Nutrients for Energy Metabolism & Blood Health Lecture Notes PDF

Nutrients for Energy Metabolism & Blood Health FN1070A Week 12: Chapters 10 & 14 Nutrients for Energy Metabolism Chapter 10  Vitamins – Organic, essential nutrients – Required in small amounts – Help to regulate processes that support growth O...

Nutrients for Energy Metabolism & Blood Health FN1070A Week 12: Chapters 10 & 14 Nutrients for Energy Metabolism Chapter 10  Vitamins – Organic, essential nutrients – Required in small amounts – Help to regulate processes that support growth Overview of Vitamins & Minerals Minerals – Inorganic, essential nutrients – Required in varying amounts – Contribute to structural components of the body – Help to regulate body processes  Differ from CHO, PRO, Lipids: – Structure – Vitamins are individual units, not linked together – Minerals maintain the same structure upon ingestion and excretion – Function – Do not yield usable energy Overview of – Assist enzymes in the release of energy from macronutrients Vitamins & – Minerals cannot be destroyed Minerals – Food contents – Vitamins – range from ug to mg – Minerals – range from ug to grams Minerals differ from vitamins: – Minerals are inorganic – Always maintain their chemical structure  Bioavailability: – The rate and extent nutrients can be absorbed and used by the body – Difficult to determine as impacted by several factors – Processing – Nutrient intake/nutritional status – Form of nutrient consumed Overview of Precursors: – Vitamins available from foods in the inactive form, converted in the body to Vitamins & the active form (Beta-carotene) Minerals Chemical nature: – Vitamins can be destroyed/lost during cooking, processing – Minerals maintain their structure, but can leach into cooking water Solubility: – Hydrophilic (CHO, protein and water soluble vitamins) – Hydrophobic (lipids and fat soluble vitamins) – Minerals – have varying solubility based on the form Nutrient Interactions B1 - Thiamine B6 - Pyridoxine B2 - Riboflavin B7 - Biotin B3 - Niacin B9 - Folate B5 - Pantothenic acid B12 - Cyanocobalamin  – B vitamins are ‘helper’ nutrients – Directly or indirectly help the body use energy from carbohydrates, fat, & protein – Act as part of coenzymes Role of B – Thiamin, riboflavin, niacin, pantothenic acid, biotin Vitamins in – all participate in the release of energy from Metabolism protein, carbohydrates, & fat – Vitamin B6 helps the body use AA to make protein – Folate & vitamin B12 help cells multiply  General symptoms of ‘B vitamin’ deficiencies include: Nausea, severe exhaustion, irritability Depression, forgetfulness, loss of appetite & weight Pain in muscles, impairment of the immune response, loss of B Vitamin control of the limbs, abnormal heart action Deficiencies Teary or bloodshot eyes, swollen red tongue, severe skin problems Cell renewal of digestive tract & blood affected A deficiency of any one B vitamin seldom shows up by itself, since nutrients are not eaten alone  Functions: Thiamin (B1) – Part of co-enzyme (TPP) in energy (CHO & protein) metabolism – Affects nerve function (special site on nerve cell membrane) – Needed for metabolism of alcohol Recommendations: RDA – Men: 1.2 mg/day – Women: 1.1 mg/day Good Food Sources: – whole grains, enriched cereals/wheat flour, beef, pork, legumes (black beans), green peas, sunflower seeds  Wernicke-Korsakoff syndrome: – Affects brain tissues – Associated with alcohol abuse – Characterized by: – apathy, irritability, mental confusion & disorientation, loss of memory, jerky eye movements, staggering gait Thiamin Beriberi (wet or dry): Deficiency – Due to prolonged thiamin deficiency – First observed in Indonesia with ‘polishing of rice’ – Characterized by: – “DRY” à affects nervous system resulting in loss of sensation in the hands and feet, muscular weakness, advancing paralysis – “WET” à affects cardiovascular system, dilated blood vessels, Na and water retention causing edema – Both types typically present together, with symptoms of one being more predominant  Functions: Riboflavin – Co-enzyme for energy (CHO, fat, & protein) metabolism (B2) – Protects skin & eyes – Interacts with vitamin B6 & folic acid Recommendations: RDA – Men: 1.3 mg/day – Women: 1.1 mg/day Good Food Sources: – milk & milk products (yogurt), whole grains & enriched cereals, eggs, meats (beef liver), green leafy vegetables (spinach/kale), mushrooms Deficiency (ariboflavinosis): – Inflammation of the membranes of the mouth, skin, eyes, GI tract – When thiamin is deficient, riboflavin may also be lacking Niacin Niacin describes 2 chemical structures: – Nicotinic acid and nicotinamide (niacinamide) – Body converts nicotinic acid à nicotinamide – Nicotinamide = major form in the blood Functions: – Co-enzyme (NAD and NADP) for energy (CHO, protein, fat, & alcohol) metabolism needed in >40 reactions – NAD protects against neurological degeneration  Recommendations: – Are in Niacin Equivalents (NE) because the body can make niacin from AA tryptophan RDA – Men: 16 mg NE/day Niacin – Women: 14 mg NE/day Good Food Sources: – Meats, fish, nuts, wholegrains, enriched cereals, mushrooms, baked potato – Adequate protein intake = no niacin deficiency  Deficiency: – Pellagra (4Ds = diarrhea, dermatitis, dementia, death) – Can be prevented by adequate protein Excess: Niacin Physiological effect = normal blood level, naturally occurring niacin in food, no harm Pharmacological effect = large amounts, leading to high blood levels (usually due to supplements), harmful Niacin Flush = dilation of the capillaries of the skin with painful tingling Occurs when nicotinic acid taken in 3-4x DRI Nicotinamide does not product this effect  Functions: – Co-enzyme for energy (CHO, fat, & protein) metabolism – Participates in gluconeogenesis, synthesis of FA, breakdown of AA Recommendations: – Needed in small amounts AI for Adults: 30 μg/day Biotin Good food sources: – Most foods of plant & animal origin Deficiency: – Rare – Symptoms: skin rash, hair loss, neurological impairment – Avidin (protein in egg white) binds biotin inhibiting its absorption – Denatured by cooking  Functions: – Co-enzyme for energy (CHO, fat, & protein) metabolism – Participates in the synthesis of lipids, steroid hormones, neurotransmitters, & hemoglobin Recommendations: AI for Adults: 5 mg/day Pantothenic Good food sources: Acid – Most foods of plant & animal origin – Beef, poultry, whole grains, potatoes, tomatoes, and broccoli Deficiency: – Rare – Symptoms: decreased function of body systems resulting in fatigue, GI distress, neurological disturbances  Functions: 3 Active forms: pyridoxal, pyridoxine, and pyridoxamine à all can be converted to coenzyme PLP Required for >100 reactions in the body Aids in metabolism of amino acids & protein hemoglobin & neurotransmitters Vitamin B6 Synthesis of non-essential & other AA metabolism E.g. tryptophan to niacin or serotonin, H-Cys metabolism Has roles in immune function & steroid hormone activity Assists in releasing stored glucose form glycogen Recommendations: RDA for Adults (19–50 yr): 1.3 mg/day UL: Adults: 100 mg/day  Good Food Sources: Meat, fish, poultry, potatoes, green leafy veg (spinach), banana, sweet potato Deficiency: – Early symptoms: Depression and confusion Vitamin B6 – Longer term symptoms: abnormal brain wave patters, convulsions – Scaly dermatitis – Microcytic anemia – Together, deficiencies of folate, vitamin B12 , B6 are linked to increased H- Cys & a severe early form of CVD Toxicity: – Nerve damage causing numbness of feet & hands, muscle weakness leading to inability to walk – Skin lesions – Depression, fatigue, irritability, headache  Other Names: Folic acid, folacin Functions: Required to make all new cells [blood cells & digestive tract most vulnerable to deficiency] Folate Aids metabolism of DNA & RNA [genetic material] Aids Homo-Cysteine metabolism [increased blood levels highly correlated with CVD] Prevents folate-deficiency anemia [related to pernicious anemia of vit B12 malabsorption]  Folate Recommendations: RDA – 400 ug/d for males and females People of childbearing age: 400 ug/d from food + 400ug from synthetic form to reduce risk of NTDs Pregnancy - 600 ug/d DFE [dietary folate