Transcript Phytochemicals - Family and Consumer Science

Phytochemicals
Presented by
Janice Hermann, PhD, RD/LD
OCES Adult and Older Adult Nutrition Specialist
Phytochemcials and Functional Foods
 Foods contain many different nutrients:
 Carbohydrates
 Fiber
 Lipids
 Proteins
 Vitamins
 Minerals
Phytochemicals and Functional Foods
 Plant foods also contain non-nutrient
compounds including – phytochemicals
 Phytochemicals are compounds in foods that
physiological activity in the body
Phytochemicals and Functional Foods
 Concept that foods provide health benefits
beyond those provided by the major nutrients
has developed from numerous
epidemiological studies demonstrating a
protective effect of plant foods on cancer and
heart disease.
Phytochemicals andFunctional Foods
 Although current research is discovering the
beneficial roles of phytochemicals have in
human health.
 Only a few of the tens of thousands of
phytochemicals have been researched, and
there are still many questions and only
indefinite answers.
Phytochemicals and Functional Foods
 Concept foods provide health benefits
beyond those of nutrients initiated name
“functional foods"
 Nature’s functional foods
 Grains rich in dietary fibers
 Fish rich in omega-3 fatty acids
 Fruits, vegetables and legumes rich in
phytochemicals and fiber
 Newest controversies is the development of
novel foods to which phytochemicals have
been added to promote health.
Phytochemicals and Functional Foods
 Phytochemicals can have profound
physiological effects in the body, functioning
as:
 Antioxidants
 Mimicking hormones
 Suppressing the development of diseases
Example Phytochemicals
 Carotenoids in deeply pigmented fruits and
vegetables (apricots, broccoli, cantaloupe,
carrots, pumpkin, spinach, sweet potatoes,
tomatoes) act as antioxidants possibly
reducing risk of cancer and other diseases.
 Curcumin in tumeric may inhibit enzymes that
activate carcinogens
Example Phytochemicals
 Flavonoids in berries, black tea, celery, citrus
fruits green tea, olives, onions, purple grapes,
purple grape juice, soy beans and soy
products, vegetables, whole wheat, and wine
act as antioxidants, scavenge carcinogens,
bind to nitrates in the stomach preventing
conversion to nitrosamines, and inhibit cell
proliferation.
Example Phytochemicals
 Indoles in broccoli and other cruciferous
vegetables and mustard greens may trigger
production of enzymes that block DNA
damage from carcinogens and may inhibit
estrogen action.
 Isothiocyanates in broccoli and other
cruciferous vegetables and mustard greens
inhibit enzymes that activate carciongoens,
trigger production of enzymes that detoxify
carcinogens.
Example Phytochemicals
 Lignans in flaxseed and whole grains block
estrogen activity in cells.
 Monoterpenes in citrus fruit peels and oils
may trigger enzyme production to detoxify
carcinogens; inhibit cancer promotion and
cell proliferation
 Organosulfur compounds in chives, garlic,
leeks, and onions may speed production of
carcinogen destroying enzymes, slow
production of carcinogen activating enzymes.
Example Phytochemicals
 Phenolic acids in coffee beans, fruits, oats,
potatoes, and soybeans may trigger enzyme
production to make carcinogens water
soluble facilitating excretion.
 Phytic acids in whole grains binds to minerals,
preventing free-radical formation.
 Phytoestrogens (genistein and daidzein) in
soybeans and other legume products mimic
estrogen and may inhibit estrogen
Example Phytochemicals
 Protease inhibitors in broccoli, potatoes, soy
beans and other legumes may suppress
enzyme production in cancer cells, slowing
tumor growth, inhibit hormone binding and
inhibit malignant changes in cells.
 Phytosterols in soybeans and other
vegetables may protect against heart disease
by inhibiting cholesterol absorption
Example Phytochemicals
 Saponins in alfalfa sprouts, green vegetables,
potatoes and tomatoes may interfere with
DNA replication, preventing cancer cells from
multiplying and stimulate immune response.
 Tannins in black-eyed peas, grapes, lentils, red
and white wine and tea may inhibit
carcinogen activation and cancer promotion
and act as antioxidants.
Protecting Against Cancer
 Many phytochemicals from many different
foods seem to protect against cancer by
preventing DNA damage.
 Soybeans, flaxseed oil, whole grains, fruits,
and vegetables are rich sources of
phytochemicals, including phytoestrogens.
 Phytoestrogens weakly mimic or modulate the
effects of estrogen in the body.
 Phytoestrogens have antioxidant activity and
seem to slow the growth of breast and prostate
cancer.
Protecting Against Cancer
 Tomatoes appears to protect against
esophagus, lung, prostate, and stomach
cancers.
 Lycopene is found in apricots, guava, papaya, pink
grapefruits, watermelon, and it is especially
abundant in tomatoes and cooked tomato
products.
 Lycopene is a powerful antioxidant that appears to
inhibit the growth of cancer cells.
Protecting Against Cancer
 Soybeans and tomatoes are examples of only
two of the many fruits and vegetables
attributed with protecting against cancer.
 Researchers hypothesize that people may cut
their risk of cancers in half by simply
consuming the recommended amounts of
fruits and vegetables daily.
Protecting Against Heart Disease
 Diets rich in whole grains, vegetables and
fruits also appear to lower risk of heart
disease.
 These foods provide an abundance of
nutrients, fiber, and phytochemicals.
Protecting Against Heart Disease
 Flavonoids - large group of phytochemicals
that may protect against heart disease.
 Flavonids found in whole grains, legumes, soy,
vegetables, fruits, herbs, spices, teas, chocolate,
nuts, olive oil, and red wines.
