BMS208 Human Nutrition Topic18: Diet and Health Brian Spurrell.

BMS208 Human BMS208 Human NutritionNutrition

Topic18: Diet and Health

Brian Spurrell

Objectives

1. Describe the immune system and the cells that compose it.

2. Identify nutrients that are known to enhance immunity.

3. Discuss the role of nutrition and lifestyle in the development of chronic disease.

4. Describe cardiovascular diseases and risk factors in the development of each.

5. Discuss the role of nutrition in the prevention and treatment of the cardiovascular disease.

6. Describe risk factors in the development of hypertension and the role of nutrition in the prevention and treatment of the disease.

7. Discuss diabetes, including types of diabetes and the role of nutrition in prevention and treatment.

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Objectives

8. Describe cancer development and dietary factors that may initiate or impede the process.

9. List the nutrition and lifestyle factors that may reduce specific types of cancer.

10. Identify recommendations for the prevention of chronic disease in individuals and groups.

11.Describe alternative/complementary medicine and nutrition-related alternative therapies.

12. Identify herbal remedies and the risks and benefits of each.

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Nutrition and Infectious Diseases

• Personal strategies to prevent infectious disease are important.

• Nutrition intervention can help prevent malnutrition and minimise the wasting that accompanies AIDS.

• There are new threats of the spread of disease-causing micro-organisms due to bioterrorism.

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• The Immune System

– Organs of the immune system fight antigens• Spleen

• Lymph nodes

• Thymus

– Phagocytes• Neutrophils and Macrophages

• Engulf and digest invaders - called phagocytosis

• Secrete special proteins called cytokines that activate a metabolic and immune response

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The Immune System

◦Lymphocytes: B-cells Produce antibodies that react selectively, part of a class of proteins

called immunoglobulins

Retain memory to react faster with the same foreign organism

Resistance to infection

◦Lymphocytes: T-cells Release powerful chemicals to destroy foreign particles

Highly specific, attacking only one antigen

Defend against fungi, viruses, parasites, some bacteria, and cancer cells

Participate in the rejection of transplanted tissue

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• Nutrition and Immunity

– Malnutrition compromises immunity.

– Immunity and infectious disease increase nutrient needs and lower food intake.

– The synergistic downward cycle of disease and malnutrition must be broken for recovery to occur.

– Opportunistic infections develop when the immune system is suppressed.

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Nutrients affecting immunity

ProteinFatty acidsVitamin AVitamin EVitamin B6

FolateVitamin CIronZincSelenium

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• HIV and AIDS

– HIV (human immunodeficiency virus) is the

• infection that attacks the immune system and

• disables the body’s defences.

– AIDS (acquired immune deficiency syndrome) is the

• infectious disease that destroys health and life.

– Epidemic

• disease that attacks many people

• in the same region

• at the same time

– Early detection and early intervention are critical.

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The Top 10 Killers!

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Nutrition and Chronic Diseases

• Four of the top ten causes of death are related to diet.

• There are also genetic and lifestyle risk factors that are important and related to chronic disease.

• Many of the nutritional factors in the treatment of chronic disease are interrelated.

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Some cancers Atherosclerosis Stroke and

heart attack

Obesity Hypertension

Gallbladder disease

Diabetes

This flow chart shows that many of these conditions are themselves risk factors for other chronic diseases. For example, a person with diabetes is likely to develop atherosclerosis and hypertension. These two conditions, in turn, worsen each other and may cause a stroke or heart attack. Notice how all of these chronic diseases are linked to obesity.

Cardiovascular Disease

• Atherosclerotic plaques can raise blood pressure, cause abnormal blood clotting, and cause heart attacks and strokes.

• There are many recommendations for prevention and treatment including

– dietary interventions,

– quitting smoking and

– engaging in regular physical activity.

• The most common form of CVD is coronary heart disease (CHD), which develops due to atherosclerosis in the coronary arteries.

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• How Atherosclerosis Develops

– Atheromatous plaque builds on artery walls and leads to inflammation.

– Causes of Atherosclerosis• Cells lining the blood vessels incur damage.

