Perspectives in Nutrition, 8Th Edition

Perspectives in Nutrition, 8th Edition Chapter 3 Outline: The Food Supply

After studying this chapter, you will be able to:

1. Compare food security and food insecurity and identify the factors that contribute to each. 2. Discuss the effects of hunger and malnutrition and their impact on children. 3. Describe U.S. government programs designed to increase food security. 4. Describe organic food production, its regulation, and its potential benefits. 5. Discuss the current and potential uses of genetically modified foods, along with concerns related to safety. 6. Explain how food preservation and processing methods affect food availability. 7. Describe the role of food additives in the food supply, along with how they are regulated. 8. List the major causes of foodborne and waterborne illnesses in the U.S. and describe how consumers can reduce the risk of these illnesses. 9. Describe common environmental contaminants (heavy metals, industrial chemicals, pesticides, and antibiotics), their potential harmful effects, and how to reduce exposure to them.

3.1 Food Availability and Access

A. General

1. Worldwide agricultural yield could provide 2720 kcal/d for each person on Earth, but 1 in 8 people (854 million) are food insecure

2. 2 billion people suffer from micronutrient deficiencies

3. Malnutrition is most common in the developing world (sub-Saharan Africa, Latin America, Caribbean, parts of Asia)

4. According to FAO, malnutrition accounts for >1/2 world’s disease burden

a. Overnutrition leads to obesity

b. Undernutrition leads to frailty, weakened immune system, etc.

5. Nutrition transition: inclusion of more meat, dairy, sugar, fat, and processed foods and fewer grains and vegetables as developing countries become westernized

6. Food security: food needs are met all of the time

7. Food insecurity: quality, variety, and/or desirability of diet is reduced and there is difficulty at times providing enough food for everyone in the household

B. Health Consequences of Food Insecurity 1. Inadequate energy intake

a. Decline of physical and mental activity

b. Retardation or cessation of growth

c. Wasting of muscle and fat

d. Weakened immune system

e. Increased susceptibility to disease

f. Increased death rates

2. Micronutrient deficiencies

a. Blindness from vitamin A deficiency

b. Mental retardation and brain damage from iodine deficiency

3. Nutrient-poor diets in developed countries

a. Impaired physical and mental health

b. Greater rate of health complaints

c. Abnormal growth

d. Behavioral problems

e. Lower educational achievement

f. Depression, suicide, psychological distress

g. Increased risk of chronic disease

4. In the US, food insecurity and poverty are linked to obesity because high-energy- density, nutrient-poor foods are less expensive than nutrient-dense foods

C. Food Insecurity and Malnutrition in the United States

1. Despite abundant, nutritious, and affordable food supply, 11% of US households are food insecure

2. 37 million people in US (more than 1/3 of whom are children) live at or below poverty guidelines (20,650 for a family of 4);increased with single-parent households and for certain racial and ethnic groups

a. 25% of African-Americans and Native Americans

b. 22% of Hispanics c. 9% of Caucasians

3. Contributors to poverty

a. Unemployment

b. Underemployment

c. Lack of health care benefits

d. High housing costs

e. Family break-ups

f. Illnesses

D. Programs to Increase Food Security in the United States

1. 60% of USDA budget is allotted for nutrition assistance programs

2. Some eligible families do not receive aid

3. Examples

a. Food Stamp Program: provides monthly benefits with Electronic Benefits Transfer card (average $93/month) to be used for food and seeds to grow food; accompanied by Food Stamp Nutrition Education in some states

b. Special Supplemental Nutrition Program for Women, Infants, and Children (WIC): provides low-income pregnant, breastfeeding, and post- partum women and their infants and children up to age 5 with vouchers to purchase specific nutrient-dense foods; accompanied by nutrition education and referrals to health care and social services

c. National School Lunch Program: helps schools provide nutritious lunches to children by subsidizing cash and food; children of low-income families can receive free or reduced-price lunches

