Introduction to functional foods
Functional foods are foods marketed for their specific health benefits, often highlighted on packaging in supermarkets. These foods fall into two primary categories: ordinary foods with natural health-promoting substances and enriched foods that are fortified with added nutrients. Common examples of ordinary functional foods include fruits, vegetables, whole grains, and various dairy products, which offer benefits such as fiber, vitamins, and minerals. Enriched foods may contain added vitamins, minerals, or probiotics, like calcium-fortified orange juice and vitamin D-enriched milk, aligning with food fortification policies.
The health benefits associated with functional foods can vary widely, from cancer prevention to heart disease support, and many products are grounded in scientific research. However, some claims lack robust evidence, and the effectiveness of added nutrients may be minimal due to taste considerations. Regulatory bodies like the FDA oversee the health claims on these foods, requiring scientific evidence but not always providing stringent validation. Overall, functional foods play a significant role in promoting health and addressing nutritional deficiencies in various populations.
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Introduction to functional foods
DEFINITION: Foods marketed as having specific health-promoting benefits.
Overview
Many foods sold in supermarkets come with health claims on their labels. Labels claim that oatmeal and soy help prevent heart disease, that milk and calcium-fortified orange juice fight osteoporosis, and that folate-enriched flour prevents congenital abnormalities. These foods are all functional foods, that is, foods marketed as offering specific health benefits.
There are two main categories of functional foods. The first and largest category consists of ordinary foods that contain health-promoting substances. This category includes all fruits, vegetables, whole grains, soy and other legumes, and numerous other foods such as herbal teas, yogurt, and cold-water fish. When these foods are presented as functional foods, their specific health benefits and healthy constituents are highlighted, constituents such as fiber, vitamins, minerals, and non-nutrient chemicals with potential health benefits.
The second category of functional foods consists of foods enriched with potentially health-promoting ingredients like vitamins, minerals, fiber, or probiotics. These foods are made according to the U.S. Food and Drug Administration's (FDA) Food Fortification Policy, established in 1980. Examples include orange juice enriched with calcium to support bone health, table salt enriched with iodine to prevent deficiencies, milk enriched with vitamin D to promote calcium absorption, and cereal with added folic acid to support development. Some teas and beverages have added herbs like echinacea to support immune health.
Some functional food products are based on science, while others are based on weak evidence or speculation. Furthermore, the requirement for good taste sometimes forces manufacturers to limit the amount of herbs, minerals, or other additives to a level so low that they are unlikely to have any effect. However, understanding, creating, and using functional foods have played an important role in global health and well-being. For example, iron-fortified wheat flour decreased anemia among children, iodized salt reduced the incidence of thyroid goiters, and niacin in bread reduced pellagra rates.
The following is a list, by condition treated, of some of the more promising functional foods and natural products that are added to food products to create functional foods.
- Cancer prevention. Diindolylmethane (found in broccoli-family vegetables), fish oil (found in salmon and other cold-water fish), flaxseed (contains lignans), folate, garlic, green tea, I3C (found in vegetables in the broccoli family), IP6 (found in nuts, seeds, beans, whole grains, cantaloupe, and citrus fruits), lycopene (found in tomatoes), resveratrol (found in grape skin), selenium, soy foods, turmeric (added to many foods as a preservative), vitamin C, and vitamin E
- Cataracts.Lutein (found in dark-green vegetables)
- Cavities.Xylitol (added to chewing gum and candy)
- Colds and flu. Echinacea (herbal tea) and garlic
- Diabetes.Chromium (whole grains, brewer’s yeast, fortified nutritional yeast, liver) and evening primrose oil
- Diarrhea and other digestive problems.Probiotics (friendly bacteria) found in yogurt, kombucha, and fermented foods
- Ear infections. Xylitol (added to chewing gum and candy)
- Easy bruising. Bioflavonoids (found in citrus fruits, buckwheat, and most fruits and vegetables)
- Eczema. Probiotics (friendly bacteria) found in yogurt
- General nutrition. Fortified grains and beverages
- Heart disease prevention. Alpha-linolenic acid (found in flaxseed oil), calcium (added to beverages; found in milk and other dairy products), garlic, fish oil (found in salmon and other cold-water fish), potassium (found in orange juice, bananas, and other foods), soy products, stanols-sterols (added to margarine and other spreads), beta-glucan fiber (such as in oats), wine and other alcoholic beverages (in moderation)
- High cholesterol.Fiber (found in whole grains and fruits, legumes, and vegetables), garlic, krill oil, soy products, stanols (added to margarine and other spreads)
- Menopausal symptoms. Soy products and magnesium
- Nausea. Ginger (beverages)
- Osteoporosis. Calcium (added to beverages; found in milk and other dairy products), vitamin D (added to butter, milk, and other beverages), soy foods
- Premenstrual syndrome. Calcium (added to beverages; found in milk and other dairy products) and krill oil
- Ulcerative colitis. Probiotics (friendly bacteria found in yogurt), Omega-3 fatty acids (salmon), kombucha
- Urinary tract infection. Cranberry juice, antimicrobials like European white birch and smooth rupturewort
- Vaginal infection. Probiotics (friendly bacteria found in yogurt), prebiotics (garlic, leeks, and wheat products)
A Note About Labeling
The FDA regulates and approves the health claims that manufacturers print on food labels similar to those used on dietary supplements. However, these foods and their claims are not approved or endorsed by the FDA. Each claim must go through a petition process, present scientific evidence of the claim, and avoid verbiage that implies a diagnosis, cure, or treatment while focusing on the decreased risk the food may offer. Some note that these labels do not require enough scientific validation for approval.
In some cases, however, the FDA has specifically authorized higher-level health claims such as “heart healthy.” These claims may be taken as representing scientific consensus. Because food supplementation is such a rapidly growing area, an increasing number of these labels should be expected.
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