by Ruth DeBusk, PhD, RD
Underlying the development of functional foods is the concept of "food as medicine," a philosophy that dates back to Hippocrates. The concept of functional foods is relatively new to the United States, but other countries such as Japan, Korea, and China have long considered certain foods to have health benefits. Powerful market forces are fueling the interest in functional foods in the United States:
- rapid advances in scientific knowledge supporting the vital role of diet in health and disease prevention
- consumer demand and the change in perspective of food, which is no longer viewed as merely a means of providing sustenance
- skyrocketing health care costs
- an aging population
- technical advances in the food industry that are allowing the development of health-promoting foods that can be marketed to health-conscious consumers at a premium
- the changing regulatory environment
Contrary to dietitians' expectations, consumers are extremely receptive to the idea of health-enhancing foods and interested to learn more about such foods and how they might provide long-term health benefits. Research conducted by Dr. Childs and presented at the NUTRACON '96 conference in Nashville, Tennessee in July 1996 found that 55% of consumers believed that food or food products could help reduce the risk of degenerative disease. Focus group studies conducted by The International Food Information Council (IFIC) in June 1996 found that consumers view functional foods as a natural evolution of the traditional foods they have always eaten.
Dietitians and other health care professionals, however, were found to have a very different expectation of consumers' reactions to functional foods. Health care professionals expected consumers to be looking for the "easy way out" and more interested in pills that could give health benefits than in learning about foods that could provide these benefits. Instead consumers were quite positive about the prospect of enhancing familiar foods with health-promoting components.
There is clearly a difference between the Western perspective on functional foods and the Eastern perspective. In the West, functional foods are viewed as a revolution and represent a fast growing segment of the food industry. Food companies, drug companies, chemical companies and boutique companies arising from grass-roots research and development efforts are all racing to bring functional foods to market.
In the Orient, in contrast, functional foods have been a part of the culture for centuries. In Traditional Chinese Medicine, foods that have medicinal effects have been documented since at least 1000 BC From ancient times, the Chinese have understood that foods have both preventive and therapeutic effects and are an integral part of health, a view that is now being increasingly recognized around the world.
Functional Foods are on the Horizon
The number of functional foods is potentially very large and encompasses natural foods, isolated components from these foods that are added to other foods or packaged as dietary supplements, and food components synthesized in the laboratory.
Examples of just a few of the functional foods or food components that already exist include: fruits and vegetables of enormous variety, black and green tea, cranberry juice, garlic and onions, edible mushrooms, probiotic-enhanced dairy foods, allyl sulfides, antioxidants, capsaicin, chitosan, ellagic acid, flavonoids, fructo- and other oligosaccharides, genistein, glucosamine, glycyrrhizin, indoles, lutein, lycopene, maitake mushroom fraction D, polyphenols, resveratrol, and sulforaphane.
Most researchers in the area of functional foods agree that any food designated as "functional" and ascribed specific health benefits should receive scientific scrutiny before specific health claims are permitted. In countries with a rich cultural tradition of belief in the health-enhancing properties of various foods and food components, many foods are associated with specific health claims but may not have scientific documentation to parallel the long-standing experience with these foods.
In the US. the 1990 Nutrition Labeling and Education Act allows, for the first time, health or disease prevention claims on a food label. Within this context the Food and Drug Administration (FDA) requires that health claims be supported by solid research and that the claims be approved by the FDA. To date only a limited number of claims have been approved, and we're probably several years away from having the necessary research that will support or disprove suspected health benefits of functional foods.
In the meantime, the results of the many studies underway will be published not only in scientific journals but likely on the front page of the nation's newspapers. Consumers are eager to act on these findings. Dietetics professionals should continue to recommend a varied, plant-based, balanced diet and follow the studies of specific foods and food components as both treatment and preventative therapy against particular diseases.
