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Diet and Health

Diet and Health. Chapter 18. Nutrition and Infectious Diseases. Nutrition cannot directly prevent or cure infectious diseases Caused by bacteria, viruses, parasites or other microbes and transmissable Good nutrition can strengthen body’s defenses Poor nutrition weakens the immune system

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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 • Caused by bacteria, viruses, parasites or other microbes andtransmissable • Good nutrition can strengthen body’s defenses • Poor nutrition weakens the immune system • Nutrition intervention can help prevent malnutrition and minimize the wasting away of tissues.

  3. The Immune System • Organs of the Immune System • Spleen • Lymph nodes • Thymus • Body’s first line of defense- the epithelium • Skin, mucous membranes, GI tract • Antigens- foreign substances that invite attack from antibodies or inflammation • Examples- bacteria, virus, toxin, allergen • Two types of white blood cells • Phagocytes • Lymphocytes

  4. White Blood Cells • Phagocytes • Scavengers of immune system • First to arrive at the scene of an invader (antigen) • Phagocytosis • Engulfment and digestion of antigen • Secrete cytokines, proteins that activate metabolic and immune responses to infection

  5. White Blood Cells • 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 • Are members of immunoglobin class of proteins

  6. White Blood Cells • Lymphocytes: T-cells practice chemical warfare • 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: each T-cell can attack only one type of antigen • T-cells destroy cancer cells • T-cells also like to reject organ transplants

  7. Nutrition and Immunity • Of all the body systems, immune system is most vulnerable to subtle changes in nutrition status • Disease and malnutrition cause synergistic downward spiral • Protein energy malnutrition (PEM)+ impaired immunity always together • Vitamin and mineral deficiencies & excesses diminish immune response

  8. Malnutrition and illness Altered metabolism and loss of appetite Immunity and infectious disease increase nutrient needs and lower food intake. Impaired nutrition status Weakened immunity Worsened illness Further deterioration of nutrition status

  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 • Disables body’s defense systems against disease • No cure • Prevention is best course • Nutrition benefits for HIV/AIDS patients • Food safety is critical • Good diet assists drug response, lengthens life

  11. Inflammation and Chronic Diseases • Immune system response to infection or injury • Acute inflammation • Increased blood supply to site, permeable blood vessels so WBC’s get to the exact location • Phagocytes engulf microbes • Release of oxidative products like hydrogen peroxide (H2O2) to kill microbes • Acute inflammation fights off infection, removes damaged tissue, heals wounds and promotes recovery

  12. Chronic Inflammation • Sustained, persistent inflammation is harmful • Produce cytokines, oxidative products, blood clotting factors, other bioactive chemicals • Chronic inflammation results in tissue damage • Sustained inflammation threatens health and worsens all the chronic diseases

  13. Nutrition and Chronic Diseases • Four of the top ten causes of death in U.S., including the top three are related to diet. • These four account for 70% of the 2+ million deaths/yr, up from 60% in 2007-2008 • Lifestyle risk factors are important and related to chronic disease. • Many of the nutritional factors in the treatment of chronic disease are interrelated. • Numerous disease associations with various nutrients • Multiple risk factors for each chronic disease • Modifiable risk factors (under your control) • Nonmodifiable risk factors (genetics)

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

  15. Interrelationships among Chronic Diseases

  16. Some cancers Obesity (especially abdominal obesity) Atherosclerosis (abnormal blood lipids) Diabetes (insulin resistance) Hypertension (high blood pressure) Stroke and heart attack

  17. Risk Factors and Chronic Diseases

  18. Cardiovascular Disease • Major causes of death around the world • Family history • Lifestyle factors • Coronary heart disease (CHD) is most common form of CVD • Usually caused by atherosclerosis • Atherosclerotic plaques can raise blood pressure, cause abnormal blood clotting, and cause heart attacks and strokes. Recommendations for prevention and treatment include dietary interventions, quitting smoking, and regular physical activity. The most common form of CVD is coronary heart disease (CHD), which develops due to atherosclerosis in the coronary arteries.

