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Complementary and Alternative Medicine

- Pages 73 - 104

Food Safety

- Chapter 18

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Functional FoodsDefinition• foods that contain physiologically active

compounds that provide health benefits beyond basic nutrition

Examples– Oat Bran Fiber– Fish Oil Fatty Acids– Phytochemicals*– Plant Sterols and Stanols*

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PhytochemicalsDefinition: non-nutrient compounds found in

plant derived foods• may promote good health but are not essential for

life• include thousands of complex chemicals including

pigments and antioxidants• benefits may include reduced risk of

cardiovascular disease, hypertension, cancer, type 2 diabetes, and others

• see Table SAN.1, pages 78 & 79 for selected examples

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Benefits of phytochemical supplements?

• information on how many phytochemical work is still unclear

• phytochemical work together, not in isolation

• the best way to add more phytochemical to your diet is to increase your consumption of fresh fruits and vegetables

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Lycopene

• a carotenoid found in tomatoes and tomato products

• has antioxidant and antiproliferative functions• epidemiological studies have shown a

correlation between a high intake of lycopene and reduced incidence of CVD, cancer, and macular degeneration

• well-designed research examining the effect of lycopene supplements has not yet been conducted

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Soybeans

• epidemiological studies have linked a high consumption of soy products to reduced risk of cancers, including colon, prostate, uterine, and breast

• contain isoflavones which acts as phytoestrogens

• recent studies show increased bone density with soy intake

• studies examining effects on cancer and CVD risk have had mixed results

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Plant Sterols & Stanols

• similar chemical structure to cholesterol• beneficial for lowering LDL

– competitively inhibit the absorption of cholesterol in the small intestine

• naturally found in vegetable oils, legumes, sunflower and sesame seeds, some fruits and vegetables

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Health claims for functions foods

• must meet government guidelines in order to make health claim

Examples– foods high in -glucan may highlight

benefits of reduced risk of CVD– functional food created by addition of plant

sterols or stanols to margarine may claim it helps lower cholesterol

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Vitamin & Mineral Supplements

• a billion dollar industry

• more than ½ of North Americans take vitamin or mineral supplements, usually self-prescribed

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Reasons to take supplements…

• to correct overt deficiencies– Rx at 2 - 10x the RDA (pharmacological dose)

• to improve nutrition status– prevention of subclinical deficiencies– habitual dieters, elderly, vegetarians

• reduce disease risks• support increased nutrient needs (e.g.

pregnancy)

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Who needs supplements?

• taking supplements to “fix” a poor diet is unwise

• foods provide not only nutrients but also fiber & other health promoting benefits

• whenever possible, nutritional needs should be met with FOOD!

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Megadoses?

• appropriate for treatment of specific conditions

Examples– nicotinic acid to lower cholesterol

– Vitamin B12 to treat pernicious anemia

– folic acid & Vitamin B6 to counteract effects of tuberculosis drugs

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Arguments against supplements…

• health risks: toxicityExamples– high doses of Vitamin C diarrhea– megadoses of Vitamin B6 nerve damage

NutrientUpper Limit

Daily Value Multivitamin-mineral

Single Nutrient Supplement

Vitamin A 3000 g 1500 g 750 - 1500 g 2400-3000 g

Vitamin C 2000 mg 60 mg 10 - 90 mg 500-2000 mg

Iron 45 mg 18 mg 18 mg 15-18 mg

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Arguments against supplements…

• interactions with other nutrients & medications– Vitamin K interferes with medication to control blood

clotting– antioxidant nutrients may counteract chemotherapy or

radiation treatment for cancer

• misinformation• expensive• supplements do not provide other compounds in

foods associated with health• may lead to false sense of security about health

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Myths & Facts

• the soil contains inadequate nutrients

• supplements provide energy

• supplements improve athletic performance and build muscle

• supplements reduce stress

• supplements can treat or cure illness and disease

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Dietary Supplements in the Marketplace

• Claims allowed– Health claims

(approved by FDA)– Nutrient content claims– Structure/function

claims• Link substance and

effect on the body• No approval required • Must have “disclaimer”

statement on label

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Dietary Supplements in the Marketplace

• Fraudulent products– Secret cure—“breakthrough”– Pseudomedical jargon—“detoxify”– Can cure a wide range of diseases– Has no side effects, only benefits– Backed by “scientific research” but none is

listed

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Herbal Therapy

• the therapuetic use of herbs and plants to promote health & treat disease– e.g. ginseng, St. John’s wort, kava, milk thistle, saw

palmetto

• Bill C-51 - facts - See link on main web page• remember: any herb that is strong enough to

help you may be strong enough to harm you!– e.g. gingko biloba may cause hemorrhage, licorice,

hawthorn & senna may interfere with cardiac drugs such as digoxin, kava may increase sedative effects of narcotics & alcohol

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Food Safety• History

– Major killers in society used to be outbreaks of devastating human diseases

– typhoid, scarlet fever, diphtheria

• Now microbes are of concern– bacteria, fungi and viruses can all cause food-

borne illness– major concern for daily health

• food additives and contaminants are also of significant concern to many

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Food-Borne Illness (F-BI)

• cause up to half the cases of diarrhea • considerable cost and death rate• loss of productivity• “travelers diarrhea”• GI tract environment (bacteria)

significantly altered with change of outside environment and food choices

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Microbes - Table 17-1• Bacteria - salmonella, e coli

– single celled organisms– some produce toxins - illness– others produce enzymes that digest substances around them

• Fungi – simple parasitic life form– molds, mildews, yeast

• Virus - hepatitis, norwalk– smallest, use host to reproduce

• Parasites - giardia• Microbes either

– directly infect intestinal wall– produce toxins in the food

• tablespoon of dirt ~ 2 billion microbes

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Mad Cow Disease

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Prions and Mad Cow Disease• Bovine spongiform encephalopathy (BSE), known as

“mad cow disease,” is a chronic degenerative disease that affects the central nervous system of cattle. Once thought to infect only cows, scientists have found that BSE can cause a rare, but fatal, brain-wasting disease in humans.