In addition to the normal expectation that any food item or ingredient be safe for consumption, functional foods have the additional safety requirements related to the novelty of the raw materials used, of the processes used to produce the food, or of the potential use in the diet. For example, it is very likely that many food components already present in foods will be found to have positive health benefits and will be used in a novel way in the diet, which could increase the amount of these foods consumed each day or might increase the use of these foods by at-risk groups that currently do not use much of these foods or their components. The safety evaluation must then take into account the effect of increased consumption on various age groups and the infirm and ask whether increased use might lead to increased exposure to potentially harmful components, such as natural toxins or pesticides.
When a functional food contains novel ingredients or is produced by a novel process, it becomes particularly important that safety as well as acceptability be considered. With traditional foods, safety assurance comes from a long history of safe use by large populations over a number of generations. Such history is lacking for novel ingredients and novel processes, and a safety assessment is required before such foods are released into the food supply.
Functional foods exist at the interface between food and drugs. There is no provision in our existing food regulations for foods intended to be consumed to prevent disease. As things stand, dietary supplements will be marketed under the Dietary Supplement Health and Education Act, and foods will be marketed under the Nutrition Labeling and Education Act.
The concept of "substantial equivalence" was developed as a practical approach for evaluating the safety of foods that contained or were produced from genetically modified organisms. This approach asks whether the novel food is substantially equivalent or sufficiently similar to its traditional counterpart. This concept was not intended to be applied to other types of novel foods but appears to be increasingly used by various regulatory agencies. The idea is that, by focusing on what is different between a novel food and a traditional food, the safety assessment can zero in on the differences and thereby minimize the expense and time required for the assessment. An International Life Sciences Institute-Europe technical committee established three different classes of equivalence and set up guidelines for safety assessments of novel foods:
- Class I foods or food ingredients are those substantially equivalent to a traditional reference food or ingredient
- Class II are those that are sufficiently similar to a traditional reference food
- Class III are those that are neither substantially equivalent nor sufficiently similar to a traditional reference food or ingredient.
In order to establish the appropriate equivalency class, extensive background information about the food is required, which ranges from the raw material source and its origins to methods of production and expected use of the novel food. Class I foods would not be subject to safety assessment, Class II foods would be but the testing would focus on the differences between it and the traditional food or ingredient, and Class III foods would be subjected to rigorous safety assessment on a case-by-case basis.
Assuming the food or ingredient passes the rigorous safety considerations, each health claim will need to be subjected to scientific evaluation as well, which could take years to carry out. In the meantime, consumers will become increasingly interested in using functional foods, and we need to stay on top of developments in this area.
Expectations for the Future
As consumers worldwide become more health conscious, the demand for health-promoting foods and food components is expected to grow. The market for such foods is predicted to be quite large. Before the full market potential can be realized, however, consumers will need to be assured of the safety and efficacy of functional foods. Current and future scientific studies are expected to provide this assurance and to inspire confidence in functional foods in the minds of consumers worldwide.
Designer foods: Coined in 1989 by the National Cancer Institute to describe foods that naturally contain or are enriched with cancer-preventing substances such as phytochemicals.
Functional foods: Defined by the Institute of Medicine of the US National Academy of Sciences as foods that encompass potentially healthful products, including any modified food or food ingredient that may provide a health benefit beyond the nutrients it contains.
Medical foods: Special dietary food intended for use solely under medical supervision to meet nutritional requirements in specific medical conditions. Although a legal classification of foods under the jurisdiction of the FDA and technically confined to enteral formulas used to feed hospitalized patients and people with rare diseases, more recently spin-offs of these formulas have begun to be marketed to the public, especially to the elderly, as a source of supplemental nutrition.
Novel foods: Food or food ingredients that have not been used for human consumption to a significant degree or have been produced by processes that result in a significant change in their composition or nutritional value or intended use.
Nutraceuticals: A term popularized by the Foundation for Innovation in Medicine that refers to "any substance that may be considered a food or part of a food and provides medical or health benefits, including the prevention and treatment of disease.
Phytochemical/Phytonutrient: Plant components that have health-promoting properties; originally this term was limited to substances found in edible fruits and vegetables that appeared to be protective against cancer. Now the term is much broader and applies to any plant component that has health-enhancing benefits.
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