Toxicology and Nutrition

Diet is one of the most important factors influencing Diet is one of the most important factors influencing human health through the whole lifehuman health through the whole life..

Human health can be affected:Human health can be affected:

If toxic components are present in our food in amounts If toxic components are present in our food in amounts sufficient to induce adverse health effectsufficient to induce adverse health effect

If benefit micronutrients in our diet do not suffice to If benefit micronutrients in our diet do not suffice to prevent the adverse effectprevent the adverse effect

If the components in the diet interact in such a way that If the components in the diet interact in such a way that blockade the benefit effect or increase the toxic effect of blockade the benefit effect or increase the toxic effect of othersothers

Nutrition ToxicologyNutrition ToxicologyWhat is the content of nutrition

toxicology?

The intake of toxic compounds with food and the adverse health effects of exposure;

The quantitative and qualitative imbalance of macro- and micronutrients in the food (e.g. excessive amount of fat, insufficient amount of fibres, inappropriate saturation with antioxidants, relationship of copper and zinc…) The interaction of nutrients and toxic components in the food (e,g, between selenium and cadmium, among nutrients and medicaments, induction of enzymes with some chemical compounds, antimutagenic and anticarcinogenic effects of micronutrients etc.)

How can toxic compounds How can toxic compounds come into our diet?come into our diet?

Man-made Man-made (anthropogenic)(anthropogenic)

Natural originNatural origin

Food additivesFood additives Toxins of vegetable Toxins of vegetable originorigin

Food contaminantsFood contaminants Toxins in mushroomsToxins in mushrooms

- inorganic- inorganic MycotoxinsMycotoxins

- organic- organic Microbial toxinsMicrobial toxins

Component produced Component produced during the technological during the technological and cooking proceduresand cooking procedures

Toxins of animal originToxins of animal origin

Products of interactions Products of interactions in human bodyin human body

Food additives

• Definition:• Substances added to food for technological

reasons during production, processing, preparation, treatment, packaging, transport, and storage.

• Purpose:• To avoid the induction of microbial, chemical, or

physical changes in food or

• to improve appearance, consistency, taste, etc.

Purpose of Purpose of treatmenttreatment

Food additiveFood additive

Protection against changes caused by microbes

Preservative

Protection against chemical changes

Antioxidants, acids, acidity regulators

Protection against physical changes

Humectants, antifoaming agents, anticaking agents

Improvement of appearance Colour, colour stabilizers, glazing agents

Improvement of consistency Emulsifiers, gelling, firming, anticaking agents, thickeners, stabilizers

Improvement of taste Sweeteners, flavours, flavour enhancers

Food additivesFood additives

Food additives are only allowed if their use is considered Food additives are only allowed if their use is considered safe. safe. Additives have to be approved, and proof of their safety Additives have to be approved, and proof of their safety must be provided by appropriate studies.must be provided by appropriate studies.FAO/WHO Expert Committee on Food Additives (JECFA)FAO/WHO Expert Committee on Food Additives (JECFA)Scientific Committee on Food of the European Union Scientific Committee on Food of the European Union (SCF)(SCF)

NOEL, NOAEL, ADI (acceptable daily intake)NOEL, NOAEL, ADI (acceptable daily intake)ADIADI = the amount of a food additive, expressed in = the amount of a food additive, expressed in mg/kg body weight, that can be ingested daily over a mg/kg body weight, that can be ingested daily over a life time without appreciable health risklife time without appreciable health riskGRASGRAS = Generally recognised as safe (USA) = Generally recognised as safe (USA)In some countries, the definition and the list of In some countries, the definition and the list of permitted food additives vary.permitted food additives vary.Codex alimentariusCodex alimentarius Czech Rep. - Czech Rep. - regulations regulations of the Ministry of Healthof the Ministry of Health 52, 53/2002 Sb. 52, 53/2002 Sb.

Artificial sweetenersArtificial sweeteners

Foodstuffs with lower energetic content (ice-creams, nonalcoholic drinks etc.)

