Exam 1 3 Review NUTR 202 23 Minerals Minerals are specific single atoms that track through body unchanged. Many are charged and may act as: Cofactors components of enzymes and proteins that cause thing to happen Electrolytes maintain proper charges and amounts of body fluids Since minerals are reactive (charged) they may form stable complexes that are not easily absorbed ie Zinc is bound to phytates in plant foods, but is readily absorbed from meats. Bioavailability of minerals in foods varies a lot (i.e. amount available for target tissue to use) Deficiencies and toxicities are both possible Calcium 99% is in bones and teeth, but 1% in blood is critical. Bones and teeth act as bank for 1% critical Calcium in blood. Bones and teeth are hard but not static tissues constantly undergoing remodeling (breakdown/buildup) processes. Teeth Fluoride combines with Calcium and Phosphorous to mineralize bones and teeth making them hard. Osteoporosis is condition of porous fragile bone resulting from loss of minerals especially Calcium affects 44 million Americans Peak bone mass is built by age 30 and declines after that particularly after menopause in women. Adequate Calcium intake with Vitamin D can prevent osteoporosis. Most in US consume too little Calcium and too much Phosphorous from cola drinks and meats Risk factors for osteoporosis include: Female Post menopause Small thin body size Deficient Calcium and/or Vitamin D Smoking and/or alcohol intake Inactivity Genetic Most Americans do not consume enough Calcium, especially women. Iron deficiency is most common mineral deficiency in US and World affecting primarily women and children and causing anemia: Weakness Fatigue Short attention span Irritable Susceptible to infection
2 Women need more than men due to monthly blood losses. Children need more due to growth stresses. Iron absorption varies a lot. Beef, liver and prune juice are good food sources. Most plant iron is tightly bound by phytates or oxalic acid. Toxicity iron supplements are most common poisoning for children and can be fatal. Excess iron is not easily excreted and many US men get too much. Sodium is essential but most in US get too much table salt. Sodium and Potassium work to maintain water balance in humans Some people are salt sensitive and develop hypertension from excessive sodium intake. Majority of people are not salt sensitive. Risk factors for hypertension major public health problem in US: Obesity Genetics High sodium consumption, especially in slat sensitive individuals Inactivity Treatment for Hypertension Achieve appropriate weight DASH diet Dietary Approaches to Stop Hypertension lots of plant foods, less sodium, low fat dairy . Label reading Drugs as last resort 24 Supplements Dietary Supplements outside realm of ordinary food not regulated as stringently as foods. Not tested for safety or efficacy (effectiveness) unless FDA receives complaints. Burden of proof and cost is on FDA not manufacturer. May make structure and function claims, but may not claim that they prevent or treat disease. FTC regulates advertising, but does not have resources to do good job. Bioavailability is uncertain as many complexes may form making them unabsorbable. Supplements do not compensate for a poor diet or bad habits. Guidelines for choosing supplements: Purchase USP, NF or CL labels (i.e. quality ingredients) Check expiration dates Don't use more than 100% Daily Value Avoid contaminants (i.e. Calcium supplements from oyster shells or bone which may contain lead or aluminum) Keep them out of reach of Children. Herbal Remedies many have long history, but not checked for safety or efficacy in US. Ephedra for weight loss is not safe and was banned in 2004. Many herbals interact with other medications. Check NIH Medline web site for guidance
