World Of Chem Food Notes PDF

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Topic 1-3, Lecture 1 Notes...

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World of Chemistry: Food Midterm 1 Jan 7- Recorded Session #1: Welcome/ Introduction to the Course Grading 10 % Quizzes 60 % Midterms (2) 30% Final Exam Important Dates Midterm 1 (Topics 1-4): Feb 9 Midterm 2 (Topics 5-7): Mar 9 Final Exam (Topics 8-10) Defintions ● Meta-analysis: the statistical procedure for combining data from multiple studies ● Observational study: Study where researchers simply collect data based on what is seen and heard and infer based on the data collected… The researcher has no control over the variables in an observational study Important ● Correlation is not the same as Causation!! ● Beware of “I heard that…” - REQUEST EVIDENCE Topic 1: Introduction- Perspectives, Health, History, Science and Society Scientific Publishing Learning goals for this topic: 1. Apply critical thinking to health claims and scientific information as it relates to food. 2. Describe the connection between food, health and society. 3. Demonstrate understanding of scientific research and publishing, including the peer review process. 4. Describe different types of research design. Welcome to CHEM181 The idea behind this course - To familiarize the public with what happens in the world of nutrition and the world of food science Topics we will discuss - Nutrients (ex. the lycopene in tomatoes and what it does for us & why garlic needs to be crushed for cooking-- it releases sulfur compounds)

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Genetic modification (genetic mutants have nothing to do with recombinant DNA technology)

Aspects of food - Red peppers are just green peppers that are more ripe - Agriculture (and farmers) are really important Macdonald Campus - Multiple acres - 25,000 kilos of fruits and vegetables Apples - When apples turn brown: chemical reaction → when you disturb the cells, it releases an enzyme, react with chemicals called polyphenols, and we get a polymer that has brown color. → The thinking is that the apple evolved to protect itself from invaders like fungi and insects with that discoloration. --> It's possible to genetically modify apples with recombinant DNA technology, to prevent browning. It is called the Artic Apple → It isn't on the market because people are reticent about genetic modification. **This course will dispel myths and give some facts that are science based.** There are no magic solutions to nutrition. - There's no single food that is going to deliver all the nutrients we need. - There are healthy diets and there are unhealthy diets. - It's all a question of the overall composition of the diet Lesson 1: A Sampling of Food Topics Video 1 A professorial story: One day there was a prof who looked out at the class, and he wanted to have an impact with a demo. So he walked over to the side of the lecture hall and picked up a bottle with a live, wriggling worm in it. Then he poured in a little bit of alcohol. The worm died. Went over, picked up another jar with yet another live worm in it, and poured a little bit of chocolate liqueur. The worm died. Did it a third time, this time pouring in a bit of tobacco ashes. Once again, the worm died. Looked out at the students, asked, what do you guys make of that? One inventive student in the back started to wave his hand, and he said, sir, I know. If you drink, smoke, and eat chocolate, you don't have to worry about worms. Well, of course, there was laughter in the class because the student had made the right observation but he had come to the wrong conclusion. Science is all about making observations and coming to conclusions.

Office for Science and Society at McGill University. ● Opened 14 years ago ● When students graduate, they still should have access to good information. ● Provides information in an unbiased fashion and receive no funding from any vested interest ● If there isn't a focal point where students, can ask questions and have them be answered in an unbiased fashion, then they end up listening to quacks. ● Mandate is to try to make sure that people are up to date on what happens in the world of science. ● Fosters critical thinking, and separate sense from nonsense. Lots of Nonsense out there ● At health food stores you can find supplements that will cure any disease known to mankind ● According to some websites if you suffer from blocked arteries, well, perhaps apple cider vinegar can clean up those blockages Why are there people who are worried about their arteries being clogged up? Because they may have had the Triple Bypass Burger. ● Invented in Arizona at the Heart Attack Grill ● Has closed down in Arizona and moved to Las Vegas (The City of Excesses). ● In Las Vegas, they've added a new item to the menu: the Quadruple Bypass Burger (9,980 calories). ● Portrays the excesses that are out there. ● Now, the Heart Attack Grill is a living cartoon. But we know that there's tremendous overindulgence in food in North America. What we should eat and what we should not eat ● LOTS of confusion ● One day, it's butter that's killing us. The next day, it's margarine. ● This is the Information Age and there's a tremendous amount of information ● We have a problem if we have too little or too much information. ● Too much becomes overwhelming and confusing. This course aims to take out the confusion by just giving the right amount of information. ● ●

