soy Protein** | soybeans and soy-based foods | 1 ounce per day may reduce risk of heat disease |
| Phytoestrogens | ||
| Isoflavones, daidzein, genistein | soybeans and soy-based foods | May reduce symptoms of menopause, such as hot flashes |
| Lignans | flax, rye, vegetables | May protect against heart disease and some cancers; lowers LDL cholesterol, total cholesterol, and triglycerides |
| Sulfides/Thiols | ||
| Diallyl sulfide | onions, garlic, olives, leeks, scallions | Lowers LDL cholesterol, maintains healthy immune system |
| Allyl methyl trisulfide, dithiolthiones | cruciferous vegetables | Lowers LDL cholesterol, maintains healthy immune system |
| Tannins | ||
| Proanthocyanidins | May improve urinary tract health and reduce risk of CVD | |
The top ten foods that consumers identify as having a health benefit beyond basic nutrition include broccoli (9 percent), fish or fish oil (9 percent), green, leafy vegetables (9 percent), oranges or orange juice (9 percent), carrots (8 percent), garlic (7 percent), fiber (6 percent), milk (6 percent), calcium (5 percent), oats/oat bran/oat-meal (6 percent), and tomatoes (6 percent). The top five foods have remained consistent for the past three surveys; they are associated with
How Can More Functional Foods Be Added to the Diet?
The most effective way to reap the health benefits from foods is to eat a balanced and varied diet, including whole grains, lean meats, low-fat dairy products, legumes, fruits and vegetables, as well as foods with added beneficial components. Watch labels and read articles for information about foods and health. Before deciding to make any major dietary changes, however, take the time to evaluate your personal health and speak to your health-care provider on ways to help reduce the risk of certain diseases. It is also important to remember that there is no magic bullet that can cure or prevent health concerns, even when eaten in abundance. The best advice is to choose foods wisely from each level of the food guide pyramid in order to incorporate many potentially beneficial components into the diet.
Advantages of functional foods: Some functional foods make it easier to meet requirements for nutrients that are often deficient in American diets. The addition of calcium to orange juice and the B-vitamin folate to enriched flour are two examples. Some functional foods make it possible to achieve higher intakes of nutrients or phytochemicals than would be realistic with natural food sources of these compounds.
Possible disadvantages of functional foods: Functional foods that contain added nutrients or phytochemicals may send confusing messages about how to plan healthful diets. Calcium-fortified orange juice is an improvement on a food that is already healthful. Calcium-fortified candy or fiber-enriched white bread, on the other hand, involve addition of beneficial substances to foods that are otherwise devoid of healthful properties.
Manufactured functional foods cannot duplicate all of the benefits of whole plant foods, some of which are not yet known. For example, plant foods like leafy green vegetables, which are naturally rich in calcium, also provide vitamin K and vitamin C, both of which are needed for healthy bones, as well as numerous nutrients and phytochemicals that protect against chronic disease. A diet based on whole plant foods is likely to be more healthful than one based on functional foods.
Best bet for healthful eating: Moderate amounts of manufactured functional foods can provide some benefits to the diet and may help to reduce disease risk. However, they don’t offer any benefits over well-planned diets based on whole grains, fruits, and vegetables. Eating foods that are naturally rich in a wide array of phytochemicals makes good nutrition sense, though. The best approach to dietary planning is to use functional foods in moderation in addition to a healthful diet.
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