equivalents] Lactation = 500 ug/d DFE [dietary folate equivalents] Folate UL – 1000 ug/d (from synthetic forms only – supplements & fortified foods) High intake can mask blood symptom of vit B12 deficiency, but will not prevent nerve damage Calculating Dietary Folate Equivalents: E.G 120ug from food and 120ug from supplements = (supplement) 120ug x 1.7 = 204ug + 120ug (food) TOTAL = 324ug DFE  Deficiency: May result from: – Inadequate intake, illnesses, excretion, medication interactions (aspirin, anti-convulsant, barbiturates, antacids) May cause: Folate – Anemia, diminished immunity, abnormal digestive function – Macrocytic or megaloblastic anemia = large, immature RBCs – Elevated risk for CVD & colon cancer, & cervical cancer in women – Neural tube defects (NTDs) – spina bifida, anencephaly, severely diminished brain size, death shortly after birth  Good Food Sources: Green leafy vegetables (spinach, kale) Folate Lentils, pinto beans Asparagus Avocado Beets Beef liver Enriched grains Cantaloupe Orange juice  Functions: – Converts folate to its active form – Helps folate make RBCs – Aids DNA & RNA metabolism Vitamin B12 – Maintains nerve fiber sheaths (Cobalamin) – Digestion: – HCl and pepsin separates B12 from the protein it is bound to in food – Absorption: – Requires Intrinsic Factor (IF) from stomach lining Vitamin B12 Recommendations: RDA: 2.4ug (adults) Good Food Sources: – Foods of animal origin [chicken liver, sirloin steak, pork roast, Swiss cheese, cottage cheese, sardines, tuna]  Deficiency: – Reflects poor absorption not poor intake – Poor absorption results from: – Lack of HCl – Lack of intrinsic factor – Pernicious anemia due to Atrophic gastritis – Commonly develops in those >50 Vitamin B12 – Damage to cells of the stomach = decrease HCl and intrinsic factor – Treated with injectable vitamin B12 or nasal spray – Who is at highest risk for inadequate intake? – Individuals following a vegan diet – Symptoms: – neurological degeneration – seen in infants whose mother follows an unsupplemented vegan diet – Macrocytic or megaloblastic anemia seen in folate deficiency since B12 is needed to convert folate to its active form  Functions: – An essential nutrient – Used to make lecithin and acetylcholine – Pregnancy – neurological development of the fetus – Adulthood – may improve cognition Recommendations: Choline – The body can make some choline, but dietary choline is also needed AI: – Men: 550 mg/day – Women: 425 mg/day UL: – Adults: 3500 mg/day  Deficiency: – Impacts not fully understood – Most Intake falls below AI – Symptoms: liver damage Toxicity: Choline – UL set as excess intake can lower BP to unsafe levels – Symptoms: sweating, salivation, reduced growth rate, liver damage Food Sources: – Milk, eggs, peanuts Minerals for Energy Metabolism  Functions: – Sulphur containing AA help determine the contour of proteins – Side chains stabilize protein structures – Higher Sulphur content in skin, hair nails – contributing to the rigid structure Sulphur Recommendations & Food Sources: – Obtained from a variety of protein containing foods – No DRI – Body can also receive Sulphur from the AA methionine and cysteine Deficiency & Toxicity: – Very rare  Iodine = nutrient in foods Iodide = in the body Functions: Iodine Part of thyroxine [thyroid hormone] Helps regulate growth and development, BMR Recommendations: RDA for Adults 150ug/day UL: 1100ug/day  Deficiency: Goiter [simple enlargement of the thyroid gland] – sluggish, gain weight Typically one of the earliest signs One of the world’s most common & preventable forms of mental impairment Cretinism – irreversible mental/physical impairment of infant; reversible if detected within 6 months of pregnancy Iodine Iodine deficiency during pregnancy Fe deficiency also common among those with iodine deficiency Fe deficiency reduces effectiveness of iodized salt Consider dual fortification Excess: – Goiter-like thyroid enlargement, similar to with deficiency – Infant exposed in-utero based on excess iodine in foods, medications, prenatal supplements can have toxic effects – can block airways and