Anticarcinogenic compounds by liaoqinmei

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									 Anticarcinogenic
compounds in food
  Non-nutritive ingredients:
      phytochemicals
                  Objectives
   What are phytochemicals?
   Where are they found?
   What are the health benefits?
   Are there any risks?
   What are functional foods and how are they
    regulated?
   What do we tell consumers?
     Definition of Phytochemicals
   Biologically active chemical compounds found
    in plants
   Not nutrients like vitamins or minerals
   Believed to have health benefits especially
    related to heart disease and cancer
           How Scientists View
         Phytochemicals in Foods
   Some phytochemicals have profound effects on the
    body through actions such as
        Acting as antioxidants
        Mimicking hormones
        Altering blood constituents in ways that may protect
         against some diseases
Mechanisms of Chemoprevention
   Antioxidants: defense against radicals
   Phase 1 enzyme inducers
   Phase 2 enzyme inducers
   Anti-proliferative agents
   Anti-hormonal compounds
   Disruption of mutational gain or loss of
    function
Is More Better?
Choose Food First

Avoid Overdosing

Avoid Self Prescribing
                                     Berries
       (sources of vitamin C, E, carotinoids, flavonoids, phytoestrogenes
                           and other phytochemicals)



        cranberries                                  cloudberry          blackberry
                                     blackthorn


                         raspberry
                                                                        gooseberry

                                              dogberry
      huckleberry
                                                          loganberry




blueberry                   strawberry       redcurrant                blackcurrant
         Spices and cancer (data based on human epidemiologic
                     studies and animal experiences)

Italy: chilli, cinnamon, clove, pepper, nutmeg
=> ↓ gastric cancer


                                                        ánizs
France and other mediterranian countries:
anise, curry, ginger, mustard, paprika, pepper, allspice =>
↑ bladder cancer

                                                                        szegfűbors
Garam masala (mixture of pepper,
clove, cinnemon, nutmeg, ginger,                                babér
cardamom, caraway, laurel) => ↓ cancer         kömény
incidence after DMBA treatment
Walnuts and oleaginous seeds (high amount of vitamin E,
selenium, ellagic acid, phytic acid, phytoestrogenes =>
protective effect)

       walnut       hazelnut        almond        pine seeds




       pistachio   sunflower seed   sesame seed   pumpkin seed




 poppy-seed
Whole Foods, Wine, and Tea

   Epidemiological evidence spanning many
    countries indicates that deaths from cancer, heart
    disease, and heart attacks are less common where
    these foods are plentiful in the diet, where tea is a
    beverage, or where red wine is consumed in
    moderation
                     Phytochemicals
   Whole Foods, Wine, and Tea
       Historically, diets containing whole grains, fruits,
        vegetables, herbs, spices, teas, and red wines have
        been reputed to possess health-promoting qualities
       These foods and beverages all have something in
        common
            Phytochemicals of the flavonoid family
                          Flavonoids
   Many flavonoids act as antioxidants
       May protect against cancers and heart disease by
        this mechanism
       More evidence is needed before any claims can be
        made for flavonoids themselves as the protective
        factor in foods
            Particularly when they are extracted from foods or herbs
             and sold as supplements
Why are antoxidants important?

   free radicals are molecules missing electrons:
    unstable
   formation of 1 free radical causes a chain
    reaction with many free radicals formed
   antioxidants prevent formation of free radicals
    or break the chain reaction by becoming
    oxidized
                       Antioxidants
   Because flavonoids often impart a bitter taste
    to food, food producers may refine away
    natural flavonoids to please consumers who
    generally prefer milder flavors
       To produce white grape juice or white wine,
        makers remove the red, flavonoid-rich grape skins
        to lighten the flavor and color of the product
            While greatly reducing its flavonoid content
                    Antioxidants
   Whether or not research confirms the cancer-
    fighting and heart-defending nature of
    flavonoids, consumers should seek out a
    variety of whole fruits, vegetables, and other
    plant-derived foods with their flavonoids intact
    in place of their more refined counterparts
       Such diets are consistently associated with low
        rates of disease
                      Antioxidants
   Flavonoid supplements have not been proved
    effective or safe
   As for red wine, the potential health benefits may not
    be worth alcohol’s immediate and substantial risk
   Other sources:
       Blueberries
       Tea
       Grapes
       Vegetables
                       Tea
   Black- most often sold, fermented and more
    processed
   Oolong- semi-fermented, heated and dried
    more than green tea but less than black, served
    in Chinese restaurants
   Green- unfermented, very little processing
   White- unfermented, very little processing,
    harvested before leaves are fully open
                            Tea
   Calorie Free
   87% of dietary
    flavonoids consumed