3 Functional Foods fortified or enhanced products offering health benefits beyond ordinary nutrition. No real legal definition or standards Prebiotics non-digestible fiber broken down by bacteria in colon that foster the growth of friendly bacteria. Probiotics Strains of friendly bacteria (lactobacillus and bifidobacteria) that have beneficial effects in GI tract and prevent growth of unhealthy bacteria. 25 Water Water is the most essential nutrient most would die in about 1 week without it. Functions: Universal biological solvent Participates in energy formation Transports nutrients and waste materials Regulates body temperature Adults are 60-70% water Muscle tissue is 75% water, Blood is 83% water, Fat is 10% water Humans need 8-12 cups per day or more if very active Most solid foods are more than 50% water Demand for fresh water is rising faster than supplies Much water is contaminated or wasted. EPA regulates safety of public water supplies in US Bottled water is calorie free, low sodium and quenches thirst well. It is generally safe and is regulated and inspected by FDA. Many new products are considered gimmicks herbal and oxygen enriched waters Strenuous work, vomiting or diarrhea, or excessive alcohol intake may lead to dehydration which may be a medical emergency. Caffeine is a diuretic, but does not cause dehydration normally Dehydration effects include: Nausea Fast heart rate Increased body temperature (decreased sweating) Dizziness and confusion Can cause kidney failure and death Water toxicity is rare but possible with excessive or fast intake leading to: Hyponatremia low blood sodium Excessive water in brain, lungs, heart Confusion / headache Nausea / vomiting Seizure / coma/ death
4 26 Genomics Nutrients can turn genes on or off Nutrient intake can sometimes compensate for abnormally functioning genes. Enzymes and proteins produced through genetic codes can affect health. Individual genes code for specific proteins Some identified nutrient gene interactions in some people: Whole oats lower cholesterol High folate intake decreases heart disease. Types of fat in diet affect blood cholesterol levels High carbohydrate increases risk of Type 2 diabetes Green tea consumption lowers risk of prostate cancer Researchers have studied single gene defects but they are rare Interactions or multiple gene defects are harder to study Gene defects can alter absorption or utilization of nutrients. PKU (phenylketonuria) Body lacks enzyme to break down phenylalanine leading to growth and mental retardation treatment is avoiding phenylalanine consumption. Celiac disease causes GI villi flattening and multiple nutrient malabsorption treatment is to avoid wheat, rye, oats Lactose intolerance body does not produce enough lactase to break down milk sugar treatment is avoid fluid milk or use treated milk with lactose broken down chemically or enzymatically Hemochromatosis individuals absorb excessive iron which has toxic effects on liver and heart treatment can filter iron from blood Many chronic diseases are interactions from multiple genetic and environmental issues Heart disease has multiple genetic and environmental factors Cancer seems to be primarily environmental Hypertension is both genetic and environmental Obesity may be genetic and environmental Some bitter tasters (genetic) do not like bitter vegetables Specific individualized gene based designer diets may be possible in future. 27 Physical Fitness Physical fitness delivers respiratory and circulatory systems capable of utilizing oxygen for prolonged periods of stress. Fitness (good health) depends on muscular strength, endurance and flexibility. Fat can be fit too. Most in US have poor fitness levels Benefits of regular physical activity include: Reduced risk of chronic disease Increased feeling of well-being Decreased depression & anxiety
5 Good stress relief healthier than eating Exercise + good diet + healthy behaviors = good health and weight control Muscle requires more calories to maintain than fat = metabolically more active Best weight loss strategy = reduced food intake + more exercise Muscles grow in size and strength with demand i.e. resistance training Aerobic fitness yields longer and harder exercise it is determined by measuring maximal oxygen consumption (VO2 max). Aerobically fit people train at 70-85% VO2 max Maximal heart rate is 220 your age Maximal heart rate X 60% is your target heart rate for exercise Flexibility is increased by warm up stretching before and cool down stretching after exercise. Good diet can provide appropriate fuel for exercise Glucose (glycogen) is primary fuel for high intensity