d. School breakfast program: similar to lunch program; must meet federal nutrition guidelines

e. Child and Adult Care Food Program: reimburses eligible child-care and nonresidential adult day-care centers that provide meals and snacks; meals must meet federal nutrition guidelines

f. Programs for seniors: Older Americans Act funds congregate meal programs, home-delivered meals (Meals on Wheels),and Senior Farmers Market Nutrition Programs; meals must meet nutrition guidelines and are available at little or no cost

g. Food distribution programs: commodity foods (canned, dry, and some fresh foods) are distributed to low-income households, emergency feeding programs, disaster relief programs, Indian reservations, and older adults

h. Many private programs (notably America’s Second Harvest) also assist low-income families at food banks, pantries, soup kitchens, and shelters

i. Table 3-1 lists ways to help fight hunger

E. Food Insecurity and Malnutrition in the Developing World

1. Most common micronutrient deficiencies

a. Iron

b. Vitamin A

c. Iodine

2. Undernutrition disproportionately affects young children and women

3. Consequences of undernutrition

a. Death

b. Underweight

c. Stunted growth

d. Susceptibility to disease

e. Learning disabilities

f. Maternal malnutrition can lead to malnutrition in fetus and breastfed infants

4. Subsistence farmers: able to grow food for their own family, but not enough to sell for income

5. Causes for food shortages

a. Poor-quality farmland

b. Lack of fertilizer, seeds, and farming equipment

c. Droughts or floods d. Limited work capacity of farmers due to undernutrition and illness

e. Natural disasters, war, and political unrest worsen food shortages

f. Government corruption plagues relief efforts

6. Migration of families from rural to urban areas results in overcrowding, poor- quality housing, and lack of access to clean water, sufficient food ,and medical care

7. Reducing malnutrition through agricultural development

a. Benefits

i. Healthier diets for farmers’ families

ii. Ability to earn income from selling food

b. Requirements

i. Funding

ii. Infrastructure (e.g., roads, irrigation, electricity, banks)

iii. Agricultural research

iv. Education

v. Healthy workers

8. United Nations Millennium Summit (2000) set goal to reduce extreme poverty and hunger by half

a. Some progress has occurred in Asia and Latin America

b. Hunger and poverty continue to increase in sub-Saharan Africa and Eastern Europe

3.2 Food Production

A. Organic Foods

1. Produced by farming practices that exclude synthetic pesticides, fertilizers, and hormones; antibiotics; sewage sludge; genetic engineering; and irradiation

2. Ever-increasing availability of organic foods to consumers

3. Contributors to consumer demand for organic foods a. Personal health

b. Environmental health

4. Organic foods are typically more expensive than those grown under conventional circumstances because they cost more to grow and produce

5. Farming practices

a. Biological pest management: use of natural predators, parasites, or pathogens to control agricultural pests

b. Composting

c. Manure application

d. Crop rotation

6. Organic Foods Production Act of 1990 established standards

a. 95% of ingredients in an organic food made from multiple ingredients must meet organic standards

b. “Made with organic”: at least 70% of ingredients are organic

7. Not all organic food producers are USDA certified, may not be labeled organic

8. Organic Foods and Health

a. Reduce pesticide intake

i. Organic foods contain fewer pesticides than conventional foods

ii. Unknown effects on health

iii. May be prudent for young children

b. Protect environment

i. Encourage sustainable agriculture practices

c. Improve nutritional quality

i. Most research does not support advantage of organic food production practices on nutrient content

ii. Some studies show increased vitamin C and antioxidant content

iii. Organic label does not make a food implicitly healthy

d. Food safety i. Concern that use of manure may increase contamination by pathogens is not supported by evidence

ii. Consumers should wash or scrub all produce under running water

B. Biotechnology - Genetically Modified Foods

1. General

a. Selective breeding improves yields, resistance to pests and adverse environmental conditions, etc.

