Functional Foods
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
Consumer Acceptance
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.
Global Perspective
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.
Health Claims
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.
Safety Issues
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.
Regulatory Issues
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.
Vocabulary:
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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Excerpted from Integrative Medicine: Your Quick Reference Guide copyright 1998
Integrative Medicine Inc., used with permission.