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This document contains Chapters 6 to 8 Chapter 6 Lipids Overview Chapter 6 focuses on the most energy dense source of calories, lipids. The structure, functions, and food sources of triglycerides, phospholipids, and sterols are presented. Sources and roles of the essential fatty acids, linoleic acid, and alpha-linolenic acid, are discussed. Students will learn about dietary recommendations for fat intake for the general population and for individuals at risk for cardiovascular disease. The association of a Mediterranean diet pattern and reduced risk of chronic disease is described. The processes of digestion, absorption, and transport are reviewed as they specifically relate to lipids. The roles of the various lipoproteins are defined. Throughout the chapter, the link between dietary fat and cardiovascular disease is emphasized, and a Clinical Perspective section explores this connection in detail. Other health concerns regarding fat intake are explored, including high fat intakes and imbalances between omega-6 and omega-3 fatty acid. Learning Outcomes 1. Recognize the basic chemical structure of fatty acids and describe how they are named. 2. Explain the functions of triglycerides, fatty acids, phospholipids, and sterols in the body. 3. Classify and evaluate the different fatty acids based on their health benefits or consequences. 4. Identify food sources of triglycerides, fatty acids, phospholipids, and sterols. 5. Discuss the recommended intake of lipids. 6. Identify strategies for modifying total fat, saturated fat, and trans fat intake. 7. Summarize the digestion, absorption, and transport of lipids in the body. 8. Explain the relationship of dietary lipids to chronic diseases. 9. Describe dietary measures to reduce the risk of developing cardiovascular disease. Teaching Strategies, Activities, Demonstrations, and Assignments 1. Assign students the Take Action activity, "Is Your Diet High in Saturated and Trans Fat?” 2. Assign students the Take Action activity, “What Is Your 10-Year Risk of Cardiovascular Disease?” 3. Have students go to a supermarket and compare the P/S ratio of butter and different margarines, including stick, tub, and squeezable. They can calculate the P/S ratio simply by dividing the grams of saturated fat into those of polyunsaturated fat. Have them report the brands of margarine with the highest P/S ratio. Also, have them collect information on the type of oil used in each of the brands. Use this activity as a springboard to discuss types of margarines and oils to use to lower the risk of coronary heart disease, as well as hydrogenation. 4. In class, compare different fats used in oil products sold in the supermarket and describe the differences in saturation. 5. Have students go to a supermarket and compare various meats for fat grams per serving. They should compare ground turkey, turkey hot dogs, chicken breasts, breaded chicken breasts, ground beef, and various brands of lunchmeats by looking at the food labels. Have students share with classmates what they found. For example, were the poultry products lower in fat grams per serving than red meats? Did breaded products contain the most fat grams per serving? What percentage of the lunchmeats was fat? 6. Bring coffee whiteners, whipped toppings, peanut butter, and mayonnaise labeled "no cholesterol" to class. Describe the amount of fat and type of fat in each, illustrating differences in the concepts of cholesterol and fat. 7. Have students purchase a T-Factor Diet Fat Gram Counter from an area bookstore or require it as a course book in your campus bookstore. Have them tally fat grams they eat for a day using this tool. Have them, on a prescribed day, report their total verbally. Use this as a springboard to discuss ways of reducing fat intake. Lecture Outline Triglycerides General The lipid family includes triglycerides, phospholipids, and sterols All lipids contain carbon, hydrogen, and oxygen Do not dissolve in water; dissolve in organic solvents (e.g., chloroform, benzene, ether) Triglycerides are most common type (95%) of lipids found in food and body Structure 3 fatty acids attached to glycerol backbone Fatty acids present in triglycerides may be same or different from each other Esterification: fatty acids bind to hydroxyl (-OH) groups on glycerol and release 1 molecule of water Re-esterification: reattaching a fatty acid to a glycerol backbone Fatty acids consist of a long carbon chain linked together and surrounded by hydrogen atoms Acid (carboxyl) group at one end Methyl group at one end Carbon Chain Length Long chain fatty acids: 12 or more carbon atoms e.g., beef, pork, lamb, and most plant oils Lengthiest digestion process Transported via lymphatic system Medium chain fatty acids: 6 - 10 carbon atoms e.g., coconut oil, palm kernel oil Digested almost as rapidly as glucose Transported via portal system Short chain fatty acids: <6 carbon atoms e.g., butter fat Rapidly digested Transported via portal system Number of Double Bonds (Saturation) Saturated fats (see Figure 6-3): maximal number of bonds possible, all bonds between carbons are single Monounsaturated fats (see Figure 6-4): one carbon-carbon double bond Polyunsaturated fats (see Figure 6-5): two or more carbon-carbon double bonds Shape (see Figure 6-7) Saturated and trans fatty acids have straight carbon chains Unsaturated cis fatty acids have bent (kinked) carbon chains Cis fatty acids: hydrogen atoms attached to double-bonded carbons are on the same side of the carbon chain (e.g., most unprocessed, unsaturated fatty acids) Trans fatty acids: hydrogen atoms attached to double-bonded carbons are on opposite sides of the carbon chain; straighter chain resembles saturated fatty acid (e.g., hydrogenated polyunsaturated fatty acids) Hydrogenation adds hydrogen to carbon chain of unsaturated fats Increases saturation Becomes increasingly solid at room temperature Naming fatty acids Omega (ω or n) system: indicates where first double bond closest to methyl (omega) end of the chain occurs Delta (Δ) system: describes fatty acids in relation to the carboxyl end of the carbon chain and indicates the location of all double bonds Essential Fatty Acids Cannot be synthesized by the human body; must be obtained through food Alpha-linolenic acid (omega-3 fatty acid) Metabolized to eicosapentaenoic acid (EPA) Metabolized to docosahexaenoic acid (DHA) Linoleic acid (omega-6 fatty acid) Metabolized to dihomo-gamma-linolenic acid Metabolized to arachidonic acid Eicosanoids: hormone-like compounds metabolized from fatty acids; affect the body in the region where they are produced Prostaglandins Prostacyclins Thromboxanes Leukotrienes Lipoxins Food Sources of Triglycerides General Most foods provide some triglycerides High fat: animal fat, vegetable oils Moderate fat: bakery items, snack foods, dairy desserts Low fat: fat-free milk and yogurt, breakfast cereals, yeast breads, fruits and vegetables (except for coconuts and avocados) Foods contain mixtures of fatty acids (see Figure 6-10) Primarily saturated Long chain: lard, beef, pork, lamb Medium or short chain: milk fat, tropical oils (coconut, palm, palm kernel) Primarily monounsaturated: olive oil, canola oil, peanut oil Primarily polyunsaturated: sunflower oil, corn oil, safflower oil, fish oil Sources of essential fatty acids Omega-3: cold water fish (salmon, tuna, halibut, sardines, mackerel), walnuts, flaxseed, hemp oil, canola oil, soybean oil, chia seeds Omega-6: beef, chicken, eggs, safflower oil, sunflower oil, corn oil Sources of trans fatty acids: margarine, shortening Hidden Fats Examples: whole milk, cheese, pastries, cookies, cake, hot