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Chemistry (1,145)
CHEM 181 (350)
David Harpp (107)
Lecture

Adverse Food Reactions

8 Pages
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Department
Chemistry
Course Code
CHEM 181
Professor
David Harpp

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Wold of Chem: Food March 20 Adverse Food Reactions Adverse Food Reactions Some adverse reactions can be fatal. Bacterial, viral contamination of food supply salmonella, E. Coli causes hemolytic anemia, which can kill you. Botulin poisoning by drinking carrot juice. Real risk or perceived risk? Perceived risks: o Salem, New Jersey 1820 lawyer Robert Gibbon Johnson noted that Italians eat tomatoes, but North Americans did not because tomatoes are from the same family as the Belladonna plant, whose seeds are highly poisonous. So he put an ad in a local newspaper to promise he would eat a tomato. Thus the North American tomato industry was born. Lycopene prevents prostate and cervical cancer (not proven yet)? o Widely believed but is not real: a perceived risk Real risks: o In 1850 English physician Arthur Hasall saw that a steel fork became coated with copper when he mashed gooseberries. They had been adulterated with copper to make them green. o In the early 1900s, chalk was added to watered down milk; arsenic and boric acid sprinkled on meat and fish to retard spoilage and lard was added to extend butter. o Copper salts added to vegetables; plaster of Paris added to flour; arsenic oxide added to meat; indigo added to tea to extend it more colour with less tea. Today we have regulations in place safer food supply. But we still have problems. Unintentional toxins o Pesticide residues not used on all crops: organic (though there are natural pesticides used). The amount allowed is carefully regulated by Health Canada and the FDA random sampling surveys about amounts on food. o Cucumbers are often treated with a pesticide called aldicarb (acetyl-cholinerase inhibitor) cause cholinergic crisis. Aldicarb is sold as a concentrated solution and must be diluted by farmers, but if the farmer makes a mistake in the dilution, then there can be catastrophic consequence. o Hg in fish. Can be a problem for pregnant women during embryonic developmental stage, the mercury is most toxic. Salmon is fine because it doesnt contain mercury, but swordfish and large tuna are not good. Naturally occurring toxins o Solanine, muscarine, mycotoxins, tyramine, histamine, tetrodotoxin, red tide toxin, cyanide, licorice, pyrollizidine alkaloids, to name a few. o Nature is not benign it is very dangerous. o Coniine in hemlock plant a naturally occurring substance. But very dangerous. o Potato contains solanine, a toxin. Can make you sick to your stomach. The presence of chlorophyll in the plant is for photosynthesis. The potato is increasing its photosynthesis and producing solanine, an anti-fungal compound. The potato is trying to protect itself from fungal infection. It can make us sick, but it is rare. Wold of Chem: Food March 20 Adverse Food Reactions o Fly agaric mushroom is one of the most poisonous mushrooms has the toxin muscarine, for example. A couple bites can kill. o Moulds produce metabolites, which can be medicinal but also highly toxic. Thus if something is mouldy, dont eat it. Mycotoxins (toxins produced by mould) in breakfast cereals, which had to be recalled and removed from the market. Aflatoxins (Very potent clas of carcinogens), ochratoxin A, patulin and fusarium: metabolites of mould. Barley and corn can be contaminated by mould o Tyramine: found in aged/fermented foods such as cheeses and wine. For most of us, it is not a problem because it is metabolised by monamine oxidase. It is a vasal presser can increase blood pressure. But people on MAO inhibitors will have a higher than normal level of tyramine in blood stream, which can trigger hypertension or stroke. o Fish start to smell quickly if not refrigerated because they harbour bacteria that can break down the components of the fish very quickly after it dies. Scromboid poisoning occurs after eating fish that contain high levels of histamine. As a result of inadequate refrigeration or preservation, bacteria convert the histidine to histamine, leading to this poisoning. Symptoms like allergies: tingling/burning sensation in the mouth, rash on face and upper body, throbbing headache, hives and itching of skin, nausea, vomiting and diarrhea. Treatment is with antihistamines like Benadryl. Rarely causes death. o Barracuda (fish) ciguatera poisoning. From algae that the barracuda eat. Also associated with nausea, vomiting, diarrhea, numbness, tingling. Hot/cold reversal can stay with you for years. The feeling of not being well can stay with you for a long time. Can ruin lives. o Puffer fish tetrodotoxin paralyses the nervous system. The cooked version is called Fugu. Chefs must remove the parts that harbour the toxin. Tingling sensation in fingers and goes up your arms after eating. If tingling stops at the elbows, then you are fine. But if it goes past your elbows, you will die. Tetrodotoxin connected with stories of zombies in Haiti. Treated with zombie cucumber to wake them up from paralysis which contains atropine and scopolamine. Atropine counteracts the toxin because it speeds up the heart. The Serpent and the Rainbow a book about the zombies in Haiti o Mussels mussel poisoning; mussels contaminated by domoic acid produced by algae. If you didnt die, the side effect is loss of long-term memory. o Cassava contains cyanide, which can be released if the cassava is left out in the sun to dry fermentation process. But if not properly processed, you can die. Cassava in the Caribbean has a low cyanide content, but in Africa the content is high. o Licorice root contains glycyrrhizinic acid, which causes excretion of potassium. You can drop your potassium levels very quickly which can cause paralysis from the waist down.Wold of Chem: Food March 20 Adverse Food Reactions o Comfrey plant. You can buy comfrey leaves in health food stores to make tea. But contain pyrrolizidine alkaloids, which can destroy your liver. Problems with body chemistry o Diabetes o Phenylketonuria A genetic disease Affects 1/15,000 children Abbreviated as PKU Inability to metabolise phenylalanine (amino acid) which builds up in the brain, which can be toxic and lead to mental illness. Thus kids need to stay away from phenylalanine early on in life (first 10 years) if they have PKU Have to avoid aspartame because aspartame is made up of amino acids, and when hydrolyzed in the body, there is phenylalanine. Most proteins have phenylalanine o Lactose intolerance Very different from an allergy (no antibody production) An adverse reaction to lactose 70% world population affected most Asians are lactose intolerant The only way to firmly diagnose lactose intolerance is a breath test monitor the amount of hydrogen you exhale in your breath. If lactase is not present in your body, the lactose will go through your intestines into the colon and bacteria will ingest it. But when they ingest it
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