• Inflammatory response using macrophages that become the cells of plaque

• Blood clots form and minerals harden the plaque.

• Fibrous connective tissue

• C-reactive protein (CRP) is a sign of inflammation of the artery walls.

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How Atherosclerosis Develops

◦Plaques Fibrous coating can be torn away with a surge in blood pressure

◦Blood Clots Platelets cover the damaged area and form a clot.

Thrombosis is a blood clot that sticks to an artery and grows large enough to restrict or close off a blood vessel.

Embolism is when a blood clot breaks free, travels, and lodges in a small artery and shuts off blood flow to tissues.

Platelets are under the control of eicosanoids, made from omega-3 and omega-6 fatty acids.

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• How Atherosclerosis Develops

– Blood Pressure and Atherosclerosis

• Arteries are narrowed due to plaque, clots, or both.

• The heart must generate more pressure to deliver blood to the tissues.

• Higher blood pressure results in further damages.

– The Result: Heart Attacks and Strokes

• Angina – pain or pressure feeling around the area of the heart

• Heart attack – restricted blood flow to the heart

• Transient ischaemic attack (TIA) or stroke – restricted blood flow to the brain

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• Risk Factors for Coronary Heart Disease

– Modifiable risk factors

• Diet and

• physical activity

– Cannot change these factors

• Age,

– Men older than 45 years of age

– Women older than 55 years of age

• Gender

– Men higher risk than women

• Family History

– Immediate family history of premature heart disease

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• Risk Factors for Coronary Heart Disease– High LDL and Low HDL Cholesterol – LDL

• Excess LDL (low-density lipoproteins) become available for oxidation, high risk

• Risk factors for LDL cholesterol– Desirable: <100 mg/dL (< 2.59 mmol/L)

– Above optimum level: 100-129 mg/dL (2.59–3.34 mmol/L)

– Borderline: 130-159 mg/dL (3.37-4.12 mmol/L)

– High: 160-189 mg/dL (4.14-4.91 mmol/L)

– Very High: >190 mg/dL (> 4.92 mmol/L)

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• High LDL and Low HDL Cholesterol

– HDL

– HDL (high-density lipoproteins) represent cholesterol being carried back to the liver, reduced risk

– Risk factors for HDL cholesterol

• Desirable: ≥60 mg/dL

• Borderline: 59-40 mg/dL

• High: <40 mg/dL

Convert these values to SI units!! (ie mmol/L)

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• High LDL and Low HDL Cholesterol

– Total cholesterol (TC)

• Desirable levels at < 200 mg/dL

• Borderline levels at 200-239 mg/dL

• High levels at ≥ 240 mg/dL

Convert to SI units!

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– High Blood Pressure (Hypertension)• Injures artery walls and

• Accelerates plaque formation

which in turn increases blood pressure

• Blood pressure (systolic and/or diastolic pressure)

– Desirable: <120/<80

– Borderline: 120-139/80-89 (pre-hypertension)

– Stage one hypertension - High: ≥140/≥90

– Stage two hypertension – Very high: ≥160/≥100

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– Diabetes

• Risk similar to people with established CHD

• CHD risk equivalents

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– Obesity and Physical Inactivity

• Obesity, especially abdominal obesity, and physical inactivity increase risk

• Body mass index

– Desirable: 18.5-24.9

– Borderline: 25-29.9

– High: ≥30

• Protective

– Weight loss and

– Regular physical activity 25



– Cigarette Smoking• Powerful increased risk

• Increases blood pressure and the workload of the heart

– Atherogenic Diet• A diet high in saturated fats, trans fats, and cholesterol and

low in fruits and vegetables elevates LDL cholesterol.

• Antioxidants and omega-3 fatty acids lower the risk of CHD.

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– Other Risk Factors• Emerging risk factors and predictions

• Elevated triglycerides (triacylglycerols = TAG) are a marker for other risk factors and being 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

– Convert to SI units!

