What is a carcinogen? A carcinogen is a substance or agent known

to cause cancer or produces an increase in incidence of cancer in animals or humans

Carcinogens may be chemical substances; physical agents, UV radiation; or biological agents, such as certain viruses and bacteria

carcinogenic substances may be inhaled, absorbed through the skin or ingested.

A carcinogen can alter or damage a cell’s DNA… A carcinogen may be the initiator —

the agent that alters or damages DNA, the basic coding system of cells

It may also be promoter — encouraging out-of-control cell growth

The different states of the cell cycle

Cancer

Cancer refers to a number of diseases characterized by uncontrolled growth and spread of abnormal cells.

Carcinogenesis Pathogenesis of cancer is complex It is a genetic disease- either

acquired genetic abnormality or inherited genetic abnormality

It arises when several mutations accumulate within genome

Path

ogen

esis

Acquired environmental factorschemicals ,radiation ,viruses

Changes in genome of somatic cells

Activation of growth promoting oncogenes

Inactivation of cancer suppressor genes

Expression all altered gene products and loss of regular gene products

MALIGNANT NEOPLASM

Genetic factors

Cancer is a global concern Cancer incidence is on the rise

worldwide World Health Organization estimates

that 80 per cent of cancers are caused by occupational or environmental factors, including exposure to hazardous chemicals

Chemicals the worst culprits Chemical substances

constitute the largest group of carcinogens

New chemical substances are being developed every year, often without prior testing on their potential toxic effects

International research trackingdown carcinogenic substances

International agencies such as the UN’s International Agency for Research on Cancer (IARC), are continually updating lists of known and suspected carcinogens.

International Agency for Research on Cancer www.iarc.fr

California’s Proposition 65

Natural carcinogens

How much do natural plant carcinogens contribute to the incidence of cancer in human populations?

The answer is still unknown, but the National Research Council has reported that excess calories pose more of a cancer threat than natural or synthetic carcinogens in food

The answer is still unknown. Why? The huge number and complexity of naturally

occurring compounds . So far, chemists have tested only a fraction of

this huge number of natural compounds particularly in food.

The limitations of the process by which we test a compound to see if it causes cancer (feeding it in relatively high doses to hundreds of laboratory animals)

Naturally-occurring Carcinogens Aflatoxins and Ochratoxin A are natural toxins made by

fungal food contaminants cause cancer in animals and humans.

Safrole, which is found in sassafras tea, cinnamon, cocoa (trace), nutmeg, and other herbs and spices is a liver carcinogen in rats.

Heterocyclic amines in cooked meats have been associated with stomach and other cancer formation.

Aristolochic acids found in different species of the genus Aristolochia are reported as carcinogenic.

Asbestos (naturally occurring silicate mineral with long, thin fibrous crystals) increases the risk of lung cancer.

Tobacco smoke (lung cancer), alcohols (liver cancer).

Cancer prevention by phytochemicals

Phytochemicals appear to have the ability to stop the conversion of a cell from healthy to cancerous at different stages.

Antioxidants stop free radicals (reactive oxygen species, ROS) from harming a healthy cell

Plant defenders can slow the process from precancer to cancer

ROS and various stages of carcinogenic process

Cancer protective and anticancer plants

Garlic Organosulfur compounds originating from

garlic inhibit carcinogen activation, boost phase 2 detoxifying processes, cause cell cycle arrest mostly in G2/M phase, stimulate the mitochondrial apoptotic pathway,

CURCUMA (Turmeric)

Curcumin, a natural component of the rhizome of curcuma has emerged as one of the most powerful chemopreventive and anticancer agents.

Its biological effects range from antioxidant, anti-inflammatory to inhibition of angiogenesis

Ginger

It is a common condiment for various foods and beverages.

Some pungent constituents (gingerol, zingerone and paradol ) present in ginger exhibit cancer preventive activity.

Liquorice

Isoliquiritigenin (ISL), a flavonoid found in licorice, has been identified as a potent anti-tumor promoting agent

Ginseng root

Ginsenoside 20(S)-protopanaxadiol, a metabolite of ginseng, may be applied as a potential therapeutic agent in the prevention and treatment of cancer.

Fenugreek

A naturally occurring edible spice as an anticancer agent.

The extract from the seeds of fenugreek, is cytotoxic in vitro to a panel of cancer but not normal cells.

Green tea Epidemiologic studies show an inverse relationship between

consumption of tea, especially green tea, and development of cancers.

Numerous in vivo and in vitro studies indicate strong chemopreventive effects for green tea and its constituents against cancers of various organs.

(-)-Epigallocatechin-3-gallate (EGCG), the major catechin in green tea, appears to be the most biologically active constituent in tea with respect to inhibiting cell proliferation and inducing apoptosis in cancer cells.

Flaxseed oil

Flax lignans belonging to the phytoestrogens are metabolised after ingestion into enterolignans that may offer a protection against the onset and development of hormono-dependant cancers.

sesame seed The mammalian lignans, which are produced

by the microflora in the colon of humans and animals from precursors in foods, have been suggested to have potential anticancer effects

Sesame seed, alone and in combination with flaxseed, produces mammalian lignans equivalent to those obtained from flaxseed alone.

Soybean It has been reported that populations

consuming high levels of soybean products have both lower cancer incidence and mortality rates in the western countries.

The soy isoflavones have antiproliferative effects on a variety of cancer types.

Lunasin of soy is a novel seed peptide for cancer prevention.

Recent studies have demonstrated a direct effect of soy saponins on cancer cells

Soybean Genistein is an isoflavone with oestrogenic activity that

is present in a variety of soy products as a constituent of complex mixtures of bioactive compounds.

