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Option A: Human nutrition and health Define nutrient. A Nutrient is a chemical substance found in foods that is used in the human body. http://www.faqs.org/nutrition/images/nwaz_02_img0168.jpg List the type of nutrients that are essential in the human diet: Amino acids are the building blocks of protein . The body has twenty different amino acids that act as these building blocks. Nonessential amino acids are those that the body can synthesize for itself, provided there is enough nitrogen, carbon, hydrogen, and oxygen available. Essential amino acids are those supplied by the diet , since the human body either cannot make them at all or cannot make them in sufficient quantity to meet its needs. Under normal conditions, eleven of the amino acids are nonessential and nine are essential. Fatty Acids Saturated fatty acids can align closely together so lipids containing primarily saturated fatty acids are usually solid at room temperature (aka Fat). The C=C double bond(s) in unsaturated fatty acids causes the molecule to "bend" (a fatty acid with one C=C bond is monounsaturated, a fatty acid with several C=C bonds is poly-unsaturated. Because they are "bent", unsaturated fatty acids are less able to interact and lipids contain primarily unsaturated fatty acids are liquid at room temperature (oils). • Trans fatty acids are manufactured fats created during a process called hydrogenation, which is aimed at stabilizing polyunsaturated oils to prevent them from becoming rancid and to keep them solid at room temperature. They may be particularly dangerous for the heart and may pose a risk for certain cancers. Hydrogenated fats are used in stick margarine, fast foods, commercial baked goods (donuts, cookies, crackers), processed foods, and fried foods. Cis and trans are terms that refer to the arrangement of chains of carbon atoms across the double bond. In the cis arrangement, the chains are on the same side of the double bond, resulting in a kink. In the trans arrangement, the chains are on opposite sides of the double bond, and the chain is straight. • • Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. The body cannot make these fatty acids on its own so omega-3s must be obtained from food. These different types of acids can be obtained in foods such as cold-water fish including tuna, salmon, and mackerel. Other important omega 3 fatty acids are found in dark green leafy vegetables, flaxseed oils, and certain vegetable oils. Omega-3 fatty acids have been found to be beneficial for the heart. Positive effects include anti-inflammatory and anti-blood clotting actions, lowering cholesterol and triglyceride levels, and reducing blood pressure. These fatty acids may also reduce the risks and symptoms for other disorders including diabetes, stroke, rheumatoid arthritis, asthma, inflammatory bowel disease, ulcerative colitis, some cancers, and mental decline. Minerals These foods are all “mineral dense” foods. Find out which minerals are in each food. http://hachten.com/monavie/wp-content/images/19-fruits.jpg Vitamins A vitamin is an organic compound required as a nutrient in tiny amounts by an organism http://www.childrenfirst.nhs.uk/teens/images/healthyeating/vitamins.jpg • This might be a useful table to help you fill in the Minerals lists. http://www.healthalternatives2000.com /minerals-nutrition-chart.html Make a table! Vitamin A B1 B2 B3 B12 C D E Name Use Deficiency disease Too much RDA Good source Water Roughage / Fibre Consists mainly of Cellulose which is insoluble and indigestible by animals. Forms bulk which allows the gut to move the food. Not enough fibre causes constipation in the short term, and may lead to spastic colon in long term and cancers of the gut due to build up of poisons. Go once a day! Good sources: Fruit and vegetables. http://fitness.resourcesforattorneys.com/images/dietary-fiber.jpg Outline the consequences of protein deficiency malnutrition. • Protein deficiency is shortage of one or more essential amino acids. • The consequences are lack of blood plasma proteins and subsequent tissue fluid retention, with swelling of the abdomen. • Development of children is likely to be both mentally and physically retarded. Kwashiorkor – a protein deficiency • Kwashiorkor is a condition that affects children who belong to areas that have experienced shortage of food. This is usually places where famine has struck. Among the lesser educated classes of society also Kwashiorkor is a fairly common