dogs, crackers, French fries, ice cream Using Nutrition Facts labels helps identify fats in foods Fat Replacements Lowering fat content of foods Replace fat with water, protein (Dairy-Lo) Replace fat with carbohydrates (Z-trim) Replace fat with fiber (Maltrin, Stellar, Oatrim) and gums Engineered fats (Olean, Benefat) made with fat and sucrose, but are not well digested, and thus contribute no or few calories Fat replacements are not extensively used Functions of Triglycerides Provide Energy 9 kcal/g Main fuel source for body cells (except nervous system and RBCs); provide 30 - 70% of energy at rest or during light activity Provide Compact Energy Source Excess calories from carbohydrate, fat, protein, and alcohol can be converted to fatty acids and then to triglycerides Ideal energy storage because they are stable and calorie dense Fat cells contain 80% lipid and 20% water and protein (compared to muscle cells, which are 73% water) Adipose cells can expand in size and weight Insulate and Protect the Body Subcutaneous fat lies just beneath skin Maintains constant body temperature Visceral fat cushions body organs Aid Fat-Soluble Vitamin Absorption and Transport Vitamins A, D, E, and K require dietary fat for absorption and transport Malabsorption may occur with: Extremely low-fat diet Use of mineral oil laxative Use of medications (e.g., orlistat) Diseases that affect fat absorption (e.g., cystic fibrosis) Essential Fatty Acid Functions Structural components of cell membranes Maintain fluidity and flexibility of cell wall to allow transport of substances through cell membranes Normal development and functioning of retina and nervous system during fetal life and infancy Nerve transmission and communication Eicosanoids, made from EFAs, have many regulatory roles Blood pressure Blood clotting Sleep/wake cycles Body temperature Inflammation Hypersensitivity reactions Stomach secretions Labor during childbirth Immune and allergic responses Cell division (possible applications for cancer research) Kidney function, fluid balance Directing hormones to their target cells Flow of substances into and out of cells Ovulation Phospholipids General Structure is similar to triglyceride, except 1 fatty acid is replaced by a phosphate-containing compound that often includes nitrogen Phospholipids have fat-soluble and water-soluble properties Fatty acid end is hydrophobic Phosphate end is hydrophilic In watery environment, hydrophobic tails cluster together and hydrophilic heads interact with water Phospholipid Functions Component of cell membranes: double-layered outer covering of cell that holds cell contents and regulates movement of substances into and out of cells Emulsifier: compound that forms a shell around fat droplets to allow fat to be suspended in water Essential for fat digestion and transportation of fats in bloodstream Used in food manufacturing and preparation to prevent separation of oils from water (e.g., lecithin in egg yolks) Sources of Phospholipids Synthesized in body Supplied by diet Egg yolks Wheat germ Peanuts Lecithin supplements (use for weight loss is not supported by evidence; conflicting data on cholesterol reduction and risk for Alzheimer’s disease) Sterols Sterol Functions Synthesis of hormones (e.g., testosterone, estrogen, active vitamin D, adrenal hormones) Synthesis of bile Cell membrane structure and function Transport of fat through bloodstream (component of chylomicrons) Sources of Sterols One-third (180 - 325 mg/day) of cholesterol comes from animal foods (e.g., meat, fish, poultry, eggs, dairy products) Absorption efficiency is 40 - 60% Not necessary in diet Remaining cholesterol (~875 mg/day) is synthesized by the body Replenish bile stores (400 mg/day) Synthesis of steroid hormones (50 mg/day) Although plants do not synthesize cholesterol, they do contain other sterols Stanols Ergosterol (form of vitamin D) Sitostanol (used in cholesterol-reducing margarine products) Recommended Fat Intakes General No RDA, but AI is set for infants Infants and children under age 2 need about half of calories from fat for normal brain development Children 2 - 3 years require 30 - 35% of total calories from fat Children 4 - 18 years require 25 - 35% of total calories from fat Institute of Medicine Recommendations AMDR for total fat is 20 - 35% of total calories for adults Prevent vitamin E and essential fatty acid deficiencies Inadequate fat may increase triglycerides and lower HDL levels Saturated fat intake should be as low as possible Trans fat intake should be as low as possible Unsaturated fat intake should comprise most of fat intake Omega-6 fatty acids should comprise 5 - 10% of calories Omega-3 fatty acids should comprise 0.6 - 1.2% of calories Cholesterol intake should be as low as possible (10% of total calories is associated with increased cholesterol deposition in the arteries May impair immune function Excessive Omega-3 Fatty Acid Intake 8 oz (2 servings) of omega-3 fatty acid-rich fish/week reduce blood clotting and favorably affect heart rhythm 4 - 8 oz fish/day can lower blood triglycerides Excessive intake of omega-3 fatty acids (e.g., from supplement overuse) can impair immune function and restrict blood clotting (hemorrhagic stroke) Imbalances in Omega-3 and Omega-6 Fatty Acids Typical American diet supplies omega-6:omega-3 ratio of 20:1 Ratio of dietary fats affects synthesis of eicosanoids, which may affect risk for various inflammatory diseases (e.g., arthritis) Intake of Rancid Fats Unpleasant odor and flavor Contain peroxides and aldehydes that can damage cells PUFAs are more susceptible to damage by oxygen, heat, metals, or light because they have more double bonds than saturated or trans fats Foods prone to rancidity Fish and vegetable oils Packaged fried foods Fatty foods with large surface area (e.g., powdered egg yolks) Preventing rancidity Sealing in airtight packaging Hydrogenation of PUFAs Addition of antioxidants (vitamin E, vitamin C) or other food additives (e.g., BHA or BHT) Diets High in Trans Fat Trans fats have been used to produce high-quality baked and fried products without cholesterol and with extended shelf-life Consumption of trans fatty acids raises blood cholesterol levels and increases risk for CVD Trans fats lower HDL Trans fats increase inflammation Animal studies indicated that trans fats increase deposition of visceral fat and body weight, which increases the risk of type 2 diabetes Reduction of trans fat intake Identification of trans fats on Nutrition Facts panel Reformulation of food products Often use interesterified fats, made by interchanging fatty acids in solid fats and liquid oils Creates a fat that is solid at room temperature, stands up to high temperature cooking methods, and stays fresh longer Interesterified fats appear to be healthier than trans fats, but more research is needed Limit fried foods, pastries, flaky bread products, and cookies Use little or no stick margarine or shortening; substitute vegetable oils, tub margarine, fruit purees Bake, pan-fry, broil, steam, grill, or stir-fry instead of deep-fat frying Replace nondairy creamers with reduced-fat milk or non-fat dry milk Diets High in Total Fat Increased risk for obesity Increased risk of cancer (e.g., colon, breast, prostate) For colon cancer, may be related to increased secretion of bile, which irritates colon cells For breast and prostate cancer, high fat diet leads to higher estrogen production High-fat diets are usually low in fiber and other phytonutrients that protect against cancer Increased risk of CVD Expert Perspective from the Field: Omega-6 Fatty Acids: Harmful or Healthful? New evidence indicates that omega-6 intake has little effect on the