  19. CVD- Atherosclerosis development • http://youtu.be/zeS-0au8ij4 • http://youtu.be/w8wXdtoW-HQ • 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 factor • Diet high in saturated/trans fat • Diet low in antioxidant-rich plant-based foods

  20. CVD- 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

  21. CVD- Atherosclerosis development • Damage from high LDL or Hcy, toxins, infections • Macrophages respond to and free radicals are produced by inflammation. LDL gets oxidized, attacked by macrophages and trapped in vessels walls. • Aneurysm- abnormal bulging of blood vessel wall • C-reactive protein (CRP): better marker of inflammation than LDL • Lipoprotein-associated phospholipase A(2) or LP-PLA(2): highly specific markers of plaque inflammation • Plaques • Plaque stability , then rupture

  22. CVD- 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 • http://www.4shared.com/video/Hh-vYomM/YouTube_-_progression_of_ather.html

  23. CVD- Atherosclerosis Results • Heart Attacks and Strokes • Angina – pain or pressure feeling around the area of the heart. • Heart attack – restricted blood flow to the heart. • Transient ischemic attack or stroke – restricted blood flow to the brain, aka “mini-stroke”

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

  25. Risk Factors for Coronary Heart Disease (CHD) Nonmodifiable risk factors • Age, Gender, and Family History • Men higher risk than women • Men older than 45 years of age. • Women older than 55 years of age. • Immediate family history of premature heart disease.

  26. Modifiable Risk Factors for Coronary Heart Disease (CHD) • Excess LDL(low-density lipoproteins) available for oxidation-inflammation • LDL is most atherogenic lipoprotein • High LDL = high risk • Desirable: 100 mg/dL. • Above optimum level: 100-129 mg/dL. • Borderline: 130-159 mg/dL. • High: 160-189 mg/dL. • Very High: 190 mg/dL.

  27. Modifiable Risk Factors for CHD • HDL (high-density lipoproteins) represent cholesterol being carried back to the liver, reduced risk. • Desirable: 60 mg/dL. • Borderline: 59-40 mg/dL. • High: 40 mg/dL. • Total cholesterol [TC = LDL + HDL + (.2 x TG)] • Desirable levels at  200 mg/dL. • Borderline levels at 200-239 mg/dL. • High levels at  240 mg/dL.

  28. Modifiable Risk Factors for CHD • Elevated triglycerides are a marker for other risk factors studied in relation to CHD. • Desirable levels of fasting triglycerides: 150 mg/dL. • Borderline levels of fasting triglycerides: 150-199 mg/dL. • High levels of fasting triglycerides: 200-499 mg/dL. • Very high levels of fasting triglycerides:  500 mg/dL.

  29. Standards for CHD Risk Factors

  30. Modifiable Risk Factors for CHD • High blood pressure (hypertension) • Relationship with heart disease risk holds true for men, women, young, and old • Injures artery walls and accelerates plaque formation • Accelerates plaque formation which in turn increases blood pressure. • Diabetes Type 2 • Increases risk of death from CHD

  31. Blood Pressure Numbers • Systolic and/or diastolic pressure • Desirable: 120/80 • Borderline (prehypertension): 120-139/80-89 • High (Stage one hypertension): 140/90 • Stage two hypertension: 160/100

  32. Modifiable Risk Factors for CHD • Obesity and physical inactivity • Increase risk for CHD • Desirable BMI: 18.5-24.9. • Borderline: 25-29.9. • High: 30. • Cigarette smoking • Smoking damages the heart directly • Toxins in cigarette smoke damages vessels • Atherogenic diet • Elevates LDL cholesterol

  33. Modifiable Risk Factors for CHD • Other risk factors • Elevated VLDL • Metabolic syndrome, a cluster of health risks, includes markers of inflammation and thrombosis • Insulin resistance • Hypertension • Dyslipidemia • Abdominal obesity

  34. Recommendations for Reducing CHD Risk • Screening • Cholesterol screening • Total cholesterol, LDL, HDL, triglycerides • Two measurements at least 1 week apart • If family history exists, draw lipoprotein A, CRP • Intervention • Lifestyle changes • Physical activity, dietary changes, lose weight, reduce exposure to cigarette smoke • Medications

  35. As Bad as it gets:Junky Diet plus Smoking • Cigarette Smoking • Powerful factor for increased risk • Increases blood pressure and heart workload • Raises LDL while hardening arteries http://youtu.be/-YjrkBYDDQM http://youtu.be/o_BF8l-tT0g • Atherogenic Diet high in saturated fats, trans fats, and cholesterol and low in fruits and vegetables • Antioxidants in fruits and vegetables + omega-3 fatty acids and other good fats lower the risk of CHD.

  36. Hypertension • Systolic and diastolic pressure with risk of death from CVD (pre-, stage 1, 2) • Physiological factors of hypertension • Cardiac output • Heart rate or blood volume increases • Peripheral resistance • Diameters of arterioles • Blood pressure is regulated by nervous system & hormones that act on the kidneys

  37. 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

  38. Diabetes Mellitus • Incidence (new cases) 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

  39. Prevalence of Diabetes among Adults in the United States

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