problem since the lack of awareness about a balanced diet often leads to a an inadequate consumption of proteins. Try this website for some amazing pictures: http://www.jamesnachtwey.com/ Explain the causes and consequences of phenylketonuria (PKU) and how early diagnosis and a special diet can reduce the consequences. • Phenylketonuria (PKU) is an autosomal recessive genetic disorder characterized by a deficiency in the hepatic enzyme phenylalanine hydroxylase (PAH) This enzyme is necessary to metabolize the amino acid phenylalanine ('Phe') to the amino acid tyrosine. When PAH is deficient, phenylalanine accumulates and is converted into phenylpyruvate (also known as phenylketone), which is detected in the urine. Watch this YouTube clip : http://www.youtube.com/watch?v=KUJVujhHxPQ • It can be managed by a patient controlling their diet with little or no side effects, just inconvenience with managing the treatment. If however the condition was left untreated, it can cause problems with brain development, leading to progressive mental retardation, brain damage, and seizures. • There is currently no cure for this disease, although some treatments are available with varying success rates. PKU is generally detected through newborn screening with a heal prick test done at 10 days of age. Evaluate the health consequences of diets rich in the different types of fatty acid. Dietary studies are difficult to control sufficiently to gain really reliable data. Where data are produced it may not be possible to conclude causal relationships from correlation. Care must be taken to think critically about nutrition-based news stories and articles. Distinguish between minerals and vitamins in terms of their chemical nature. • Minerals are elements in ionic form. • Vitamins are organic compounds. Outline two of the methods that have been used to determine the recommended daily intake of vitamin C. Some of the experiments used to determine necessary levels of vitamin consumption were done using conscientious objectors during the second world war. This raises ethical questions about trials in which the experimental subjects could be harmed or suffer. Look at this website for detailed description of what they did! It is fascinating. http://ije.oxfordjournals.org/cgi/content/full/35/3/ 556 • • • During World War II, 36 conscientious objectors participated in a study of human starvation conducted by Ancel Keys and his colleagues at the University of Minnesota. The Minnesota Starvation Experiment, as it was later known, was a grueling study meant to gain insight into the physical and psychological effects of semi-starvation and the problem of re-feeding civilians who had been starved during the war. During the experiment, the participants were subjected to semi-starvation in which most lost >25% of their weight, and many experienced anemia, fatigue, apathy, extreme weakness, irritability, neurological deficits, and lower extremity edema. In 2003–2004, 18 of the original 36 participants were still alive and were interviewed. Many came from the Historic Peace Churches (Mennonite, Brethren, and Quaker), and all expressed strong convictions about nonviolence and wanting to make a meaningful contribution during the war. Despite ethical issues about subjecting healthy humans to starvation, the men interviewed were unanimous in saying that they would do it all over again, even after knowing the suffering that they had experienced. • Life magazine photograph of conscientious objectors during starvation experiment. Life Magazine - July 30, 1945. Volume 19, Number 5, p. 43. Credit: Wallace Kirkland/Time Life Pictures/Getty Images Animal trials on Vitamin C • Guinea pig trials: observed the effect of vitamin C concentration on collagen structure. After periods of varying vitamin C supplementation and measurement of blood and urine vitamin C levels, guinea pigs were sacrificed and the structure of collagen fibres observed. Guinea pigs with restricted vitamin C showed weaker collagen. • Think ethics! What is vivisection? Can it be justified? http://www.woodwindsanimalhotel.com/images/guinea-pig.jpg What is rebound malnutrition? • Rebound malnutrition can occur when a normally adequate intake of a vitamin follows a period of excessive intake and excretion. List the sources of vitamin D in human diets. • Vitamin D can be produced by skin as a response to sunlight. It also can be found (in a slightly different form) in foods: fatty fish, fish oils, liver, eggs and some mushrooms. In some countries, milk is supplemented with vitamin D. Finding balances…… Vitamin how D is synthesized Suggest you might in But too much Ultraviolet Suggest how the skin the skin with exposure ensure you get enough to radiationitself can from cause Skin protects skin Vitamin D sunlight. in a Cancer cancer. Norwegian winter. Now using your food diary….. Go to http://www.myfoodrecord.com/mainnat.html 1. For the 24 hours you recorded in homework do a diet analysis. 