Sorbitol (E 420), xylitol (E 967), mannitol (E 421), laktitol (E 966)

Acesulfam K (E 950)Aspartam (E 951)Derivatives of cyclamic acid (E 952)Saccharin (E 954)Thaumatin (E 957)Neohesperidin (E 959)

Food contaminantsFood contaminants

DefinitionDefinition (according to the Codex Alimentarius): (according to the Codex Alimentarius): ““Food contaminants include any substance not Food contaminants include any substance not

intentionally added to food, which is present in such intentionally added to food, which is present in such food as a result of the production, manufacture, food as a result of the production, manufacture, processing, preparation, treatment, packing, processing, preparation, treatment, packing, packaging, transport or holding of such food, or as packaging, transport or holding of such food, or as a result of environmental contamination”.a result of environmental contamination”.

IncludeInclude: environmental chemicals, residues of : environmental chemicals, residues of pesticides, veterinary drugs, feed additives, and pesticides, veterinary drugs, feed additives, and substances migrating from food contact material.substances migrating from food contact material.

Food chain:Food chain: soil, water, air – vegetation – soil, water, air – vegetation – herbivorous animals – omnivorous animals - herbivorous animals – omnivorous animals - humanhuman

Food contaminantsFood contaminants

InorganicInorganic: toxic metals, nitrates, nitrites…: toxic metals, nitrates, nitrites…

OrganicOrganic: : Persistent chlorinated organic compounds (PCBs, Persistent chlorinated organic compounds (PCBs,

dioxins, pesticides – DDT, HCH, HCB, dioxins, pesticides – DDT, HCH, HCB, polybrominated dibenzoethers etc.), insecticides, polybrominated dibenzoethers etc.), insecticides, herbicides etc.herbicides etc.

PhthalatesPhthalates

Polycyclic aromatic hydrocarbonsPolycyclic aromatic hydrocarbons

MycotoxinesMycotoxines

Microbial toxinsMicrobial toxins

Toxic metalsToxic metals

CadmiumOccupational exposure (inhalation) –

environmental exposure (oral)Phosphate fertilisers - soil

contamination - vegetable (mostly root), cereals, rice, mushrooms.

Smoking (20 cig./day > average daily uptake with food)

Japan Water from lead – zinc – cadmium mines has been directed into a river used for irrigating rice fields.

Itai Itai – pain in the bones and joints, damage of kidney tubules = proteinuria, hypercalcuria, transport of calcium from the bones, osteomalacia.

Biomarker of body burden: Cd in blood (recent exposure), in urine (cumulated exposure).

CadmiumCadmium

Cadmium - toxicologyCadmium - toxicology

• Extremely long half-life period. Accumulation in the kidneys. Critical concentration in the renal cortex is estimated to be 200 mg Cd/kg

• Carcinogen for human (IARC, group 1). Affinity for prostate tissue.

• Cd does not substantially cross the placenta. The Cd body burden increases continuously with age and reaches its maximum at about 50 years.

• Association of exposure with atherogenesis• Interaction with selenium and zinc

MercuryMercuryElementary mercury – inorganic salts – organic Elementary mercury – inorganic salts – organic

compoundscompounds Elemental mercuryElemental mercury – acute exposure – lung (bronchitis, – acute exposure – lung (bronchitis, pneumonia) CNS – tremor, excitability, gastroenteritispneumonia) CNS – tremor, excitability, gastroenteritisChronic exposure Chronic exposure Neurasthenia (micromercurialism) Neurasthenia (micromercurialism) Loss of sensation in the extremities, pareLoss of sensation in the extremities, paressthesis, in-thesis, in-coordination (ataxia), difficulty in speaking and hearing, coordination (ataxia), difficulty in speaking and hearing, eretism, delirium, hallucination. Stomatitis, gingival ulceration eretism, delirium, hallucination. Stomatitis, gingival ulceration Inorganic compoundsInorganic compoundsKidney – necrosis, polyuria, anuria, GIT – diarrhoeaKidney – necrosis, polyuria, anuria, GIT – diarrhoeaOrganic mercury compounds Organic mercury compounds (more dangerous) (more dangerous)Methyl mercury = possible human carcinogen, 2B according to Methyl mercury = possible human carcinogen, 2B according to IARC.IARC.Treatment of seed with fungicides containing mercuryTreatment of seed with fungicides containing mercuryLatency in days (Iraq epidemic – contaminated grains) or years Latency in days (Iraq epidemic – contaminated grains) or years (Minamata disease – contamination of fish).(Minamata disease – contamination of fish).