Genistein can act as an oestrogen agonist resulting in proliferation of E-dependent human breast cancer tumours in vivo and its activity can be modulated by the presence of other bioactive compounds.

A large, population-based, prospective cohort study provided strong evidence of a protective effect of soy food intake against premenopausal breast cancer.

Cruciferous vegetables Indole-3-carbinol (I3C), a naturally

occurring compound found in vegetables of the Brassica genus, such as broccoli and cabbage, is a promising anticancer agent shown to induce a G(1) cell-cycle arrest in the cells of human lymph node carcinoma of prostate.

Cruciferous vegetables decreased the risk of breast cancer by 40 percent.

Tomato Epidemiological studies have provided evidence that

high consumption of tomatoes effectively lowers the risk of reactive oxygen species (ROS)-mediated diseases such as cardiovascular disease and cancer by improving the antioxidant capacity.

Tomatoes are rich sources of lycopene, an antioxidant carotenoid reported to be a more stable and potent singlet oxygen quenching agent compared to other carotenoids

Tomato Lycopene shows an array of biological

effects including cardioprotective, anti-inflammatory, antimutagenic and anticarcinogenic activities.

The anticancer activity of lycopene has been demonstrated both in in vitro and in vivo tumour models.

Wheat germ and whole grains

Tocotrienols are naturally occurring isoprenoid compounds highly enriched in palm oil, rice bran, oat, wheat germ, barley and rye.

Tocotrienols have antioxidant properties as well as potent anticancer properties.

Fibers in the bran is colon-protective

Citrus fruits Epidemiological and animal studies

suggest that flavonoids (hesperidin) have a protective effect against cardiovascular diseases and some types of cancer.

Limonoids are a prominent group of secondary metabolites in citrus fruit with anticancer effect

Spinach leaves Spinach leaves, containing several active components,

including flavonoids, exhibit antioxidative, antiproliferative, and antiinflammatory properties in biological systems.

Spinach extracts have been demonstrated to exert numerous beneficial effects, such as central nervous system protection and anticancer and antiaging functions.

The glycolipids fraction from spinach is potentially a source of food material for a novel anticancer activity

Strawberry The most abundant phytochemicals are ellagic

acid, and certain flavonoids: anthocyanin, catechin, quercetin and kaempferol

Compounds in strawberries have demonstrated anticancer activity in several different experimental systems, blocking initiation of carcinogenesis, and suppressing progression and proliferation of tumors.

Change your lifestyle to be more protected It has been estimated that 30-40 percent

of all cancers can be prevented by lifestyle and dietary measures alone.

Try to avoid carcinogens and factors increasing cancer risk.

Have more cancer protective substances and be physically active.

Factors increasing cancer risk

Obesity. Nutrient sparse foods such as concentrated

sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes).

Low fiber intake. Consumption of excess red meat, saturated

fats & the imbalance of omega 3 and omega 6 fats.

Regular consumption of alcohol and tobacco

Types of Free Fatty AcidsTypes of Free Fatty Acids SaturatedSaturated

Fatty acids are Fatty acids are saturatedsaturated with with hydrogen molecules hydrogen molecules

Semi-solid or solid at room Semi-solid or solid at room temperaturetemperature

MonounsaturatedMonounsaturated (omega-9) (omega-9) Fatty acid contains one double Fatty acid contains one double

bondbond Liquid at room temperatureLiquid at room temperature

PolyunsaturatedPolyunsaturated (omega-6 & (omega-6 & omega-3)omega-3) Fatty acid contains 2 or more Fatty acid contains 2 or more

double bondsdouble bonds Liquid at room temperatureLiquid at room temperature

HydrogenatedHydrogenated Industrial hardening of edible Industrial hardening of edible

oils to make products hard at oils to make products hard at room temperatureroom temperature

Essential Fatty Acids (EFA)Essential Fatty Acids (EFA) Omega-6 Dietary Sources:Omega-6 Dietary Sources:

Sunflower oil, safflower oil, cottonseed oil, corn oil, & Sunflower oil, safflower oil, cottonseed oil, corn oil, & processed foods made with these oils.processed foods made with these oils.

Omega-3 Sources:Omega-3 Sources:Cold-water fish (i.e., salmon, trout, sardines, herring), Cold-water fish (i.e., salmon, trout, sardines, herring),

flaxseed, walnuts, pumpkin seeds, canola oil, & soybeans.flaxseed, walnuts, pumpkin seeds, canola oil, & soybeans.

Omega-9 Fatty AcidsOmega-9 Fatty Acids Olives, extra-virgin olive oil, canola oil, avocadoes, sesame & Olives, extra-virgin olive oil, canola oil, avocadoes, sesame &

almonds.almonds.

Have more cancer protective substances Vegetables, fruits, whole grains, herbs,

nuts and seeds contain an abundance of phenolic compounds, terpenoids, sulfur compounds, pigments, and other natural antioxidants that have been associated with protection from and/or treatment of conditions such as cardiovascular disease and cancer.

Some valuable advice Enjoy fruit as a snack or dessert Add fruits to breakfast cereal Try whole-grain or multigrain toast and

sandwiches Eat three different colors of vegetables with

dinner Fill half of the dinner plate with vegetables Include salad with lunch

Some valuable advice Add sweet corn to salads Limit red meat to 3-4 serves each week

(a serve of meat is 65-100 grams) Choose fish, skinless chicken, legumes, eggs

or nuts on the other days Try a new vegetarian meal every week Limit processed meats Select foods low in fat Try a wide variety of vegetables and fruits.