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In the past if food tasted good, we ate it. That's all that mattered. These days, we analyze and criticize. We want to know what's in our food. Does it have nitrites? What is the vitamin content? What minerals are present? We want to know about trans fats. We want to know about cholesterol. Calorie content? Not unreasonable because we are what we eat.

We are what we eat: a statement of scientific fact.

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Food is the only raw material that ever goes into our body. Our flesh, our bones, our brains must be built of whatever we put into our mouth.

Chemicals ● We are nothing but a large bag of chemicals. ● Unfortunately, the word "chemical" has become synonymous with poison, toxin. ● The world, is made up of chemicals. There are some 60 million known chemicals registered by chemical abstracts, of which about 100,000 are man-made or synthetic ● Most of the chemicals to which we are exposed are perfectly natural. ● Something that is natural does not necessarily equate to safe, and synthetic certainly does not equal to danger. ● It is a question of what we know about the substance, not its origin. How do we know what a substance is? Because we read. ● We are what we read as well as what we eat. ● Whatever you hear on TV or the radio originally appeared somewhere as a written word. ● So virtually every day, we are bombarded by some novel information. Never know what it's going to be. ● One day, it may turn out poutine is the new devil. It isn't surprising that it isn't particularly good for us. Why? Because it tastes good. ● Unfortunately the rule of thumb is if something tastes good, you don't want to have too much of it. If you don't like it, you can eat as much as you want. ● We have virtually every day some new toxin du jour, or toxin of the day. Video 2 Every day brings advice about some new miracle food. ● One day, it may be pomegranate juice. ● Pomegranate juice has been prized since biblical era. ● Is that enough for us to start indulging in it? No. We need evidence. Science in the Bible. ● Everyone says Eve tempted Adam with an apple ● The Bible however, does not name what the fruit of the tree of knowledge is. ● The reason we think it's an apple is that that's the way that artists in the Middle Ages depicted it. → That's the fruit that they knew. ● Pomegranates were unknown to artists in the Middle Ages ● But it likely was pomegranates (if that tree of knowledge existed) because pomegranates grew in that part of the world since time immemorial and apples weren't found there until much later. Pomegranates has anticancer properties. ● Contain compounds called aromatase inhibitors. ● Studies have shown is that if you take cultured breast cancer cells in the laboratory in a Petri dish, and you douse them with pomegranate juice, they multiply less quickly.

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In the lab, the multiplication of cultured breast cancer cells is reduced when bathed in pomegranate juice We cannot assume that pomegranate has any effect on humans.

Advertisement of pomegranate juice ● Advertisers will take a smidgen of scientific information and then blow it out of perspective. ● By cherry-picking data, and portraying this as if it were some kind of a miracle. ● That's how you get pomegranate juice being advertised as a way of cheating death. ● That's how it becomes a superhero or the doctor in disguise. ● That's how pomegranate juice puts you on life support ● The Federal Trade Commission in the US slapped the manufacturers of POM on the wrist because they had overstepped the boundaries. ● Pomegranate juice may actually have some beneficial properties. But you have to be careful about overstating what those properties may be. ● It is possible to make such claims for virtually any fruit or vegetable because they all have some interesting properties. Example ● In the foothills of the Himalayas, the diet features a lot of dried apricots because that's what they have. → One could then portray the dried apricots as being some kind of miracle fruit. → They contain beta-carotene which is an antioxidant. → Even people who don't know very much about antioxidants have heard enough about them to want more in their diet than less. ● James Hilton located his classic novel, Shangri-La, in the foothills of the Himalayas, where people lived to ripe, old ages, supposedly forever. ● Today, people there still claim to have impressive longevity, to live to 120 → The trouble is they make those claims without birth certificates. ● One could suggest that if you have a diet that is high in dried apricots, which they do, then you can lead a long life because they apparently have a long life. It may have nothing to do with the fact that they eat dried apricots but by cherry-picking data, one could make such an association and suggest that it is actually cause and effect. ● Markers do things like that when selling apricot extracts or apricot pits as health items (overstepping the boundaries) ● Ex. apricot pits: much talked about as the raw material from which a chemical called Laetrile is extracted. → Laetrile turned out to be a bogus cancer remedy, but at one time it was very popular. → Steve McQueen, the actor, used Laetrile when he suffered from a terrible disease called mesothelioma, which is a type of lung cancer. It didn’t work. → there are books that portray apricots and apricot pits as the answer to cancer.