MercuryMercury

Minamata disease (Japan)Minamata disease (Japan)

1952-1960 – symptom of intoxication caused by 1952-1960 – symptom of intoxication caused by consumption of methyl mercury-contaminated fish from consumption of methyl mercury-contaminated fish from the Minamata bay area, which was heavily polluted by the Minamata bay area, which was heavily polluted by industrial waste discharges.industrial waste discharges.

25 cases of fetal and 31 cases of neonatal exposure were 25 cases of fetal and 31 cases of neonatal exposure were recorded and 13 of exposed children died.recorded and 13 of exposed children died.

IraqIraq

Consumption of bread made from seed grain containing Consumption of bread made from seed grain containing ethyl-Hg as a fungicideethyl-Hg as a fungicide

Neurological disorders, motor deficiency and behavioral Neurological disorders, motor deficiency and behavioral alterationalteration

The immature brain is especially vulnerableThe immature brain is especially vulnerable

MercuryMercury

General populationGeneral population

Amalgam in teeth filling – inorganic Hg Amalgam in teeth filling – inorganic Hg

Fish consumption – methyl HgFish consumption – methyl Hg

Risk – benefit of fish consumptionRisk – benefit of fish consumption

Pregnant womenPregnant women

Transplacental transport of metyl Hg to fetusTransplacental transport of metyl Hg to fetus

EFSAEFSA

LeadLeadSaturnism in the Roman EmpireAir – water – soil - foodEstimated daily lead intake and absorption

IntakeIntake AbsorptiAbsorptionon

FoodChildren <6 y

200-300 ug/d

10%42-50 %

20-30 ug/dCca 100 ug/d

Drinking water

> 20 ug/L 10%, 20 L/d

> 4 ug/d

Air 1 ug/m3 30%20m3/d

30-40 ug/d

Lead – toxic effectsLead – toxic effects

Acute toxicityAbdominal pain, nausea, constipation, diarrhoea, Capillary spasm, neurological changes, encephalopathy

Chronic toxicityHaematopoietic system – anaemiaGastrointestinal tractDisorders of both central and peripheral neurological systems

- encephalopathy Mental disorders, diminution of IQ in children Possible damage of kidney tubules, nephropathyImmunodepressionPossible carcinogenic effect - group 2B according to IARCThe lead content of bones increases with age

Children are more at risk than adults.

Lead – differences in absorptionLead – differences in absorption

Irregular food intake (fasting increases GIT absorption. PbIrregular food intake (fasting increases GIT absorption. Pb ingested without food is absorbed from 35 %, ingested ingested without food is absorbed from 35 %, ingested with food about 8 %)with food about 8 %)

High fat intake. High lecithin uptake in foodHigh fat intake. High lecithin uptake in food

Marginal calcium ingestion. Pb is known to mimic Ca in Marginal calcium ingestion. Pb is known to mimic Ca in various biological systems.various biological systems.

Subtle iron deficiency – increases Pb absorption, but not Subtle iron deficiency – increases Pb absorption, but not excretionexcretion

ArsenicArsenic

Component of some pesticidesComponent of some pesticides, , Drinking water wellsDrinking water wellsCumulation in seafoodCumulation in seafoodAcute toxicity – inhalative, oralAcute toxicity – inhalative, oralChronic toxicity – inhalative, oral Chronic toxicity – inhalative, oral ((Dermatological, neurologic, haematologicDermatological, neurologic, haematologic,, CVD, GITCVD, GIT disordersdisorders

Special toxicity:Special toxicity: reproduction, mutagenicity, reproduction, mutagenicity, Carcinogen for humans - group 1 (IARC)Carcinogen for humans - group 1 (IARC)