b. Recombinant DNA technology: transfer of DNA into a plant or animal to confer a specific trait

i. Genetically modified food

ii. Genetically engineered food

iii. Transgenic plant or animal

2. GM Foods

a. Common GM crops in US

i. Soybean

ii. Corn

iii. Cotton

iv. Papayas

v. Canola

vi. Squash

b. Primary uses are for pest management

i. Enhance crops’ tolerance for herbicides

ii. Bacillus thuringiensis (Bt) protein allows corn to produce toxin to ward off caterpillars

c. Although GM animals are under development, none are currently approved for market (concerns over compatibility of wild and transgenic species)

d. Recombinant bovine growth hormone (rBGH) increases milk production in cows i. BGH is released from the pituitary gland and stimulates the production of insulin-like growth factor, which stimulates milk production

ii. Increases risk for mastitis in cows, may necessitate increased use of antibiotics

iii. Although IGF is associated with certain cancers in humans, there is no evidence that drinking milk produced with rBGH increases these cancers

iv. No rBGH is used in production of organic milk

v. rBGH is not approved for use in Canada or Europe e. Chymosin (rennin; used to make cheese) can be produced by genetically engineered bacteria or yeast rather than being harvested from the stomachs of calves f. GM Foods of the Future

i. Increased crop yields

ii. Tolerance of crops to harsh conditions (e.g., drought, cold, salinity)

iii. Extended shelf-life

iv. Increased nutrient density (e.g., golden rice has increased levels of beta-carotene; more heart-healthy vegetable oils; non- allergenic foods) g. Although biotechnology has great potential to reduce hunger and malnutrition, many barriers exist

i. Lack of access of poor farmers to biotechnology

ii. Most biotechnology research has focused on crops with industrial uses rather than on dietary staples h. Regulation of GM Foods

i. FDA: ensures food safety

ii. USDA: ensures than GM foods are safe to grow

iii. EPA: regulates pesticide content

iv. Labeling of GM foods or GM ingredients is not required in the US i. Safety of GM Foods

i. Introduction of new allergens: no evidence of harmful reactions or effects in humans

ii. Possibility of gene flow: hybridization may lead to resistance of weeds to herbicides and insecticides

iii. Development of Bt-resistant insects: may lead to increased pesticide use by nonorganic farmers

iv. Loss of genetic diversity

v. Insufficient regulation and oversight of GM plants and animals

j. Biopharming: bioengineering plants to produce medications

3. Meat and Milk from Cloned Animals

a. Cloning: making genetically identical animals by nonsexual reproduction

b. Parthenogenesis: some animals (e.g., worms, frogs) clone on their own

c. Agricultural interest in cloning stems from desire to reproduce the best livestock for economic gain

d. In 2008, FDA determined that meat and milk from cloned cattle, swine, and goats are safe to eat; USDA has not given approval for marketing of cloned milk and meat

3.3 Food Preservation and Processing

A. General

1. Food preservation processes extend shelf-life by slowing the rate at which microorganisms and enzymes cause food spoilage

2. Methods that decrease water content to deter microbial growth

a. Drying

b. Salting

c. Sugaring

d. Smoking

3. Methods that increase acidity or alcohol to deter microbial growth a. Fermentation

b. Pickling

4. Methods that use heat to eradicate or reduce microbes

a. Pasteurization

b. Sterilization

c. Canning

5. Methods that slow rate of microbial growth

a. Refrigeration

b. Freezing

6. Methods that inhibit microbial growth

a. Chemical preservatives

b. Irradiation

B. Food Irradiation

1. Uses radiant energy from gamma rays, X rays, or electron beams to extend shelf life and control growth of insects and pathogens in foods

