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Diet and Health

Diet and Health. Chapter 18. Nutrition and Infectious Diseases. Nutrition cannot directly prevent or cure infectious diseases Good nutrition can strengthen body’s defenses Poor nutrition weakens the immune system. The Immune System. Body’s first line of defense

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Diet and Health

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  1. Diet and Health Chapter 18

  2. Nutrition and Infectious Diseases • Nutrition cannot directly prevent or cure infectious diseases • Good nutrition can strengthen body’s defenses • Poor nutrition weakens the immune system

  3. The Immune System • Body’s first line of defense • Skin, mucous membranes, GI tract • Antigens • Examples • Two types of white blood cells • Phagocytes • Lymphocytes

  4. The Immune System • Phagocytes • Scavengers of immune system • First to arrive at the scene of an invader • Phagocytosis • Engulf and digest antigen • Secrete cytokines

  5. The Immune System • Lymphocytes – B-cells • Rapidly divide and produce antibodies • Travel through bloodstream to site of infection • Stick to surfaces of antigens • Make it easy for phagocytes to ingest • Antibodies react selectively • Retain a memory

  6. The Immune System • Lymphocytes – T-cells • Travel directly to invasion site • Recognize antigens on surface of phagocyte cells • T-cells multiply in response • Release chemicals to destroy antigen • Signal to slow down immune response • Highly specific • Organ transplants

  7. Nutrition and Immunity • Immune system responds to subtle changes in nutrition status • Synergistic downward spiral • Protein energy malnutrition (PEM) • Impaired immunity • Vitamin and mineral deficiencies & excesses • Diminish immune response

  8. Nutrition and Immunity

  9. Effects of PEM on the Body’s Defense Systems

  10. HIV/AIDS • Human immunodeficiency virus (HIV) • Develops into acquired immune deficiency syndrome (AIDS) • Transmitted by direct contact with body fluids • No cure • Prevention is best course • Nutrition benefits for HIV/AIDS patients • Food safety is critical

  11. Inflammation and Chronic Diseases • Immune system response to infection or injury • Acute inflammation • Phagocytes engulf microbes • Release of oxidative products to kill microbes • Inflammation fights off infection and promotes recovery • Chronic inflammation • Harmful

  12. Nutrition and Chronic Diseases • Leading causes of death in U.S. • Relationship with diet • Chronic diseases • Interrelationships among chronic diseases • Numerous disease associations with various nutrients • Multiple risk factors for each chronic disease • Modifiable risk factors • Nonmodifiable risk factors

  13. Ten Leading Causes of Death in the U.S.

  14. Interrelationships among Chronic Diseases

  15. Risk Factors and Chronic Diseases

  16. Cardiovascular Disease • Major causes of death around the world • Family history • Lifestyle factors • Coronary heart disease (CHD) is most common form • Usually caused by atherosclerosis

  17. Cardiovascular Disease • Atherosclerosis development • Accumulation of fatty streaks along inner arterial walls • Streaks enlarge and harden • Encasement in fibrous connective tissue • Plaques stiffen arteries and narrow passages • Well-developed plaques by age 30 • Dietary factors

  18. Cardiovascular Disease • Atherosclerosis development • Inflammation • Damage to cells lining the blood vessels elicits inflammatory response • Immune system sends in macrophages • LDL cholesterol becomes trapped and engulfed by macrophages • Macrophages swell; eventually become cells of plaque

  19. Cardiovascular Disease • Atherosclerosis development • Inflammation • Aneurysm • C-reactive protein (CRP) • Lipoprotein-associated phospholipase A(2) or LP-PLA(2) • Plaques • Plaque stability – rupture

  20. Cardiovascular Disease • Atherosclerosis development • Blood clots • Platelets and other factors form blood clots • Prostaglandins and thromboxanes • Omega-3 fatty acids • Blood pressure • Plaques increase pressure • Atherosclerosis is a self-accelerating process

  21. Cardiovascular Disease • Atherosclerosis development • The results • Heart attack • Transient ischemic attack (TIA)

  22. Risk Factors for Coronary Heart Disease (CHD) • By middle age, most adults have at least one risk factor • Regular screening and early detection

  23. Risk Factors for Coronary Heart Disease (CHD) • Age, gender, and family history • Nonmodifiable risk factors • Older vs. younger people • Men vs. women • Early CHD in immediate family members

  24. Risk Factors for Coronary Heart Disease (CHD) • High LDL and low HDL cholesterol • Total cholesterol • LDL – most atherogenic lipoproteins • Plaque instability • Inflammatory process • HDL indicate a reduced risk of atherosclerosis

  25. Standards for CHD Risk Factors

  26. Risk Factors for Coronary Heart Disease (CHD) • High blood pressure (hypertension) • Relationship with heart disease risk holds true for men, women, young, and old • Injures artery walls • Accelerates plaque formation • Diabetes • Increases risk of death from CHD