production of inflammatory eicosanoids Several studies have reported that low intake of omega-6s were associated with an increased risk of heart disease Omega-6 fatty acids may lower cholesterol Replacing saturated fat with omega-6 fatty acids reduced heart disease risk For optimal health, the American Heart Association recommends consuming 5-10% of total calories from omega-6 fatty acids Clinical Perspective: Cardiovascular Disease (CVD) General Major reason for death in North America 500,000 deaths annually in US (60% more than from cancer) 1.5 million heart attacks annually in US 2:1 ratio for heart attacks among men compared to women Women develop CVD 10 years later than men For each person who dies of CVD, 20 more have symptoms Symptoms are not obvious and are slow to develop Development of CVD Arterial lining damaged by smoking, diabetes, hypertension, homocysteine, LDL, viral and bacterial infections, and chronic inflammation Plaque forms to repair arterial injury Plaque thickens over time, causing arteries to harden and become less elastic Blood pressure increases Clot or spasm in narrowed artery restricts blood flow and leads to heart attack or stroke Factors that may precipitate a heart attack Dehydration Severe emotional stress Unusual strenuous physical activity Sudden awakening High-fat meal Risk Factors for CVD Non-modifiable risk factors Age >65 years Male gender Genetics (close relative who died prematurely (before age 50) from CVD, defects that affect lipoprotein metabolism or blood clotting) Race (African heritage, Hispanic/Latino, Native American, Native Hawaiian decent, some Asian groups) Modifiable risk factors Blood cholesterol levels (see Table 6-4) (total cholesterol >200 mg/dl, LDL >160 mg/dl) Blood triglyceride levels (hypertriglyceridemia: triglycerides >150 mg/dl) Hypertension (systolic blood pressure >140 mmHg; diastolic blood pressure >90 mmHg) Smoking (2 - 4 times increased risk) Physical inactivity Obesity Diabetes Liver and kidney disease and low thyroid hormone levels Assessing CVD Risk National Cholesterol Education Program recommends that all adults over 20 years of age have blood lipid profile every 5 years (fast 12 - 14 hours prior to test) NCEP tables calculate risk based on age, total and HDL cholesterol levels, blood pressure, smoking Preventing CVD Keep total fat intake between 20 and 35% of kcal Keep saturated fat intake to less than 7% of kcal Keep trans fat intake low Keep PUFA intake under 10% of kcal Keep MUFA intake under 20% of kcal Lower cholesterol intake to <200 mg/day Include 2 g/day of plant stanols/sterols Increase soluble fiber intake to 20 - 30 g/day Moderate sugar intake Keep body weight at healthy level Increase physical activity Eat foods rich in antioxidants (e.g., fruits, vegetables, nuts, plant oils) Possible vitamin E supplementation under physician supervision Heart Attack Symptoms Symptoms may be sudden and severe or subtle At first sign of heart attack, take aspirin to reduce blood clotting and call 911 Warning signs Intense, prolonged chest pain or pressure, sometimes radiating to other parts of the upper body (men and women) Shortness of breath (men and women) Sweating (men and women) Weakness (men and women) Nausea and vomiting (especially women) Dizziness (especially women) Jaw, neck, and shoulder pain (especially women) Irregular heartbeat (men and women) Symptoms of Stroke Blood clot blocks flow of blood to brain (ischemic stroke) or blood vessel bursts in brain (hemorrhagic stroke) Major risk factor is high blood pressure Early medical treatment increases survival Warning signs Sudden numbness or weakness in face, arm, or leg, especially on one side of body Sudden confusion and/or trouble speaking or understanding Sudden trouble seeing in one or both eyes Sudden trouble walking, dizziness, and/or loss of balance or coordination Sudden, severe headache with no known cause Chapter 7 Proteins Overview In Chapter 7, students will learn about the structure, function, and food sources of proteins. The difference between essential and nonessential amino acids, and how this relates to complete (high-quality) or incomplete (low-quality) dietary protein sources is explained. The processes of transcription, translation, and conformational organization of proteins are described. Dietary recommendations for protein intake and the concept of protein quality are discussed in relation to the typical American diet. The processes of protein digestion, absorption, and transport are reviewed. Functions of protein, from fluid balance to acid-base balance to synthesis of enzymes, hormones, and neurotransmitters, are presented. Finally, common health issues related to protein intake, such as protein-energy malnutrition, appropriate meal planning for vegetarian diets, and food allergies, are described. Learning Objectives Describe how amino acids form proteins. Define essential and nonessential amino acids and explain why adequate amounts of each of the essential amino acids are required for protein synthesis. Distinguish between high quality and low quality proteins and list sources of each. Describe how two low quality proteins can be complementary to each other to provide the required amounts of essential amino acids. Explain the methods used to measure the protein quality of foods. List the factors that influence protein needs. Calculate the RDA for protein for a healthy adult with a given body weight. Explain positive nitrogen balance, negative nitrogen balance, and nitrogen equilibrium, and list the conditions under which they occur. Describe how protein is digested and absorbed in the body. List the primary functions of protein in the body. Describe the types of protein-energy malnutrition. Describe the symptoms and treatment of food allergies. Develop a vegetarian diet plan that meets the body’s protein needs. Teaching Strategies, Activities, Demonstrations, and Assignments Assign students the Take Action activity, "Meeting Protein Needs When Dieting to Lose Weight.” Assign students the Take Action activity, “Protein and the Vegan.” Have students plan a low cost, lactovegetarian menu that meets their particular RDA for protein. They could use the food-group plan for lacto-vegetarians and the exchange system as tools to do this. From what students have learned about vegetarianism and plant protein sources, have them, as a class, plan two well-balanced vegetarian dinners that they would be willing to try. Make sure they vary the texture, temperature, color, and taste of each meal. This could be done during a class period, soliciting suggestions from the class and writing the suggestions on a transparency, board, poster paper, or similar medium. Have students collect information on protein and/or amino acid supplements that could be obtained from health food stores, sporting supply stores, or ordered from magazines for athletes and/or body builders. Have them work individually or in small groups to evaluate these products in relation to cost, protein quality and quantity, and presence of other nutrients. Develop a table comparing the quality of protein in supplements to dietary sources. Have individual or small groups of students visit supermarkets, food co-ops, health food stores, or other food suppliers, and determine what plant sources of protein are available. Develop a table with food supplier, address, telephone number, sources of plant protein available, and approximate cost per unit. Have students develop and discuss ways in which these items could be incorporated in a meal; focus on complementation. This could include developing a recipe or combining various food items to make an appetizing, protein-complementary meal. You also