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– Metabolic Syndrome

• Also called Syndrome X or

• insulin resistance syndrome

– Insulin resistance is a risk factor

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• Metabolic Syndrome

– Any three of the following factors

• Abdominal obesity

– Men: Waist circumference > 102 cm

– Women: waist circumference > 89 cm

• Triglycerides: ≥150 mg/dL (SI? convert to g/L)

• HDL: <40 mg/dL in men, <50 mg/dL in women

• Blood pressure: ≥130/85 mm Hg

• Fasting glucose: ≥100 mg/dL (≥ 5.56 mmol/L)

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Recommendations for Reducing Coronary Heart Disease Risk

◦Cholesterol Screening – twice at least one week apart

◦Lifestyle Changes Balance energy intake with energy needs.

Include lean meats, vegetables, and low-fat milk products.

Limit foods with high concentrations of saturated fatty acids (< 7% of total kJ) and trans-fatty acids (< 1% of total kJ).

Limit foods with high content of cholesterol (< 300 mg/day).

Examples? ---

Choose foods high in soluble fibre:

vegetables, fruits, and whole grains.

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Lifestyle Changes◦ High-potassium, low-sodium foods

◦ Limit sodium to 2,300 mg/day.

◦ Limit intake of added sugar.

◦ Consume fatty fish at least twice a week for omega-3 fatty acids.

◦ Consume foods with plant sterols or stanols added.

◦ Use soy products in place of animal foods that are high in saturated fat and cholesterol.

◦ Limit alcohol consumption to 1 drink/day for women or 2 drinks/day for men.

◦ Exercise at least 30 minutes most days of the week to expend 8,400 kJ weekly.

◦ Reduce exposure to tobacco smoke.

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Hypertension

• Hypertension with accompanying atherosclerosis can cause heart attacks and strokes.

• Weight control is the most effective dietary strategy for treating hypertension.

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Hypertension

• How Hypertension Develops

– Blood flow to the kidneys is reduced

• the kidneys expand blood volume and

• constrict peripheral blood vessels,

=> increased peripheral resistance and

thus raising blood pressure.

– Cardiac output increases

• => increased work of the heart.

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Hypertension

• Risk Factors for Hypertension

– Age – risk increases with age

– Genetics – family history, African-American

– Obesity – 60% with hypertension are obese

– Salt sensitivity

– Alcohol may raise blood pressure and is associated with strokes.

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Hypertension

• Treatment of Hypertension

– Weight control

• Is one of the most effective treatments.

– Physical activity will help

• Moderate aerobic for 30-60 minutes most days

– The DASH Diet

• Dietary Approaches to Stop Hypertension

• Conundrum?

– DASH diet lowers HDL cholesterol => risk of CHD??

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Hypertension

• The DASH Diet

– Grains: 6-8 ounces

– Vegetables: 2-2 ½ cups

– Fruits: 2-2 ½ cups

– Milk (low-fat or fat-free): 2-3 cups

– Meat (lean): 6 ounces or less

– Nuts, seeds, legumes: 4-5 ounces per week

– 2000 kcalories

– An Exercise for you:

• Convert these quantities to SI units.

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Hypertension

• Treatment of Hypertension

– Drug Therapy

• Diuretics and antihypertensive agents

– Increase urinary output => lose potassium

– Watch potassium levels

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Diabetes Mellitus

• Diabetes is characterized by

– high blood glucose (hyperglycaemia) and

– either insufficient insulin, ineffective insulin, or both.

• Diabetes treatment involves the coordination of

– diet and/or drugs and

– physical activity to control blood glucose fluctuations and

– control or lose weight.

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Diabetes Mellitus

• How Diabetes Develops

– Impaired glucose tolerance or prediabetes

– Type 1 Diabetes• 5-10% prevalence in diabetic population

• Autoimmune disorder

• Usually diagnosed in childhood or adolescence

• Relatively severe symptoms

• Associated with viral infection and heredity

• Insulin is required

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Diabetes Mellitus

• How Diabetes Develops

– Type 2 Diabetes

• 90-95% prevalence in diabetic population

• Occurring in children and adults

• Relatively moderate symptoms

• Cells are resistant to insulin

• Associated with obesity, heredity, and aging

• Sometimes insulin is required

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Diabetes Mellitus

• Complications of Diabetes

– Diseases of the Large Blood Vessels

• Atherosclerosis

– tends to develop early and is more severe.