short duration exercises that does not require oxygen power lifting, sprinting Fat burning requires oxygen and is primary fuel for long term exercise aerobics, long distance running, swimming Stiff muscles improve with more exercise. Physical activity increases the body's need for water should weigh same at end of exercise as at start of exercise. Good hydration is critical to good performance. Physical fitness is a constant work in progress that exercises all muscle groups Moderate exercise at least 30 60 minutes per day is beneficial. Some exercise is better than none, but people with chronic diseases should check with a physician before embarking on a new exercise program. Obesity rates in children and adults seem related to lack of activity Physical fitness activities should be enjoyable so they will be repeated. 28 Nutrition & Physical Fitness Physically fit people have good respiratory and circulatory systems Regular physical activity reduces the risk of developing many chronic diseases as well as improving sense of well-being Regular exercise + good nutrition provides synergistic (multiplicative) effects for controlling weight and health Physical fitness components are strength (maximum force), endurance (length of time) and flexibility (range of motion) Aerobic fitness delivers respiratory and circulatory fitness (can work harder and longer) Aerobic fitness is measured by maximal oxygen consumption (VO 2 max) when working at maximal intensity Aerobic fitness goals are set at 40-60% VO2 max Aerobically fit persons can train at 7080% VO2 max Heart rate can be determined by counting pulse at wrist or neck for a 10 second period and multiply that number by 6 to get heart beats/minute Target heart rate = (220 age) X %Maximum Heart Rate for training
6 Flexibility exercises protect against muscle and connective tissue injury, stiffness and pain Muscles can use carbohydrate, fat, and amino acids for energy Sedentary activities fat provides most of energy Fat is primary fuel for low to moderate activity Oxygen is required Carbohydrate is primary fuel for high intensity activities breakdown can be anaerobic, but will lead to accumulation of lactic acid which leads to pain and pH drop in blood Water is most important nutrient for active bodies load before, during and after activity Beneficial effects of physical fitness diminish after 2 weeks and disappear at 2-8 months Resistance training 2-3 times per week builds muscle (metabolically more active) Bulk up with more weights Endurance & strength with lighter weights and more reps Aerobic Training 3 or more sessions per week build cardiorespiratory fitness Flexibility stretching 3-7 times per week prevents muscle/joint damage Some exercise is better than none - burns more calories People with chronic health conditions should check with Dr. before exercising Most Americans have poor physical fitness Children are a special concern should be allowed to play actively and develop good habits 28 Nutrition and Physical Performance Endurance is influenced by genetics, training and nutrition "Hit the wall" running out of muscle glycogen for intense activity "Bonking" running out of liver glycogen & developing hypoglycemia (low blood sugar) can cause loss of consciousness and dangerous falls. All macronutrient substrates (carbs, fats, proteins) can be broken down to ATP energy the currency of cells Glucose breakdown can be anaerobic (no oxygen required) to form pyruvate Pyruvate forms lactic acid in absence of oxygen which drops blood pH and causes muscle soreness Only the liver can clear lactic acid from the blood Conversion of pyruvate or fatty acids to ATP requires oxygen Fats have very little oxygen compared to carbohydrates so provide 9 calories/gm rather than 4 Carbohydrate (glycogen) loading of muscle and liver tissue is possible through training and eating a high carbohydrate diet. Muscle cells actually build extra mitochondria (powerhouse of cells) Glycogen stores are normally limited due to their affinity for water which is bulky Glycogen loading is beneficial in endurance sports lasting 1 hour of longer Carbohydrates raise blood insulin levels increasing transfer of amino acids into muscle cells after exercise.
