Transcript HSSP_2.ppt
The Science of Nutrition A Microscopic to Macroscopic Approach Today’s Agenda JEOPARDY 2. Lipids 3. Vitamins & Minerals 4. Nutritional Density 1. JEOPARDY Split into two equal teams and get out your note books. 4 Lipids Types of Lipids Fatty Acids Fats, and Oils Chemical Properties of Triglycerides 5 Types of Lipids Lipids with fatty acids Waxes Fats and oils (trigycerides) Phospholipids Sphingolipids Lipids without fatty acids Steroids What foods contain fat? 7 Fats Fat refers to the class of nutrients known as lipids. The lipid family includes triglycerides (fats and oils), phospholipids, and sterols. Every triglyceride contains one molecule of glycerol and three fatty acids. 8 Fatty Acids Fatty acids are chains of carbon atoms with hydrogen atoms attached that have an acid group (COOH) at one end and a methyl group (CH3) at the other end. 9 Fatty Acids Long-chain carboxylic acids Insoluble in water Typically 12-18 carbon atoms (even number) Some contain double bonds corn oil contains 86% unsaturated fatty acids and 14% saturated fatty acids 10 Saturated v. Unsaturated Fatty Acids Saturated fatty acids carry the maximum possible number of hydrogen atoms, while unsaturated fatty acids lack hydrogen atoms and have at least one double bond between carbons. 11 Structure of Fatty Acids Saturated = C–C bonds Unsaturated = one or more C=C bonds C OOH p a lm itic a c id , a s a tu ra te d a c id C OOH p a lm ito le ic a c id , a n u n s a tu ra te d fa tty a c id 12 Structures Saturated fatty acids Fit closely in regular pattern C OOH C OOH C OOH H Unsaturated fatty acids C Cis double bonds H C cis d o u b le b o n d C OOH 13 Properties of Saturated Fatty Acids Contain Closely Strong High only single C–C bonds packed attractions between chains melting points Solids at room temperature 14 Properties of Unsaturated Fatty Acids Contain one or more double C=C bonds Nonlinear chains do not allow molecules to pack closely Few interactions between chains Low melting points Liquids at room temperature 15 Fats in Your Diet • Try not to eat any trans fats – Increases bad (LDL) cholesterol, lowers good (HDL) cholesterol – risk of heart disease • Keep saturated fat consumption to a minimum • Monounsaturated and polyunsaturated fats – between 15-30% daily caloric intake – Sources: olive oil, safflower oil, peanut oil and corn oil • Avoid hydrogenated or partially hydrogenated oils – added hydrogen to make it solid, preserve – check labels! 1.What foods are high in trans fat? 2.What foods are high in saturated fat? 3.What foods are high in unsaturated fat? 4. What do you want to avoid in your diet? 17 Benefits of Dietary Fats • Fat is an essential part of your diet • Vital for your cell membranes and some cellular functions • Insulates our body • Energy supplier • Absorption and transportation around body of fat soluble vitamins A, D, E and K • Fat surrounds and protects organs, including our kidneys What do you notice? Peanut Butter Jelly NUTRITIONAL DENSITY A Different Approach to Thinking about Nutrition WHAT IS DESNSITY? WHAT IS NUTRITIONAL DESNITY? Nutritional Density = Nutrients/Calorie How much nutritional value (mass) per one calorie (volume) Two Types of Nutrients Macronutrients Micronutrients B Vitamins Folate Citrus, tomatoes, peppers, leafy greens Vitamin D Vitamin K Almonds, seeds, asparagus Vitamin C Leafy greens Vitamin E Bananas, seeds, green vegetables, sweet potato, nuts Cauliflower, Broccoli, Brussle Sprouts, Greens Vitamin Carrots, broccoli,mango, cantaloupe Vitamins Vitamins are organic substances bodies need to grow, metabolize, and develop normally. Deficiencies in vitamins can lead to disease and poor health. Macrominerals Calcium Phosphorus Magnesium Sodium Potassium Sulfur Chloride Trace Minerals Iron Zinc Copper Selenium Manganese Minerals Minerals are the building blocks that make up muscles, tissues, and bones and are components of hormones, oxygen transport, and enzyme systems. Flavonoids Glucosinolates Resveratrol Anti-Inflammatory Ellagic Acid Cruciferous Vegetables Keep Cancer in Check Berries Carotenoids Provide fruits and vegetables with red, yellow and orange color Phytonutrients Phytonutrients are natural chemicals found in plants. There are over 25,000 of them, and they help fight disease and keep the body working Does anything surprise you? A Final Note about Health Vitamins and Minerals 29 30 The Nature of Vitamins Vitamins are organic (carbon) compounds needed for normal function, growth and maintenance. Vitamins are cofactors, they don’t do anything by themselves. They are not a source of calories. 