How to Combat this ● Look at those kinds of things with a grain of salt ● Analyze all of the information that is out there in the scientific literature ● The National Cancer Institute does this → They looked at Laetrile because it's not inconceivable that some food extract can have a beneficial property → Apricot pits contain a compound that can release cyanide, and the argument was that the cyanide will preferentially kill cancer cells → It doesn’t make sense because why should it kill cancer cells and not other cells → They argued that cancer cells are multiplying more quickly, and therefore the cyanide will have a bigger impact on that. → The argument was not undreasonable so they tested it and the data show that Laetrile does not have an effect on cancer. ● In the world of science, what we do is go by the data. We go by the peer-reviewed scientific literature, not by hearsay, not by they say, and not by emotion. Activity 3: Fact of Fiction Brown eggs are more nutritious than white eggs. FICTION - Both types of eggs are equally nutritious (assuming they are not labeled omega 3). The difference in appearance is an indicator of the colour of the feathers and ear lobes of the hen that laid the egg. Frozen vegetables can be more nutritious than fresh vegetables. FACT - Vegetables that are frozen are typically picked and processed at their peak ripeness when they are most nutrient packed compared to fresh vegetables that are often picked under ripe for shipping. The exception would be locally grown vegetables. Coffee is the number one source of antioxidants in the North American diet. FACT - While other foods, such as cranberries and grapes, contain more antioxidants on a weight per weight basis, North Americans consume significantly more coffee. This was shown in a 2005 study by Dr. Joe Vinson at the University of Scranton when he compared per capita consumption and the antioxidant concentration of 100 different types of food. Video 3 Peer-reviewed literature is the cornerstone of science. The altar at which we worshipsometimes we actually worship a bit too much because we kind of assume that just because something has been in the peer-reviewed literature, it must be correct. There are good publications, there are some very poor publications and there are mostly mediocre publications. We, tend to look at the ones that have great impact: New England Journal of Medicine, The Lancet, Journal of the American Medical Association, Journal of the American Chemical Society,

