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Midterm 2 Readings Notes

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CHEM 181
David Harpp

World of Chem – Food Midterm 2 Readings Diet and Heart Disease (Oats and Soluble Fibre 69-73)  Oats take a long time to digest and therefore keep you feeling full longer o In a study comparing oatmeal with corn flakes for breakfast, subjects who ate oatmeal consumed 1/3 fewer calories for lunch. o Oats can help you lose weight!  Porridge sticks to the stomach and scrubs the bowels o Contain both soluble and insoluble fibre o Fibre cannot be broken down by enzymes in our digestive tract and therefore cannot provide nutrition o Insoluble and soluble fiber o Cellulose: insoluble fibre; pectin: in fruits; soluble fibre. o Insoluble fibre reduces the risk of diverticulitis and helps eliminate substances that may play a role in colon cancer. o Beta-glucan is the soluble fibre in oats.  Consuming oats regularly can lower blood cholesterol, reduce high blood pressure, keep our arteries healthy and help control diabetes.  Oat bran, the outer covering of the grain, is an excellent source of soluble fibre, which had the ability to reduce cholesterol (according to studies)  Beta-glucan absorbs water in the intestine and traps cholesterol and bile acids from food. Since bile acids are made in the body from cholesterol, their removing from the digestive tract forces more to be synthesized. Thus a depletion of cholesterol is found in the blood.  To reduce blood cholesterol by 5%, one needs to eat 3-4g beta-glucan a day. But induces fullness, bloating and gas. o A reduction of 5% can lower the risk of a heart attack by 10%  Oats lower blood pressure probably by modifying insulin response. The pancreas secretes insulin, which is needed to allow cells to absorb glucose from the bloodstream after a meal. A glucose surge triggers an insulin response but if these surges are frequent, insulin is less effective and more needs to be produced. Thus, insulin resistance – can elevate blood pressure by constricting blood vessels. Soluble fibre slows the absorption of nutrients from the gut and blunts the insulin response.  Oats contain antioxidants including avenanthramides, which prevent LDL from being converted to the oxidized form that damages arteries.  Barley is rich in beta-glucan, in the entire kernel instead of only the outer layer of oats. World of Chem – Food (Grapes and Resveratrol 105-112)  French have the lowest death rate from heart disease in the EU. Resveratrol is an antioxidant in red wine!  Oxidized cholesterol is the one that causes heart attacks  Antioxidants can curtail production of oxidized cholesterol; thus reduce risk of heart attacks.  Resveratrol can also reduce the blood`s clotting ability.  Long-lived yeasts produce sirtuin, an enzyme that can repair damaged DNA. SIR2, the gene that codes for the enzyme, becomes more active when yeast cells are starved of nutrients.  Humans who eat 30% fewer calories than recommended live longer than average (research shows)  Resveratrol mimics the effect of calorie restriction. o One glass increases life expectancy by 10 years!  Drinking red wine may prevent Alzheimer`s disease  Beta-amyloid is a protein that can accumulate in the brain and has been implicated in Alzheimer`s. wine consumption caused fewer deposits of beta-amyloid. The structure of the protein was altered by the wine that prevented it from being deposited in the brain.  White Wine called Chardonnay has the same properties of red wine. Called Paradoxe Blanc.  Some prostaglandins can suppress immunity and stimulate tumour cell growth. resveratrol is a COX-2 blocker, which catalyzed the conversion of arachidonic acid (a dietary component) into prostaglandin.  Also good for stroke damage in humans. World of Chem – Food Minerals (Fortifying With Iron 157-161)  Iron deficiency is the most common nutritional disorder in the world, affecting 25% of the population and 5% of North Americans.  Spinach contains iron and iron can increase energy. But not that much iron in spinach and is not readily absorbed by the body.  Increasing iron intake to boost energy only works if there is iron deficiency to begin with.  Iron is an integral part of hemoglobin, the oxygen-carrying molecule in red blood cells.  Lack of iron caused anemia – tiredness, impairment of mental acuity and itchiness.  Iron reacts with thiocyanate to form a red colour. Can calculate the amount of iron in foods.  Meat contains heme iron, the most absorbable form. Beans, nuts and prunes are all good sources. Fortified fluor is the most prominent source.  Vitamin C enhances iron absorption.  Absorption is a problem when dealing with iron fortification. Elemental iron powders are used, though less absorbed, instead of ferrous sulphate because it affects colour and taste of food.  Whole grain flour is difficult to fortify because of the presence of phytates, which bind iron strongly.  Adding vitamin C is viable in foods that are not heated.  Chelated iron compounds can be used as well – the iron is complexed with either glycine (amino acid) or with EDTA to prevent binding to phytates.  Iron-deficiency anemia can cause complications during pregnancy, increased infant mortality and impairment of physical and mental development.  Iron overload (Bantu in South Africa)  Hemochromatosis – increased absorption of iron – 3/1000 people affected. o Symptoms very similar to anemia o Misdiagnosis can be fatal o Bloodletting is the appropriate treatment  Study: men with higher levels of ferritin, the body’s iron-storage protein, had an increased risk of heart attack. Iron can catalyze the formation of free radicals, which can lead to build up of plaque.  Also related to Parkinson’s disease.  Only need 8 mg/day! No need for supplements.  Women who have a heavy period, pregnant women, people with low-calorie diets and endurance athletes need 18 mg/day – thus maybe supplements are needed. World of Chem – Food (Milk and Calcium 149-154)  Milk is linked with reducing heart disease, breast cancer, colorectal cancer and bone fractures.  Heart disease is more prevalent in countries where dairy consumption is high, but these countries have a diet high in total saturated fat. Milk contains saturated fat but that does not matter.  In studies, milk drinkers had a lower risk of heart disease and stroke!  Calcium can reduce blood pressure. It is known to increase the rate at which the body produces nitric oxide, which relaxes blood vessel walls.  Cow’s milk is a source of estrogens. Calcium depletes blood levels of a form of vitamin D hat has been linked with protection against cancer. But only correlations!  Conjugated linoleic acids (CLAs) may be protective against breast cancer; present in milk.  Milk drinking somewhat increases the risk of ovarian cancer but reduces the risk of colorectal cancers, which are far more common.  Some people cannot digest lactose – lactose intolerance. 70% of population lack the ability ot produce the enzyme beta-galactosidase aka lactase.  Side effects of lactose-intolerance: diarrhea and abdominal cramps. o Diarrhea probably due to increased water flow into the intestine in response to lactose build up. Fermentation of lactose by bacteria resul
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