Anticarcinogenic compounds in food

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Anticarcinogenic compounds in food

• Non-nutritive ingredients phytochemicals

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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?

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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

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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

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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

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Is More Better?
Choose Food First
Avoid Overdosing
Avoid Self Prescribing
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Berries (sources of vitamin C, E, carotinoids,
flavonoids, phytoestrogenes and other
phytochemicals)
blackberry
cloudberry
cranberries
blackthorn
raspberry
gooseberry
dogberry
huckleberry
loganberry
strawberry
blackcurrant
redcurrant
blueberry
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Spices and cancer (data based on human
epidemiologic studies and animal experiences)

• Italy chilli, cinnamon, clove, pepper, nutmeg
• gt ? gastric cancer

ánizs
France and other mediterranian countries anise,
curry, ginger, mustard, paprika, pepper, allspice
gt ? bladder cancer
szegfubors
Garam masala (mixture of pepper, clove, cinnemon,
nutmeg, ginger, cardamom, caraway, laurel) gt ?
cancer incidence after DMBA treatment
babér
kömény
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Walnuts and oleaginous seeds (high amount of
vitamin E, selenium, ellagic acid, phytic acid,
phytoestrogenes gt protective effect)
walnut
hazelnut
almond
pine seeds
pistachio
sunflower seed
sesame seed
pumpkin seed
poppy-seed
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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

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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

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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

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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

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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

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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

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Antioxidants

• Flavonoid supplements have not been proved
  effective or safe
• As for red wine, the potential health benefits
  may not be worth alcohols immediate and
  substantial risk
• Other sources
• Blueberries
• Tea
• Grapes
• Vegetables

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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

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Tea

• Calorie Free
• 87 of dietary flavonoids consumed
• Antioxident polyphenols including flavonoids
• Catechin
• EGCG
• Proanthocyanidins

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Cancer

• Protects against free radical damage
• Decrease growth of abnormal cells
• Associated with decreased risk of rectal, colon
  and skin cancer

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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

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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

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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

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Chocolate

• Chocolate consumption promotes weight gain
• Three ounces of sweetened chocolate candy contain
  over 400 calories
• A significant portion of most peoples daily
  calorie allowance
• Chocolate contributes few nutrients save fat and
  sugar

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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

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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

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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

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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

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Soybeans

• We know with certainty that phytoestrogens are
  plant-derived chemical relatives of the human
  hormone estrogen
• They weakly mimic or modulate the hormones
  effects on some body tissues
• They act as antioxidants

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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 womens risk of cervical
  cancer and many other diseases

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Tomatoes

• A lesson about supplements can be learned from
  experience with lycopenes 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

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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

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Garlic

• Among garlics 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

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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

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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

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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 garlics
  characteristic odor
• But is rich in antioxidants and other compounds
• From the scientists point of view, no evidence
  that large doses of concentrated chemicals from
  garlic may improve a persons health or injure it

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• 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

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What do we tell consumers?

• Eat more fruit
• Increase vegetable portions
• Use herbs and spices
• Replace some meat
• Add grated vegetables
• Try new foods

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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
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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
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• Scientific publications
• Questions

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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.
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FIG. 1. STRUCTURES OF FARNESOL AND LANOSTEROL
FARNESOL
LANOSTEROL
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APOPTOSIS INDUCTION BY S-ALLYLCYSTEINE, A GARLIC
CONSTITUENT, DURING 7,12-DIMETHYLBENZAANTHRACEN
E-INDUCED HAMSTER BUCCAL POUCH CARCINOGENESIS.
INDOLE-3-CARBINOL HAS POSSIBLE ANTICARCINOGENIC
ACTIVITY
TOMATO AND GARLIC CAN MODULATE AZOXYMETHANE-INDUCE
D COLON CARCINOGENESIS IN RATS
IDENTIFICATION OF POTENTIAL ARYL HYDROCARBON
RECEPTOR ANTAGONISTS IN GREEN TEA
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Phytochemicals Foodstuffs (fruits, vegetables)
Ditions (isothiocyanate, benzyl-isothiocyanate, phenyl-ethyl-isothiocyanate, sulforaphan) Brassicas, peas
Terpenoids (D-limonene, geraniol, menthol, carvone) Citruses
Flavonoids - kvercetin - kemferol, tangeretin, nobiletin, rutin Generally all vegetables and fruits berries, tomato, broccoli, onion - savoy cabbage, endivia, citruses, horse-radish
Phenols (ellagic acid) Tea, fresh harvested fruits and vegetables, walnuts, berries
Glucosinolates, indoles Brassicas
Sterols (beta-sitosterol, campesterol, stigmasterol) Vegetables
Coumarine compounds Manioc, citruses
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Fruits and Vegetables The Real Thing
Matters!Being Fit with Phytochemicals
One of sources of the lecture

• Mollie Smith, MS, RD
• California State University, Fresno
• Department of Food Science and Nutrition