cause suffocation  Good Food Sources: – Iodized table salt – Seafoods – Bakery products (dough conditioners) – Dairy products (iodine used in disinfecting milking equipment) – Iodine in food varies – Based on soil plants are grown in Iodine – Based on amount in soil of foods animal graze on – Plentiful in oceans – Canada: – All table salt is iodized – Speciality salts are not – Labelling: – No requirement/law for manufacturers to include whether iodized salt was used or not  Functions: – Body contains a very small amount – Found in bones, liver, kidney, pancreas – Cofactor for enzymes in the metabolism of CHO, lipids and AA – Assist in bone formation Manganese Recommendations: AI Men: 2.3 mg/day Women: 1.8 mg/day UL for Adults: 11 mg/day  Deficiency: – Rare – Absorption inhibited by Fe, Ca – High supplementation use may cause inadequate absorption and manganese status Toxicity: Manganese – More likely to occur from environmental contamination than excess intake – Symptoms: disorders of the nervous system, brain disease, alteration in behaviours Food Sources: Nuts, whole grains, green leafy vegetables, tea  Functions: – Participates in lipid and CHO metabolism – Works with insulin to regulate & release energy from glucose – Evidence remains controversial re: claim supplements can promote wt loss and build muscle Recommendations: AI Chromium Men: 35 μg/day Women: 25 μg/day Good Food Sources: – Liver, unrefined wholegrains, meats, brewers yeast – Easily lost during processing Deficiency: – Abnormal glucose metabolism - diabetes-like “high blood glucose”  – Why do people take supplements? – Perceived health benefit (prevention of illness/disease) – To ensure they are getting adequate amounts – Multi-nutrient vs single-nutrient supplements – Argument for supplements: – Correct overt deficiencies – may prescribe 2-10x RDA (or AI) Highlight 10: – Individuals with increased nutrient needs Vitamin & – – To improve nutritional status To improve the body’s defenses Mineral – Argument against supplements: Supplements – May cause nutrient imbalances or toxicities – Certain circumstances may increase risk and individuals should avoid supplement use – Toxic overdose in children more common – Fruit flavoured, character shaped supplements – Unknown needs – False sense of security – Misinformation – Belief that vitamins/minerals will give them energy or enhance athletic performance  Considerations when choosing a supplement: – Form – Chewable, liquid, pill – Safety Vitamin & – Those with an 8-digit Natural Products Number (NPN) have been assessed for safety, quality, and efficacy by Health Mineral Canada – Avoid high doses – more is not better Supplements – Content – Avoid those that provide more than UL for any nutrient – Avoid large dose of Fe unless prescribed by a physician – Misleading claims – Cost Nutrients for Blood Health Chapter 14  – Composed of plasma, RBCs, WBCs and platelets – Continuously delivers oxygen and nutrients to tissues – Removes waste products from cells – Takes ~ 1 minute for blood to circulate from heart, around the body and back to the heart About Blood – ~5L of blood in women and 5.5L in men  Functions: – Help synthesize proteins that clot blood – Important to repair damaged tissues/cells – Vitamin K activates several proteins involved in this process – Necessary for the synthesis of protein needed in bone formation together with vitamin D Vitamin K  Recommendations: AI – Men: 120 μg/day – Women: 90 μg/day Sources: Vitamin K – Bacteria in GI tract, however, does not supply enough to meet full needs – Foods: – Liver – Leafy green vegetables – Cabbage-type vegetables – Milk – Canola, olive, and other oils  Deficiency: – Rare – Can result in decreased ability for blood to clot resulting in hemorrhaging or decreased wound healing – Infants – GI tract sterile at birth; no vitamin K producing bacteria – Low plasma prothrombin levels = reduce risk of fatal blood clotting during birth – Single dose of vitamin K is given at birth via intramuscular Vitamin K injection to prevent hemorrhagic disease Toxicity: – Rare – High intake can decrease