– Diseases of the Small Blood Vessels

• Microangiopathies

– Affect kidney function and retinal degeneration

– Long-term, intensive intervention targeting multiple factors can reduce risk.

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Diabetes Mellitus

• Complications of Diabetes

– Diseases of the Nerves

• Neuropathy

• Hands and feet

• Careful of injuries and infections

• Gangrene may develop and amputation may be required.

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Diabetes Mellitus

• Recommendations for Diabetes

– Total Carbohydrate Intake

• Consistent intake helps to regulate blood sugar.

• Too little carbohydrate can lead to hypoglycaemia.

– Carbohydrate Sources

• Glycaemic effect (index) of food to be considered.

– Low GI better?

• Avoid foods and beverages with added sugar.

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Diabetes Mellitus


– Dietary Fat• Saturate fat: <7% of total kJ

• Cholesterol: <200 mg/day

– Protein• No need to modify intake as long as there is normal kidney

function

• 15-20% of total kJ

– Alcohol Use in Diabetes• Alcohol should be used in moderation.

• One drink/day for women two drinks/day for men 46

Diabetes Mellitus


– Recommendations for Type 1 Diabetes• Adjust insulin doses

• Optimal nutrition status

– Control blood glucose with consistent carbohydrate intake at meals and snacks.

– Achieve desirable blood lipids.

– Control blood pressure.

– Prevent and treat complications.

• Physical activity

– Be careful of hypoglycaemia.

– Monitor blood glucose. 47

Diabetes Mellitus


– Recommendations for Type 2 Diabetes

• Moderate weight loss is helpful (4.5 – 9.0 kg).

• Regular, long-term physical activity

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Cancer

• Cancer is the growth of malignant tissue.

• Dietary factors that initiate cancer development include alcohol and

heavily smoked foods.

• Dietary factors that promote cancer once it has started include saturated fat and trans fat.

• Dietary factors that serve as anti-promoters (protect against development of cancer) include fibre, antioxidant nutrients, and phytochemicals.

• To lower cancer risk Eating a variety of healthful foods and

adopting a physically active lifestyle is the best advice.

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Cancer

• How Cancer Develops

– Carcinogenesis is the development of cancer from mutated cells and can result in the formation of an abnormal mass, or tumour.

– Carcinogens are substance an individual is exposed to that can lead to cancer.

– Tumours can metastasize, or spread to other areas of the body.

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W&R, Fig. 18-7, p. 643

Normal cells

Mutagens alter the DNA in a cell and induce abnormal cell division.

Promoters enhance the development of abnormal cells, resulting in formation of a tumour.

The cancerous tumour releases cells into the bloodstream or lymphatic system (metastasis).

Malignant cellsNormal cells

Initiation PromotionFurther tumour development

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Cancer


– Environmental Factors

• Exposure to

– radiation and sun,

– water and air pollution, and

– smoking are known to cause cancer.

• Physical activity (environmental factor?)

– may protect against certain types of cancer.

• Obesity

– increases risk for cancer.52

Cancer


– Dietary Factors – Cancer Initiators

• Additives and pesticides

• Minimize carcinogens when cooking

– use foil on grill

– do not burn foods and

– marinate meat beforehand

• Alcohol and smoking

• High red meat intake and colon cancer ??

• Acrylamide is produced when starches are cooked at high temperatures

– French fries and potato chips 53

Cancer


– Dietary Factors – Cancer Promoters• High-fat diets correlate with high cancer rates but

inconclusive

• High-kJ diets correlate with high cancer rates

• High-saturated fat and high-trans fat diets correlate with high cancer rates

– Although omega-3 may protect

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Cancer


– Dietary Factors – Anti-promoters (chemoprotectants)

• Fruits and vegetables

– Correlate with a low incidence of cancer

• Fibre-rich diets

– Might protect against colon cancer

• Phytochemicals found in cruciferous vegetables

– activate enzymes that destroy carcinogens.

• Antioxidant nutrients are effective

– vitamin C,

– vitamin E, and

– beta-carotene

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Cancer

• Recommendations for reducing cancer risk

– Healthy body weight

– Eat a variety of healthy foods.

