Presented by: Navdeep Kaur Apoorva Tandon M.Sc.(Foods and
Nutrition)3 rd sem.
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1. Introduction 2. Biology of cancer 3. Causes of cancer 4.
Factors increasing cancer risk 5. Metabolic effects of cancer 6.
Types/Sites of cancer 7. Free radicals 8. Formation of free
radicals 9. Free radicals in biological system 10. Antioxidants 11.
Classification of antioxidants 12. Absorption of antioxidants 13.
Enzymes as antioxidants in cells 14. Plasma antioxidants 15.
Cellular antioxidants 16. Antioxidant vitamins (A,C,E) 17.
Neutraceuticals 18. Isothiocyanates (Cruciferous vegetables) 19.
Allium foods( diallylsulfide) 20. Chemotherapy 2
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INTRODUCTION CANCER----->>> CRAB 2 nd leading cause of
death. Age- a major determinant of risk Characterized by abnormal
cell growth Reproduction is unstructured and excessive Leads to
Tumor/ Neoplasm More than 100 types known 90% being due to
avoidable factors 3
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Biology of Cancer By Development of cells, : escaped normal
regulation of growth, :normal replication and differentiation
:which invades surroundings. Cellular and tissue
integrity,>>>> series of processes :cell division and
DNA replication :growth and differentiation :apoptosis(cell death)
4
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Cancer develops when---- cells acquire the ability to escape
that regulation. Cancer cells display characteristics/ capabilities
(not present in normal cells) which affects :cell growth
:replication :interaction with neighboring cells :interaction with
environment 5
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Genetic change in single cell, its uncontrolled multiplication.
The 2 Types of regulatory genes involved in the development of
cancer: oncogenes antioncogenes Oncogenes are the cancer causing
genes. Cancer suppressor genes or antioncogenes regulate cell
proliferation. *their loss removes growth control of
cells-->>several tumors 7
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Types of Tumors Benign Do not spread Can be often removed
Malignant Spread to other parts of the body Difficult to remove
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The growth of malignant tumor is a long, slow process that
involves 3 key steps : 1. Initiation of potentially cancerous
changes in a cells DNA. 1. The promotion uncontrolled growth in a
damaged cell. 1. The progression of a cancerous lesion into a mass
that can invade other tissues. 9
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ETIOLOGY / CAUSES 10
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A cause of any disease is any usual exposure that, if removed,
reduces the likelihood of the disease developing, or its severity.
-A factor that alone can result in disease is called sufficient
cause; if more than one factor is required,these are termed as
contributory causes; if a disease cannot occur in the absence of a
factor, then necessary cause. 11
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CAUSES CHEMICAL CARCINOGENS RADIATION ENERGY VIRUSES 12
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Almost 80% of human cancers are caused by chemical carcinogens
in nature. Entry 0f chemical in body may be due to. Occupation
(asbestos,benzene) Diet (contaminated food) Drugs
(diethylstilbestrol) Life style(smoking) 13
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Chemicals Occupation Life style DrugsDiet 14
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Some of chemicals on their own are not carcinogenic. Certain
substances known as promoting agents make them carcinogenic.
Example:Application of benzo-(a)pyrene to the skin, as such not
cause tumor development, however if this is followed by the
application of croton oil, tumors develop.here,croton oil acts as a
promoting agent or promoter. 15
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RADIATION 16
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Radiation damage to genes may come from x-rays, radio active
materials, atomic exhausts or wastes, or from sunlight. UV rays,
X-rays and gamma-rays have been proved to be causing cancers. These
rays damage DNA which is the basic mechanism to explain the
carcinogenicity of radiation energy. X-rays cause the production of
free radicles,which is responsible for the carcinogenic effects of
radiation. 17
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Carcinogenic viruses ROUS /1911 18
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Tumor inducing virus, interfering with the function of
regulatory genes have been identified. 19
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Disease viruses act as parasites, taking over the the cell
machinery to reproduce themselves. 20
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Stress factors 21 Stressful states make a person more
vulnerable to other cancer producing factors through their
influence on the- Integrity of the immune system Food behavior
Nutritional status
MOUTH/ PHARYNX CANCER Accounts for about 6% worldwide, common
in developing countries. Salted fish consumption enhances the risk
of nasopharynx cancer & betel nut chewing that of oral cancer.
Excessive consumption of alcohol & smoking enhance risk of
cancer in all sites. Fruit has a protective role in these cancers,
according to study. Effect of vegetable is less consistent 25
OESOPHAGUS CANCER Its very according to nutritional status of
people. Obesity, Alcohol & smoking are most important factor.
Obesity might leads the increasing rates of tumor, and may be
affect the gastro esophageal. Poorly stored corn by toxin from
fungus also cause this. fruits and vegetables are good in lowering
the risk. 27
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STOMACH CANCER Its about 2-4% every year. Rates in men are
double than women. High salt consumption is a causative factor.
Fruit &vegetables lower 50% risk. Highest rates in Japan.
