Chapter 8-10 (EXAM 3) PDF

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Ali Price SPH-N 220 QUIZ 3 10/22/18 OVERVIEW OF MICRONUTRIENTS AND PHYTOCHEMICALS ● You are craving peaches, but it is only March. Fresh peaches won’t be in season until midsummer. The produce aisle at the supermarket has some peaches in stock, but how fresh are they? Would it be better to buy them canned or frozen instead? Which of the following would you choose? ○ Frozen peaches with no added ingredients ● Vitamins (overview) ○ Vitamins are necessary for health, but the body is unable to synthesize enough  of the compound to sustain life ○ Vitamins do NOT cure all ills, nor do supplements provide all of the many disease-preventing benefits of vitamin-rich foods such as vegetables, fruits, and whole grains ■ Vitamins differ from macronutrients by: ● Function: do not yield energy when metabolized, rather many assist the enzymes that participate in the release of energy from macronutrients ■ Vitamins are similar to macronutrients in that they are: ● Some water-soluble vitamins are synthesized by GI tract bacteria and absorbed by Ig. intestine, but not in quantities great enough to meet the body’s needs, thus all vitamins are essentials ● Primary site of micronutrient absorption is small intestine ○ Can only function if they are intact ■ Vulnerable to destruction by heat, light, and chemical agents ■ A,C, & E work together to protect the body from damage by free radicals ● Absorption and Storage of Vitamins in the body ○ Fat soluble ■ Absorbed with dietary fat in small intestine ● After intestinal absorption, fat soluble vitamins are packed into chylomicrons and travel in the lymph ■ Anything interfering with fat absorption will impair fat soluble absorption ■ More potential for toxicity ● Can be stored in body, mostly in liver & fatty tissue ○ Water Soluble ■ Relatively high bioavailability ■ Less likely be toxic ● Readily excreted in excess ● Vitamin Toxicity ○ Fat Soluble

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■ A,D,E,& K not readily excreted from the body ● Toxicity by vitamin A most frequently observed ○ Water soluble ■ Excess filtered by kidneys and excreted in urine ○ Avoid megadoses: 2-10 times the estimated needs to prevent a deficiency Vitamin Preservation in Foods ○ Vitamin content is greatest when a fruit or vegetable is ripe ○ Freezing helps retain nutrients ○ Water soluble vitamins are particularly susceptible to destruction by heat, light, air exposure, cooking in water and alkalinity Minimizing nutrient losses ○ To slow degradation of vitamins, refrigerate most fruits and vegetables ○ Store fruit and vegetables that have been cut in closed, airtight containers ○ Microwave or steam vegetables in a small amount of water Vitamins: classifications and function- fat soluble ○ Carotenoids are pigments derived from plants, a “phytonutrient” (aka phytochemical) with health promoting chemicals; some of which can be converted to vitamin A ○ Vitamin D: ■ Main role= bone health ■ Body can synthesize vitamin D ● Cholesterol serves as the major precursor for the body’s synthesis of vitamin D (need sunlight for synthesis) ■ Few natural food sources of vitamin D ■ Fortified milk (10 mcg/ quart or 2.5 mcg/cup)- most reliable source of dietary vitamin D ○ Vitamin E: ■ Main action is an antioxidant: to stop chain reaction of free radicals from producing more free radicals ○ Vitamin K ■ Involved in blood clotting ■ As it can be synthesized by gut bacteria ○ B vitamins ■ Do not provide the body with fuel for energy, rather they help body use macronutrients for fuel ● Chief function is coenzyme participation as they assist enzymes with energy release from macronutrients Vitamins: classification & functions- water soluble ○ Folate (folic acid) ■ Folate required as a coenzyme for DNA synthesis for all rapidly growing cells ■ Increased need during pregnancy ■ Actually more bioavailable in synthetic form ■ Green, leafy vegetables (“foliage”)- highest in folate ○ Vitamin B-12

