A seminar on
FUNCTIONAL FOODS AND THEIR HEALTH BENEFITS
By
Devraj Acharaya
B. Tech. (Food) 4th Year
Roll No: 6/060
Submitted To:
Food Technology Instruction Committee
Central Campus of Technology
Institute of Science and Technology
Tribhuvan University,
Hattisar, Dharan
INTRODUCTION
There is no universally accepted definition of functional foods; however, several
organizations have attempted to define this emerging food category. The
International Food Information Council (IFIC) defines functional foods as foods
that provide health benefits beyond basic nutrition. This definition is similar to
that of the International Life Sciences Institute of North America (ILSI), which
has defined functional foods as foods that, by virtue of physiologically active
food components, provide health benefits beyond basic nutrition. The Institute
of Medicine of the National Academy of Sciences limits functional foods to those
in which the concentrations of one or more ingredients have been manipulated
or modified to enhance their contribution to a healthful diet.
According to these definitions, unmodified whole foods such as fruits and
vegetables represent the simplest example of a functional food. For example,
broccoli, carrots, or tomatoes would be considered functional foods because
they are rich in such physiologically active components as sulforaphane, beta
carotene, and lycopene, respectively. Modified foods, including those that have
been fortified with nutrients or enhanced with phytochemicals or botanicals,
also fall within the realm of functional foods. The general category includes
processed food made from functional foods ingredients, or fortified with health-
promoting additives, like "vitamin-enriched" products, and also, fresh foods (e.g.
vegetables) that have specific claims attached. Fermented foods with live
cultures are often also considered to be functional foods with probiotic benefits.
Although the term "functional foods" may not be the ideal descriptor for this
emerging food category, recent focus-group research conducted by IFIC showed
that this term was recognized more readily and was also preferred by consumers
over other commonly used terms such as "nutraceutical" or "designer foods".
In other words, functional foods do more than meet your minimum daily
requirements of nutrients; they also can play a role in reducing risk of disease
and promoting good health. While all foods are functional in that they provide
nutrients, "functional foods" tend to be those with health-promoting ingredients
or natural components that have been found to have potential benefit in the
body. They can include whole foods as well as fortified, enriched or enhanced
foods and dietary supplements that have a beneficial effect on health.
OBJECTIVES:
1. To introduce the term functional food on nutritional status of
Nepal.
2. To give the knowledge of taking balanced or complete diet by
following functional foods.
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3. To suggest the people to take different variety of food for
different diseases prevention and health promotion.
4. To suggest people using functional foods to overcome increased
health care cost.
SCIENTIFIC RESEARCH ON FUNCTIONAL FOODS
The scientific evidence for functional foods and their physiologically active
components can be categorized into 4 distinct areas: (a) clinical trials, (b) animal
studies, (c) experimental in vitro laboratory studies, and (d) epidemiologic
studies. Much of the current evidence for functional foods lacks well-designed
clinical trials; however, the foundational evidence provided through the other
types of scientific investigation is substantial for several of the functional foods
and their health-promoting components. A summary of selected functional foods
and the scientific evidence supporting their health benefit(s) is presented in
Table 1. Only a brief overview of the research is presented here.
The strongest scientific evidence of clinical efficacy is for functional foods
that are available or have been developed in accordance with the use of Food and
Drug Administration (FDA) approved health claims delineated by law under the
Nutrition Labeling and Education Act (NLEA) of 1990. The health claims
authorized under NLEA are statements that describe a relationship between a
food substance and a disease or other health related condition. Scientific support
under NLEA includes all types of research from in vitro to randomized, controlled
clinical trials and focuses on the reduction of common chronic diseases. Basic
examples of functional foods that fall into this realm are foods naturally rich in
soluble fiber, such as oat bran or psyllium, which has been associated with
reduced incidence of coronary heart disease. Another example would be fruits
and vegetables and the association between increased consumption and reduced
risk for cancer or coronary heart disease. Soy protein is an additional example;
however, a final regulation authorizing a health claim related to soy protein
intake and reduction of risk for coronary heart disease has yet to be issued by
FDA.
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Other functional foods may have substantial scientific support, but currently
lack an FDA-approved health claim because the food industry has not yet
petitioned the FDA. Examples would be garlic and n-3 fatty acids found in fish,
which have been shown in clinical trials to reduce serum cholesterol levels in
subjects with elevated levels. This group of functional foods might also include
new products such as the plant stanol-enriched or sterol-enriched table spreads
that have been shown in clinical trials to significantly reduce serum cholesterol
levels in subjects with mild to moderate hyperlipidemia.