could have students compare the price of one serving of animal protein and one serving of a plant protein. Have students taste tofu, a quality plant protein. Tofu with different firmness can be cut into sampling pieces for the students to taste. Also present tofu in a tasty recipe such as a dip. Get their impressions of it. Ask the students to think of ways that tofu can be used in a vegetarian or omnivorous diet. Have students visit the campus bookstore, a library, or area bookstore and locate five vegetarian resources, including cookbooks. Have them reference each resource, noting the number of pages, whether it is soft cover or hard cover, and the price (if known). Compile a list of vegetarian resources for the students. Have students visit an ethnic restaurant and order a meatless meal. During class ask them to report how they achieved complementary protein from the dishes they ordered. Lecture Outline Structure of Proteins Amino acids Composed of carbon, hydrogen, oxygen, and nitrogen (some also contain sulfur; see Figure 7-2) Amino group Carboxyl group Hydrogen molecule Side chain (R) differentiates one amino acid from another Building blocks of proteins 20 amino acids are required for human function Non-essential amino acids can be synthesized by the body and do not need to be obtained in the diet (11) Essential amino acids cannot be synthesized by the body and must be obtained in the diet (9) Conditionally essential amino acids may become essential during infancy, disease, or trauma Tyrosine for people with PKU Glutamine and arginine for trauma patients or following infection Synthesis of Nonessential Amino Acids (see Figure 7-3) Transamination: transfer of an amino group from 1 amino acid to a carbon skeleton to form a new amino acid Deamination: loss of amino group from an amino acid Amino group is usually incorporated into urea by liver and excreted by kidneys Remaining carbon skeleton can be used for fuel or synthesized into other compounds Amino Acid Composition: Complete and Incomplete Proteins Complete (high quality) proteins contain sufficient amounts of all nine essential amino acids to support protein synthesis in the body (e.g., all animal proteins, with the exception of gelatin) Incomplete (low quality) proteins are lacking at least one of the nine essential amino acids (e.g., all plant proteins, with the exception of soy protein and quinoa) Cells require a pool of amino acids for synthesis of body proteins Limiting amino acid: absence of one essential amino acid restricts protein synthesis Legumes: methionine, tryptophan Nuts and seeds: lysine Grains: lysine Complementary proteins: combination of various sources of low quality proteins to yield a high quality protein Legumes + grains, nuts, or seeds Mixed diets generally provide high quality protein Complementary proteins need not be consumed at same meal, but can be balanced throughout the day Adding a small amount of animal protein to plant-based dish provides adequate essential amino acids Synthesis of Proteins General Amino acids are linked by peptide bonds, which form between the amino group of one amino acid and the carboxyl group of another Dipeptide: 2 amino acids Tripeptide: 3 amino acids Oligopeptide: 4 - 9 amino acids Polypeptide: 10 or more amino acids Most body proteins are polypeptides with 50 - 2000 amino acids Transcription and Translation of Genetic Information Gene expression begins with replication of DNA to build body proteins DNA Double-stranded molecule in a helical form Four nucleotides in specific order: adenine, guanine, cytosine, and thymine Each nucleotide binds to a complementary nucleotide (A with T, C with G) Codons are units of three nucleotides that code for a specific amino acid Some amino acids are coded by just one codon, others are coded by up to six codons Having the correct codons in the right sequence is critical for producing the needed amino acid and a normal protein Protein synthesis occurs on ribosomes in cytosol of cells; DNA code must be transferred from the nucleus to the cytosol to allow for protein synthesis (see Figure 7-5) Transcription: mRNA carries genetic information from DNA in nucleus to cytosol DNA uncoils Complementary single-stranded mRNA molecule is formed by enzymes (A, G, C, and uracil) Primary mRNA transcript undergoes processing in the nucleus to remove any parts of DNA code that do not code for proteins) mRNA travels to ribosomes in cytosol Translation: synthesis of polypeptide chains by ribosome according to information coded by mRNA Synthesis starts with AUG and continues until a stop codon is reached Amino acids are added sequentially according to mRNA transcript by tRNA Addition of amino acids to polypeptide chain requires energy When synthesis of polypeptide is complete, the polypeptide and mRNA are released from the ribosome Polypeptide twists and folds into complex 3-D structure Errors in DNA lead to formation of abnormal polypeptide Sickle-cell anemia results from replacement of glutamic acid with valine, causes abnormally shaped red blood cells with limited ability to transport oxygen Protein Organization Primary structure: sequential order of amino acids that determines protein’s shape Secondary structure: spiral-like or pleated sheet shape of polypeptide chain resulting from chemical bonds between amino acids; stabilizes protein structure Tertiary structure: 3-D folding of a protein, which determines physiological function Quaternary structure: 2 or more polypeptides may interact to form the appropriate configuration for an active protein Denaturation of Proteins Alteration of protein’s 3-D structure, and therefore its biological function Causes Acid Alkaline Enzymes Heat Agitation Benefits of denaturation Digestion Destruction of harmful bacteria Makes food more pleasing to eat Negative consequences of denaturation Illness may lead to changes in gastrointestinal acidity, body temperature, or body pH that denature proteins Adaptation of Protein Synthesis to Changing Conditions Protein turnover: constant state of breakdown, rebuilding, and repair that allows cells to adapt to changing circumstances Allows cell to synthesize proteins or break them down when needs change Sources of Protein General Dietary sources (65 - 100 g/day) Typical North American diets supply 70% of protein from meat, poultry, fish, milk, cheese, legumes, and nuts Worldwide diets supply only 35% of protein from animal sources Plants can provide ample dietary protein with benefits of fiber, vitamins, minerals, and phytochemicals, while avoiding cholesterol and high levels of saturated fat Recycling of body proteins (250 - 300 g/day) Tips to increase intake of plant sources of protein Try veggie burger Top salads with nuts or sunflower seeds Add nuts to bread, muffins, or pancake batter Consume edamame or roasted soy beans for snacks Use peanut butter instead of butter or cream cheese Use calcium-fortified soy milk Substitute beans for meat in tacos Make stir fry with tofu, cashews, and vegetables Evaluation of Food Protein Quality General Indicate ability of food protein to support body growth and maintenance Digestibility Animal proteins: 90 - 100% Plant proteins: 70% Amino acid composition Applies only to conditions in which protein intakes are equal to or less than protein required for essential amino acids As protein intake increases, efficiency of protein use decreases because excess amino acids cannot be readily stored and are primarily degraded for use as energy Biological Value (BV) Measure of how efficiently an absorbed food protein is converted to body tissue protein Determined by comparing nitrogen retention in body to nitrogen content of food protein Higher