• Researchers believe that prions—proteins found in the cells of humans and other mammals—are responsible. When mammals eat tissues contaminated with abnormal prions, they can develop BSE. Cooking and irradiation do not kill or deactivate abnormal prions.

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Impact of F-BI• Can be more severe and prolonged reaction

in some who are more susceptible– infants, children and elderly– liver disease, diabetes, HIV– cancer patients– pregnant women– condition can become lengthy and lead to food

allergies, seizures, blood poisoning

• F-BI often results from unsafe food handling– World Health Organization rules

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Why so Common?

• Increase in central processing – large scale impact when microbe growth

does occur

• increased consumption of raw animal products

• goal of increased shelf life• science becoming more aware of its

prevalence

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Food Preservation

• Historical preservatives– salt, sugar, smoke, fermentation, drying

• alter composition of food, to be unsuitable as host for microbes

• decrease free water• fermentation, pickling

– highly acidic and alcoholic environment, no microbe growth

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Preservation• Also pasteurization, sterilization, refrigeration,

freezing, irradiation, canning, chemical preservation, aseptic processing

• aseptic processing– sterilization of food and packaging - boxed juice,

milk

• irradiation– alters composition of food– does not become radioactive

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Food Technology: Irradiation

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Food Safety: Consumer’s Role

• Keeping food safe– Clean– Separate– Cook– Chill

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General Rules • Purchasing

– select perishables last, keep separate, store quickly

– don’t by or use food from broken or bulging containers

– purchase only pasteurized milk and cheese

• Preparation (* raw meat *)– wash hands with soapy hot water– use clean equipment (counters, cutting boards)– thaw in fridge, cold water or microwave

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General Rules• Cooking Food

– cook food thoroughly (*meat*)– consume cooked food immediately– serve animal products on clean plate, not on the one

used for preparation.

• Storing and Re-heating– keep hot / keep cold– intermediate temperatures facilitates growth - fig

17.7– reheat leftovers to cooking temperature (not just

warm)– Cover and seal stored foods– Leftovers in fridge for 2-4 days maximum

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Temperature Guide

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Treatment• Drink lots of fluids• bed rest • wash hands frequently• consult physician if severe for 2-3 days• Report to authorities if :

– food eaten at large gathering– food from restaurant,…..– food was a commercial product

• ie. high potential for large # of infections

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Food Additives• intentional added to improve :

– palatability, nutrient content, shelf life, ease of processing

– the three most common additives are sugar, salt, & corn syrup

• incidental (contaminants)– find there way into our food

• GRAS – Generally Recognized As Safe– list of compounds, used and considered safe in 1958– FDA must now prove these substances are harmful to

get them removed from safe list

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Testing Food Additives• Must use two animal species• NOEL

– no observable effect limit– highest dose that produces no effect– short term/high dose ????

• Delaney Clause– prevents addition of products that cause cancer

• Incidental food additives– industrial chemicals, pesticides ...– Canadian Food Inspection Agency (FDA in US) -

cancer safety margin

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New Food Additives

• Canadian Food Inspection Agency (FDA in US) testing for approval

• Manufacturer must provide– identity, composition, source, method of

content analysis and description of use, applicability and necessity

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Additives• Most used in processing, enhancement

of consumer appeal, and to prevent spoiling

• recall - problems with F-BI increased with central food production– become largely unnecessary if buy fresh,

locally produced food and prepare at home

• variety and moderation can prevent negative impact on health

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Natural Substances

• Many natural produced compounds are potentially harmful

• many cultures traditionally avoid these (differences)

• safrole - cancer - mace, nutmeg

• solanine - green potatoes

• mushroom toxins

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Food Safety• Harmful substances in food

– Chemical contamination• Pesticides

– Organic alternatives

• Animal drugs• Pollutants

Photo © Photodisc

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Environmental Toxins• Lead

– anemia, kidney disease, and nervous system damage

– changes in last 25 years– lead paint, gasoline, canning soldering, (let taps

run)

• Dioxins– chlorine and benzene– created by incinerating plastic an paper together -

cancer– also accumulate in bottom feeding fish - great lakes

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Environmental Toxins• Mercury

– birth defects, acute toxicity– large predatory fish

• Urethane– forms during fermentation– cancer causing– fruit brandies, saki

• PCB’s – liver tumors, reproductive problems– fish (freshwater, industrial )

• BPA ?

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Toxins in the Food Chain

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Organic Foods• Choosing organic can reduce overall use of

pesticides– Pesticide contamination is low in all foods - its use is

damaging to environment however

• Organic produce has higher content of phytochemicals - natural defenders against foreign agents

• Choosing local produce reduces shipping costs, use of green house fuels and the need for preservatives

• Genetically modified organisms (GMO)– Prevalence is quite high, labeling now required in Europe– Unknown long term consequences

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Genetically Modified Foods: Plant Genetics

• Traditional breeding– Cross two plants, develop

hybrids, takes time

• Genetic engineering– Transform specific

genes– Less time to get desired

effects