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1. Intro to Food & Food Perspectives.docx

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McGill University
CHEM 181
David Harpp

L ECTURE 1 (Jan. 7 ), Introduction by Joe Schwarcz What should we put on our plate? • Many look up to the USDA (United States Department of Agriculture) for dietary advice. o Food pyramids have been replaced by the “food plate”, which gives us an idea of the proportions of food components we should consume in a healthy diet. o It has been widely criticized though for not being detailed enough, for suggesting that dairy should be consumed at every meal, and for not considering fats at all. • Alternative healthy eating plate of the Harvard School of Public Health: o They include healthy fats. o Don’t advocate consuming dairy every meal. o More detailed info about types of grains one should be eating, etc. o No political/industrial affiliations.  This is not the case with the USDA→ afraid to be against sugar or white flour. • UK has its own “eatwell plate”. • High-fat low-carb diet plate (acc. toAtkins’ people). It has some merit in weight loss. • Vegan plate (no animal products). • Paleo dieters suggest that we should eat the way our cavemen did. Diet based on meat consumption. • Low calory diet: Key to longevity. • Canadian Food Guide suggests eating, for instance, lots of carbohydrates (despite many scientific opinions against this idea). • Despite a lot of research, there is still much controversy. E.g. of some agreed facts: the less sugar, the better. Trans-fats are not beneficial. • Nowadays, there is simply too much information. We can back up with evidence almost anything we want. There is no shortage of food in NorthAmerica. • We have a wide variety of fruits, vegetables (cooked or raw), meats (chicken, beef, spiced, temperature of cooking, processed meat, etc.), breads (refined flour, whole-grain flour), cheeses, deserts to pick from! • Conundrum of food additives: preservatives, artificial flavours and colours. • People around the world have different diets. Scientists try to relate diets to the health of the population. Alot of advice about nutrition is available in books. • • Wheat Belly: avoiding anything • Sweet Poison, Why Sugar Makes Us made with wheat/grain. Fat: too much fructose in liver • Milk, The Deadly Poison • Sweet Deception: artificial • Toxic Oil sweeteners are supposed to be • The whole soy story: soy is said to carcinogenic. contain many dangerous toxins. • Beware of the food you eat. • My Beef with Meat What is THE healthy diet? • We don’t lack information; it’s what we do with it. • When we have little or too much information, it leads to confusion. We need the RIGHT amount of information. • We used to be concerned only about the taste of food. Now, we’re very critical about everything we eat. We wonder if we should eat vitamin C to neutralize nitrites (if contained in our food) so that they get converted into nitric oxides, for instance. • Eating has become a clinical experience; we want to know the cholesterol content of food, the vitamin content, whether our food is genetically modified or not, etc. You are what you eat: Statement of scientific fact. Food is the only raw material that goes into our body, so we are constructed of what we eat. Obviously, there has to be a link between food and health, although food is not the only determinant of health. Genetics play a huge part, but food consumption is what we can CONTROL. • We are a large “bag” of hundreds of thousands chemicals. o In an apple bite, there are about 300 different compounds. o When we sniff coffee, we smell over a thousand different compounds. You are what you read: our knowledge comes from reading, so we need to be selective about the information we read. We may learn one day that it’s poutine that’s killing us, but the next day the news can give us comforting information that we can avoid all disease if we eat pomegranates, a miracle fruit! Only because it’s been used for a long time, it doesn’t mean it’s been effective. • One rule of nutrition: If it tastes good, you should be careful and not eat too much of it. • Bible story (where it all started): The story is that of Eve temptingAdam to eat an apple. The bible, however, never mentions the fruit of the tree of knowledge. It couldn’t have been an apple however, since this fruit didn’t grow in that part of the world at the time; apples were only introduced in the middle ages. It could have been pomegranates. o Pomegranates contain natural aromatase inhibitors. These types of inhibitors, when synthesized in the lab, can be used in medicine to help treat breast cancer for example.  The multiplication of cultured breast cancer cells is reduced when bathed in pomegranate juice. This observation is not sufficient enough for us to extrapolate that pomegranates are a preventative measure or treatment for breast cancer.  