effectiveness of anticoagulant medications – Continue to consume regular diet – Best approach is to be consistent with intake of these foods – Blood clotting times can be monitored and medications adjusted – Toxicity with supplements of synthetic version if given to infants or pregnant women  Functions: Every living cell contains iron ~80% in blood Part of hemoglobin in RBCs Carries O2 from the lungs to the tissues Part of myoglobin in muscles Carries & stores O2 for the muscles Iron Necessary for many enzymes in energy pathways to release energy Needed to make new cells, AA, hormones, & neurotransmitters Ability to perform in both an oxidized and reduced state Hepcidin Hormone that regulates iron balance Absorption, transportation, storage, recycling and losses Produced in the liver  Ferritin Iron storage protein Captures Fe from food and stores in intestinal cells Released from cells to transferrin (transport protein) to deliver iron to the body Unused iron is shed with intestinal cells and excreted Iron Absorption Types of Iron From Food Heme iron – from meat/fish/poultry; well absorbed Non-heme iron – from plant-based foods; less absorbed Enhancers - Vitamin C, MFP factor Inhibitors - phytates (legumes, whole grain cereal), polyphenols – tannic acid (coffee, tea, red wine), calcium (milk)  Recommendations: RDA – Women: 18 mg/d (19-50), 8mg/d (51+), 27mg/d (pregnancy) – Men: 8 mg/d – Vegetarians 1.8x RDA Iron UL: 45mg/day Food sources: – Meat, poultry, fish, eggs – Kale/spinach, oats, lentils, beans, avocado  Contamination Iron: – Foods cooked in iron cookware take up iron salts – Depends on cook-time and acidity of food Iron Iron supplements – Medical protocol for pregnancy; vegetarians/vegans Ferrous sulphate and iron chelate best absorbed May cause some GI upset, constipation  Iron deficiency: – Depleted iron stores without being anemic – Decrease physical work capacity and mental productivity – More common in overweight children/adolescents than healthy weight – research on-going to explain rationale – High risk populations: – Women in reproductive years Iron – – Pregnancy Infants and young children – Teenagers Iron deficiency anemia (IDA) Severe depletion of iron stores resulting in low blood hemoglobin; RBCs shrink & lose color Symptoms – weakness, pallor, headaches, reduced resistance to infection, poor attention, tendency to feel cold, fatigue Affects ~40% are preschool children and pregnant women  Stages of Iron Deficiency 1. Reduced iron stores (ferritin) 2. Decrease in transport iron 1. Serum iron decreases à 2. Transferrin increases (to adapt to reduced levels in attempt to increase absorption) 3. Decreased hemoglobin production 1. Hemoglobin and hematocrit values decline Iron 2. Hemoglobin precursor (erythrocyte protoporphyrin) accumulates Pica Abnormal appetite for ice, clay, paste, soil, & other non-nutritious substances – seen in women and children of lower-income groups Poorly understood and cause unknown  Toxicity: – Difficult to excrete from the body – Iron overload (hemochromatosis) – caused by a hereditary defect where the intestine absorbs excess iron at a high rate despite excess build up in cells Iron – Symptoms – fatigue, infections (bacteria love iron-rich blood), mental depression, abdominal pains, liver failure, abnormal heartbeats, etc. Possible increased risk of HD, colon CA (free iron is a powerful oxidant, starts free-radical reactions) – Iron overdose from supplements – # 1 cause of fatal, accidental poisoning among young children  Functions: Assists >200 enzymes used to metabolize CHO, protein, fat Makes part of the cells’ genetic material Highest concentration found in muscle and bone Assists in immune reactions Zinc Essential to taste perception, wound healing, sperm production, fetal development, growth & development in children Liberates vitamin A from storage in the liver to support vision Involved in disposal of damaging free radicals Affects behavior & learning  Recommendations: RDA – 8 mg/day (females) – 11 mg/day (males) UL: 40mg/d Good food sources: Zinc – Oysters, shrimp, beef, poultry, enriched