  27. Risk Factors for Coronary Heart Disease (CHD) • Obesity and physical inactivity • Increase risk for CHD • High LDL, low HDL, hypertension, & diabetes • Cigarette smoking • Smoking damages the heart directly • Toxins in cigarette smoke damages vessels • Atherogenic diet • Elevates LDL cholesterol

  28. Risk Factors for Coronary Heart Disease (CHD) • Other risk factors • Elevated triglycerides • VLDL • Measurement of triglycerides • Metabolic syndrome • Cluster of health risks • Markers of inflammation and thrombosis

  29. Recommendations for Reducing CHD Risk • Screening • Cholesterol screening • Total cholesterol, LDL, HDL, triglycerides • Two measurements at least 1 week apart • Intervention • Lifestyle changes • Physical activity, dietary changes, lose weight, reduce exposure to cigarette smoke • Medications

  30. Hypertension • Systolic and diastolic pressure with risk of death from CVD • Physiological factors of hypertension • Cardiac output • Heart rate or blood volume increases • Peripheral resistance • Diameters of arterioles • Regulated by nervous system & hormones • Kidneys

  31. Hypertension • Risk factors • Aging • Genetics • Obesity • Salt sensitivity • Alcohol • Treatment • Weight control • Physical activity • DASH diet • Lowers LDL & total cholesterol • Salt/sodium intake • Drug therapy

  32. Diabetes Mellitus • Incidence has risen dramatically • Prediabetes • Sixth among leading causes of death • Underlies or contributes to several other major diseases • Heart disease is leading cause of diabetes-related deaths

  33. Prevalence of Diabetes among Adults in the United States

  34. Diabetes Mellitus • Diabetes development • Characteristics • High blood glucose concentrations • Disordered insulin metabolism • Two main types • Type 1 • Type 2

  35. Features of Type 1 and Type 2 Diabetes

  36. Diabetes Mellitus • Type 1 diabetes • Less common type • Autoimmune disorder • Pancreas loses ability to synthesize insulin • Commonly occurs in childhood & adolescence • Energy metabolism changes • May threaten survival • Need insulin injections or external pump

  37. Diabetes Mellitus • Type 2 diabetes • Most prevalent form of diabetes • Exact cause is unknown • Risk factors • Insulin resistance • Hyperinsulinemia • Amount of insulin is insufficient to compensate for diminished effect in cells • Chronic inflammation

  38. Diabetes Mellitus • Complications • Acute • Chronic • Conversion of glucose to sugar alcohols • Loss of circulation and nerve function • Infections • Diseases of large blood vessels • Diseases of small blood vessels • Diseases of the nerves

  39. Metabolic Consequences of Untreated Diabetes

  40. Diabetes Mellitus • Recommendations for diabetes • Total carbohydrate intake • Carbohydrate sources • Fiber and sugar • Glycemic index • Dietary fat • Protein • Kidney function

  41. Diabetes Mellitus • Recommendations for diabetes • Alcohol • Moderation • Type 1 diabetes • Adjust insulin to accommodate meals, physical activity, and health status • Nutrition therapy • Type 2 diabetes • Diet and regular moderate physical activity

  42. Cancer • Second leading cause of death in U.S. • Development of cancer – carcinogenesis • Mutations in genes that control cell division • Effects of mutations • As tumor develops, a network of blood vessels develops • Metastasis • Causes

  43. Cancer Development

  44. Normal cells Malignant cells Normal cells Further tumor development Initiation Promotion Promoters enhance the development of abnormal cells, resulting in formation of a tumor. Mutagens alter the DNA in a cell and induce abnormal cell division. The cancerous tumor releases cells into the bloodstream or lymphatic system (metastasis). Stepped Art Fig. 18-6, p. 626

  45. Cancer • Development of cancer – carcinogenesis • Environmental factors • Sun, water, air pollution, and smoking • Obesity • Exposure to estrogen

  46. Cancer • Development of cancer – carcinogenesis • Dietary factors – cancer initiators • Alcohol and tobacco use • Cooking meats at high temperatures • Grilling meats • Diets high in red meats & processed meats • Presence of acrylamide

  47. Cancer • Development of cancer – carcinogenesis • Dietary factors – cancer promoters • Types of fat in diet • Dietary factors – antipromoters

  48. Factors Associated with Cancer at Specific Sites

  49. Cancer • Recommendations for reducing cancer risks • Fruit and vegetable intake • Phytochemical protective benefits • Rich sources of fiber • Fruits, vegetables, legumes, & whole grains • Maintenance of healthy body weight • Physical activity

  50. Recommendations for Chronic Diseases • Comparison with Dietary Guidelines for Americans • Healthy Eating Pyramid • Links between diet and health • Weight control • Diet • Individualized recommendations • Human genome

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