NUTRITION AND CANCER- Role of antioxidants in Cancer - PowerPoint Presentation

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NUTRITION AND CANCER- Role of antioxidants in Cancer

Presented by:

N

avdeep

K

aur

Apoorva

Tandon

M.Sc.(Foods and Nutrition)3

rd

sem.Slide2

Contents…

Introduction

Biology of cancer

Causes of cancerFactors increasing cancer riskMetabolic effects of cancerTypes/Sites of cancerFree radicalsFormation of free radicalsFree radicals in biological systemAntioxidantsClassification of antioxidantsAbsorption of antioxidantsEnzymes as antioxidants in cellsPlasma antioxidantsCellular antioxidantsAntioxidant vitamins (A,C,E)NeutraceuticalsIsothiocyanates (Cruciferous vegetables)Allium foods( diallylsulfide)Chemotherapy

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INTRODUCTION

CANCER----->>> CRAB

2nd

leading cause of death.Age- a major determinant of riskCharacterized by– abnormal cell growthReproduction is unstructured and excessiveLeads to Tumor/ NeoplasmMore than 100 types known90% being due to avoidable factors3Slide4

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) 4Slide5

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 5Slide6

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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 antioncogenesOncogenes are the cancer causing genes.Cancer suppressor genes or antioncogenes regulate cell proliferation.*their loss removes growth control of cells

-->>several tumors7Slide8

Types of Tumors

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The growth of malignant

tumor is

a long , slow process that involves 3 key steps :Initiation of potentially cancerous changes in a cell’s DNA.

The promotion uncontrolled growth in a damaged cell.The progression of a cancerous lesion into a mass that can invade other tissues. 9Slide10

ETIOLOGY / CAUSES

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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

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CAUSES

CHEMICAL CARCINOGENS

RADIATION ENERGYVIRUSES12Slide13

CHEMICAL

CARCINoGENS

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)13Slide14

Chemicals

Occupation

Life style

DrugsDiet14Slide15

Promoters of carcinogenesis

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.

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RADIATION

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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.17Slide18

Carcinogenic viruses

ROUS /1911

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Tumor inducing virus, interfering with the function of regulatory genes have been identified.

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Disease viruses act as parasites, taking over the

the

cell machinery to reproduce themselves.

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Stress factors

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Stressful states make a person more vulnerable to other cancer producing factors through their influence on the-

Integrity of the immune systemFood behaviorNutritional statusSlide22

FACTORS

Environmental

Carcinogenic chemicalsOccupationalFood contaminationSmokingPollutionInfectious agentsViruses

BacteriaFungi22Slide23

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Types of cancerSlide24

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MOUTH/ PHARYNX CANCER

MOUTH CANCERSlide25

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 25Slide26

MECHANISM-:

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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.

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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.

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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.30Slide31

The role of colonical microbial flora is central To the causation of cancer. the flora is large & diverse & dependent on residues for nutrition.

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STARCH

SUGAR

CHOAnaerobic fermentationSlide34

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MECHANISM:

CHO having no. of implications for protection agents large bowel cancer.

Increase stool weight.Dilution of colonical contents in gut.Faster transit time .35Slide36

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.

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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.38Slide39

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 menopauseLate 1st pregnancy

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METABOLIC EFFECTS

Cancer cachexia

In advance disease ,this complex metabolic syndrome is a major cause of morbidity & mortality.AnorexiaEarly satietyWeight lossWastingWeakness ,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.40Slide41

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.41Slide42

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.

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Restrict spicy foods

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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/kgIf 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.44Slide45

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 :to replace gastrointesinal losses from fever, infection, vomitting or diarrhoea.

To help kidneys dispose off metabolic breakdown products from destroyed cancer cells and from toxic drugs used in chemotherapy.45Slide46

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.

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Medical treatments

Three major forms of therapies are used today as medical treatment for cancer:

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.