This is the kind of claim advertisers would use to sell the fruit, but in doing so they lead to misinformation. • There is no miracle food, but it’s possible to make any food sound that way by selectively looking at the scientific literature. o One could convince us that dried apricots are the way to go. o At the foot of the Himalayas, in Shangri- La, the diet is very high in dried apricots due to its availability. The book “Lost Horizon” by James Hilton explores the idea that people should live forever there. People from that region claim to have impressive longevity (120- 30 years), but this cannot be verified since they do not have birth certificates.  Assuming it is true, we can then make the claim that dried apricots contain a lot of beta-carotene, which is an antioxidant and is beneficial for health.  Apricot pits have laetrile, which was once promoted as a cancer remedy. The scientific research done by the National Cancer Institute suggests otherwise (see next page). • To prevent such confusion and misinformation, in science, we rely on peer-reviewed literature. Not 100% true, since there is no guarantee that the submitted work has actually been done and that the results are accurate; we have to assume that it has been the case. o Andrew Wakefield academic paper that scared people away from vaccination wasn’t accurate in terms of what was actually done in the experiment. 2500 years ago, people were already concerned about what we should and shouldn’t eat. • Hippocrates said, “Let Thy Food Be Thy Medicine.” • People were even more concerned about food in those times, since they didn’t have drugs, so the only way of improving their health was through selection of the right food. • Less wisely, Hippocrates also argued that “lettuce cools the body and curbs the passion,” that “pigeon droppings are great for baldness” and that “flax is great for the intestines.” o Flax acts very effectively as a laxative, facilitating bowel movements and relieving constipation. o Flax seeds also contain beneficial omega-3 fats. These fats contain compounds called lignans, which have anti-cancer effects (at least on cells in laboratory conditions), and fiber, which are good for the intestinal health. • Nutritional science: a mix of sense and nonsense. We simply have more of both now. • We are continuously extrapolating from laboratory data, combining it with human epidemiological evidence, which is quite often inaccurate being based on “recall” (questionnaires/surveys) since we can’t remember frequencies of food consumption and estimate amounts precisely. o Alternative: use “food diaries” and write down what and when we ate. • Details are important when analyzing scientific results.An example comes from a study by Lillian Thompson from University of Toronto: risk of breast cancer is reduced by dietary phytoestrogen (lignans and isoflavones) intake but ONLY in premenopausal overweigth women. • No geese lay golden eggs, but some chickens do: Omega 3 eggs. o Egg yolk is burdened with cholesterol, which is often linked (supposedly) to heart problems. Egg sales were declining as a result of this association, so a new marketing angle was chosen. o While egg sales were dropping, food with Omega 3 fats (mostly found in fish oil) were very popular, because these fats were associated with reduced risk of irregular heart beat, reduced attention deficit disorder, and increased IQ in children whose mothers have eaten omega 3 fats during pregnancy. o Solution: incorporating flax seeds in the chicken diet, which contain a similar type of omega 3 fats as that in fish oil. People’s attention was distracted away from the cholesterol content of egg yolks.  The increase in the omega 3 content in eggs is not considerable, however. To eat enough eggs so that their input in our omega 3 diet requirement is significant would involve us consuming more eggs than we should (>5-7 eggs/week). So, it doesn’t matter what types of eggs we buy. o We technically don’t need the chicken (i.e. the middlemen). We can eat flax seeds directly, by sprinkling them over cereal, baking them into bread or buying bagels with 20g of flax seeds – the amount Dr. Thomson of UofT has shown to be beneficial to reduce breast cancer occurrence.  These bagels are better for us than sugary donuts which contain a lot of trans fats, that are harmful for us, make us gain weigth, and increase our blood cholesterol. Adose-controlled study claimed that beta-glucan in oatmeal and oat bran (outer covering of oat grain) could lower cholesterol. Beginning of oat-bran mania; it became a quasi medicine (before, farmers used to get rid of it by giving it to animals to eat). • But HOW MUCH oat bran is there in the commercialized products? How much of them should we eat to avail ourselves of the benefits? o The active ingredient in the oat bran is a chemical called beta- glucan, a form of soluble fiber. o To ingest 3 grams of beta glucan – the quantity required for lowering blood cholesterol – we would need.  1 cup of oat bran hot cereal.  