Urinary As concentrations are good indicators Urinary As concentrations are good indicators of exposureof exposure

Nitrates, nitritesNitrates, nitrites

Fertilisers, wastes - vegetable, drinking waterFertilisers, wastes - vegetable, drinking waterAdditive compound - processed meat - ham, Additive compound - processed meat - ham, sausagesausageReduction (bacterial) to nitrite - Reduction (bacterial) to nitrite - Infant Infant methaemoglobinaemia (blue child)methaemoglobinaemia (blue child) Production of nitrosamines Production of nitrosamines (reaction with secondary and tertiary amines)(reaction with secondary and tertiary amines)

Nitrosamines belong to the carcinogenic Nitrosamines belong to the carcinogenic compounds (stomach, oesophagus, colon, rectum, compounds (stomach, oesophagus, colon, rectum, urinary bladder)urinary bladder)

Nitrosamines

Nitrates

Nitrites

Infant methemoglobinemia

(+ amines)

Nitrosamines

Bacterial reductases

+ acidic pH

Vit. C, E

Persistent chlorinated organic Persistent chlorinated organic compounds:compounds:

Polychlorinated (polyhalogenated) biphenyles Polychlorinated (polyhalogenated) biphenyles (PCBs), dioxins, dibenzofurans(PCBs), dioxins, dibenzofurans, PBDE, PBDE

Chlorinated pesticides - DDT, HCB, Chlorinated pesticides - DDT, HCB, , , , , HCH, HCB, etc.HCH, HCB, etc.

Organochlorine pesticides Organochlorine pesticides

PhthalatesPhthalates

Organic contaminantsOrganic contaminants

EDC in the environmentEDC in the environment

The group of The group of „„enendocrine disrupting docrine disrupting chemcals - echemcals - evironmental estrogensvironmental estrogens““ represent a diverse group of chemicals represent a diverse group of chemicals that includes compounds that directly that includes compounds that directly modulate steroid hormone receptor modulate steroid hormone receptor pathways and aryl hydrocarbon receptor pathways and aryl hydrocarbon receptor (AhR(AhR) agonists: pesticides, PCB ) agonists: pesticides, PCB congeners and mixtures, fungal and plant congeners and mixtures, fungal and plant toxins, plasticizers, and alkylphenolstoxins, plasticizers, and alkylphenols..

Examples of chemical compounds in Examples of chemical compounds in the environment with ED functionthe environment with ED function

1.1. POPs (persistent organic pollutants - POPs (persistent organic pollutants - pesticipesticidesdes, PCB, PCBss, dioxin, dioxins, PAHs)s, PAHs), ,

2.2. MMyyccotoxinotoxinss (zearalenon, some (zearalenon, some fumonisins)fumonisins)

3.3. PhytoPhytotoxintoxins with ED functions with ED function (genistein) (genistein)

4.4. PPlasticizlasticizersers (phthalates)(phthalates)

5.5. Alkylphenols (Bisfenol A)Alkylphenols (Bisfenol A)

6.6. CadmiumCadmium

Persistent organic Persistent organic pollutantspollutants

• Chlorinated pesticides (DDT and its metabolites, Chlorinated pesticides (DDT and its metabolites, HCB,HCB, a, b, g -HCHa, b, g -HCH etc.)etc.)

• Polychlorinated biphenyls (PCBs)Polychlorinated biphenyls (PCBs)• Polychlorinated dioxins (PCDDs) and Polychlorinated dioxins (PCDDs) and

dibenzofurans (PCDFs)dibenzofurans (PCDFs)• Polybrominated biphenyls (PBBs)Polybrominated biphenyls (PBBs)• Polybrominated dibenzoethers (PBDEs)Polybrominated dibenzoethers (PBDEs)• Polycyclic aromatic hydrocarbons (PAHs)Polycyclic aromatic hydrocarbons (PAHs)

..and others....and others..

Characteristics of POPs?Characteristics of POPs?