   Antioxident
    polyphenols including
    flavonoids
       Catechin
       EGCG
       Proanthocyanidins
                     Cancer
   Protects against free radical damage
   Decrease growth of abnormal cells
   Associated with decreased risk of rectal, colon
    and skin cancer
                 Other Benefits
   Memory
   Immune function
   Oral health
   Decreased risk of kidney stones
   Obesity

   Mostly epidemiological research and research on tea
    consumption, concentrated tea extracts may not be
    safe
                          Antioxidants
   Chocolate
       Research subjects were instructed to eat three
        ounces of dark (bittersweet) chocolate chips
            Flavonoid antioxidants from chocolate accumulate in
             the blood
                 The level of certain harmful oxidizing compounds dropped
                  40%
            The antioxidant effects of dark chocolate may turn out
             to be as powerful as those of tea or red wine
                      Chocolate
   In theory, chocolate may also “thin the blood”
    by reducing the tendency of blood to clot
       Blood clots are a major cause of heart attacks and
        strokes
       No evidence exists to indicate that people who eat
        chocolate suffer fewer heart attacks or strokes than
        people who do not
                           Chocolate
   Chocolate consumption promotes weight gain
       Three ounces of sweetened chocolate candy
        contain over 400 calories
            A significant portion of most people’s daily calorie
             allowance
       Chocolate contributes few nutrients save fat and
        sugar
                     Antioxidants
   For most people,
    antioxidant
    phytochemicals are best
    obtained from nutrient-
    dense low-calorie fruits
    and vegetables and
    calorie -free green or
    black tea
       With chocolate enjoyed
        as an occasional treat
                       Soybeans

   Compared with people living in the West, Asians
    living in Asia suffer less frequently from:
        osteoporosis
        cancers, especially of the breast, colon, and prostate
        heart disease
        Asian women also suffer less from symptoms related to
         menopause
                      Soybeans
   When Asians migrate to the U.S. and adopt
    Western diets and habits they experience these
    disease and problems at the same rates as
    native Westerners
   Among many differences between the diets of
    the two regions
       Asians consume far more soybeans and soy
        products such as miso, soy drink, and tofu than do
        Westerners
                       Soybeans
   Soybeans contain phytochemicals known as
    phytoestrogens
       Researchers suspect that the phytoestrogens of soy
        foods, their protein content, or a combination of
        these factors may be responsible for the health
        effect in soy-eating peoples
       Research, though ongoing, is limited and
        inconsistent
                     Soybeans
   We know with certainty that phytoestrogens
    are plant-derived chemical relatives of the
    human hormone estrogen
       They weakly mimic or modulate the hormone’s
        effects on some body tissues
       They act as antioxidants
                           Soybeans
   We know that breast cancer, colon cancer, and
    prostate cancer are estrogen-sensitive
       They grow when exposed to estrogen
       It is unknown if actions of phytoestrogens may
        alter the course of estrogen-sensitive cancers
            Results from recent breast cancer studies do not support
             the idea unless soy is consumed beginning in childhood
              Soybeans: genistein
   Symptoms of menopause
       Phytoestrogens may reduce risk of adult bone loss
        and the sensation of elevated body temperature
        known as “hot flashes”
       A diet high in soy may offer bone protection
        rivaling that of hormone replacement therapy
        (HRT)
       May not reverse bone loss but may prevent it
                  Soybeans
   Because HRT involves some serious health risks,
    supplements of soy are often sold to menopausal
    women as a “natural” alternative
   Research does not support taking phytoestrogen
    supplements for bone mineral retention or hot
    flashes
                      Soybeans
   Phytoestrogen supplement use may involve
    some risk
       While studying one soy phytoestrogen, genistein,
        researchers found that instead of suppressing
        cancer growth, high doses appeared to speed
        division of breast cancer cells in laboratory
        cultures and in mice
                         Soybeans
   Findings on the health effects of phytoestrogens
    should raise a red warning flag against taking
    supplements
       Especially in women whose close relatives have developed
        breast cancer
   Until more is known, a safer route to obtaining soy
    phytoestrogens is to include moderate amounts of
    soy-based foods in the diet
       As generations of Asian people have safely done through
        the ages
                   Flaxseed
Historically, people have used flaxseed for
relieving constipation or digestive distress
   Currently, flaxseed and its oil are under study for
    potential health benefits
   Contains lignans, compounds converted into
    biologically active phytoestrogens by bacteria that
    normally reside in the human intestine
                   Flaxseed