7 Fat loading has not be nearly as successful as glycogen loading Hydration is important for cooling and maintaining blood volume and consistency Water is sufficient for exercise lasting less than 1 hour Sports beverages with carbohydrate are beneficial for longer activities replacing water and electrolytes lost in activity and sweating in heat Dehydration occurs when 2% of body weight is lost heat stroke is a medical emergency Hyponatremia (low blood sodium) occurs with too much water consumption rare - but does occur in endurance sports can be prevented by sports beverage consumption Athletes are generally lean, but less than 3% body fat in men and 12% in women is dangerous. Men generally 10-20% body fat Women generally 20-30% body fat to help nourish a pregnancy Female athlete triad low calorie consumption yields lack of estrogen thus lack of a monthly period (amenorrhea) which yields lack of estrogen and calcium absorption and utilization. Then stress fracture never heals which ends competitive career. Wrestling has similar problems with dangerous weight losses. Many female athletes need iron supplements Sports anemia often occurs early in training after off season inactivity as athlete needs more iron for building muscle and increased blood. It self corrects usually in 6 weeks without supplements. Most ergogenic aids are not really useful, many are now illegal to use and some actually have toxic effects. 29 Pregnancy and Breastfeeding Good nutrition is critical during pregnancy, but many pregnancies are unplanned US ranks 24th in infant mortality Critical periods are times when essential nutrients for energy and growth are needed for optimum development of the fetus if organs or critical tissues like the brain and spinal cord do not have appropriate raw materials many defects can occur. The most critical period is in first trimester when woman may not realize she is pregnant brain and spinal cord as well as other structural and specialized and organ tissues are being developed and may be impaired. Birth weight is one of the primary indicators of good health for a baby. Underweight babies have many more health problems. Pregnant woman should gain 25-35 lbs before delivery Even obese women should gain 15 lbs. Diet needs to be high quality to provide nutrients that baby and mother need calories, protein, folate, Vitamin B6, iron, calcium and zinc are of special concern. Folate is especially important to prevent neural tube defects (brain and spine)
8 Vitamin B6 helps prevent morning sickness Vitamin A is important for membrane health and visual activity. Calcium helps prevent bone and teeth defects Iron is important for hemoglobin production and oxygenation. Zinc is also important to membranes and helps produce shorter labor. Good diets take planning Fetal alcohol syndrome may develop in babies of women who drink alcohol yielding permanently small mentally impaired children Vitamin and mineral supplements should be tailored to needs of the woman and child. Teen pregnancy is a public health problem children are often not finished growing themselves and often do not have physical or monetary resources to support a pregnancy or baby Breast milk is the best food for a young baby. It is inexpensive, sanitary, and contains many immunity factors not easily replicated in formulas. Cholostrum (earliest milk) has high levels of protein, minerals and antibodies designed for very small tummies. Employed women returning to work find many barriers to breast feeding in US. Most women produce plenty of milk when properly hydrated. Milk production requires 300-500 calories per day and may help with pregnancy weight loss Caffeine, alcohol and environmental contaminants as well as the AID's virus and some food components and some drugs can be transmitted in breast milk. Infants grow and develop very fast first year triple birth weight. Growth charting can be important tool for assessing health head and brain development are primary. With rapid growth and small tummies they need feeding every 3-4 hours. Breast milk or formula should be exclusive food for 4-6 months. Solid foods should be introduced 1/week (to check for allergy issues) and rice cereal is generally first solid. Infant may need iron, fluoride and Vitamin D supplements. By 1 year most babies can eat soft table foods. Reduced fat milk is not recommended before 2 as babies need fat for brain and nerve development Unpasteurized honey may contain botulism toxins If baby needs bottle to sleep, it should contain water only to prevent baby bottle tooth decay. Food preferences are learned and infants should be offered healthy varied diet Best method of teaching a healthy diet is by parent example Feeding should be pleasurable 30- Childhood & Adolescence Periods of rapid growth and development of good habits Small children eat what is offered Adolescents begin making own choices Lifelong habits are established at both stages Nutrients available can affect ultimate size, health and even mood