Lowest rates in Gambia & Kuwait. 28
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Beta carotene Vitamin E Selenium Low Stomach cancer 29
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LARGE BOWEL CANCER Second most cancer in many societies. Affect
up to 6% of men & women by age of 75. Highest risk in
Australia, new Zealand,USA,parts of N.Europe. Lower risk in Africa,
China& INDIA. It is strongly +vely associated with fat meat
consumption. Strongly vely associated with starch& vegetables
consumption. In men overweight is also at risk. Exercise reduce the
risk at some level. 30
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The role of colonical microbial flora is central To the
causation of cancer. the flora is large & diverse &
dependent on residues for nutrition. 31
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33 STARCH SUGAR CHO Anaerobic fermentation
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SCFA Acetate propionate Butyrate Increase in microbial cell
mass 34
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MECHANISM: 1. CHO having no. of implications for protection
agents large bowel cancer. Increase stool weight. Dilution of
colonical contents in gut. Faster transit time. 35 Low stool weight
Constipation cancer
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2.One of the SCFA butyrate is of particular interest because It
is anti proliferative agent. Arresting cell growth. Inducing
differentiation in cell lines. 3.Studies shown that BRAN appeared
to have consistency protective affect against chem- carcinogensis.
Soluble fiber are associated with tumor enhancement. 36
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37 Fat Bile acid flora Deoxycholic acid cancer
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LUNG CANCER The most common cancer in the world. Cause
cigarette smoking. HYPOTHESIS: lung cancer risk can be suppressed
by beta-carotene & vitamine,found in fruit & vegetables by
studies. 38
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BREAST CANCER Commonest cancer in women. Risks increases with
age, but there is a decreases rate of increases in incidence after
the menopause. Early menopause Late menopause Late 1 st pregnancy
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METABOLIC EFFECTS Cancer cachexia In advance disease,this
complex metabolic syndrome is a major cause of morbidity &
mortality. Anorexia Early satiety Weight loss Wasting
Weakness,characterize the syndrome. Alteration in
energy,CHO,proteins and fat metabolism, acid base balance,enzyme
activities,enodocrine homeostasis& immunologic states are seen.
Metabolic rate usually increases in leukemia. 40
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Impaired glucose tolerance Decreased insulin production Insulin
resistance. Skeletal muscle mass is reduced. Hypoalbuminemia.
Negative nitrogen balance in spite of sufficient intake. Urinary
excretion of Na & K is increased. 41
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ANOREXIA Frequent finding in advanced cancer. Weight loss is
due to reduction in food intake associated with anorexia.
Alteration in taste & smell are advance in cancer. Some having
increase threshold for sweet or sour taste. Some additives make
food more acceptable to these patients Subsection of protein
sources so that protein intake is not compromised. 42
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Nutritional Needs Energy Hypermetabolic nature and its healing
requirements place greater energy demands on the cancer. Adult
patient---- 2000 kcal or 25-30 kcal/kg If malnourished----
2500-3000 kcal or 35-40 kcal/kg, or more, depending on the extent
of tissue injury. Protein Necessary tissue building for healing and
to offset tissue breakdown by the disease requires essential amino
acids and nitrogen. Adult patient----80-100 gm ( high quality) If
malnourished----100-150 gm, to restore negative nitrogen balance.
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Vitamins and minerals - They also play important role in
building and maintaining strong tissue. Thus an optimal intake of
vitamins and minerals is needed. Fluid Adequate fluid must be
ensured for : i. to replace gastrointesinal losses from fever,
infection, vomitting or diarrhoea. ii. To help kidneys dispose off
metabolic breakdown products from destroyed cancer cells and from
toxic drugs used in chemotherapy. 45
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Fiber Dietary fiber is postulated to exert a protective effect
against colon cancer by several mechanisms. It has a possible role
in prevention of colon cancer by decreasing transit time, so that
in contact with the colon for a shorter time which reduces the
contact of carcinogens in the colon wall. Selenium- high levels of
selenium intake have been found to be anti tumorigenic. It has been
found to be beneficial in the fight against free radicals. Sea
foods, grains, muscle meats have the highest concentrations of
selenium. 46
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Medical treatments Three major forms of therapies are used
today as medical treatment for cancer: 1. Surgery an operation to
remove or repair part of the body to diagnose or treat cancer. May
be used as the only mode or in combination chemotherapy or
radiation therapy. 47
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Impact of surgery SITESYMPTOMS Oral cavity Difficulty in
chewing and swallowing Sore mouth Alterations in taste and smell
Larynx Alterations in normal swallowing Lung Shortness of breath
Stomach Dehydration Early satiety Pancreas Hyperglycemia Vitamin
and mineral malabsorption 48
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Nutritional therapy for this treatment Nutritional supplements
drinks Enteral nutrition (feeding through a tube into the stomach
or intestine) Medications to improve the appetite 49
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2. Radiation therapy It is a cancer treatment that uses high
energy X- rays or other types of radiation to kill cancer cells.