Journal of Clinical Nutrition. That's where we draw our information from, and it is as a reliable as can be. People were interested in what happens to their bodies long before there was peerreviewed literature. There was interest in food from the ancient Greeks and the time of Hippocrates. Hippocrates coined the expression, "Let thy food be thy medicine." Today, we think, ya ofc, because food is the only raw material that ever goes into our body. But back in those days, they didn't know anything about chemistry, or biology, or physiology, or the chemical composition of food. So that was quite an inventive idea to suggest that there was a link between what we ate and our health. Not everything that Hippocrates said was equally wise. For example, he thought that lettuce cooled the body and curbed the passions. We don't really have any evidence that it does that. He also thought the pigeon droppings were great for baldness. Mercifully, you didn't have to eat them, you would rub them on head. But as you can see from his personal evidence, didn't work very well. He also suggested that flax was great for the intestines, which it is. It has a very strong laxative effect, which, at times, can be very important. As you can see, we go back to the time of Hippocrates, and what we see is a mix of sense and nonsense. We see the pigeon droppings, and we see the flax seed, two sort of extremes. And we have the same kind of spectrum of information today. There's a lot of nonsense out there, but of course, there's a lot of very, very credible information which we rely on. Hippocrates happened to have been correct about flax seeds. One interesting bit of chemistry in the flax seed. Most people, of course, don't feature flax seeds in their diet, but they are a staple in the health food business and legitimately so, actually, because flax seeds contain compounds called omega-3 fats. Now, you may have heard about these because they have been talked about as the wonder products present in fish. The omega-3 fats that are found in flax seed are actually not as good physiologically as the ones that are found in fish. But if you can't eat fish, they're second best, and they have been linked with a variety of beneficial effects including reduction in risk of cardiac arrhythmia. And there have been even stories about feeding it to pregnant women, for example, and having them give birth to more intelligent children. But I can tell you that for every such positive study, there are others that criticize it. But nevertheless, omega-3 fats are something that we should think about in terms of incorporating into the diet. But flax seeds also contain compounds called lignans, and those are very interesting because they have estrogen-like properties. Now, we will refer to so-called phytoestrogens, or plant-based estrogens, periodically during our discussions because they are controversial chemicals. Estrogen, of course, is a naturally-occurring substance in the body. And chemicals that have estrogen-like behavior can have very strong biological effects both pro and con. Well, lignans, apparently, do have beneficial estrogen-like effects, and I'll mention that in a moment. But the flax seeds also contain all kinds of fiber, both soluble fiber and insoluble fiber. Now, fiber is the indigestible component of foods, so it doesn't get broken down in the stomach or small intestine. Fiber passes through to the colon, where bacteria can manipulate it, break it down, and some of it then is absorbed, much of it is excreted. That's why it results in a laxative effect. The soluble fiber part is actually very interesting because it can reduce cholesterol. We will talk about that later as well. And the insoluble fiber has a beneficial effect of speeding substances through the gut and regulating us. So flax seeds are pretty interesting. Now, I mentioned the lignans, which have estrogen-like properties. And anything that has estrogen-like properties is, in fact, controversial because it can be both good and bad depending on the dosage. Well, it turns out that there have been a number of studies done with lignans and their

potential benefits. Many of these studies done by Dr. Lilian Thompson at the University of Toronto, who is kind of the guru in this particular area, and she has concluded that eating lignans, which are found in flax seed, for example, can have an effect on breast cancer. Now, it is not a very dramatic effect. It turns out that the effect is seen only in pre-menopausal women who are overweight. But you know, that's not a small category of women. And these studies show that intake of flax seed, because of the lignans, reduces the risk of breast cancer because there are breast cancers that are stimulated by the body's over-production of estrogen, and the lignans seem to block those estrogen receptors. It's not a miracle, but one can make good arguments for sprinkling flax seed on top of your cereal every morning, of course with fruit in between the cereal and the flax seed. But people don't want sort of subtle hints about health. They want information about miracles. They want to live forever by doing simple things. Unfortunately, we can't present anything like that because it doesn't exist. There are no geese out there that lay golden eggs. Miracles are very, very hard to come by. There are good diets, and there are bad diets, but it's hard to tell the difference between them. Of course, we can talk about which components should be present in a good diet and which in a poor diet. But people want to be told that there's this certain food that is going to produce only good things, and this component that is going to kill you. It doesn't work like that. So our emphasis will be looking at overall diets, and yes, they can be good or bad. But there are no miracles, no geese that lay golden eggs. However, interestingly enough, there are some chickens that do lay golden eggs, at least for the farmer who is selling those eggs as omega-3 eggs. Well, here's an interesting, little nutritional story. How did this come about? Well, as you know, eggs have a checkered history. They have been linked with heart disease because the egg yolk contains a lot of cholesterol, about 300 milligrams, and high blood levels of cholesterol have been linked to heart disease. Of course, that is not the same thing as saying that eggs are linked to heart disease. And there's a lot of controversy about that as well, which we'll address later on. But in any case, the public perception is that eggs are dangerous. So egg marketers, of course, are concerned because sales have been plummeting. On the other hand, sales of fish have been increasing because of all the benefits of the omega 3 eggs, or of the omega-3 fats. So the egg manufacturers thought, gee, you know, how can we jump on that bandwagon? How can we get some omega-3 fats into our eggs? Well, one way of doing that would be to feed fish meal to the chickens, but that has a side effect of making the eggs fishy. Then they thought, gee, well, you know, flax seeds contain omega-3 fats, so ...