9 Many children are becoming obese as we increase high calorie food offerings and reduce exercise opportunities leading to earlier development of chronic disease. Prevention is better than remediation society must make some changes Food preferences are learned and taste is prime factor Child food guide pyramid is similar to adult, but serving sizes are smaller 1 Tablespoon.year of age/ serving. Saturated fats should be limited and for many, milk is still primary source of needed Calcium. Soft drinks with Phosporous should also be limited. 31- Adult Nutrition Health varies more widely as we age depending on our health habits. Aging processes start at cellular level Maintaining health as we age is important to preventing rising health care costs Prevention is more important than remediation U S Population is aging due to less infant deaths, less infectious disease and better nutrition and medical care. Factors associated with better health include: Consumption of fruits and vegetables and whole grain cereals Less saturated fats Alcohol in moderation Eating breakfast Maintaining healthy weight Maintaining proper hydration Many older people become dehydrated thirst not as accurate Many taste changes occur meds and brain changes affect it Meal preparation is more troublesome shopping if can't drive, depression if alone, etc. 32 Food Safety Major food safety issue in US is bacteria and virus contamination to FDA 76 million cases of food-borne illness/ year reported to CDC Over 5,000 deaths Primary needs of bacteria to grow are water and protein & (40-140F) Heat and good sanitation are primary control factor Raw fruits and vegetables are a concern if not properly washed or pealed Manure fertilizers must be properly composted to prevent spread of bacteria from animals that may harm humans Bacteria on food more concern than bacteria in food unless food is ground Shellfish concentrate contaminants in water Cross contamination is a huge issue cutting boards, utensils, hands, raw juices dripping on salad stuffs Salmonella on poultry and eggs flu like symptoms 2 days later Other concerns include: Antibiotic resistance from intensively cultivated livestock
10 Hormones used as growth promoters Pesticides Contamination with environmental toxins PCB's cause cancer Food-borne Illness Consequences include vomiting, diarrhea, and even death High risk groups are very young, elderly and compromised immunity Food-borne Infections 1-8 days onset often include flu like symptoms and are vastly under reported Salmonella and Campylobacter are most common E coli 0157:H7 is most deadly Norwalk-like virus is difficult test to detect Foodborne intoxications onset 2-8 hours, very noticeable often 2 bucket disease from ingesting preformed toxin developed after bacteria are heat stressed Staphlococcus areus is most common Clostridium botulinum is most deadly canning processes are designed to prevent this disease which is 60% deadly Seafood issues Mercury contamination form industrial pollution of water concentrates in larger fish Ciguatera toxin from microbes in reefs is not destroyed by cooking, freezing or digestion it is a neurotoxin Red tide is from microbes that produce a neurotoxin has been detected in Brazos River in summer months Parasites killed by adequate heat or growth is inactivated by freezing Mad Cow Disease Bovine Spongioform Encephalopathy is transmitted by prions that cause a deadly neurological disease danger is small but deadly Food safety Regulations Food and Drug Administration (FDA) packaged foods inspection US Dept of Agriculture (USDA) Meats and Poultry inspection Irradiation Cold pasteurization/sterilization method that does not impact sensory quality of many foods Consumer Responsibility Cleanliness Wash hands thoroughly (20 seconds of scrubbing with warm water and soap) Keep hot foods hot and cold foods cold (Bacterial dangerous growth zone is 40-140F). If in doubt, throw it out! Follow Safe handing rules Thaw foods properly refrigerated or quick in microwave Keep raw meats separated from other foods Cook thoroughly - use meat thermometer Keep foods hot or refrigerate leftovers immediately or discard Canned foods Never use swollen or damaged cans and don't taste contents
11 Travelers Diarrhea prevalence is 50% with International travel Take an anti-diarrhea and an anti-diuretic drug with you when traveling Internationally Avoid fresh fruits and vegetables that might not be properly washed Avoid foods from street vendors that may not have proper sanitation facilities Drink bottled water as local water supplies may not fit US standards for santiation 33 Global Nutrition Currently the world produces enough food to feed everyone but it is poorly distributed and stored Contaminated water supplies are a major source of infection in many developing countries Poverty is a major source of malnutrition United Nations Agencies include World Health Organization (WHO) monitors food and health status Food and Agriculture Organization (FAO) United Nations Children's Emergency Fund (UICEF) Women and Children are targets for malnutrition leading to more infections Iron deficiency is 50-70% Vitamin A deficiency is 21% -leading to night blindness Zinc deficiency is 30% Marasmus starvation of calories and protein children are very emaciated as body uses its own tissue for energy Kwashiokor inadequate protein intake may be faces and bellies swollen as food is not processed due to enzyme deficiency and fluid is retained Malnutrition may cause permanent mental retardation Lack of protein impacts immune system adversely Breastfeeding prevents many infections in infants 42 million of World's poorest people have AIDs Most malnutrition is due to natural or man-made disasters People need support, sanitation, education and employment to end poverty Improvements are being made, but progress is slow Generous food supplies may backfire as thrifty genes kick in leading to chronic disease development.