Persistence in the environmental mediaPersistence in the environmental media

Transport on long distance (transboundary)Transport on long distance (transboundary)

Complex mixture of chemicals with similar Complex mixture of chemicals with similar structure, but not similar effect structure, but not similar effect

Bioaccumulation, biomagnification (in fish and Bioaccumulation, biomagnification (in fish and seafood) seafood)

Lipophilicity (deposition in fatty tissues)Lipophilicity (deposition in fatty tissues)

Long half-lifeLong half-life (in years) (in years)

Toxicity, adverse health effectsToxicity, adverse health effects

Mechanisms of adverse health Mechanisms of adverse health effectseffects

• Binding to Ah receptor (dioxin-like Binding to Ah receptor (dioxin-like effects): effects): PCDDs, PCDFs, some PCBs, some PCDDs, PCDFs, some PCBs, some PAHsPAHs

• Other, non dioxin-like mechanisms Other, non dioxin-like mechanisms (neurotoxicity)(neurotoxicity)

Production and usageProduction and usage

Chlorinated pesticides, polychlorinated biphenyls Chlorinated pesticides, polychlorinated biphenyls (PCBs), polychlorinated dioxins (PCDDs) and (PCBs), polychlorinated dioxins (PCDDs) and dibenzofurans (PCDFs) belong to the most important dibenzofurans (PCDFs) belong to the most important organohalogen environmental pollutants. organohalogen environmental pollutants.

Chlorinated pesticides and PCBs were intentionally Chlorinated pesticides and PCBs were intentionally produced and had wide agricultural and industrial produced and had wide agricultural and industrial application in the past.application in the past.

PCDDs and PCDFs are nonintentional and unwanted PCDDs and PCDFs are nonintentional and unwanted by-products of industrial and thermal processes.by-products of industrial and thermal processes.

The production and intensive use of persistent The production and intensive use of persistent organochlorine chemicalsorganochlorine chemicals have led to widespread have led to widespread contamination of the environment.contamination of the environment.

Polychlorinated biphenylsPolychlorinated biphenyls

Source:Source:

Commercial PCB mixtures have been Commercial PCB mixtures have been industrially industrially produced beginning about 1929 produced beginning about 1929 (USA), since 50ies in (USA), since 50ies in Europe and Japan, since 1960´s in Slovakia) Europe and Japan, since 1960´s in Slovakia) by several by several manufactures under different trade names (Aroclor, manufactures under different trade names (Aroclor, Kanechlor, Clophen, Phenoclor, Pyralen, Fenchlor, Kanechlor, Clophen, Phenoclor, Pyralen, Fenchlor, DelorDelor).).

UsageUsage::

organic diluents, plasticizers, adhesives, cutting oils, organic diluents, plasticizers, adhesives, cutting oils, flame retardants, heat transfer fluids, dielectric fluids flame retardants, heat transfer fluids, dielectric fluids for transformers, hydraulic lubricants, and in for transformers, hydraulic lubricants, and in carbonless copy paper. PCBs were added into paints, carbonless copy paper. PCBs were added into paints, which were then used for coating the grain silos, which were then used for coating the grain silos, feeding trough, water basins, etc..feeding trough, water basins, etc..

What are Dioxins?What are Dioxins?

2,3,7,8 - tetrachlordibenzofuran(PCDF)

O

Cl

Cl

Cl

Cl2,3,7,8 - tetrachlordibenzo-p-dioxin(PCDD)

O

O

Cl

Cl Cl

Cl

2,3,7,8-2,3,7,8-TCDDTCDDPCDD – 75 PCDD – 75 congenerscongeners

PCDF – 135 PCDF – 135 congenerscongeners

Sources of Dioxins and Sources of Dioxins and DibenzofuransDibenzofurans

They were never intentionally produced.They were never intentionally produced.

1.1. Combustion including volcanic eruption, Combustion including volcanic eruption, fires, domestic heating, incinerators, fires, domestic heating, incinerators, cremation, cars, smoking. cremation, cars, smoking.

2. Contaminants of industrial processes 2. Contaminants of industrial processes during the industrial production of during the industrial production of chlorinated pesticides, PCBs and other chlorinated pesticides, PCBs and other chlorinated compounds, paper bleaching chlorinated compounds, paper bleaching etcetc..