 Flavonoids are strong antioxidants that may
help to protect LDL cholesterol against
oxidation and reduce blood platelet
stickiness, making blood clots less likely.
Protecting Against Heart Disease
 In addition to flavonoids, fruits and
vegetables are rich in carotenoids.
 Diets rich in carotenoids is also associated
with a lower risk of heart disease.
 Two carotenoids that may defend against
heart disease are lutein and lycopene.
Protecting Against Heart Disease
 Phytosterols found in soybeans and other
vegetables appear to protect against heart
disease.
 Phtosterols are similar in structure to
cholesterol and inhibit the absorption of
cholesterol decreasing blood cholesterol
levels.
 Phytoestrogens may also protect against
heart disease by functioning as antioxidants
and lowering blood pressure.
Phytochemicals in Perspective
 Because foods deliver thousands of
phytochemicals in addition to dozens of
nutrients, consumers must be careful in giving
credit for particular health benefits to any
one compound.
 Diets rich in whole grains, legumes,
vegetables, and fruits seem to be protective
against disease, but identifying the specific
foods or components of foods that are
responsible is difficult.
Phytochemicals in Perspective
 Foods contain many phytochemicals.
 Broccoli may contain as many as 10,000 different
phytochemicals
 Each with the potential to influence some action in
the body.
 The effect of different phytochemicals in food
may be synergistic.
 This reinforces the principle of variety.
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 Functional foods...
 from nature
 from manufacturers
Oklahoma Cooperative Extension Service
Functional Foods
 Because foods naturally contain thousands of
phytochemicals, whole foods, in reality, are
functional foods.
 Cranberries may help protect against urinary tract
infections
 Garlic may help ower blood cholesterol; and
tomatoes may protect against certain types of
cancers
Functional Foods
 In addition to naturally occurring functional
foods, food manufacturers are trying to
create functional foods as well – becoming
the fastest growing trend in the food supply.
 Foods may be fortified or enhanced with nutrients,
phytochemicals or herbs
 Sometimes an entirely new food is created
Foods or Drug?
 Such functional foods raise the question – is it
a food or drug?
 In the past, most could agree what was a food
and what was a drug.
 Functional foods have distorted the
distinctions.
 Functional foods have characteristics of both
foods and drugs, but do not fit clearly into
either category.
Foods or Drug?
 For example, yogurt contains Lactobacillus
and other living bacteria that ferment milk
into yogurt.
 These microorganisms, called probiotics, alter
the gastrointestinal population of
microorganisms, which protects the
gastrointestinal tract against disorders.
Foods or Drug?
 Research is investigating whether probiotics:
 Help to alleviate diarrhea, inflammatory bowel
disease, and lactose intolerance
 Enhance immune function
 Protect against gastrointestinal cancer
 Lower blood cholesterol
Food or Drug?
 An example of where food manufactures are
developing products with added
phytochemicals is margarine.
 Consuming nonhydrogenated margarine
sparingly may lower blood cholesterol slightly
over several months and falls clearly falls into
the category of a food.
 Whereas, the drug Lipitor lowers blood
cholesterol significantly within weeks and
clearly falls into the category of a drug.
Food or Drug?
 Consider, margarine enhanced with the
phytosterol. Phytosterol is a phytochemcial
that is structurally similar to cholesterol, and
has been found to lower blood cholesterol
levels by inhibiting cholesterol absorption.
 Margarine enhanced with phytoserol falls
between the categories of a food and drug.
Food or Drug?
 Use of functional foods to result in beneficial
effects results in a whole new set of dietplanning problems.
 Just as drugs, functional foods may need to
be consumed several times a day for several
months or years to have beneficial effects.
Sporadic use may have disappointing results.
Food or Drug?
 For example:
 Margarine with added phytosterols consumed four
times a day for four weeks lowered cholesterol by
8 percent.
 But cholesterol lowering drugs lowered cholesterol
by 32 percent.
 Functional foods may be more useful for
prevention and mild disease cases than for
intervention and more severe
Cost Differences
 There may also be a difference in cost as
well.
 Functional foods such as fruits and vegetables
have no added costs
 Foods manufactured with added phytochemcials
can be expensive, costing much more than their
conventional counterparts
Unanswered Questions
 To achieve a desired health effect, which is
the better choice: to eat a food designed to
affect some body function or simply to adjust
the diet?
 Does it make more sense to use a margarine
enhanced with a phytosterol that decreases
cholesterol absorption, to consume foods naturally
high in phytosterol or limit the amount of
saturated fat in the diet?
Unanswered Questions
 One concern is that the food industry moves
too fast for science and the FDA to keep up.
 Consumers were able to modified foods while
research is still being conducted as to the
safety and efficacy.
What Should Consumers Think
 Does it work?
 Research is generally lacking and inconclusive
 How much does it contain?
 Research is lacking as to what level is effective or
dangerous
 Is it safe?
 Functional foods can act like drugs, they contain
ingredients that can alter body functions.
 Is it healthy?
 Adding phytochemcials to a food doesn’t
magically make it a healthy choice
What Should Consumers Think
 Researchers have not identified the perfect
combination of nutrients and phytochemciasl
for optimal health.
 Yet food manufacturers are freely adding
various phytochemicals to foods.
What Should Consumers Think
 Important to remember foods naturally
provide a variety of nutrients and nonnutritive compounds that may be beneficial
to health, most of which have yet to be
identified or understand.
 A well balanced diet, from a variety of foods
can in itself provide the variety of nutrients
and non-nutrients for health and well-being.