A third category of functional foods are those that have been fortified to
enhance the level of a specific nutrient or food component that has been
associated with the prevention or treatment of a disease or other clinical
condition. Many of these products bear authorized health claims for product
marketing. This category would include products such as calcium-fortified orange
juice, pasta, or rice marketed to maintain good bone health and reduce
osteoporosis risk, as well as fiber-supplemented snack bars or folate-enriched
cereals. Many other functional foods in this category may lack sufficient evidence
to warrant an authorized health claim at this time. This would include, for
example, beverages with added vitamin E for reduced heart disease risk and salad
dressings with n-3 fatty acids to reduce the inflammatory response of rheumatoid
disease.
A fourth category of functional foods includes whole foods that have been
associated with reduced risk of disease. For these whole foods, in vitro, in vivo,
or epidemiologic research is available to support the health benefits of these
whole foods; however, no health claim exists, partially because of the limited or
improperly designed clinical trial data or lack of scientific agreement as to the
strength of the evidence. This category includes:
Øð Tomato products rich in lycopene, a carotenoid, whose consumption
is associated with reduced cancer rates in epidemiologic studies (42);
Øð Eggs with n-3 fatty acids, which may potentially reduce cholesterol
levels (43)
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Øð Black and green teas, which are rich in polyphenols, have been
associated experimentally and in human studies with cancer prevention and
control (29);
Øð Non-digestible oligosaccharides (prebiotics), especially fructans,
which may potentially provide health benefits for cardiovascular disease, type 2
diabetes, and intestinal infectious diseases (37,38);
Øð Fermented dairy products (probiotics), which have been shown to
improve gastrointestinal health (44); and
Øð Dairy products and red meat with conjugated linoleic acid, which
may alter cancer carcinogenesis (45).
For each of these, an association with reduced disease risk has been
observed but has not reached scientific consensus.
Finally, there exists a growing selection of functional food components
marketed under the umbrella of dietary supplements. For the majority of these
products, the evidence for their structure/function claims is currently limited,
incomplete, or unsubstantiated. Examples include antioxidant-enriched beverages
or candies, chewing gum with phosphatidylserine, and snack bars with chromium.
This category also includes a large number of herbal-enriched products that make
a variety of structure/function claims. Examples include cereal fortified with
ginkgo biloba, which is marketed as reducing symptoms of dementia, or juices
with echinacea, which are marketed for boosting the immune system. Both claims
do have support in controlled clinical trials. Other evidence for botanical-
enriched products has shown conflicting results in clinical trials such as the use of
echinacea to reduce cold and flu symptoms or kava to reduce anxiety. Still other
structure/function claims have no clear therapeutic efficacy, such as the use of
goldenseal for immune enhancement or ginseng for energy or enhanced physical
performance. Others, such as ma huang, may be harmful. Historically, evidence
for the clinical efficacy of select botanicals was limited primarily because of poor
research design (e.g., inconsistency in dosage form or amount, small sample size,
and frequently the lack of a placebo control, in part resulting from insufficient
funding for research in this area). Yet many of these botanicals are being
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introduced into our food supply--sometimes irresponsibly--in the form of
functional foods. ADA must call on industry to fund additional research in this
emerging area.
Evaluation of the efficacy of individual functional foods must be completed
using a scientifically valid risk-benefit model that clearly assesses all physiological
effects, both positive and negative. Review of the in vitro, animal, epidemiologic,
and clinical data is essential before functional foods are marketed to consumers
for their health-promoting qualities.
THE VALUE OF A VARIED DIET
The weight of scientific evidence indicates that the optimal approach for
achieving a health benefit from the intake of nutrients and other physiologically
active constituents is through the consumption of a varied diet that is rich in
plant foods. In reality, each vegetable contains numerous different nutrients and
phytochemicals--a biological circumstance that is not currently replicated in pill
form. In addition, the assumption that a combination of plant constituents that
are naturally occurring is maintained at equivalent levels of biological activity
when extracted, dried, and compacted into pill form is likely unfounded.
Pharmaceutical companies have isolated many food components into
supplement form, including allyly sulfides, genistein, anthocyanin (bilberry
extract), and glycyrrhizin (licorice) to name only a few. In the United States, tens
of billions of dollars are spent annually on dietary supplements. The rapid growth
in functional foods might be considered the food industry's response to growing
sales of dietary supplements. Supplements can provide nutrients and other
physiologically active components in a potentially unbalanced and concentrated
form that may be far different from the form used in research studies. Nutrients
and other bioactive food components that occur naturally in foods act
synergistically with other dietary elements such as fiber to promote health. The
food industry and dietetics professionals have a unique opportunity to promote
whole foods as an alternative to dietary supplementation through the integration
of appropriate functional foods into a varied eating plan for consumers. In
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addition, using sound scientific evidence, functional food products can be
developed that further enhance the health benefits of food.