2. Irradiated food is not radioactive

3. Irradiated foods are safe for human consumption according to FDA and other health authorities

a. Fresh meat and poultry

b. Wheat and wheat powder

c. White potatoes

d. Spices and dry vegetable seasonings

e. Fresh shell fish

f. Eggs

g. Fresh produce

4. Irradiated foods (except for spices and dry vegetables seasonings) must be labeled with Radura symbol

5. Barriers to use a. Consumers’ lack of familiarity with the technology

b. Higher cost

c. Concerns about taste and safety

C. Food Additives

1. Historical examples

a. Salt

b. Vinegar

c. Alcohol

2. Pure Food and Drugs Act of 1906 led to regulation of food additives for safety

3. Food additive: substance added to foods to produce a desired effect (e.g., increased shelf life, greater nutritional value, color)

D. Intentional vs. Incidental Food Additives

1. General

a. Intentional food additive: purposely added, listed among food ingredients on label

b. Incidental (indirect) food additives: unintentionally incorporated into food through some aspect of food production, processing, packaging, transport, or storage; have no function, but may pose risks

i. Benzene forms when benzoate salts react with vitamin C

ii. Acrylamide forms when high carbohydrate foods are fried

iii. Pesticide residues

2. Synthetic vs. Natural Additives

a. Toxicity is determined by effects on body, not whether an additive is natural or synthetic

b. Cancer researchers estimate we ingest at least 10,000 times more natural toxins than synthetic additives or pesticides

3. Uses of Food Additives

a. Improve freshness and safety

i. Antimicrobial agents ii. Antioxidants

iii. Curing agents

iv. Acidic agents

b. Alter nutritional value

i. Enrichment and fortification

ii. Alternative sweeteners

iii. Fat replacers

c. Enhance flavor or color

i. Flavors and spices

ii. Flavor enhancers

iii. Color additives

iv. Certifiable color additives

d. Enhance functional characteristics

i. Emulsifiers

ii. Anticaking agents

iii. Humectants

iv. Stabilizers, thickeners

v. Enzymes

vi. Leavening agents

e. Food additives may not be used to

i. Hide defective food ingredients or poor food quality

ii. Deceive customers

iii. Replace good manufacturing practices

4. Regulation and Safety of Food Additives

a. General i. 1958 Food Additives Amendment of the Food, Drug, and Cosmetics Act gave FDA jurisdiction over safety of food additives

ii. Manufacturers must obtain FDA approval prior to use of additives in foods; are responsible for testing and proving safety b. Prior-Sanctioned Substances and the GRAS List

i. Substances that the FDA or USDA deemed safe for use in foods prior to 1958 Food Additives Amendment are deemed prior sanctioned substances

ii. Generally Recognized as Safe list contains substances with a history of use before 1958 or that have been deemed safe by published scientific evidence

iii. Some additives have been removed from the GRAS list due to toxicity or carcinogenicity c. Food Additive Safety Tests

i. Intentional food additives must be tested on at least 2 animal species to determine the no-observable-effect level (NOEL)

ii. NOEL/at least 100 is the amount of an additive allowed in food

iii. Delaney Clause of the 1958 Food Additives Amendment prohibits use of any food additive shown to cause cancer in humans or animals at any dose

iv. FDA sets acceptable levels for incidental additives that may cause cancer d. New Food Additive Approval

i. Accomplish intended purpose in a food

ii. Safe

iii. To be used in no greater amounts than needed to achieve it purpose

iv. Provide FDA with information about manufacturing and laboratory testing of the additive e. Concerns about Food Additives i. Many additives on the GRAS list have not been adequately tested

ii. New research methods may reveal safety or danger of additives

iii. Aspartame used as artificial sweetener: concern over cancer, dizziness, headaches

iv. Sodium nitrate and sodium nitrite used to prevent growth of Clostridium botulinum: can be converted to carcinogenic nitrosamines in the stomach; conversion limited by ascorbic acid or erythorbic acid

v. Some artificial colors have been reported to cause allergic-type reactions in children or linked to cancer in animals

vi. Cyclamate was banned due to a study indicating it was a carcinogen, but recent studies refute this evidence, and many countries now permit use of cyclamate

vii. Adverse symptoms for sensitive people: sulfites, MSG

viii. Consumer demand for natural foods: free of colors and synthetic substances

ix. Consuming fewer processed, packaged, convenience foods will decrease intake of additives