cereal, porkchop, leavened (with yeast) bread – Plant-based sources if eaten in large quantities: – Legumes, nuts, wholegrains Supplements: – Zinc lozenges for the common cold – Controversial and inconclusive – Zinc gluconate may decrease duration of symptoms – Side effects: bad taste, nausea  Deficiency: Population groups at risk for deficiency – Pregnant women – Young children – Elderly – Lower socioeconomic status Zinc Impairs all functions resulting in: Growth failure in children (thyroid function disturbed & slows energy metabolism) Abnormal vision Delayed sexual maturation Alters digestion/absorption causing diarrhea Abnormal taste, loss of appetite Poor wound healing (impaired immunity) Vitamin deficiencies  Toxicity: Vomiting, diarrhea Headaches Exhaustion Loss of appetite Zinc Impaired immunity Copper and Fe deficiencies Blocks copper absorption (leads to degeneration of heart muscles in animals); may reduce HDL concentration Inhibits iron absorption from GIT due to competition with protein carrier; likewise, too much iron inhibits zinc absorption  Functions: – Helps form hemoglobin & collagen – Part of several enzymes (oxygen handling ability) to release energy Copper – Plays role in handling of iron and energy release & controlling free radical activity in tissues  Recommendations: RDA for adults: 900ug/day UL for Adults: 10 000 μg/day (10 mg/day) Copper Good food sources: – Organ meats, seafood, nuts & seeds, drinking water (copper plumbing pipes)  Deficiency: Rare Severely disturbs growth & metabolism in children Can impair immunity & blood flow through arteries in adults Excess zinc interferes with copper absorption and can cause deficiency Genetic disorder called Menkes Disease: Intestinal cells absorb copper but do not release it Copper Treatment is IV copper Toxicity: – Genetic disorder called Wilson’s Disease: – Accumulation of copper in the liver and brain – Treatment includes: decreasing intake, use of chelating agents to bind/excrete, increase Zn intake to impair absorption – Supplements can cause copper toxicity – Symptoms: vomiting, diarrhea, liver damage  – Research is difficult due to small quantities – No DRI currently exists for nickel, silicon, vanadium, cobalt, and boron – Contaminant minerals – Heavy metals (lead, mercury, cadmium) can be poisonous Other Trace – Enter food supply chain by soil, water, air pollution Minerals – Lead – Accumulation in the body can compromise growth and development – Competes with other nutrients in place of their absorption (Fe, Ca, Zn) – Decrease exposure in Canada over last few decades  – Non-nutrient compounds – Found in plant-derived foods – In the body: – Act as antioxidants – Stimulate enzymes Phytochemicals – Mimic hormones – Suppress inflammation – Destroy bacteria – In foods: – produce aromas, taste and colours – May have adverse affects when taken in large amounts from supplements  Defending Against Cancer – Soy – May protect against some types – Soybeans contain isoflavones – Limiting growth and spread of cancer – Due to similarity to estrogen, could be beneficial, but also could disrupt hormone balance and be harmful to health Phytochemicals – Use of phytoestrogen or soy concentrate supplements is not advised – may promote growth of estrogen dependent cancers – More research needed on recommendations of soy containing foods and breast-cancer survivors – Lycopene – Antioxidant, may inhibit growth of cancer cells – Limited evidence currently exists  Defending Against Heart Disease – Flavonoids – Antioxidant – Found in fruits, vegetables, whole grains, legumes, nuts, soy, herbs, spices, teas, olive oil, red wine – May protect LDL against oxidation Phytochemicals – May decrease inflammation – Slow progression of atherosclerosis and blood clot formation – Plant sterols – Found in all plants – May inhibit cholesterol absorption  – Exert potential health benefits – Whole, natural foods are really functional foods based on the Functional natural ingredients and their benefits Foods – Through processing and fortification with nutrients, manufacturers label other foods as “functional foods”