Most severely it damages the cells that are actively dividing and
making new DNA such as tumor cells. 50
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Impact of Radiation Therapy SITESYMPTOMS Brain and spinal cord
Nausea Vomiting Fatigue Headache, lethargy Larynx Sore mouth and
tongue Alterations in taste and smell Ulceration Thorax Dysphagia
Heartburn Loss of appetite Dry cough Abdomen and pelvis Lactose
intolerance Loss of appetite Diarrhoea Maldigestion 51
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Nutritional therapy Nutritional supplements Eating small meals
Enteral nutrition 52
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3. Chemotherapy It is the use of chemical agents or medications
to treat cancer. Cytotoxic drugs destroy cancer cells by
interfering with the synthesis and function of nucleic acids in the
cells. Healthy cells can also be damaged. Bone marrow, hair
follicles, and mucosa of the alimentary tract are most susceptible
to damage. 53
OXYGEN Existence Toxic and damages tissues [ Not synonyms ]Not
synonyms Free radical 1 or more unpaired electrons in its outer
orbit( R ) Electron imbalance High reactivity For more stable
species, eg. NO, NO2 56 High concentrations
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57 Generation of ROS Antioxidant defences Superoxide [O2]
Hydroxyl radical [OH] Singlet oxygen [O2] Hypochlorous acid
[HOCl]
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Antioxidants in Food Neutralize free radicals in food
Protection from diseases 58
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Formation of Free Radicals By-products of aerobic cellular
metabolism O2 + e - O 2 - (Superoxide radical) Free radicals
Environmental pollutants OzoneSunlight 59
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a) o 2 + e - 0 2 - (superoxide radical) b) Fe 2+ + 02 Fe 3+ + o
2 - (superoxide radical) c) o 2 - +e - + 2H + H2O2 d) o 2 - + o 2 -
+ 2H + H2O2 + O2 e) H2O2 + e- +2H+ H2O + OH (hydroxyl radical) f)
Fe 2+ +H2O2 Fe 3+ + OH - + OH g) o 2 - + H2O2 O2 + OH - + OH Fe
salt catalyst 60 BACK
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Common characteristic features of free radical are: Highly
reactive Very short half life Can generate new radicals by chain
reaction Cause damage to biomolecules, cells and tissues 61
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Free Radicals in Biological System ABA B BCB C Non-radical 62
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Damage Protein Breakage of DNA strands Initiate lipid
peroxidation OH - 63
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Damage to thousands of fatty acid molecules & Formation of
Fatty acid peroxyl radicals Lipids, proteins, nucleic acids 64
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Anti-oxidants in Biological System 65
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Classification of Anti-oxidants Lipid peroxidation-- 66
Absorption of Antioxidants Vitamin A: Vitamin C: Rapidly
absorbed from the intestine. It is not stored in the body to a
significant extent and is excreted in the urine as such. 69
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Vitamin E: Absorbed along with fat in the small intestine
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Important Cancer Antioxidants 72 Vitamin status Risk for
cancer
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Anti-oxidant Vitamins(A,C,E) and cancer 73 Low intakes of
vitamin A from fruits and vegetables or low levels of retinoids
resulted in increased risk for certain cancers. (esp. lung cancer)
The mechanism through which vitamins inhibit tumorigenesis has not
been explained, but 3 levels at which these act are known.
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as inhibitors of carcinogenic precursors. as blocking agents
preventing carcinogens from acting at a target site. as supressing
agents that diminish the effect of a carcinogen already present.
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Inverse associations between: Lung,Oral, esophageal, bladder,
reproductive, stomach cancer. Vitamin A Colon, esophageal, stomach,
lung,oral cancer. Vitamin C Lung, breast cancer. Vitamin E 75
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76 Antioxidants are abundant in fruits and vegetables, as well
as in other foods including nuts, grains, and some meats, poultry,
and fish.
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Enzymes as Antioxidants Superoxide dismutase (SOD) is one of
the important enzymes that function as cellular antioxidants.
Present in cell cytoplasm and in mitochondria. Catalyses
dismutation of superoxide anion, 2 O2 - + 2H + O2 + H2O2 77 Lethal
Absence Detrimental Too much Production of H2O2 at toxic rate
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Extracellular form of SOD exists in plasma, lymph and synovial
fluid. Functions at cell surfaces Catalase, is a heme protein that
catalyses the reaction in which H2O2 is detoxified 2H2O2 O2+ 2H2O
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Plasma Antioxidants Most important antioxidant proteins of
plasma include--- Bilirubin (bound to albumin) and uric acid are
good scavengers of oxyradicals. 79 CeruloplasminAlbuminTransferrin
HemopexinHaptoglobin
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Neutraceuticals Foundation of Innovation in Medicine defined
them as--- Any substance considered a food or part of a food that
provides medical or health benefits, including prevention or
treatment of diseases. Food components trigger the enzymes that
block or supress DNA damage and reduce tumor size. 80
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Hghj Free radicals Precarcinogens 81 DNA Vitamin E,C;
carotenes; tea; tomatoes. Carcinogens Phase 1 Garlic etc. inhibit
this reaction DNA damage Inactive compounds Cauliflower, broccoli
etc. stimulate this reaction
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Allium foods 82 Allium vegetables are members of the lily
family and include: Garlic Onion Leeks