2. Make up an ‘ideal’ MacDonalds Day diet, of breakfast, lunch afternoon snack and dinner. Each meal must be different! Answer the following questions: • What was your diet good for? • What mineral, vitamin or other nutrient was lacking in your diet? • What suggestions could you make to improve your diet? Compare the energy content per 100 g of carbohydrate, fat and protein. Food type Energy per 100g (kJ) carbohydrates 1,760 protein 1,720 fats 4,000 Compare the main dietary sources of energy in different ethnic groups. The 5 most grown carbohydrate sources are: Crop Wheat Production (Million ha) 624 Rice 608 Maize 705 Barley 155 Sorghum 60 http://www.darfu4b.da.gov.ph/images/New%20Folder/cassava_pic.JPG Maize http://en.wikipedia.org/wiki/File:MaizeYield.png Wheat http://upload.wikimedia.org/wikipedia/commons/1/10/WheatYield.png Rice http://en.wikipedia.org/wiki/File:RiceYield.png Explain the possible health consequences of diets rich in carbohydrates, fats and proteins. Outline the function of the appetite control centre in the brain. Hormones/Nervous impulse Hormones are produced by the pancreas and small intestine after eating and by adipose tissue in response to fat storage. These pass to an appetite control centre in the brain, which makes the person feel that they have eaten enough. Horn, Robert. Appetite and Metabolism and Obesity. MedBio.info. [Online] 2006. [Cited: June 24, 2009.] Appetite is controlled in the hypothalamus of the brain. Control is both nervous and hormonal: some hormones trigger appetite-stimulating neurons, others trigger appetite-inhibiting neurons. An empty stomach releases the hormone gherin, which triggers appetite-stimulating hormones, leading to hunger. When food enters the stomach, gherin production is stopped, reducing hunger. 1. Food entering the intestine stimulates release of PYY3-36 hormone. 2. Carbohydrate and protein digestion stimulate release of insulin hormone from the pancreas. 3. Fat storage stimulates release of leptin hormone from the pancreas. This is enhanced by insulin. These three hormones trigger appetite-inhibiting neurons in the appetite control centre. There are strong links to malfunction of any of these pathways and obesity, as the individual eats more than is required. Calculate body mass index (BMI) from the body mass and height of a person. BodyMass ( Kg ) • BMI = 2 Height ( m ) Limitations of the BMI using this table: • Race, gender and age are not considered • No distinction is made on body fat/water/muscle composition Work out the BMI for the following: Height (m) Body Mass (kg) 1.70 54 BMI Category We is getting’ fat……. • Increased levels of obesity world-wide… Childhood obesity has more than tripled in the past 30 years. An estimated 17 percent of children and adolescents (ages 2-19 years) are obese in the U.S. Obese children are at risk for numerous health problems during their youth and into adulthood. Children who are obese are more likely to have high blood pressure, high cholesterol, and Type 2 diabetes. Why? http://www.getamericafit.org/images/american-obesity-trends.gif http://www.yisongyue.com/silly/misc/ObeseMouse.jpg http://media.photobucket.com/image/obese/grimrecords/Obese.jpg?o=4 http://images.mirror.co.uk/upl/m4/dec2009/2/0/obese-flight-passenger-pic-kieran-daly-94182647.jpg http://maxcdn.fooyoh.com/files/attach/images/591/206/098/005/chinese_obese_7caa7.jpg http://resources3.news.com.au/images/2011/03/23/1226026/741679-obese-todler.jpg http://joannaburns.files.wordpress.com/2008/11/mcdonalds.jpg http://3.bp.blogspot.com/_DQXAKB1OvOw/TSQJ2R1rAzI/AAAAAAAAANg/Y4QDJNUUtkE/s1600/fat_american_walking_dog_from_car-1.jpg http://health.lifegoesstrong.com/sites/default/files/imagecache/reg/article_media/fat_office_worker.jpg increasing use ofactive vehicles Cheap A change High from energy foods to for transport, sedentary Large portion occupations. sizes At the other extreme…. http://medicallywiseinfo.co m/wpcontent/uploads/2010/03/ Anorexia-nervosa0.jpg http://www.womenshealth zone.net/eatingdisorders/anorexianervosa/effects/img/1287. gif