Problem: Usually exist in complex mixtures with Problem: Usually exist in complex mixtures with PCBsPCBs

PCBs – Exposure and Health EffectsPCBs – Exposure and Health Effects

Fatty food of animal origin, fish, eggs – more than Fatty food of animal origin, fish, eggs – more than 90 %90 %

Resorption more than 90 %Resorption more than 90 %

Accumulation in fatAccumulation in fat

Persistence, long half-lifePersistence, long half-life

AccidentsAccidents: :

Yusho – Japan 1968 (contaminated rice oil)Yusho – Japan 1968 (contaminated rice oil)

Yusheng – Taiwan 1976 (dtYusheng – Taiwan 1976 (dttto)o)

Seveso – Italy 1976Seveso – Italy 1976 (chemical plant) (chemical plant)

Vietnam war, agent orange - defoliantVietnam war, agent orange - defoliant

Environmental exposureEnvironmental exposure

We all are exposed (food containing animal We all are exposed (food containing animal fat)fat)

Belgium affair – 1997Belgium affair – 1997

German affair - 2005German affair - 2005

Contamination of Contamination of animalanimal f feedeed (about 1500 ton) (about 1500 ton) with fat containing PCB and dioxins) (Company with fat containing PCB and dioxins) (Company producing feed wants to spare money)producing feed wants to spare money)

FloodsFloods – PCBs and dioxins were washed-out from – PCBs and dioxins were washed-out from sediments, increased contamination of food chain. sediments, increased contamination of food chain.

Vicinity of plantsVicinity of plants producing pesticides o producing pesticides orr PCBs in PCBs in past past

Adverse health effects of EDCAdverse health effects of EDC

Developmental toxicity

Carcinogenicity

Immunotoxicity

Neurotoxicity

Hormonal effects (estrogenic, antiestrogenic, androgenic, antiandrogenic, thyroid hormonal)

PCBs –Health EffectsPCBs –Health Effects

Accidentally high exposure:Accidentally high exposure:

Elevated serum lipid levelsElevated serum lipid levels

Increased level of some serum enzymesIncreased level of some serum enzymes

Chloracne and dermal lesionsChloracne and dermal lesions

Hepatic damageHepatic damage

CVD and respiratory problemsCVD and respiratory problems

Long-term health effects in general Long-term health effects in general populationpopulation

ChildrenChildren are the most sensitive and vulnerable are the most sensitive and vulnerable population group (ED-compounds can cross the population group (ED-compounds can cross the placenta and are present in human milk)placenta and are present in human milk)

NeurotoxicityNeurotoxicity

Reproduction disordersReproduction disorders

HypothyreosisHypothyreosis

Worsening of psychomotoric development of childrenWorsening of psychomotoric development of children

However, the adverse health changes are mostly However, the adverse health changes are mostly transitional.transitional.

POPs and breast feedingPOPs and breast feeding

Breast feeding is the best way for the nutrition of children

Benefit of breast feeding outweighs the adverse health risk, because:

• biological half life is only several months in infants

• There is no much fat in infants, therefore almost all POPs are excreted through feces

• PWTI is calculated for the whole life exposure, breastfeeding period is relatively short

PhthalatesPhthalates

Industrial use in the production of plasticsIndustrial use in the production of plastics (plasticizers)(plasticizers)

ExposureExposure: : Inhalation (combustion of plastics)Inhalation (combustion of plastics)

Peroral: Peroral:

Water (bottled water?)Water (bottled water?)