3.4 Food and Water Safety

A. Foodborne Illness

1. Sickness caused by ingestion of food containing pathogenic microorganisms (foodborne infection) or toxins made by these pathogens (food intoxication)

2. Despite relatively safe food and water supply in North America, foodborne illness remains a significant public health problem

3. WHO estimates that 1/3 population in developed nations suffers foodborne illness each year

4. ¼ of population in US is at high risk for foodborne illness

a. Weakened immune system due to diseases or medical treatments

b. Pregnant women and fetuses

c. Lactating mothers d. Infants and young children

e. Elderly persons

5. Many cases are unreported

6. Common symptoms

a. Nausea/vomiting

b. Diarrhea

c. Intestinal cramping

7. Severe effects

a. Development of food allergies

b. Seizures

c. Blood poisoning

d. Chronic complications (e.g., arthritis)

e. Death

8. Large-scale production practices, common in developed countries, increase the impact of contamination

9. Heavy reliance on food prepared outside the home increases risk due to mishandling of foods

10. Mishandling of foods during home preparation is also a risk factor on a smaller scale

B. Microbial Pathogens

1. Routes of transmission

a. Contamination by human or animal feces (fecal-oral route)

i. Using contaminated water during food preparation

ii. Lack of handwashing after using the bathroom or changing diapers

b. Contamination by an infected individual

i. Open wound

ii. Coughing or sneezing onto food iii. Pets, via unwashed hands of food handlers

c. Cross-contamination: uncontaminated food comes in contact with a pathogen-contaminated food or object (e.g., cutting board, knife)

2. Bacteria: single-cell organisms; many are harmless, but some are pathogenic

a. Examples are detailed in Table 3-3

i. Salmonella species

ii. Campylobacter jejuni

iii. Escherichia coli

iv. Shigella species

v. Staphylococcus aureus

vi. Clostridium perfringens

vii. Listeria monocytogenes

viii. Clostridium botulinum

ix. Vibrio species

x. Yersinia enterocolitica

b. Proliferate with nutrients, water, and warmth (41° - 135°F; see figure 3- 4)

c. Most bacteria do not multiply when food is held above or below the danger zone, but Listeria can multiply at refrigeration temperatures

d. High temperatures kill bacteria, but not toxins already produced in food

e. Most pathogenic bacteria require oxygen, but Clostridium botulinum and Clostridium perfringens only grow in anaerobic environments

f. Acidity typically deters bacterial growth, but E. coli can grow in acidic foods

g. Some bacteria survive harsh conditions through spore formation

3. Viruses

a. Only reproduce after invading living cells

b. Examples are detailed in Table 3-4 i. Norovirus, human rotavirus

ii. Hepatitis A virus

c. Avian flu is not a foodborne illness

4. Parasites

a. Live in or on another organisms, from which they absorb nutrients

b. Protozoa: one-celled animals

c. Helminths: tape worms and round worms

d. Examples are detailed in Table 3-5

i. Trichinella spiralis

ii. Anisakis

iii. Tapeworms

iv. Toxoplasma gondii

v. Cyclospora cayetanensis

vi. Cryptosporidium

5. Prions

a. Infectious protein particle that invades the nervous system

b. Transmitted by consuming infected animal products

c. Example: bovine spongiform encephalopathy (mad cow disease), Creutzfeldt-Jakob disease (human variant)

d. Survive high temperatures; best prevention is to keep infected meat out of the food supply