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■ Vegan: need fortified soy milk or B12 supplements ○ Vitamin C ■ Vitamin C enhances iron absorption by protecting iron from oxidation The minerals- an overview ○ Inorganic elements ■ Always retain chemical identity and cannot be destroyed by heat, air, acid or mixing ○ Bioavailability varies ■ Minerals from animal products are better absorbed than those from plants ■ Plant foods contain binders ■ Mineral content of plants can greatly vary based upon mineral concentrations of the soil in which they are grown ■ Refining and processing foods can decrease trace mineral content Mineral classification and function- major minerals ○ Sodium ■ Primary regulator of fluid balance ■ Nerve impulse transmission and muscle contraction ○ Potassium ■ Required to maintain fluid and electrolyte volume/ balance ■ Aids in nerve impulse transmission and muscle contraction ● Potassium intakes ○ Potassium can decrease hypertension ○ Calcium ■ Most abundant mineral in the body ■ Part of bone structure ● Calcium, phosphorus, magnesium and fluoride mainly serve as structural component of bones and teeth ■ Helps to maintain normal blood pressure ○ Phosphorus ■ Part of ATP ○ Magnesium ■ More than half is found in bones Mineral classification and function- trace minerals ○ Iron ■ Component of hemoglobin ■ Vitamin C (ascorbic acid) ■ Iron deficiency anemia: severe depletion of iron stores that results in low Hgb ● RBC’s cannot carry enough O2 to tissues = energy metabolism in cells filters ○ Iodide ■ Component of the thyroid hormones ○ Fluoride ■ Inhibits the initiation and progression of dental caries Mineral toxicities

○ Supplements pose biggest problem for toxicity ○ Look for brands with USP for supplements ● Preservation of Minerals in Foods ○ Refined grains= lower levels of vitamin E, B vitamins & trace minerals ● Should you take a supplement? ○ Eating recommended serving of fruits, vegetables, and grains is the healthiest approach to ensure nutrient adequacy ● Which supplement should you choose? ○ Read labels carefully, look for USP symbol FLUID & ELECTROLYTE BALANCE ● Water is the best choice for everyday hydration because it quenches thirst without calories. There are currently many “water” choices available. Do you need water that contains vitamins and minerals? What is the difference between spring water and mineral water? Is bottled water safer to drink than tap water? As you peruse the store shelves, which is the healthiest choice to take along to the student recreation center for your workout? ○ Reusable bottle filled with tap water ■ Tap water has added fluoride (one of the best dietary sources), bottled water is often much lower or deficient in fluoride ● Water and the Body Fluids ○ ~75% weight of lean tissue and ~25% of fat tissue ■ Which of the following people is likely to have the highest percentage of body weight as water? ● A highly trained male athlete who is 20 years old ● Water functions ○ Carries nutrients and waste products ○ Aids in regulation of body temperature ○ Maintains blood volume ● Water is the universal solvent ○ Water transports nutrients and wastes ● Water contributes to Body Temperature Regulation ○ Water temperatures change slowly because water has a great ability to hold heat ○ When the body is overheated, it cools itself through perspiration and evaporation: ■ Body perspires/sweats and as perspiration evaporates, heat energy is removed from the skin, cooling the body ● When body temperature increases, blood vessels in the skin become larger, allowing greater water loss through perspiration ● ADH (antidiuretic hormone) ○ Water-conserving hormone that stimulates the kidneys to reabsorb more water (excrete less) ○ Alcohol depresses ADH activity → resulting in fluid losses and dehydration ● Dehydration