BVs result when food’s amino acid composition is similar to body’s amino acid composition Egg white protein BV = 100 Most animal proteins have high BV Protein Efficiency Ratio (PER) Compares weight gained by growing laboratory animal consuming a standardized amount of the protein being studied compared to weight gained by an animal consuming a reference protein (e.g., casein) Animal proteins have higher PER than plant proteins Method is used in labeling of foods intended for infants Chemical Score Amount of each essential amino acid in a gram of food protein is divided by the “ideal” amount for that amino acid in a reference protein (e.g., egg whites) Lowest (limiting) amino acid ratio is chemical score, range from 0 - 1.0 Protein Digestibility Corrected Amino Acid Score (PDCAAS) Most widely used measure of protein quality Multiply food’s chemical score by its digestibility Ranges from 0 - 1 For nutrition labeling, protein content (% Daily Value) is reduced if PDCAAS <1; rarely reported on food labels because PDCAAS is expensive to determine Nitrogen Balance General Equilibrium: protein intake replaces protein losses from urine, feces, sweat, skin cells, hair, and nails Negative protein balance: intake losses; requires anabolic hormones (e.g., insulin, growth hormone, testosterone) in addition to adequate protein intake Growth Recovery from injury, trauma, or illness Measured as nitrogen balance Nitrogen makes up 16% amino acid weight Nitrogen (g) x 6.25 = Protein (g) Measurement is only practical in hospital or research environments More convenient to estimate protein needs based on RDA Recommended Intakes of Protein For most adults, RDA for protein = 0.8 g/kg/day based on healthy weight RDA does not address additional protein requirements for recovery from illness or injury or for highly trained athletes (0.8 - 2.0 g/kg) Typical American diet supplies ample protein to meet RDA Excess protein cannot be stored as such; carbon skeletons are used to meet energy needs or used for other purposes Protein Digestion and Absorption Digestion (see figure 7-11) Begins with cooking, which denatures proteins and softens connective tissues in meat Stomach HCl denatures proteins Pepsin begins to break long polypeptide chains into shorter peptides through hydrolysis reactions Gastrin controls the release of pepsin and HCl Stimulated by thinking of or chewing food Small intestine CCK and secretin released from intestinal walls stimulates pancreas Pancreas secretes enzymes to hydrolyze polypeptides into short peptides and amino acids Trypsin Chymotrypsin Carboxypeptidase Absorption Short peptides and amino acids are actively absorbed into small intestinal cells Inside small intestinal cells, any short peptides are broken down to amino acids by peptidase enzymes Amino acids enter portal vein and travel to liver Protein synthesis Energy needs Conversion to carbohydrate or fat Release into bloodstream for transport to other cells Except during infancy, intact proteins are usually not absorbed; delay introduction of commonly allergenic foods to infants Functions of Proteins Producing Vital Body Structures Structural proteins make up 1/3 of body protein; provide matrix for bone, muscle, and connective tissue Collagen Actin Myosin During growth, proteins are synthesized; during malnutrition or disease, protein synthesis declines and wasting occurs Maintaining Fluid Balance Albumin and globulin remain in bloodstream and counteract the force of blood pressure that forces body fluids into interstitial spaces With inadequate protein intake, blood protein levels decline and excessive fluid collects in tissues (edema) Contributing to Acid-Base Balance pH describes acid-base balance Reflects the concentration of hydrogen ions Low pH is more acidic High pH is more alkaline Proteins act as buffers: maintain acid-base balance by accepting and releasing hydrogen ions as needed Forming Hormones, Enzymes, and Neurotransmitters Hormones: messengers, regulate body functions Enzymes: facilitate chemical reactions Neurotransmitters: released by nerve endings Dopamine synthesized from tyrosine Norepinephrine synthesized from tyrosine Serotonin synthesized from tryptophan Contributing to Immune Function Antibodies bind to antigens (foreign proteins) and prevent their attack on target cells Without sufficient protein, immune system is compromised (anergy) and ability to fight infection is reduced Transporting Nutrients Carry nutrients through bloodstream Hemoglobin carries oxygen Lipoproteins transport lipid molecules Allow nutrients to cross cell membranes Retinol binding protein: carrier for vitamin A Transferrin: carrier of iron Ferritin: storage of iron Ceruloplasmin: carrier for copper Forming Glucose If carbohydrate intake is inadequate to maintain blood glucose levels, liver and kidneys make glucose from amino acids in body tissues (gluconeogenesis) Chronic use of amino acids for gluconeogenesis leads to cachexia (muscle wasting) Providing Energy Under most conditions, body uses fats and carbohydrates for energy Proteins are a costly source of energy Expert Perspective: Nutrition and Immunity Innate (non-specific) immunity Present at birth First barrier against antigens General, non-specific response Components Physical barriers (e.g., skin, mucous membranes) Chemical secretions (e.g., HCl) Physiological barriers (e.g., fever) Phagocytic cells Acquired (specific) immunity Initiated by recognition of specific antigen Develops throughout lifespan Adaptive immunity Bone marrow and thymus produce antibodies (immunoglobulins) and other specialized immune cells to destroy specific antigens Breastfeeding is recommended for infants to transfer immune components (e.g., immunoglobulins and lactoferrin) from mother to infant Importance of nutrition for immune function Malnutrition leads to loss of antigen-producing tissue, decreased number and effectiveness of antibodies, and a breakdown of physical barriers to antigens Severe PEM with accompanying micronutrient deficiencies, infections, and diarrhea impair immunity Nutrients that increase immune protection during critical illness and trauma (immunomodulators) Arginine Glutamine EFAs Maintaining optimal nutritional status supports immune function Health Concerns Related to Protein Intake Protein-Energy Malnutrition General Protein deficiency usually occurs in combination with deficiencies of other nutrients Most common in developing areas of world Most devastating for children Poor growth Diarrhea Infections Diseases Early death High-risk populations Poverty Isolation Substance abuse Anorexia nervosa Debilitating diseases (e.g., AIDS or cancer) Hospitalized patients, due to poor health, low dietary intakes, and increased protein needs Kwashiorkor: severe protein (with moderate energy) deficit “The disease that the first child gets when the new child comes” due to abrupt shift from breast milk to starchy roots and gruels Bulk of diet limits energy and protein intake Increased protein needs due to parasites and other infections Characteristics Edema Mild to moderate weight loss Growth impairment Apathy Diarrhea Listlessness Infections Withdrawal from environment Marasmus: severe protein and energy deficiency “To waste away” Usually occurs in infants who are not breastfed or are weaned early; formula is improperly diluted, use of unsafe water supplies Characteristics Extreme weight loss Muscle and fat wasting (skin and bones appearance) Severely impaired growth Poor cognitive and intellectual development High-Protein Diets Diets supplying >35% energy from protein Overburden kidneys’ capacity to excrete nitrogen wastes (greatest concern for those with impaired kidney function) Inadequate