Dietary (food packed in plastics)Dietary (food packed in plastics)

Children's toysChildren's toys

Health effects:Health effects:Carcinogenicity (IARC 2B)Carcinogenicity (IARC 2B)

Peroxisome proliferation (oxidation stress in cell Peroxisome proliferation (oxidation stress in cell membranes)membranes)

Endocrine disrupting effectsEndocrine disrupting effects

Toxic compounds of natural originsToxic compounds of natural origins

Intoxication with mushroomsIntoxication with mushrooms (real – false) (real – false)Real: Real: Amanita phalloidesAmanita phalloidesIt contains a spectrum of phalotoxines and more toxic It contains a spectrum of phalotoxines and more toxic amatoxines - extremely dangerousamatoxines - extremely dangerousTwo phases - gastrointestinal disorders during 12 hoursTwo phases - gastrointestinal disorders during 12 hours - failure of liver and kidney functions started 4th - - failure of liver and kidney functions started 4th - 5th day5th dayDamage of liver cellsDamage of liver cellsDamage of kidneyDamage of kidney

Amanita muscaria2 types of toxins . Atropine-like effectGyromytra esculentaLiver dystrophy Haluciogenic mushrooms

Amanita phaloidesAmanita phaloides

Amanita phaloidesAmanita phaloides

Intoxication:

Time of latency (6 – 24 hours) !

gastrointestinal (choleriform) phase 1 – 3 dayshepatorenal phase (4. – 7. day)

Mortality: 10 - 20 %

Toxic compounds of natural originToxic compounds of natural origin

In: aquatic animals (some mussels, fugu – In: aquatic animals (some mussels, fugu – tetrodotoxin), terrestrial animalstetrodotoxin), terrestrial animals

Plant toxinsPlant toxins: (carcinogenic, phototoxic, allergenic, : (carcinogenic, phototoxic, allergenic, cytotoxic, psychotropic, neurotoxic, myotoxic, cytotoxic, psychotropic, neurotoxic, myotoxic, hematotoxic, nefrotoxic, hepatotoxic, GIT or hearthhematotoxic, nefrotoxic, hepatotoxic, GIT or hearth damage.damage.

Cycasin - glycoside (Cycas circinalis)Cycasin - glycoside (Cycas circinalis)Betel nutsBetel nutsPyrrolizidine alcaloids in herbal teasPyrrolizidine alcaloids in herbal teasEugenol, estragol and other compounds in spicesEugenol, estragol and other compounds in spices

Stomach carcinoma

Risk factors Mechanisms Protective factors

Mechanisms

Oversalted foodSmoked meatNitrates, nitritesAlcohol, smokingHelicobacter pyloriLower pH in stomachDeficiency of vitamins E, C and other antioxidants

Production of nitrosamines in stomach

Reduction of nitrates to nitrites

Chronical irritationí

Quick division of cells

vegetable, fruit, green teaj

Antioxidants

Treatment of infections

Regulation of nitrates in food and water

Antioxidative efect

Blocade of nitrosamine production increase of cell defension

Nutrition toxicology in Nutrition toxicology in pediatrypediatry

Differences in food basket: breast milk, milk products, sweet, Differences in food basket: breast milk, milk products, sweet, etc.etc.

Differences in amount of food in relation to body weightDifferences in amount of food in relation to body weight

Dif. according to developmental stage of child: prenatal – infant Dif. according to developmental stage of child: prenatal – infant – toddler – preschool age – school age – puberty – adolescence– toddler – preschool age – school age – puberty – adolescence

Dif. in physiological processes: growth, immature immune Dif. in physiological processes: growth, immature immune system, biotransformation enzymessystem, biotransformation enzymes

Different lifestyle of children – hand-to-mouth activitiesDifferent lifestyle of children – hand-to-mouth activities

Different behavior. Children are unable to recognize danger, Different behavior. Children are unable to recognize danger, natural or man-made toxins to avoid exposurenatural or man-made toxins to avoid exposure

Message to take withMessage to take with

Diet is one of the most important factors influencing Diet is one of the most important factors influencing human health through the whole lifehuman health through the whole life

Adverse effects depend not only on the presence of Adverse effects depend not only on the presence of toxic compounds in food but more on quantity we toxic compounds in food but more on quantity we consumeconsume

In certain situations, home produced food (e.g. In certain situations, home produced food (e.g. eggs, chicken, vegetable) may contain more toxic eggs, chicken, vegetable) may contain more toxic compounds than the same product on the marketcompounds than the same product on the market

The efficient prevention is consumption of The efficient prevention is consumption of reasonable amount of variety of food reasonable amount of variety of food commoditiescommodities