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○ Inadequate intake of water to replace losses ■ 1-2% body water loss → feeling of thirst ● By the time one is thirsty, dehydration has already set in ● 4% → fatigue, dizzy/ low blood pressure, elevated heart rate ● 10% → inability to regulate body temperature (cold and heat intolerance) Urine production ○ Largest percentage of daily water loss is attributed to urine losses ■ Other loses from perspiration, lung respiration and water in feces ○ A way to determine adequacy of fluid intake is to observe urine color: ■ Clear or light yellow is good hydration ■ Dark yellow and pungent is poor hydration Is thirst a good indicator of hydration? ○ If thirsty, you are already dehydrated Osmosis ○ Passage of water through a membrane from less concentrated compartment to more concentrated compartment Understanding Fluid Balance ○ If intracellular (inside cell) concentration of ions/solutes is greater than extracellular (outside cell) concentration of ions, what will happen in order to maintain fluid balance? ■ Fluid will move into the cell ○ If extracellular (outside cell) concentration of ions/solutes is greater than intracellular (inside cell) concentration of ions, what will happen in order to maintain fluid balance? ■ Fluid will move out of the cell Electrolytes and Nerve Function ○ Electrolytes control nerve impulse conduction Sodium (Na+) ○ Table salt= sodium chloride = NaCl ○ 1 tsp of salt= 2300 mg sodium ■ No more than 2,300 milligrams (mgs) a day and an ideal limit of less than 1,500 mg per day for most adults, especially for those with high blood pressure. Food sources of Sodium ○ High Sodium foods: ■ Packaged foods ■ Processed foods ● Processed meats, cheeses ■ Fast food ■ Canned food ■ Frozen prepared meals ○ Low sodium foods: ■ Fruits and vegetables ■ Whole grains

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■ Meats w/o sauces ■ Unprocessed foods ● Except milk- its a higher sodium food Getting too much sodium ○ Kidneys main regulator of blood sodium concentration ■ Excess sodium increases urine output to rid body of sodium, leading to dehydration ○ Increases blood pressure (hypertension) ○ High salt intake (>2000 mg) associated with increased calcium excretion = over time, a diet high in sodium can lead to bone loss RDN ○ Takes ~ 8 weeks before you can sense salt at a lower taste threshold Potassium (K+): functions ○ Nerve impulse transmission and muscle contraction ○ Potassium imbalances are the most common electrolyte associated with irregular heart rhythms ○ Increasing potassium intake can help lower blood pressure (DASH diet)influences hypertension in a good way Food sources of potassium ○ Potassium is highest in fruits and vegetables Potassium: Deficiency ○ Can be caused from: ■ Deficiency typically caused by low intake of fresh fruits and vegetables ■ Eating disorders ■ Low calorie diets ○ Symptoms include: ■ Muscle cramps/ weakness ■ Irregular heart beat ■ Increase in blood pressure Chloride ○ Food sources ■ Abundant in processed foods as salt (NaCl) Calcium in Body Fluids ○ Helps to maintain normal blood pressure ■ Stabilize smooth muscle cells of blood vessel and releases relaxing factors from blood vessel cell walls Sports drink ○ Using your knowledge of carbohydrates, weight management & now fluid/electrolytes, who would you recommend consume a sports beverage containing fluid, carbs & electrolytes? ■ An athlete who has involved in vigorous exercise for an hour or more Hypertension ○ Defined as a systolic/diastolic blood pressure at or above 130/80 Why Control blood pressure? ○ Lowers cardiovascular disease risk

○ Lowers kidney disease risk ○ Decrease risk of stroke ○ Prevent declines in brain function ● DASH DIET ○ Dietary Approaches to Stop Hypertension- is effective in lowering BP

NUTRIENTS INVOLVED IN BODY DEFENSES ● Intestinal cells ○ Gut- associated lymphoid tissues (GALT) ■ Clusters of specialized immune cells found in the GI tract that help keep pathogens from entering bloodstream ● ~70% of lymphoid tissue ● Lymphoid tissue: specialized cells and tissues that participate in the immune response ● Two categories of immune response ○ Refined carbohydrates, added sugars, saturated fats, and excess calories thought to promote inflammation ○ Fruits and vegetables, plant proteins, unsaturated fats from plant oils and fish, whole grain associated with lower inflammation and lower risks of chronic disease ● Nutrients that support the immune response ○ Consuming 5-9 servings of a variety of fruits and vegetables per day will bolster the immune system ● Antioxidant nutrients protect immune cells ○ Vitamins A, C, E, Zinc and Selenium ■ Antioxidants protect the body’s white blood cells from being damaged by oxidation reactions ● Antioxidant Review ○ Free radicals: a molecule with 1 or more unpaired electrons making it unstable and highly reactive ■ Generated by normal metabolic processes ○ Antioxidants neutralize free radicals by donating electrons ● Free radicals ○ DNA within cells can be damaged ○ Oxidative damage of DNA is thought to contribute to cancer development and many chronic diseases ● Defense against free radicals ○ The best way to imrpove body’s defense against free radicals is to consume plenty of fruits and vegetables ● Vitamin A ○ Carotenoids are provitamin A