fluid intake may increase the risk of dehydration High intake of animal proteins may present several problems Low fiber intake Low vitamin C, E, and folate intake Low magnesium and potassium intake Low phytochemical intake High saturated fat and cholesterol intake May increase risk for cardiovascular disease High intakes of cured meats may increase risk for certain types of cancer Increase urinary calcium losses, influencing risk of osteoporosis; most likely a concern for those with marginal calcium intakes Protein and amino acid supplementation by athletes may result in amino acid imbalances and toxicity risk Clinical Perspective: Food Protein Allergies Some food proteins (allergens) cause hypersensitivity reactions and trigger immune response Mild reactions: runny nose, sneezing, itching skin, hives, digestive upset Anaphylaxis: decreased blood pressure, respiratory distress, possibly death Common food allergens Peanuts/tree nuts Milk Soy Wheat Eggs Fish/shellfish Avoiding food allergens For all ages Food labeling Know menu ingredients Sanitation of food preparation environment and serving dishes/utensils to prevent cross-contamination with allergenic foods To prevent development of allergies in infants and children Maternal dietary restrictions during pregnancy and lactation (e.g., avoiding peanuts and tree nuts) appear to not play a significant role in preventing food allergies Exclusively breastfeed or formula feed for first 6 months Delay introduction of cow’s milk and milk products until 1 year Delay introduction of egg whites until 2 years Delay introduction of peanuts, tree nuts, fish, and shellfish until 3 years Global Perspective: How big is your foodprint? Many scientists believe that meat-rich diets and the agricultural practices that support food production for these diets negatively affect the environment Meat-rich diets may cause greater emissions of greenhouse gases that are associated with global warming Concern that continued global warming may in turn decrease agricultural productivity, reduce famers’ incomes, and increase global food insecurity Other scientists believe that consuming a small amount of dairy and/or meat may actually increase land use efficiency Can use lower-quality farmland Meat substitutes are highly processed and require energy-intensive production methods Vegetarian Diets Statistics 2.5% and 4% of adults in U.S. and Canada, respectively, follow vegetarian diets 20 - 25% of Americans eat at least 4 meatless meals/week Rationale Religion Philosophy Ecology Raising meat protein requires 40% of world’s grain production Health Increased antioxidant nutrients Increased fiber Decreased saturated fat and cholesterol Many health agencies promote vegetarian diets as a way to reduce risk for chronic diseases Types of plant-based diets Vegan: only plant foods Lacto-vegetarians: exclude meat, poultry, eggs, and fish, but do consume dairy Lacto-ovo-vegetarians: exclude meat, poultry, and fish, but do consume eggs Vegetarian diets require careful planning to ensure high quality protein (i.e., complementary proteins) and other key micronutrients Riboflavin Vitamin D Vitamin B-12 Calcium Iron Zinc Use of fortified breakfast cereal and other fortified foods may close any nutritional gaps Special Concerns for Infants and Children With use of complementary proteins and good sources of problem nutrients, nutritional requirements of vegetarian and vegan infants and children can be met Iron Vitamin B-12 Vitamin D Zinc Calcium Bulk of high-fiber diet may lead to early satiety, thus limiting energy intake May substitute some refined grains, fruit juices, and peeled fruit for high fiber foods Include concentrated sources of energy Fortified soy milk Nuts Dried fruits Avocados Chapter 8 Alcohol Overview Chapter 8 covers the production, metabolism, and health effects of alcohol. The chapter begins with a discussion of the processes of fermentation and distillation that are used to produce alcohol. The three pathways used to metabolize alcohol - the alcohol dehydrogenase pathway, the microsomal ethanol oxidizing system, and the catalase pathway - and factors that affect alcohol metabolism, are explained. Statistics regarding alcohol consumption among North Americans are provided with particular emphasis on the perils of binge drinking on college campuses and underage drinking in general. Although there are some health benefits of moderate alcohol consumption, these must be viewed in light of the many mental, interpersonal, and physiological dangers of alcohol abuse and alcoholism. The interactions of alcohol abuse and nutritional status are discussed and women are warned against drinking during pregnancy and breastfeeding. Chapter 8 wraps up with a discussion of alcohol dependency and recovery from it. Learning Outcomes Describe the sources of alcohol (ethanol) and the calories it provides. Define standard sizes of alcoholic beverages and the term moderate drinking. Outline the process of alcohol absorption, transport, and metabolism. Explain how alcohol consumption affects blood alcohol consumption. Define binge drinking and describe the problems associated with it. Discuss potential health risks and benefits of alcohol consumption. Describe the effects of chronic alcohol use on the body and nutritional status. List the signs of alcohol dependency and abuse. Teaching Strategies, Activities, Demonstrations, and Assignments 1. Assign students the Take Action activity at the end of the chapter, "Do You Know Why These Are Alcohol Myths?" Have students discuss the myths they previously believed vs facts they now understand. 2. Have students investigate alcohol use with the CAGE questionnaire. Have them complete the CAGE questionnaire. Ask students to share observations they have made. 3. Have students, as groups, read and discuss the Case Study found in Chapter 8. After groups have discussed the scenario, have them share their thoughts with the entire class. 4. Have students, as groups, brainstorm a variety of approaches to curb binge drinking on college campuses and determine ways in which they could aid friends and family members who exhibit alcohol abuse. After groups have thought of various approaches to curb binge drinking and ways in which they could aid alcohol abusers, have them share their thoughts with the entire class. 5. Have students create a chart that summarizes the three metabolic pathways of alcohol metabolism. 6. Bring in containers that represent a standard-sized drink for beer, wine, and liquor. Have students bring in their favorite drinking glass and compare their drink sizes to a standard-sized drink. After comparing a standard-sized drink to the typical-size drink a student consumes, have them discuss how their views have changed. 