3-5 muffins of oat bran muffins.  1.5 cups of oatmeal.  5 servings of cheerios (at which point this equals an overdose of sugar). • The literature aimed at the consumers rarely talks about numbers and only mentions what is good and bad for us. o “Fit for Life” by Harvey and Marilyn Diamond: The writers were, at the time, a married couple who portrayed themselves as people protecting us from an unholy alliance between scientists who try to undermine the health of the public. They divorced later and each married a partner half their age.  E.g. of absurdity they wrote: • “Within atoms & molecules reside vital elements we know as enzymes. Enzymes are not things, substances. They are the life principle in the atoms & molecules of every living cell.” (i.e.enzymes are the living entity in a food; cooking a food or adding preservatives destroys enzymes). • “The greatest threat to your health is processed food. The day science entered the food indudstry was a sad, sad day indeed.” o No, it was a good day. Today, we have a better food supply than ever in human history, if chosen wisely. Sliced white bread is made with preservatives, e.g. calcium propionate (in bread), which to the Diamonds were synonymous with toxins and poison. • Although it’s obvious that whole-grain bread is better for us, preservatives are important to prevent molds from forming and releasing very toxic metabolites. • Before a chemical is added to a food as an additive, the baker has to submit a lot of data to Health Canada and UFFDA(?) to be approved. Calcium propionate is an approved food additive, since it’s actually produced by the body – they are metabolic breakdown products of fats and are found in our sweat. French lifestyle: Baguettes grow hard starting after 17 sec, since they have no preservatives. • The French Paradox and beyond: Live Longer with Wine & the Mediterranean Lifestyle by Lewis Perdue → describes how Frenchmen who smoked more, exercised less, ate more butter- filled croissants and stuffed geese livers have fewer heart attacks than us? How is it that the coronary artery disease (CAD) death rate is about ¼ of that in NorthAmerica? It’s definitely not because French people watch Jerry Lewis more than anyone else (!). We could plot a graph: the more Jerry Lewis, the less heart disease, but this association doesn’t translate into cause-and-effect. • The attribute in the French Paradox is to red wine. French people drink 30x more red wine than we do in North America, which is said to protect them. We have the same problem here: this statement is only an association and not a cause-and-effect relationship! • Red wine contains resveratrol, an antioxidant with some anti-cancer effect & cholesterol lowering, that “underlies” the lower CAD death rate. o To confirm this is true, we would need to conduct a controlled study: a group consuming resveratrol and a control group not consuming it. We don’t have such evidence – look back to the difficulties of epidemiological studies mentioned earlier. o Marketers don’t wait for such explorations: resveratrol pills are already available in health food stores. Not sure if these pills contain much resveratrol, since it’s a very unstable compound. • Ethanol (alcohol) in red wine is a known carcinogen (cancer-causing agent). Had alcohol not been a natural product, but synthetic, and if producers tried to introduce it to the market now, they would never have succeeded. Remember: there are NO superfoods; it’s an invention of marketers and book writers. • E.g. “The Cure is in The Cupboard: How to use Oregano for Better Health” by Dr. Cass Igram → oregano is a medicine chest in a bottle. It can reverse many ailments, including: • It’s a MISLEADING CONCEPT however (there is no evidence for all that). The secret of eating healthier is simply not as seductive as the idea of miracle foods existing. Obesity is a real problem, especially in NorthAmerica. This condition is linked to cancer, heart disease, and diabetes. • Alot of it comes from the overconsumption of sugar (while until now, fats were mostly blamed). The amount of sugar in soft drinks, for example, is staggerring. Keep in mind that, although the same amount of sugar is found in apple/orange juice, at least there are some vitamins and minerals along with it. • Another factor is how we cook food. High temperature is the enemy of health. When we charcoal boil a steak, we introduce a variety of heterocyclic aromatic amines and polycyclic hydrocarbons, which lead to all kinds of health issues. • Processed food:Astudy tells us that consuming an average of 60 grams of processed meat (with nitrites) a day increases the risk of developing colorectal cancer by 50%. o The vegetarian diet might seem the way to go, but many argue that this leads to lack of the specific nutrients found in meat. Obviously, the more vegetables we eat the better. We need to be more careful with fruits du
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