- День рождения:
- 10 апр 1992 (Возраст: 32)
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- День рождения:
- 10 апр 1992 (Возраст: 32)
That foods might provide therapeutic benefits is clearly not a new
concept. The tenet, “Let food be thy medicine and medicine be thy food”
was embraced 2500 years ago by Hippocrates, the father of medicine.
However, this “food as medicine” philosophy fell into relative obscurity
in the 19th century with the advent of modern drug therapy. In the 1900s,
the important role of diet in disease prevention and health promotion came
to the forefront once again.
During the first 50 years of the 20th century, scientific focus was on the
identification of essential elements, particularly
vitamins
, and their role in the prevention of various dietary deficiency
diseases. This emphasis on nutrient deficiencies or “undernutrition”
shifted dramatically, however, during the 1970s when diseases linked to
excess and “overnutrition” became a major public health concern. Thus
began a flurry of public health guidelines, including the Senate Select
(McGovern) Committee's Dietary Goals for the United States (1977), the
Dietary Guidelines for Americans (1980, 1985, 1990, 1996, 2000— a joint
publication of the USDA and the Department of Health and Human Services),
the Surgeon General's Report on Nutrition and Health (1988), the
National Research Council's Diet and Health (1989) and Healthy People
2000 and 2010 from the U.S. Public Health Service. All of these reports are
aimed at public policy and education emphasizing the importance of
consuming a diet that is low in saturated fat, and high in vegetables,
fruits, whole grains and legumes to reduce the risk of chronic diseases
such as heart disease, cancer, osteoporosis, diabetes and stroke.
Scientists also began to identify physiologically active components in
foods from both plants and animals (known as phytochemicals and
zoochemicals, respectively) that potentially could reduce risk for a
variety of chronic diseases. These events, coupled with an aging, health-
conscious population, changes in food regulations, numerous technological
advances and a marketplace ripe for the introduction of health-promoting
products, coalesced in the 1990s to create the trend we now know as
“functional foods.” This report includes a discussion of how functional
foods are currently defined, the strength of the evidence both required and
thus far provided for many of these products, safety considerations in
using some of these products, factors driving the functional foods
phenomenon, and finally, what the future may hold for this new food
category.
What are functional foods?
All foods are functional to some extent because all foods provide taste,
aroma and nutritive value. However, foods are now being examined
intensively for added physiologic benefits, which may reduce chronic
disease risk or otherwise optimize health. It is these research efforts
that have led to the global interest in the growing food category now
recognized as “functional foods.”
Functional foods have no universally accepted definition. The concept was
first developed in Japan in the 1980s when, faced with escalating health
care costs, the Ministry of Health and Welfare initiated a regulatory
system to approve certain foods with documented health benefits in hopes of
improving the health of the nation's aging population (1). These foods,
which are eligible to bear a special seal, are now recognized as Foods for
Specified Health Use (FOSHU).3 As of July 2002, nearly 300 food products
had been granted FOSHU status in Japan.
In the United States, functional foods have no such regulatory identity.
However, several organizations have proposed definitions for this new food
category. In 1994, the National Academy of Sciences' Food and Nutrition
Board defined functional foods as “any modified food or food
healthcare
ingredients that may provide a health benefit beyond the traditional
nutrients it contains” (2). The International Life Sciences Institute
defines them as “foods that, by virtue of the presence of
physiologically-active components, provide a health benefit beyond basic
nutrition” (3). In a 1999 position paper, the American Dietetic
Association defined functional foods as foods that are “whole, fortified,
enriched, or enhanced,” but more importantly, states that such foods must
be consumed as “… part of a varied diet on a regular basis, at effective
levels ” for consumers to reap their potential health benefits (4).
Another term often used interchangeably with functional foods, although it
is less favored by consumers, is “nutraceuticals,” a term coined in 1991
by the Foundation for Innovation in Medicine to refer to nearly any
bioactive component that delivers a health benefit. In a 1999 policy paper,
Zeisel (5) astutely distinguished whole foods from the isolated components
derived from them in his following definition of nutraceuticals: “those
diet supplements that deliver a concentrated form of a presumed bioactive
agent from a food, presented in a nonfood matrix, and used to enhance
health in dosages that exceed those that could be obtained from normal
food.”
Several factors are responsible for the fact that this is one of the most
active areas of research in the nutrition sciences today: 1) an emphasis in
nutritional and medical research on associations between diet and dietary
constituents and health benefits, 2) a favorable regulatory environment, 3)
the consumer self-care phenomenon, and 4) rapid growth in the market for
health and wellness products.
Criteria for sound science
According to the Department of Health and Human Services, diet plays a role
in 5 of 10 of the leading causes of death, including coronary heart disease
(CHD), certain types of cancer, stroke, diabetes (noninsulin dependent or
type 2) and atherosclerosis. The dietary pattern that has been linked with
these major causes of death in the United States and other developed
countries is characterized as relatively high in total and saturated fat,
cholesterol, sodium and refined sugars and relatively low in unsaturated
fat, grains, legumes, fruits and vegetables. An accumulating body of
research now suggests that consumption of certain foods or their associated
physiologically active components may be linked to disease risk reduction
(6). The great majority of these components derive from plants; however,
there are several classes of physiologically active functional food
ingredients of animal or microbial origin.
Claims linking the consumption of functional foods or food
advanced health ingredients with health outcomes require
sound scientific evidence and significant scientific agreement. The Food
and Drug Administration (FDA) outlined the criteria for “significant
scientific agreement” in a guidance document released on December 22, 1999
(7). As summarized in the schematic shown in Figure 1, there is a clear
discrepancy between “emerging evidence” (characterized by in vitro or
animal studies, uncontrolled human studies, and inconsistent
epidemiological evidence) and “significant scientific agreement.” To
reach such agreement requires the support of a body of consistent, relevant
evidence from well-designed clinical, epidemiologic and laboratory studies,
and expert opinions from a body of independent scientists. Claims about the
health benefits of functional foods should be based on sound scientific
evidence, but too often only so-called “emerging evidence” is the basis
for marketing some functional foods or their components. Table 1
categorizes a variety of functional foods according to the type of evidence
supporting their functionality, the strength of that evidence and the
recommended intake levels.
Functional foods of animal origin
Probably the most intensively investigated class of physiologically-active
components derived from animal products are the (n-3) fatty acids,
predominantly found in fatty fish such as salmon, tuna, mackerel, sardines
and herring (8). The two primary (n-3) fatty acids are eicosapentaenoic
acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6). DHA is an essential
component of the phospholipids of cellular membranes, especially in the
brain and retina of the eye, and is necessary for their proper functioning.
DHA is particularly important for the development of these two organs in
infants (9), and just recently, the FDA cleared the use of DHA and
arachidonic acid for use in formula for full-term infants (10). Hundreds of
clinical studies have been conducted investigating the physiologic effects
of (n-3) fatty acids in such chronic conditions as cancer, rheumatoid
arthritis, psoriasis, Crohn's disease, cognitive dysfunction and
cardiovascular disease (11), with the best-documented health benefit being
their role in heart health. A recent meta-analysis of 11 randomized control
trials suggests that intake of (n-3) fatty acids reduces overall mortality,
mortality due to myocardial infarction and sudden death in patients with
CHD (12).Взаимодействовать