Chapter 12 Lecture Chapter 12: Nutrients Involved in Blood Health and Immunity â 2017 Pearson Education, Inc Blood Functions • • • • Transports nutrients and oxygen to cells Removes waste products generated from metabolism Immune function (white blood cells) Mechanism for heat transfer © 2017 Pearson Education, Inc Components of Blood • • • • Erythrocytes: red blood cells transport oxygen through the body Leukocytes: white blood cells are key to our immune system Platelets: cell fragments assist in blood clotting Plasma: fluid portion of the blood maintains adequate blood volume © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Micronutrients That Maintain Healthy Blood • Minerals • • • • Iron Zinc Copper Vitamins â 2017 Pearson Education, Inc Vitamin K Vitamin B6 Folate Vitamin B12 © 2017 Pearson Education, Inc Iron • • Iron is a trace mineral Component of oxygen-carrying hemoglobin in erythrocytes and myoglobin in muscles • • Heme groups depend on iron to carry oxygen in hemoglobin Component of cytochromes, electron carriers within the metabolic pathways for energy production from macronutrients • • Part of antioxidant enzyme system DNA synthesis and cognitive development © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Maintaining Iron Homeostasis • • Regulation of iron digestion, absorption, transport, storage, and excretion Factors that alter iron digestion and absorption â 2017 Pearson Education, Inc Individual's iron status Level of dietary iron consumption Type of iron in foods Amount of stomach acid for digestion Dietary factors enhance or inhibit absorption © 2017 Pearson Education, Inc Vitamin B12 • Recommended intake • • RDA for adults is 2.4 µg/day Sources of vitamin B12 • Found primarily in dairy products, eggs, meats, poultry, fish, and shellfish (animal sources) • Vegan diet may obtain vitamin B12 from fortified foods, supplements, or injections © 2017 Pearson Education, Inc Vitamin B12 • Factors that alter vitamin B12 digestion, absorption, and balance • Requires acidic environment (stomach) and protein intrinsic factor for absorption â 2017 Pearson Education, Inc Stored in the liver Four levels of vitamin B12 deficiency Vitamin B12 • Too much vitamin B12 • • No known adverse effects Not enough vitamin B12 • Deficiency is rare, but associated with dietary insufficiency or reduced absorption â 2017 Pearson Education, Inc Gastrointestinal and neurologic effects (destroyed myelin sheaths) Pernicious anemia (macrocytic) results in reduced intrinsic factor production Immune System • A healthy immune system: • • • • Protects the body from infectious diseases Helps heal wounds Guards against the development of cancers How does it function? â 2017 Pearson Education, Inc Nonspecific immune function Specific immune function Nonspecific Immune System • Body's primary defense against microbes, airborne particles, venom, ingested toxins • • • • Also called innate immunity Intact skin and healthy mucous membranes Stomach acid destroys food-borne bacteria Inflammatory response causes discomfort, loss of appetite, fatigue, and fever â 2017 Pearson Education, Inc A macrophage is a type of nonspecific immune cell The one shown here is about to engulf an invading microbe © 2017 Pearson Education, Inc Specific Immune System • • Directed against recognized antigens Induces antibodies to destroy invader • • • Memory cells remain in circulation Two main types of cells: B cells and T cells Acquiring specific immunity • • • © 2017 Pearson Education, Inc Have disease or vaccinations (immunizations) Maternal antibodies Antiserum injection (snakebite) Immune System • Malfunction causes chronic inflammation and infection • • • • © 2017 Pearson Education, Inc Allergic reactions Autoimmune response Common in malnourished Immune deficiency diseases Nutrition and the Immune System • • • A nourishing diet provides all the nutrients the immune system needs Single-nutrient subclinical deficiencies can cause subtle abnormalities in immunity Protein-energy malnutrition and severe micronutrient deficiencies reduce immune function © 2017 Pearson Education, Inc Protein-Energy Malnutrition • • • Malnutrition increases the risk for infection Infection depresses appetite and often causes vomiting and diarrhea Decreased appetite, vomiting, and diarrhea cause malnutrition, which increases vulnerability to infection • Decreased immunocompetence is a sensitive indicator of reduced nutritional status â 2017 Pearson Education, Inc Obesity • • • Increases incidence of infections Delays wound healing Poor antibody response to vaccination Inflammatory state may increase asthma, hypertension, cardiovascular disease, and type diabetes among obese individuals © 2017 Pearson Education, Inc Essential Fatty Acids • • Essential fatty acids are precursors for signaling molecules eicosanoids Supplementation with EPA and DHA reduces inflammation and may treat chronic inflammatory conditions like rheumatoid arthritis, inflammatory bowel disease, and cardiovascular disease © 2017 Pearson Education, Inc Vitamins and Minerals • • • Vitamin A maintains mucosal surface Vitamins C and E protect cell membrane from reactive oxygen species Zinc important for immune function, gene expression and enzyme activation (B and T cell proliferation) © 2017 Pearson Education, Inc Vitamins and Minerals (cont.) • Selenium: • • • • Promotes B and T cell proliferation Antibody production Iron and copper: • • • Coenzyme for glutathione peroxidase Part of superoxide catalase and dismutase Deficiencies reduce immune response (B and T cell function) Excessive iron can impair immunity © 2017 Pearson Education, Inc Infections Alter Nutrient Status • • • • Reduced food intake: illness/infection reduces appetite and overall energy intake Increased nutrient loss (diarrhea, vomiting, inflammation) Increased resting metabolic rate with fever Redistribution of energy and nutrients to enhance the immune response © 2017 Pearson Education, Inc ... hemoglobin Component of cytochromes, electron carriers within the metabolic pathways for energy production from macronutrients • • Part of antioxidant enzyme system DNA synthesis and cognitive... Type of iron in foods Amount of stomach acid for digestion Dietary factors enhance or inhibit absorption © 2017 Pearson Education, Inc Iron • Two types of iron in foods • Heme iron: part of hemoglobin... Zinc is a trace mineral Functions of zinc • • • © 2017 Pearson Education, Inc Component of enzymes (heme synthesis) Maintain structural integrity and shape of proteins (zinc fingers) Assist in