LEVELS OF INTAKE
Safe levels of intake must be considered when evaluating functional foods in
the context of a healthy diet. For the majority of research studies, the optimal
levels of nutrients and other physiologically active components in functional foods
have yet to be determined. Animal research has provided some indication of
desired intake; however, these data are difficult to extrapolate to human dietary
requirements. Table 2 lists the approximate levels of intake for health promotion
associated with select nutrients, phytochemicals, and other food constituents.
However, for the majority of functional food components, precise levels of
recommended intake will be established only when the clinical trials have been
documented in the scientific literature.
Many functional foods or food components will require continued in vivo and
in vitro research, as well as pharmacokinetic studies, before specific levels for
clinical trial investigations can be determined. Once clinical trials have been
completed, more specific recommendations can be formulated. In addition, a
large percentage of dietary data collected historically provides limited
information regarding the exact intake of physiologically active food components
because few databases for nonnutritive food components have been developed.
Current dietary measurement tools are limited in data collection related to
herb, spice, condiment, and/or flavoring intake, despite the fact that several
physiologically active components have been identified in these foods. The
adequacy of intake of nutrients and other physiologically active dietary
components found in functional foods must include evaluation of these foods
(e.g., herbs, spices) and the interactions among the various nutrients and
bioactive food components in the diet.
Dietary constituents appear to act synergistically to improve absorption of
nutrients or physiologically active dietary components. One example is lycopene
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in tomatoes and the enhancement of its absorption when consumed along with
fat. The specific intake levels recommended to reduce the risk of disease in a
healthy population can be altered in the presence of a disease such as cancer or
cardiovascular disease. Therefore, dietary advice regarding approximate levels of
intake for functional foods and their components will need to be evaluated based
on currently available scientific information in the context of the specific
populations or individual variance.
CONCLUSION
Hence the knowledge of the role of physiologically active food components, both from
phytochemicals and zoochemicals has changed the role of diet in health. Functional foods
have evolved as food and nutrition science has advanced beyond the treatment of primary
deficiency syndromes to reduction of disease risk. Foods can no longer be evaluated only in
terms of macronutrient and micronutrient intake. Analyzing the content of other
physiologically active components will be necessary. The availability of health promoting
functional foods in the diet has the potential to help ensure a healthier population. However,
each functional food should be evaluated on the basis of scientific evidence to ensure
appropriate integration into a varied diet.
Although functional foods remain undefined under current food regulation of some
developed and developing countries, they are usually understood to be any potentially
healthful food or food ingredient that may provide a health benefit beyond the traditional
nutrients it contains. The term "functional" implies that the food has some identified value
leading to health benefits including reduced risk for disease, for the person consuming it.
Finally, the functional foods are also medicinal foods including whole foods and fortified,
enriched foods, have a potentially beneficial effect on health when consumed as part of a
varied and balanced diet on a regular basis at effective levels. It is also important to
remember that there is no single "magic bullet" food that can cure or prevent most health
concerns, even when eaten in abundance. So before deciding to make any major dietary
changes, it is necessary to take time to evaluate personal health to reduce the risk of certain
diseases.
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Reference
http://www.google.com/functional foods/a report on functional foods: Their
role in disease prevention and health promotion.htm
http://www.google .com/functional food/ a report on functional foods:
position of American Dietetic Association (ADA).htm
http://www.ific.org/functional foods question.htm
http://www.wikipedia.org/functional food.htm
http:// www.google.com/2005 food research.pdf
TABLE 1
Selected functional foods, key components, potential health benefits, scientific
evidence, and regulatory classification.