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Impact of surgery

SITE

SYMPTOMSOral cavity

Difficulty in chewing and swallowingSore mouthAlterations in taste and smellLarynx Alterations in normal swallowing Lung Shortness of breathStomach DehydrationEarly satietyPancreas Hyperglycemia Vitamin and mineral malabsorption48Slide49

Nutritional therapy for this treatment

Nutritional supplements drinks

Enteral nutrition (feeding through a tube into the stomach or intestine)Medications to improve the appetite49Slide50

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.50Slide51

Impact of Radiation Therapy

SITE

SYMPTOMSBrain and spinal cord

NauseaVomiting FatigueHeadache , lethargyLarynx Sore mouth and tongueAlterations in taste and smellUlcerationThoraxDysphagiaHeartburnLoss of appetiteDry coughAbdomen and pelvisLactose intoleranceLoss of appetiteDiarrhoeaMaldigestion 51Slide52

Nutritional therapy

Nutritional supplements

Eating small mealsEnteral nutrition 52Slide53

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.

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Impact of chemotherapy

CYTOTOXIC DRUGS

SYMPTOMSAnorexa

Vomiting FatigueNauseaVomiting DiarrhoeaFatigueGlucose intoleranceOsteoporosisNauseaFluid retentionHot flashesNausea 54Slide55

Free Radicals and Antioxidants

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OXYGEN Existence

Toxic and damages tissues [ Not synonyms ] Free

radical 1 or more unpaired electrons in its outer orbit( R )Electron imbalanceHigh reactivityFor more stable species, eg. NO, NO2Oxygen free radicals / Reactive oxygen species (ROS)56High concentrationsSlide57

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Generation of ROS Antioxidant

defencesSlide58

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Formation of Free Radicals

By-products of aerobic cellular metabolism

O2 + e- O2 - (Superoxide radical)59Slide60

a) o

2

+ e- 02- (superoxide radical)b) Fe2+ + 02 Fe 3++ o2

- (superoxide radical)c) o2- +e- + 2H+ H2O2d) o2- + o2- + 2H+ H2O2 + O2e) H2O2 + e- +2H+ H2O + OH (hydroxyl radical) f) Fe 2+ +H2O2 Fe 3+ + OH- + OH g) o2- + H2O2 O2 + OH - + OH

Fe salt catalyst

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BACKSlide61

Common characteristic features of free radical are:

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Free Radicals in Biological System

B

C

Non-radical

Non-radical

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OH

-

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Damage to thousands of fatty acid molecules

&

Formation of Fatty acid peroxyl radicals

Lipids , proteins, nucleic acids64Slide65

Anti-oxidants in Biological System

Substance that significantly delays or inhibits oxidation of a substrate.

Scavengers of free radicals Oxidation is a

chemical reaction that transfers electrons from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When the chain reaction occurs in a cell, it can cause damage or death. 65Slide66

Classification of Anti-oxidants

Lipid

peroxidation--

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Nature and action--

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Location--

Intracellular anti-oxidants

Catalase

, glutathione

peroxidase

, superoxide dismutase

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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.69Slide70

Vitamin E: Absorbed along with fat in the small intestine

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Important Cancer Antioxidants

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Anti-oxidant Vitamins(A,C,E) and cancer

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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.Slide74

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Inverse associations between:

Low intake of

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Antioxidants are abundant in fruits and vegetables, as well as in other foods including nuts, grains, and some meats, poultry, and fish.Slide77

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

77Production of H2O2 at toxic rateSlide78

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+ 2H2O78Slide79

Plasma Antioxidants

Most important antioxidant proteins of plasma include---

Bilirubin (bound to albumin) and uric acid are good scavengers of oxyradicals.

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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.

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Hghj

Free radicals

Precarcinogens 81

DNAVitamin E,C; carotenes; tea; tomatoes.Carcinogens Phase 1 Garlic etc. inhibit this reaction

DNA damage

Inactive compounds

Cauliflower, broccoli etc. stimulate this reactionSlide82

Allium foods

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Allium vegetables are members of the lily family and include: Garlic Onion Leeks Slide83

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