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■ A provitamin is a substance that may be converted to a vitamin within the body ■ Carotenoids are pigments derived from plants ● Beta-carotene is the carotenoid with the greatest provitamin A activity ■ Retinoids, form of vitamin A, that come from animals (preformed Vitamin A) Functions of Vitamin A and carotenoid ○ Vitamin A is necessary to maintain integrity of epithelial cell tissue ○ Vitamin A deficiency leading cause of blindness worldwide ○ Vision ■ Night blindness ■ Lower level of carotenoids (beta-carotene, lutein, and zeaxanthin) in the diet is correlated with greater risk of age-related macular degeneration ● Leading cause of blindness among older adults ■ Adequate carotenoid consumption may reduce the risk of cataracts ○ Carotenoids may inhibit oxidation of low-density lipoproteins (LDLs) Getting enough carotenoids ○ Beta-carotene (greatest provitamin A activity) ■ Dark green and yellow-orange vegetables and fruits ■ In green vegetables, orange pigments of provitamin A carotenoids are masked by chlorophyll ○ Cooking frees carotenoids for better bioavailability / absorption Functions of Vitamin C ○ Collagen synthesis ○ Antioxidant ○ Enhances iron absorption ○ Vital for immune function Getting enough vitamin C ○ Smokers need an extra 35 mg because of increased oxidation by tobacco smoke in lungs Food sources of vitamin C ○ Citrus fruits ■ Oranges, lemons, limes ○ Strawberries and blueberries ○ Bell peppers ○ Brighter fruits and vegetables = more vitamin C ○ Exposure to air (oxygen) decreases vitamin C content of food Avoiding too much vitamin C ○ Kidney Stones ○ Diarrhea ○ GI distress Function of Vitamin E (Tocopherols) ○ Principle function is as an antioxidant

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■ Especially important in cells continuously exposed to oxygen → vitamin E is vital in RBC’s and cells lining lungs Vitamin E: Deficiency ○ Rare because the primary source of vitamin E is plant oils and our diets are high in fat ○ Smokers also at risk for vitamin E deficiency as smoking destroys vitamin E in lungs Getting enough vitamin E ○ Only synthesized by plants, plant products best sources, especially oils ■ The vitamin in plant oils naturally protects the unsaturated lipids in oils from oxidation ● The avocado in guacamole and the oil in the tortilla chips are good sources of Vitamin E Selenium functions ○ Aids the activity of body’s natural antioxidant enzymes Functions of Zinc ○ Immunity: vital for white blood cell formation and function Phytochemicals ○ Phytochemical (aka phytonutrient): a chemical found in plants that may contribute health benefits Functions of phytochemicals ○ Antioxidants ○ Inhibit cancer ○ Decrease inflammation Probiotics ○ Live microorganisms (bacteria) with positive effects on human health Prebiotics ○ Not living, ingredients serve as fuel for beneficial bacteria in the gut Contributions of Calorie and Fat intakes to cancer risk ○ Excess calorie intake and obesity responsible for cancer death Etiology of Cancer ○ Heavy consumption of red meat, especially processed cancers ○ Direct relationships between cancer risk and the following ■ Saturated fat intake ■ Alcohol intake ■ Smoking, salting, and pickling foods and high temperature cooking of meats ■ Metabolic syndrome Cancer-inhibiting constituents of foods ○ Fruit and vegetable consumption ■ Fruit and vegetable intake reduces risk of nearly all types of cancer ■ Cruciferous vegetables, are especially rich in cancer-preventing phytochemicals ● Cauliflower, cabbage, bok choy, broccoli, brussel sprouts ■ Intake of whole grains, fiber, and vitamin D...