Functional Key component(s) Potential health Scientific Regulatory
Food benefits evidence classification
Low in total fat or Reduce risk of Clinical trials FDA approved
Low-fat saturated fat cancer health claim
foods as part Reduce risk of
of a low-fat coronary
diet (eg, heart disease
cheese,
snack foods,
meats, fish,
dairy)
Sugar alcohols Reduce risk of Clinical trials FDA approved
tooth decay health claim
Foods
containing
sugar
alcohols in
place of
sugar (gum,
candies,
beverages,
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snack foods)
Beta glucan soluble Reduce Clinical trials FDA approved
fiber cholesterol health claima
Oatmeal/oat
bran/whole
oat products
Calcium Reduce risk for Clinical trials FDA approved
osteoporosis health claima
Milk -- low
fat
Vitamins, Reduce cancer Epidemiologic FDA approved
phytochemicals, risk studies/animal health claima
Vegetables
fiber Reduce studies
and fruits
heart disease
risk
Folic acid Reduce risk for Clinical trials FDA approved
neural tube health claima
Cereal with
defect
added
folic acid
Calcium Reduce risk for
Juice, pasta,
osteoporosis Clinical trials FDA approved
rice,
health claima
snack bars,
and other
foods
with calcium
Psyllium fiber Reduce risk of Clinical trials FDA approved
coronary health claima
Psyllium-
heart disease
containing
products (eg,
pasta, bread,
snack foods)
Fiber Reduce risk of Clinical trials Notification of
certain cancers FDA pursuant to
Whole-grain
Reduce risk of FDAMAa
bread/high-
heart disease
fiber cereals
Echinacea Dietary support No direct Food, Drug, and
for the immune evidence Cosmetic Act
Snack foods
system (FDCA) -
with
structure/function
echinacea
claim
No direct
evidence FDCA --
structure/function
Phosphatidyl serine Improve claim
Gum with
concentration
phosphatidyl
serine
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Vitamins E and C, Improve overall No direct FDCA --
beta carotene health evidence structure/function
Beverages
Support normal, claim
with
healthy
antioxidants
cardiovascular
function
Antioxidant Support heart No direct FDCA --
nutrients, health evidence structure/function
phytochemicals Support overall claim
Candies with
health
antioxidants,
vegetable or
fruit extracts
Variety: echinacea, Variety of Data for select FDCA --
gingko, kava, health benefits botanicals structure/function
Beverages
ginseng, (not in the claim
with herbal
Saw palmetto form of
additives
functional
foods)
Phenols, resversatrol Support normal, Epidemiologic FDCA --
Grapes/grape
healthy studies structure/function
juice
cardiovascular claim
function
Plant sterols, plant Support normal, Clinical trials FDCA --
stanol esters healthy structure/function
Modified
cholesterol claim
margarine
levels
products
Fructoligosaccharides Support normal, Animal FDCA --
healthy studies; structure/function
intestinal clinical trials claim
Jerusalem
microflora
artichokes,
chicory root,
bananas,
garlic
Echinacea, Improve immune No direct FDCA --
St John's wort function evidence structure/function
Soups with
Reduce claim
herbal
depression
additives
Soy protein Reduce risk for Clinical trials
Petition for
coronary
Soy
health claim
heart disease
pending at FDA
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Beta carotene Reduce risk for Epidemiologic
No health claim
cancer studies
Carrots
submitted
Sulforaphane Reduce risk for Animal data;
No health claim
cancer epidemiologic
Broccoli
petition
studies
submitted
Lycopene Reduce risk for Animal studies
No health claim
prostate cancer (cancer)
Tomato
petition
Reduce risk for Epidemiologic
products
submitted
myocardial studies
infarction
Catechins (eg, EGCG) Reduce risk for Epidemiologic
No health claim
coronary heart studies
Tea, green or
petition
disease Epidemiologic
black
submitted
Reduce risk for Studies and
gastric, clinical trails
espohageal,
skin cancers
Fish n-3 Fatty acids Reduce risk for Epidemiologic
No health claim
coronary heart studies (fish);
petition
disease clinical trials
submitted
(n-3 fatty
acids)
Conjugated linoleic Reduce risk for Animal studies
No health claim
acid (CLA) maminary tumors
Beef, dairy,
petition
lamb
submitted
Probiotics Epidemiologic
Reduce No health claim
studies
Fermented
cholesterol petition
Epidemiologic
dairy
Reduce risk for submitted
studies
products
cancer
Clinical trails
Control enteric
pathogens
Eggs with n-3 n-3 Fatty acids
Reduce Clinical trails No health claim
fatty acids
cholesterol petition
submitted
Garlic Organosulfur Epidemiologic
Reduce risk for No health claim
compounds studies/animal
cancer petition
Studies
submitted
Clinical trials
Reduce risk for
coronary
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heart disease Clinical trials
Control
hypertension
Medical food L-arginine Improve vascular Clinical trials
Medical food
bar with health
health claim
arginine
Medical food Sucrose, protein, Control blood Clinical trials
Medical food
bar uncooked cornstarch glucose
health claim
overnight;
prevent
hypoglycemia
TABLE 2
Approximate intake levels for select functional foods or food components to
promote optimal health status.
Food / food component Level of intake Disease association
Green or black tea 4-6 cups/day Reduced gastric and
esophageal cancer risk
(29,30)
25 g/day
Soy protein Reduced low-density
60 g/day lipoprotein cholesterol,
non-high-density
lipoprotein.
Reduced menopausal
symptoms
Garlic 600-900 mg/day Reduced blood pressure
(Approximately 1 fresh Reduced serum
clove/day) cholesterol
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Vegetables and fruit 5-9 servings/day Reduced risk of cancer
(colon, breast, prostate)
Blood pressure reduction
Fructooligosaccharides 3-10 g/day Blood pressure reduction
Beneficial effect on lipid
metabolism, improved
gastrointestinal health,
and serum cholesterol
reduction
Fish rich in n-3 fatty >180 g (6 oz) /week Reduced risk of heart
acids disease
Grape juice or red wine 8 to 16 oz/day Platelet aggregation
reduction
8 oz/day
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