7. Have the students visit the website awareawakealive.org and choose one tool to present to the class that they learned about through the website. Lecture Outline Sources of Alcohol General Common sources vary in alcohol and calorie content (see Table 8-1) Beer Wine Distilled spirits Liqueurs Cordials Hard cider Ingredient in foods Alcohol “proof” = twice the percentage of alcohol content Standard drink provides ~14 g alcohol 12 ounces of beer 10 ounces of wine cooler 5 ounces of wine 1.5 ounce of hard liquor Moderate alcohol intake 1 drink/day for women 2 drinks/day for men Production of Alcoholic Beverages Carbohydrate-rich foods are fermented by yeast, which convert simple sugars (e.g., glucose or maltose) to alcohol and CO2 at room temperature Malting is the process of allowing grain to sprout, which produces enzymes that break down starch to simple sugars First stage of fermentation is aerobic; yeast cells multiply and produce small amount of alcohol Second stage of fermentation is anaerobic Fermentation ceases when alcohol content inactivates yeast Alcohol maybe distilled by boiling and condensation to separate it from water and concentrate it; used to produce hard liquor Alcohol Absorption and Metabolism Alcohol Absorption Requires no digestion Requires no specific transport mechanisms or receptors to enter cells Rapid absorption by simple diffusion 20% absorbed in the stomach Remainder absorbed in the duodenum and jejunum Rate of alcohol absorption is influenced by types and amounts of foods consumed Empty stomach leads to rapid absorption High fat meal slows absorption Alcohol is dispersed wherever water is distributed in the body Alcohol diffusion through cell membranes causes damage to membrane proteins Alcohol Metabolism: 3 Pathways Alcohol cannot be stored; takes priority in metabolism as a fuel source Metabolic pathways Alcohol dehydrogenase (ADH) pathway metabolizes majority (90%) of alcohol consumed at low or moderate levels Alcohol dehydrogenase converts ethanol to acetaldehyde (toxic) Aldehyde dehydrogenase converts acetaldehyde to acetyl-CoA (converted to carbon dioxide and water or used for fatty acid synthesis) Cells lining stomach metabolize 10 - 30% of alcohol via ADH pathway Liver is primary site for alcohol metabolism Microsomal ethanol oxidizing system (MEOS) helps to metabolize moderate to excessive amounts of alcohol Occurs in the liver Also used to metabolize drugs and toxins; because alcohol metabolism takes first priority, use of MEOS for alcohol metabolism may increase risk for drug interactions and toxicities Like ADH pathway, produces acetaldehyde and then acetyl CoA, but requires energy to function Increasing efficiency of MEOS with repeated exposure to alcohol contributes to alcohol tolerance: increasing amounts of alcohol are needed to produce the same effect Catalase pathway Minor contributor to alcohol metabolism Takes place in liver and other cells ADH, MEOS, and catalase pathways metabolize nearly all alcohol consumed; small percentage is excreted through lungs, urine, and sweat Factors Affecting Alcohol Metabolism Ethnicity People of Asian descent have normal to high ADH activity, but very low aldehyde dehydrogenase activity; buildup of acetaldehyde leads to flushing, dizziness, nausea, headaches, rapid heartbeat, and rapid breathing Gender Women produce less ADH in cells of stomach lining, leading to 30 - 35% more alcohol absorption from stomach directly into bloodstream Smaller body size, higher body fat content, and less total body water of women leads to greater concentration of alcohol in blood and other tissues Age: enzymes of ADH pathway decline with age Alcohol content of beverage Amount of alcohol consumed Usual alcohol intake Large amounts of alcohol on a regular basis activates the MEOS pathway, thereby increasing alcohol metabolism and tolerance Rate of Alcohol Metabolism Social drinker, 150 lbs., normal liver function: metabolizes 5 - 7 g alcohol/hour When rate of alcohol consumption exceeds liver’s metabolic capacity, BAC rises and symptoms of intoxication appear (see Figure 8-2) BAC determined by measuring amount of alcohol excreted by the lungs, which is directly related to BAC (breathalyzer test) Acute alcohol intoxication (alcohol poisoning) can cause respiratory failure, aspiration of vomit, and death Confusion, stupor Vomiting Hypoglycemia Severe dehydration Seizures Slow or irregular breathing and heartbeat Blue-tinged or pale skin Hypothermia Unconsciousness Binge drinking is defined as having 4 or more drinks for females and 5 or more drinks for males on a single occasion Alcohol Consumption Statistics 65% of North American adults consume alcohol 5.8% of women consume alcohol daily 10.8% of men consume alcohol daily 5% are excessive drinkers >7 drinks/week women >14 drinks/week men Drinking on college campuses Young, white college students are largest drinking population in North America Many drinkers are not of legal drinking age Considered “rite of passage” into adulthood Advertising targets college students Drinks that combine alcohol and stimulants such as caffeine and guarana are popular in college campuses Lead to excess alcohol intake, as individuals are less able to judge their degree of intoxication Drinkers may be unaware of the harmful acute and chronic effects of alcohol Binge drinking is associated with (see Table 8-4) Vandalism Violent crime Traffic accidents and injuries Sexual abuse Suicide Hazing deaths Serious acute health risks Poor habits contribute to lifelong problems Health Effects of Alcohol Guidance for Using Alcohol Safely Non-drinkers should not start consuming alcohol because risks often outweigh benefits, but moderate alcohol has some benefits Recommendations for individuals who choose to drink alcohol Drink alcohol sensibly and in moderation (up to 1 drink/day for women; up to 2 drinks/day for men) Some individuals should not consume alcohol Unable to restrict alcohol intake Women who are or may become pregnant Anyone younger than the legal drinking age Use of medication that interacts with alcohol Certain medical conditions Alcoholic beverages should be avoided by individuals engaging in activities that require attention, skill, or coordination Potential Benefits of Alcohol Intake Reduced anxiety and stress Stimulation of appetite among elderly adults Lowered risk of cardiovascular disease and overall mortality; may be due to resveratrol in red wine Decreased LDL Increased HDL Decreased platelet aggregation Reduced risk of type 2 diabetes Reduced risk of dementia Risks of Excessive Alcohol Intake Excessive alcohol consumption contributes to 5 of 10 leading causes of death in North America Heart failure Cancer Cirrhosis Motor vehicle and other accidents Suicides Figure 8-5 summarizes effects of excessive alcohol on body Cognitive deficits Vasodilation and flushing of skin Cancer of the oral cavity, throat, larynx, and esophagus Heart muscle damage and resulting arrhythmias Breast cancer Irritation of the stomach lining and stomach cancer Fatty infiltration of the liver, alcoholic hepatitis, cirrhosis, ultimate liver failure, and liver cancer Impaired pancreatic function, hypoglycemia, pancreatic cancer Malabsorption of nutrients in the small intestine Abdominal fat deposition and fluid accumulation (ascites) Cancer of the colon and rectum Osteoporosis Intestinal bleeding Depressed immune function Sleep disturbances Impotence Nutrient deficiencies High blood triglycerides Cirrhosis of the Liver Roles of liver Nutrient storage Protein and enzyme synthesis Metabolism of protein, fats, and carbohydrates Detoxification Drug metabolism Progression of alcohol-induced liver disease Steatosis (fatty liver); usually reversible Alcoholic hepatitis (inflammation of liver cells), leading to nausea, poor appetite, vomiting, fever, pain, and jaundice; usually reversible but frequently progresses to cirrhosis Cirrhosis (loss of functioning hepatocytes) leading to decreased production of blood proteins, ascites, and poor nutritional status; irreversible Statistics 50% chance of death within 4 years without liver transplant Cirrhosis develops in 10 - 15% cases of alcoholism Commonly associated with drinking equivalent of 6 standard size drinks/day, but may be less, especially for women Susceptibility to cirrhosis Amount of alcohol consumed Duration of alcohol consumption Genetic factors Obesity Diabetes Exposure to hepatotoxins Iron overload disorders Infections with hepatitis Mechanisms for liver damage Increased concentration of acetaldehyde may damage liver Accumulation of fat in liver cells causes inflammation and cell damage