   Studies of populations suggest that women who
    excrete more phytoestrogens in the urine (an
    indicator of phytoestrogen intake from flaxseed
    and other sources) have lower rates of breast
    cancer
   Animal studies show a decrease in tumors of the
    breast and lung when fed flaxseed
                           Flaxseed
   Studies of the direct effects of giving flaxseed
    to people are lacking
   Some risks are possible with its use
       Flaxseed contains compounds that may interfere
        with vitamin or mineral absorption
            Thus high daily doses could cause nutrient deficiency
             diseases
       Large quantities can cause digestive distress
                            Flaxseed
   Although no clear role has been established for
    flaxseed in the prevention of human cancer
       Including a spoonful or two of flaxseed in the diet
        may not be a bad idea
       Flaxseed richly supplies linolenic acid
            A needed nutrient often lacking in the U.S. diet
      Choose most fats from sources of
    monounsaturated and polyunsaturated
                fatty acids

   Keep the amount within calorie needs
   Choose more fish, nuts and vegetable oils
   Use lean meats and low fat dairy products
   Limit saturated and trans fats
   To provide essential fatty acids and vitamin E
    while keeping calories controlled and
    cholesterol and saturated fat low
                     Tomatoes

   People around the world
    who eat the most
    tomatoes, about 5
    tomato-containing meals
    per week, are less likely
    to suffer from cancers of
    the esophagus, prostate,
    or stomach than those
    who avoid tomatoes
                      Tomatoes
   Among the phytochemical candidates for
    promoting this effect is lycopene
       A red pigment with antioxidant activity
       Found in guava, papaya, pink grapefruit, tomatoes
        (especially cooked tomatoes and tomato products),
        and watermelon
                           Tomatoes
   Lycopene may inhibit the reproduction of
    cancer cells
       Some research suggests that low blood levels of
        lycopene and related compounds correlate with
            increased risk of breast cancer
            elevated incidence of heart disease, heart attack, and
             stroke
       May also protect against the damaging sun rays
        that cause skin cancer
                         Tomatoes
   In one study, women who consumed a diet rich in
    fruits and vegetables had high lycopene
    concentrations and a greatly reduced concentration of
    an indicator of cervical cancer
   Do scientists conclude that lycopene prevents cervical
    cancer? No.
       The suggestion is that a diet rich in fruits and vegetables
        with their host of nutrients and phytochemicals reduces
        women’s risk of cervical cancer and many other diseases
                      Tomatoes
   A lesson about supplements can be learned
    from experience with lycopene’s chemical
    cousin
       The normally beneficial vitamin A relative beta-
        carotene
   Diets high in fruits and vegetables that contain
    beta-carotene often correlate with low rates of
    lung cancer
       When beta-carotene supplements were given to
        smokers lung cancer rates increased
                             Garlic



   Descriptions of its uses for headaches, heart disease,
    and tumors are recorded in early Egyptian medical
    writings
   In modern medical research, over 3,000 publications
    have investigated the potential health benefits of garlic
        Many have reported positive findings
                              Garlic
   Among garlic’s active compounds are
    organosulfur compounds
       Reported to inhibit cancer development in
        laboratory animals
       suppress the formation of certain harmful
        oxidizing compounds that damage DNA and
        trigger cancerous changes
            This evidence hints that eating garlic may be beneficial
             against some forms of cancer in human beings
                          Garlic
   More potential roles for garlic
       allergies
       heart disease
       bacterial cause of ulcers
       fungal infections
       reduce the clotting of the blood
       improve levels of blood cholesterol in people
        whose cholesterol is too high for heart health
                                  Garlic
   Volatile sulfur compounds are not present as such in
    intact cells.
   The reaction between
       The enzyme allinase and
       The volatile precursors
            S-alk(en)yl cysteine sulfoxide and
            Sulfonic acid
        takes place when cells are ruptured
       Results in the formation of
            Different thiosulfonates and
            Related sulfonic acid derivatives
                              Garlic
   Studies of garlic supplements, such as powders
    and oils, have been disappointing
       Positive results seem to be associated with an aged
        preparation of garlic that lack garlic’s
        characteristic odor
            But is rich in antioxidants and other compounds
       From the scientist’s point of view, no evidence that
        large doses of concentrated chemicals from garlic
        may improve a person’s health or injure it
   People who eat the recommended amounts of a
    variety of fruits and vegetables may cut their risk of
    many diseases by as much as half
   Replacing some meat with soy foods or other
    legumes may lower heart disease and cancer risks
   In the context of a healthy diet, foods are time-tested
    for safety, posing virtually no risk of toxic levels of
    nutrients or phytochemicals
     What do we tell consumers?
   Eat more fruit
   Increase vegetable portions
   Use herbs and spices
   Replace some meat
   Add grated vegetables
   Try new foods
                MECHANISM OF ACTION
         ON NUTRITIONAL ANTICARCINOGENESIS I.