6. Toxins

a. Molds, algae, and plants produce disease-causing toxins

b. Molds are a type of fungus that grow in dark, moist places

i. May cause food spoilage, crop destruction, allergies or respiratory problems

ii. Mycotoxins: cause blood diseases, nervous system disorders, kidney and liver damage c. Examples are detailed in Table 3-6

i. Aflatoxin

ii. Ergot

iii. Ciguatera toxin

iv. Shellfish poisoning

v. Scombroid poisoning

vi. Tetrodotoxin

vii. Safrole

viii. Solanine

ix. Mushroom toxins

x. Herbal teas (senna, comfrey)

xi. Lectins

d. Mycotoxins are rarely a problem in industrialized nations because food production practices minimize mold growth and foods are closely monitored

e. Natural toxins are produced by plants to protect from predators; production increases when plants are stressed

i. Licorice

ii. Cyanide in lima beans and almonds

iii. Nutmeg, bananas, and some herbal teas contain substances that can cause hallucinations

f. Proper food storage, cooking, and varied diet limit the effects of natural toxins

C. Water Safety

1. General

a. Public water supplies are regulated by the EPA under the Safe Drinking Water Act

i. Bacteria

ii. Chemical contaminants iii. Toxic metals

b. Local municipal water departments deliver safe water

c. Water treatment involves disinfection (usually by chlorine-based chemical); risk of cancer from chlorine exposure is small

d. Private water supplies (e.g., wells) are not regulated by EPA

e. Bottled water manufacturers must list source on label

i. Artesian water

ii. Distilled water

iii. Purified water

iv. Spring water

v. Mineral water

f. Bottled water safety is regulated by FDA

2. Threats to Safe Water

a. Agricultural runoff

b. Inappropriate disposal of chemicals

c. Municipal solid waste

d. Inadequate treatment of human waste

e. Pollution from boats and ships

3.5 Preventing Foodborne and Waterborne Illnesses

A. “Farm to fork” approach: food growers, processors, distributors, and consumers share responsibility for food and water safety

B. Consumer food safety practices

1. Select and purchase foods carefully

a. Avoid leaking, bulging, dented, cracked cans or jars

b. Don’t taste foods that smell or look odd

c. Discard canned foods that spurt liquid when opened d. Shop for perishable items (milk, eggs, raw meat, poultry, seafood) last

e. Separate perishable foods from other foods in the cart (e.g., with plastic bags)

f. Take groceries home and refrigerate or freeze perishable goods promptly

g. Use the sell-by, use-by, and expiration dates

2. Avoid unsafe food and water

a. Avoid foods likely to be contaminated with pathogens (e.g., raw sprouts, raw or undercooked meat, fish, shellfish, poultry, and eggs)

b. Drink only pasteurized milk and fruit juices

c. High-risk populations should avoid soft cheese, cold deli salads, cold smoked fish, and heat hot dogs and deli meats to 165°F before consumption

d. Use only purified water for drinking, cooking, and washing food and food preparation equipment; have well tested for pathogens

3. Practice good personal hygiene

a. Thoroughly wash hands for 20 seconds with warm, soapy water after using the bathroom, changing diapers, playing with pets, coughing, sneezing, or smoking

b. Wash hands before and after handling food; plain soap works as well as antibacterial soap

c. Cover cuts, burns, sores, or infected areas

d. Avoid preparing food when sick with diarrhea

4. Keep a clean kitchen

a. Prevent cross-contamination by cleaning counters, cutting boards, dishes, and other equipment thoroughly before and after use; use hot, soapy water or the dishwasher or sanitize with dilute bleach solution

b. Regularly clean surfaces and equipment with dilute bleach solution

c. Replace sponges and wash kitchen towels frequently

d. Use non-porous, smooth cutting boards

5. Handle food safely a. Wash fresh fruits and vegetables under running water just prior to eating

b. Scrub firm produce under running water with a brush before slicing

c. Discard soft or liquid foods that are moldy; trim mold from firm-textured foods at least 1 inch below mold

d. Prevent mold growth by storing food and cold temperatures and using food promptly