Increased production of free radicals Impact of nutritional status Even with nutritious diet, alcoholism still causes liver damage Nutrient deficiencies increase vulnerability of liver to toxicity Effects of Alcohol Abuse on Nutritional Status General Alcohol abusers tend to replace some or all of food with alcohol, a poor source of nutrients Protein-energy malnutrition can result Micronutrient deficiencies result from poor intake and impaired absorption or metabolism of nutrients Water-Soluble Vitamins Thiamin deficiency (Wernicke-Korsakoff Syndrome): alcohol is a poor source of thiamin Irreversible paralysis of eye muscles Loss of sensation in lower extremities Loss of balance with abnormal gait Memory loss Niacin deficiency: alcohol metabolism requires large quantities of niacin Vitamin B-6 deficiency: alcohol metabolism increases urinary excretion of vitamin B-6 Increased risk of anemia Peripheral neuropathy Vitamin B-12 deficiency: excessive alcohol intake can impair absorption of vitamin B-12 Folate deficiency Fat-Soluble Vitamins Vitamins A, D, E, and K: chronic alcohol abuse damages liver and pancreas, which impairs secretion of bile and enzymes that digest fat Vitamin A: alcohol abuse decreases liver’s rate of breakdown and excretion of vitamin A and decreases liver’s production of the protein that transports vitamin A throughout the body; deficiency may lead to night blindness Vitamin K: decreased ability to synthesize vitamin K-containing compounds for blood clotting Vitamin D: decreased ability of liver to convert vitamin D to active form; increased risk for osteoporosis Minerals Calcium: low intake and poor absorption due to decreased ability of liver to convert vitamin D to active form Magnesium: increased urinary excretion; leads to tetany Zinc: decreased absorption and increased urinary excretion; leads to changes in taste and smell, loss of appetite, and impaired wound healing Iron: damage to gastrointestinal tissues causes bleeding, malabsorption, iron deficiency Alcohol Consumption During Pregnancy and Breastfeeding Pregnancy Slows nutrient and oxygen delivery to developing fetus; retards growth and development, especially in the 12-to-16-weeks stage, when organs are undergoing major developmental steps Alcohol displaces nutrient-dense foods in maternal diet Fetal alcohol spectrum disorders (see Figure 8-8) Facial malformations Growth retardation (smaller than normal brain size) Birth defects Learning difficulties Short attention span Hyperactivity Nervous system abnormalities Fetal alcohol syndrome Facial malformations Growth deficits CNS problems Within minutes of consumption, alcohol reaches fetus through maternal blood supply Small size Immature metabolism No safe level of alcohol consumption during pregnancy is known Women planning pregnancy should avoid alcohol because first trimester, when many women do not know they are pregnant, is time of highest vulnerability Breastfeeding Reduces milk production Decreases infant milk consumption Leads to disrupted sleep patterns for infant Alcohol consumption is not advised for breastfeeding mothers, but if consumed, limit amount to 1 to 2 drinks and wait 2 hours before breastfeeding Global Perspective: Alcohol Intake Around the World According to WHO, residents of Russia and Europe drink the most alcohol Worldwide, nearly half of men and two-thirds of women do not drink. In the U.S., only 36% abstain from alcohol consumption Alcohol intake around the world is increasing Worldwide, about 4% of deaths are attributed to alcohol intake. However, in Russia more than half of the deaths of men aged 15 to 54 years are due to alcohol Alcohol, typically wine, consumed with meals is a tradition enjoyed in many cultures Moderate alcohol intake may offer some health benefits Risks increase when many alcoholic beverages are consumed in rapid succession, resulting in alcohol poisoning and death Alcohol Use Disorders: Alcohol Abuse and Alcoholism General Alcohol abuse (at least one of the following) Failing to fulfill major responsibilities at work, school, or home Drinking when it is physically dangerous (e.g., driving) Having recurring alcohol-related legal problems Having social or relationship problems that are worsened by alcohol intake Alcoholism (alcohol dependency) Craving Loss of control Withdrawal symptoms (e.g., nausea, sweating, anxiety, shaking) Tolerance Unsuccessful attempts to cut down on alcohol use Statistics 1 in 3 Americans abuses or becomes dependent on alcohol over a lifetime 8.5% of U.S. population meet criteria for alcohol abuse or dependence 30% of U.S. population is at high risk of developing alcohol-related problems Genetic Influences Account for 40 - 50% of risk May be due to genetic polymorphisms of enzymes of alcohol metabolism, antioxidant enzymes, neurotransmitters or receptors, or immune factors Those with family history of alcohol dependence should be alert for early signs Effect of Gender Men are at higher risk for alcohol dependency: 4 male:1 female Women are more susceptible to adverse effects of alcohol due to smaller size, lower body water content, and lower alcohol dehydrogenase in stomach Liver disease Heart muscle damage Cancer Brain injury Age of Onset of Drinking Underage alcohol consumption contributes to 4500 deaths/year in U.S. 45% of youth who drink before age 14 develop alcohol dependence, compared to 10% of those who delay drinking until after age 21 40% of high school youth report current alcohol consumption Ethnicity and Alcohol Abuse High use Native American Indians High rate of motor vehicle accidents and unintentional injuries due to alcohol High rate of alcohol-related suicide and domestic abuse High rate of fetal alcohol syndrome Alaska Natives Native Hawaiian Low use Asian Americans Uncomfortable side effects from low aldehyde dehydrogenase activity Mental Health and Alcohol Abuse Alcohol abuse may aggravate or cause depression or anxiety disorders People with mental health disorders may seek alcohol to self-medicate Majority of suicides and interfamily homicides are alcohol-related Clinical Perspective: Diagnosis and Treatment of Alcoholism Two-phase problem Problem drinking Alcohol addiction Signs of alcoholism (in addition to those listed in section 8.5) Alcohol odor Flushed face CNS disorders (e.g., tremors) Unexplained work absences Frequent accidents Falls or injuries of vague origin Laboratory tests Impaired liver function High triglycerides High uric acid concentration Determining Whether a Problem with Alcohol Intake Exists CAGE questionnaire (1 or more positive responses) C: Have you ever felt you ought to cut down on drinking? A: Have people annoyed you by criticizing your drinking? G: Have you ever felt bad or guilty about your drinking? E: Have you ever had a drink first thing in the morning (eye-opener) to steady your nerves or get rid of a hangover? Recovery from Alcoholism Behavioral therapy Identify ways to compensate for the loss of pleasure from drinking Total abstinence is the ultimate objective Co-existing mental health disorders must be treated Medication Naltrexone (ReVia): blocks craving for alcohol and pleasure of intoxication Acamprosate (Campral): acts on neurotransmitter pathways to decrease desire to drink Disulfiram (Antabuse): causes physical reactions (e.g., vomiting) with alcohol consumption Mutual-help programs Alcoholic Anonymous Al-Anon for friends and family members Recovery rates are 60% or higher for job-related alcoholism treatment programs Successful recovery depends on early detection and intervention Instructor Manual for Wardlaw's Perspectives in Nutrition Carol Byrd-Bredbenner, Gaile Moe , Jacqueline Berning , Danita Kelley 9780078021411