I. Inhibition the binding to DNA
brocoli, cabbage, brussels sprout,   - phenylisotiacyanats
savoy cabbage (brassicans)           - ellagil acid
greens, fruits,                      - ellagil acid
seeds, hazel nut                     - flavonoids
II. Inhibition of promotion
green yellow vegetables,             - retinoids
fruits (melon, squash,               - beta carotin
carrot, brussels, etc.)
hazel nut, seeds                     - vitamin E
paprika, tomato, lemon, chili        - vitamin C
orange
garlic, onion                        - organic sulphur chemicals
curry                                - curcumin
chili pepper                         - capsaicin
              MECHANISM OF ACTION
       ON NUTRITIONAL ANTICARCINOGENESIS II.

III. Modulation of biotransformation
brokkoli, cukkini, káposzta,               - indol-3-carbinol
kel, kínai kel, spenót, cékla,
karalábé, karfiol
garlic, grains, seal oil, olive            - selenium
sea-fish oils
IV. Induction of physical features, changing of absorption
greens, fruits,                            - fiber
nut, hazel nut, cereals, grains
greens, nut, hazel nut,                    - riboflavin - chlorophyl
cereals, fungus
Other
soyabean, olive, maize, sesame, coconut oil, butter, fish coice, poultries,
bran, rye
Scientific publications:
      Questions
S-ALLYLCYSTEINE INHIBITS CIRCULATORY LIPID PEROXIDATION AND
PROMOTES ANTIOXIDANTS IN N-NITROSODIETHYLAMINE-INDUCED
CARCINOGENESIS.


ALTERED CYTOKERATIN EXPRESSION DURING CHEMOPREVENTION
OF HAMSTER BUCCAL POUCH CARCINOGENESIS BY S-ALLYLCYSTEINE.


DIETARY SOY AND INCREASED RISK OF BLADDER CANCER:
THE SINGAPORE CHINESE HEALTH STUDY



EFFECTS OF TEA ON PRENEOPLASTIC LESIONS
AND CELL CYCLE REGULATORS IN RAT LIVER


CHEMOPREVENTIVE EFFECT OF FARNESOL AND LANOSTEROL
ON COLON CARCINOGENESIS I.
FIG. 1. STRUCTURES OF FARNESOL AND LANOSTEROL




       FARNESOL




                             LANOSTEROL
APOPTOSIS INDUCTION BY S-ALLYLCYSTEINE, A GARLIC CONSTITUENT,
DURING 7,12-DIMETHYLBENZ[A]ANTHRACENE-INDUCED HAMSTER BUCCAL
POUCH CARCINOGENESIS.



INDOLE-3-CARBINOL HAS POSSIBLE ANTICARCINOGENIC ACTIVITY



TOMATO AND GARLIC CAN MODULATE AZOXYMETHANE-INDUCED
COLON CARCINOGENESIS IN RATS




IDENTIFICATION OF POTENTIAL ARYL HYDROCARBON RECEPTOR
ANTAGONISTS IN GREEN TEA
           Phytochemicals                    Foodstuffs (fruits, vegetables)
Ditions (isothiocyanate, benzyl-           Brassicas, peas
isothiocyanate, phenyl-ethyl-
isothiocyanate, sulforaphan)
Terpenoids (D-limonene, geraniol,          Citruses
menthol, carvone)
Flavonoids                                 Generally all vegetables and fruits
- kvercetin                                - berries, tomato, broccoli, onion

- kemferol, tangeretin, nobiletin, rutin   - savoy cabbage, endivia, citruses,
                                           horse-radish
Phenols (ellagic acid)                     Tea, fresh harvested fruits and
                                           vegetables, walnuts, berries
Glucosinolates, indoles                    Brassicas

Sterols (beta-sitosterol, campesterol,     Vegetables
stigmasterol)
Coumarine compounds                        Manioc, citruses
One of sources of the lecture:




    Fruits and Vegetables – The Real Thing Matters!
          Being Fit with Phytochemicals
                 Mollie Smith, MS, RD
           California State University, Fresno
        Department of Food Science and Nutrition

								
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