e. Avoid prolonged refrigeration; freezing keeps foods safe indefinitely

f. Store raw meats and poultry below other foods in the refrigerator

g. Prevent recontamination of cooked food with raw meat or juices on hands, cutting boards, or dirty equipment

h. Cook food completely at picnic site; no partial cooking in advance

6. Keep foods out of the danger zone and cook foods appropriately

a. Thaw foods in the refrigerator, under cold running water, or in a microwave oven

b. Cook foods immediately after thawing in the microwave

c. Marinate food in the refrigerator

d. Cook food to a safe internal temperature; use a food thermometer (see Figure 3-5 for safe cooking temperatures)

e. Cook eggs until yolks and whites are firm

f. Avoid homemade ice cream, eggnog, mayonnaise, and other foods made with unpasteurized raw eggs

g. Avoid eating raw animal products; sushi is safest if made with very fresh fish that have been commercially frozen, and purchased from a reputable establishment

h. Cook stuffing separately from poultry or stuff immediately before cooking and cook to 165°F and transfer to a clean bowl after cooking

i. Immediately consume or refrigerate/freeze cooked foods within 2 hours (1 hour for hot weather)

j. Cool foods in shallow pans

k. Reheat leftovers thoroughly to 165°F 3.6 Environmental Contaminants in Foods

A. Lead

1. Damaging to every organ system, especially nervous system and kidneys

2. Impairs synthesis of hemoglobin

3. Particularly toxic for children, whose nervous system is still developing

a. Lower IQ

b. Behavior disorders

c. Impaired coordination

d. Impaired growth and hearing

e. Predisposition for hypertension and kidney disease later in life

4. Avoiding lead ingestion

a. Let cold water run for 1 minute before using from pipes in homes built before 1986; hot water should not be used for food preparation

b. Keep hands and objects that may be placed in the mouth clean to prevent ingestion of lead dust from lead-based paint in homes built before 1978

c. Never serve or store food in lead-containing containers

5. Other sources of lead

a. Some candies from Mexico

b. Vegetables grown in contaminated soil

c. Mineral and/or herbal supplements

d. Toys painted with lead-containing paints

6. Preventing lead poisoning

a. Remove lead from environment

b. Ensure adequate iron intake

B. Dioxins

1. Chlorine and benzene-containing chemicals; byproducts of industrial processes and incineration of waste products 2. Effects

a. Increases cancer risk

b. Liver and nerve damage

c. Adverse effects on reproduction

d. Increased risk of type 2 diabetes mellitus

3. Routes of exposure

a. Food contamination (animal fats and fish from contaminated waterways)

b. Inhalation

4. Limiting exposure

a. Avoid certain species of fish and those caught in contaminated waterways, as identified by EPA

b. Consume a variety of fish species

C. Mercury

1. Abundant in environment; converted to neurotoxin by bacteria

2. Effects

a. Birth defects

b. Nerve damage

c. Fatigue

d. Poor learning

3. Highest risk populations are children and pregnant/breastfeeding women

a. Avoid shark, swordfish, king mackerel, tilefish

b. Limit albacore tuna to 6 oz (1 meal)/week

c. Limit intake of low-mercury fish (e.g., shrimp, light tuna, Pollock, salmon, catfish) to 12 oz (2 meals)/week; small portions for children

d. Be aware of EPA advisories for mercury contamination of local waterways

4. Ongoing research suggests that benefits of fish consumption (source of essential fatty acids) outweigh risks or mercury D. Polychorinated Biphenyls (PCBs)