31 The Nature of Vitamins Food processing can preserve nutrients. 32 The Nature of Vitamins Nutritional Value lost by: Light Heat Oxidation Bacteria Enzymes Insects (Nutritional value of baby food must be assured.) Effect of packaging on nutrient loss in milk. Vitamin Requirements Daily Values (DV): standard nutrient intake values developed by FDA Includes DRIs (Daily Recommended Intakes for Individuals) and (DRVs) Daily Recommended Values (Proteins, etc.) Disease prevention Best met through a consumption of a wide variety of foods 34 Vitamin Requirements Dietary Reference Intakes (DRI): recommendation for individuals (more accurate, but would be impossible to label) Age Gender Pregnancy Lactation 35 Vitamin Requirements Daily Reference Values (DRV): standards established for protein and other dietary components lacking a RDA or nutrient standard Constitute part of the Daily Values (DV) used on food labels 36 The Nature of Vitamins cofactors – what is a cofactor? Physiological role – specific metabolic function Prevents disease – unlike “supplements” which may promote “some thing” or have general metabolic effect (ex. Omega 3s, fibers) Natural = Synthetic (except Vitamin E) Organic Dietary Supplements $6 Billion Market They are classified as “Nutritional Supplements” They are not foods, and not drugs.* Supplements are “Product intended to supplement the diet and contains vitamins, minerals, botanicals, amino acids, and their extracts.” NOT consumed as a food replacement Loosely regulated, “not evaluated by FDA” “drug” is used to “prevent, treat or cure” disease. By definition a These terms cannot be used with supplements. Use of some supplements is backed by scientific data. 38 Fat Soluble Vitamins – orange, carotenoids, vision, antioxidantused as color and antioxidant A – we make it with sunlight, deficiency causes rickets, in milk, regulates Ca:P ratios D – tocopherols, antioxidants, role in preventing stroke, cancer, heart diseaseused as antioxidant E K – contributes to blood clotting factor A LOW FAT DIET MAY CAUSE MALABSORBION 39 Vitamin A Lots of double bonds, good anti-oxidant 40 Vitamin A Carrotinoids Used in food industry as a colorant (orange) Antioxidant Important for sight Dietary deficiency common in developing countries Blindness, bone abnormalities, susceptibility to viral infections such as measles and pneumonia If you take a dietary supplement: teens 14-18 should not consume more than 2800mcg; 19+, 3000mcg Cooking and storage do not reduce Vitamin A Carrotenosis Vitamin A cont. SOURCES Carrot juice (450%) /raw carrots (175%) QUICK: CARROTS Boiled (270%)/raw (55%) spinach Vegetable soup (115%) Boiled Peas (20%) Baked sweet potato with skin Cantaloupe (110%) Steamed broccoli Chicken (245%)/beef (545%) liver 42 Vitamin D Also known as calciferol due to its role in calcium absorption Main role is to maintain calcium and potassium levels It is the only fat soluble vitamin that we can make- in the presence of sunlight Part of Immune System and Nerve Signaling <1/3 of people meet dietary requirement Can be made from cholesterol 43 Vitamin D Can be stored in fat tissues (as can all fat soluble vitamins) We get vitamin D form fortified milk and cereal Toxicity is very dangerous Occurs only from excess supplementation Can lead to calcium deposits in kidneys, heart and blood vessels 44 Vitamin E A family of eight naturally occurring compounds anti-oxidant Since aging is considered an “oxidation” reaction, many “anti-oxidants” are used as dietary supplements Protect skin, cell communication, from foods protects against prostate cancer and Alzheimer’s E in supplements = alpha-tocopherol; in food, gamma-tocopherol Role is stroke, cancer, heart, and immune response Americans spend $300 million per year on vitamin E supplements E dependent on C, B3, selenium and glutathione Vitamin E cont. QUICK: NUTS Low-fat diet may cause Vitamin E deficiency (because Vitamin E is fat-soluble!) Common in vegetable oils SOURCES Wheat germ oil Dry roasted sunflower seeds Dry roasted almonds Safflower/sunflower oil Dry roasted hazelnuts Peanut butter/peanuts Boiled spinach Vitamin K QUICK: GREENS Vital for blood clotting, protects bones Works as a cofactor for an enzyme that makes two bone proteins Resilient to cooking/freezing Estimated daily value need is 80 micrograms SOURCES Boiled kale (1/2 cup, 660%) Boiled (1110.6%)/raw spinach Raw parsley (153%) Green leaf lettuce Boiled green beans (25%) 47 Water Soluble Vitamins Relatively cheap to add to food Only Vitamin C is used