Comparison of Human Milk and Formula NUTRIENT FACTOR BREAST MILK CONTAINS Fats •Rich in brain-building omega 3s, namely DHA and AA -Automatically adjusts to infant's needs; levels decline as baby gets older -Rich in cholesterol -Nearly completely absorbed -Contains fat-digesting enzyme, lipase FORMULA CONTAINS -No DHA -Doesn't adjust to infant's needs -No cholesterol -Not completely absorbed -No lipase Protein -Soft, easily-digestible whey -More completely absorbed; higher in the milk of mothers who deliver preterm -Lactoferrin for intestinal health -Lysozyme, an antimicrobial -Rich in brain-and-body- building protein components -Rich in growth factors -Contains sleep-inducing proteins -Harder-to-digest casein curds -Not completely absorbed, more waste, harder on kidneys -No lactoferrin, or only a trace -No lysozyme -Deficient or low in some brain-and body-building proteins -Deficient in growth factors -Does not contain as many sleep-inducing proteins. Carbohdrates -Rich in lactose -Rich in oligosaccharides, which promote intestinal health -No lactose in some formulas -Deficient in oligosaccharides Immune Boosters -Rich in living white blood cells, millions per feeding -Rich in immunoglobulins -No live white blood cells-or any other cells. Dead food has less immunological benefit. -Few immunoglobulins and most are the wrong kind Vitamins and Minerals -Better absorbed, especially iron, zinc, and calcium -Iron is 50 to 75 percent absorbed. -Contains more selenium (an antioxidant) -Not absorbed as well -Iron is 5 to 10 percent absorbed -Contains less selenium (an antioxidant) Enzymes and Hormones -Rich in digestive enzymes, such as lipase and amylase -Rich in many hormones: thyroid, prolactin, oxytocin, and more than fifteen others -Varies with mother's diet -Processing kills digestive enzymes -Processing kills hormones, which are not human to begin with -Always tastes the same Cost -Around $600 a year in extra food for mother -Around $1,200 a year -Up to $2,500 a year for hypoallergenic formulas -Cost for bottles and other supplies -Lost income when baby is ill Breast is best…….. (Discuss the benefits of breast feeding) Look at some of these sites: http://www.pregnancyandchildren.com/pregnancy/pregnancy _breast_milk_versus_formula.htm http://www.webmd.com/parenting/baby/your-babys-feedingbreast-vs-bottle http://www.007b.com/breast_versus_bottle.php http://www.burpingbaby.net/breast_vs_bottle.htm Make a table of the pros and cons of breast- and bottle-feeding: Issue Breast feeding Bottle feeding Costs Free? US$600 per year on extra food for mother US$1200- 2000 on formula and equipment for one year. Loss of earnings while baby is ill Immunity Legality Privacy Drugs Alcohol Disease (Mother’s) Diabetes (type II) • Go to this site: http://en.wikipedia.org/wiki/Diabetes_mellitus_type_2 1. Outline the causes and symptoms of type II diabetes. What is polyuria, polydipsia and polyphagia? 2. What are the differences in susceptibility between ethnic groups and suggest a reason why? (especially Native Australians, Native Americans, Latinos, Pacific Islanders. 3. Explain the dietary advice that should be given to a patient who has developed type II diabetes. Discuss the ethical issues concerning the eating of animal products, including honey, eggs, milk and meat. Look at this great page….. http://debatepedia.idebate.org/en/index.php/Debate:_Vegetarianism#Dominion:_Do_ humans_NOT_have_dominion_over_animals_.28and_a_right_to_eat_them.29.3F Discuss the concept of food miles and the reasons for consumers choosing foods to minimize Go to this website – this is where I found these 2 posters… http://hawthornevalleyfarm.org/fep/food.html Evaluate the benefits of reducing dietary cholesterol in lowering the risk of coronary heart disease. Take a look at these websites: 1. An editorial introduction to the debate: http://drpeterdingle.blogspot.com/2010/09/cholesterol-debate.html 2. Link between cholesterol and heart disease- A bit long but detailed: http://www.cholesterol-and-health.com/Does-Cholesterol-Cause-HeartDisease-Myth.html 3. Functions of cholesterol: http://www.cholesterol-and-health.com/Steroid-Hormones.html http://www.cholesterol-and-health.com/Cholesterol-Cell-Membrane.html http://www.cholesterol-and-health.com/Memory-And-Cholesterol.html http://www.cholesterol-and-health.com/Bile-Acids.html http://www.cholesterol-and-health.com/Vitamin-D.html 4. For the alternative viewpoint look at this site: http://www.bhf.org.uk/heart-health/conditions/high-cholesterol.aspx