1. Historically used for industrial products; still detectable in environment

2. Health effects

a. Liver damage

b. Reproductive problems

3. To limit exposure, exercise variety and moderation in fish consumption

E. Pesticides

1. General

a. Types of pesticides

i. Insecticides

ii. Herbicides

iii. Fungicides

iv. Rodenticides

b. Uses

i. Limit damage to crops

ii. Improve appearance of fruits and vegetables

iii. Prevent formation of carcinogenic aflatoxin

iv. Farms, homes, businesses, schools, health-care facilities

c. Synthetic pesticides: many early types resist breakdown and have remained in the environment despite being banned; today’s pesticides are less persistent

i. Organophosphates: toxic to nervous system of insects and animals

ii. Carbamates: similar to organophosphates, but less toxic

iii. Organochlorine insecticides: many have been banned due to environmental effects and persistence (e.g., DDT and chlordane)

iv. Pyrethroid pesticides: mimic naturally occurring pesticides found in chrysanthemums, which are neurotoxic d. Biopesticides

i. Microbial pesticides (e.g., Bacillus thuringiensis)

ii. Genetic modification of plants to produce their own pesticides (e.g., Bt protein)

iii. Biochemical pesticides that limit reproduction or growth of pests

e. Problems associated with pesticide use

i. Development of pesticide resistance

ii. Pesticide drift to non-target sites

iii. Persistence of pesticides in the environment (e.g., soil, water, animal fat)

iv. Unintended effects on non-target species

2. Regulating Pesticides

a. EPA

i. Determines whether or not a pesticide is beneficial or poses unreasonable health or environmental risks

ii. Sets limits on amounts used on food during growth and processing and how much may remain on final product (tolerance)

iii. Food Quality Protection Act of 1996 requires EPA to consider children’s pesticide exposure from foods they normally eat

b. FDA and USDA

i. Test foods for pesticides

ii. Enforce EPA pesticide tolerances; reports show that although residues are present, only 0.2% of foods have residues exceeding tolerances

3. Minimizing Exposure to Pesticides

a. Health risks

i. Accidental poisonings related to careless use or storage of pesticides ii. Higher rates of asthma, Parkinson’s disease, prostate cancer, leukemia, and other cancers among people who work with pesticides (e.g., farmers)

iii. Concern about chronic, low-level exposure (e.g., pesticide residues in foods)

iv. Infants and children are at heightened risk because of developing organ systems, higher doses per kg body weight, inefficient metabolism

b. Steps to minimize exposure

i. Wash and peel fruits and vegetables

ii. Trim fat in meat

iii. Select a variety of foods

c. Benefits of eating a variety of produce exceed risks of pesticide exposure

d. Certified organic foods are grown without synthetic pesticides, but still may contain small amounts of pesticide residues due to background contamination and pesticide drift

F. Antibiotics

1. Used to promote animal growth and prevent disease in food animals (60 - 80% of all antibiotics produced in the US)

2. Concerns about development of antibiotic resistance

3. Use of antibiotics is prohibited in organically produced animals

3.7 Expert Perspective: Organic Foods and Local Food Systems

A. Benefits of consuming organic foods

1. Avoid exposure to pesticides, antibiotics, and synthetic hormones

2. Humane animal treatment

B. Benefits of local food systems

1. Increased biodiversity

2. Increased access to fresh foods

3. Decreased environmental impact 4. Greater community economic development

C. Characteristics of an ideal food system

1. Healthy

a. Optimal nutritional value

b. Free of preservatives and additives

c. Does not promote chronic disease

2. Green

a. No or low environmental impact

b. Balanced ecosystems

c. Uses minimal nonrenewable energy

d. Recycles wastes

3. Fair

a. Does not exploit anyone or anything

b. Promotes self-sufficiency of farmers

c. Contributes to economic development of community

4. Affordable and accessible

a. Safe

b. Nutritious

c. Produced in a sustainable manner

d. Equally and regularly available to everyone

D. Limited budgets

1. Buy fruits, vegetables, dairy, eggs, or meat from local organic farmers, identified through farmer’s markets, co-ops, Community Supported Agriculture farms, or Cooperative Extension System websites

2. Buy fresh foods when in season

3. Focus on specific foods with high pesticide residues

a. Apples b. Peaches c. Bell peppers d. Celery e. Nectarines f. Strawberries g. Cherries h. Lettuce i. Imported grapes j. Pears