for its functionality 48 Water Soluble Vitamins B1, thiamine B2, riboflavin B6, pyridoxamine B12 Biotin Panothenic acid Niacin Folacin Vitamin C Water Soluble Vitamins Vitamin B1 Thiamine Involved in carbohydrate metabolism Helps body metabolize glucose, affects central nervous system B2- riboflavin Energy metabolism 50 Water Soluble Vitamins B6 - Pyridoxamine Neurotransmitter, co-enzyme in over 100 reactions B12 – Development of red blood cells Lack of it makes one anemic Hard for vegans to get Vitamin B12 cont. QUICK: FISH SOURCES Calf’s liver (689.8%) Sardines (137%) Baked/broiled snapper (66.2%) Steamed/boiled shrimp (28.2%) Baked/broiled salmon (54.2%) Beef tenderloin (48.7%) Low-fat yogurt (23%) 52 Water Soluble Vitamins Biotin – Involved in fatty acid synthesis Deficiency causes skin disease and hair loss Panthothenic acid Found in many foods Essential for metabolism of carbohydrates, protein, alcohol and fat 53 Vitamin C High in citrus fruits, limes, (Limeys) Very inexpensive to add to food, marketing tool. Antioxidant Anti-oxidant, helps immune system, improve iron absorption Deficiency leads to bleeding gums, hemorrhages In supplements as ascorbic acid – in most multivitamins – check the label! Vitamin C cont. Highly sensitive to air, water and temperature! Fresh, raw form is best QUICK: ORANGE SOURCES Raw bell peppers (291%) Steamed broccoli (84.8%) Boiled cauliflower (91.5%) Strawberries (136%) Romaine lettuce (44.8%) Papaya (313.1%) Grapefruit, oranges, cantaloupe, raspberries… 55 Minerals Issues Absorption Bioavailability 56 Minerals Percent of Body weight Calcium Phosphorus Potassium Sulfur Sodium Chloride Magnesium Iron 2% 1% 0.3% 0.2% 0.1% 0.1% 0.05% 0.04% Sodium and Chloride Small amount is essential to live; excessive consumption increase blood pressure (stroke, heart disease…) Ideally, limit sodium to 1500mg a day; maximum 2300mg Most sodium intake from processed and pre-packaged foods (food preservative, enhance taste) – check labels! Sodium & Chloride cont. NATURALLY LOW CONTENT Fruits Vegetables Fat-free or low-fat dairy Fresh seafood and meat products HIGH SODIUM CONTENT Un-salted anything Salad dressing Soy sauce / ketchup Chips/Pretzles Fast food Processed food Potassium Reduces blood pressure, help muscle and nerve function Kidney strictly regulates levels of potassium Significant loses when cooked Athletes – support muscles Adults – 4700mg a day (so figure a bit less for teens) Potassium cont. QUICK: BANANA SOURCES Baked sweet potato (20%) Baked potato (17%) Non-fat yogurt (17%) Various fish Banana (12%) Spinach (12-20%) Iron Oxygen transport in blood, regulate cell growth Two forms: heme (absorbed better) and nonheme (most dietary iron) 14-18 men 11mg; women 15mg 19+ men 8mg, women 18mg Iron deficiency anemia (too few red blood cells) Iron cont. HEME SOURCES NONHEME SOURCES Chicken liber (70%) Fortified cereal (100%) Oysters (25%) Fortified oatmeal (60%) Turkey (8-10%) Boiled soybeans (50%) Beef (20%) Kidney or lima beans (25%) Tuna (4%) Spinach (10-20%) Calcium Bone health, nerve and muscle function Intake over 3000mg daily can lead to hypercalcemia Not affected by cooking or storage Vitamin D accelerates absorption, potassium reduces urinary excretion Calcium cont. To improve absorption, take with meals – food in stomach - > hydrochloric acid, which breaks down calcium carbonate SOURCES Milk Boiled spinach (24.5%) Turnip/collard/mustard greens Low-fat yogurt (44.7%) Mozzarella cheese, part-skim (18.3%) 65 Calcium Risk Factors- By Mayo Clinic staff Your gender. Age. Race. Frame size. Eating disorders. Low calcium intake. Excess soda consumption (Ca:P ratio). The link between osteoporosis and caffeinated sodas isn't clear, but caffeine may interfere with calcium absorption and its diuretic effect may increase mineral loss. In addition, the phosphoric acid in soda may contribute to bone loss. Bone density can be improved at any time. 67 Soda is the devil’s drink Extra calories Poor nutrient density Interferes with calcification Replaces more nutritious drinks 68 Minerals Sulfur Necessary for collagen formation Magnesium Abundant in plants Fortification vs Enrichment Fortification - restores lost nutrients due to processing – adds nutritional value to meet a specific standard Enrichment Old London Restaurant Style Croutons. Seasoned Sourdough. Enriched Bread, [Enriched Flour (Flour, Niacin, Ferrous Sulfate, Thiamin Mononitrate, Riboflavin, Folic Acid), Water, Yeast, Sugar, Salt, Partially Hydrogenated Soybean Oil , Vinegar, Ascorbic Acid] Bean Oil with BHT added as a Dextrin