– Five or more cups of fruits and vegetables

– Whole grains

– Limit red meats.

– Limit consumption of alcoholic beverages.

– Adopt a physically active lifestyle.56

Cancer

• Classifications of cancers

– Adenomas – glandular tissues

– Carcinomas – epithelial tissues

– Gliomas – glial cells of central nervous system

– Leukaemias – white blood cells

– Lymphomas – lymph system

– Melanomas – pigmented skin cells

– Sarcomas – muscle, bone or connective tissues 57

Recommendations for Chronic Diseases

• Recommendations for the Population

– Make dietary changes to forestall or prevent disease is the preventive or population approach

• Recommendations for Individuals

– Urge dietary changes for people who need them is the medical or individual approach

• Recommendations for Each Individual

– Genomics may allow for individual nutritional recommendations.

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Chronic disease states

• Some factors to manage them.– Physical activity– Moderate weight loss

• Benefits– Improved blood glucose– Lower blood lipids– Lower blood pressure

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Complementary and Alternative Medicine

Highlight 18

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Complementary and Alternative Medicine

• Alternative therapies come in many different practices and products.

• Benefits and risks may be great, small or nonexistent.

• Wise consumers and health care professionals accept the beneficial effects that have been confirmed by research to be safe and effective.

• They reject those practices that cause harm.

• Making healthful choices requires understanding and seeking out reliable sources of information.

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Defining Complementary and Alternative Medicine

• Complementary and alternative medicine: diverse medical and health care systems, practices, and products that are not currently considered part of conventional medicine

• Conventional medicine: diagnosis and treatment of diseases as practiced by medical doctors, doctors of osteopathy, and allied health professionals

• Integrative medicine is an approach that incorporates alternative therapies into the practice of conventional medicine.

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Examples

Acupuncture – uses long, thin needles to relieve pain or illness

Aromatherapy – uses plant or flower oil extracts to enhance health

Ayurveda – uses herbs, diet, meditation, message, and yoga to prevent and treat disease

Bioelectromagnetic medical applications – uses electrical or magnetic energy to increase healing

Biofeedback – allows individuals to learn how to control body functions

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Examples

• Biofield therapeutics – uses a healing force

• Cartilage therapy – uses connective tissue to increase health

• Chelation therapy – removes toxic substances from the body

• Chiropractic – manipulation of the spine

• Faith healing – use of divine intervention in healing

• Herbal medicine – uses plants to treat disease

• Homeopathy –

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Examples

• Hydrotherapy – use of water to heal and relax

• Hypnotherapy – uses power of suggestion

• Imagery – guided visual relaxation

• Iridology – study of the eye and how it is related to disease

• Macrobiotic diets – a restricted diet of grains and vegetables

• Massage therapy – manipulation of the muscles to promote healing

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Examples

• Meditation – calming and relaxation of the mind

• Naturopathy – includes several natural healing practices

• Orthomolecular medicine – use of large doses of vitamins to treat disease

• Ozone therapy – use of ozone gas to boost the immune system

• Qi gong – uses movement, meditation, and breathing to change energy flow in the body

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Sound Research, Loud Controversy

Little researchfolklore, tradition, and testimonials

Placebo effect a healing effect in people who believe they are receiving

treatment

Risks versus Benefits

◦ There are herbal remedies that are safe and reasonably effective.

◦ Some therapies are not hazardous or costly but help mood and reduce stress.

◦ Some are dangerous, posing great risks.

◦ Some are dangerous but have some benefits.

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Nutrition-Related Alternative Therapies

• Foods

– Potential health benefits of soy in relation to heart disease are documented.

– More research is needed on phyto-estrogens of soy to manage symptoms of menopause

• Vitamin and Mineral Supplements

– Research on some vitamins and minerals might be appropriate in preventive care.

– Safety and effectiveness issues

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• Herbal Remedies

– Used throughout history

– Benefits

• Contribute to about 50% of modern medicines

• Development of new drugs

– Safety

• Synthesized medicines contain exact doses

• Herbal preparations can vary from batch to batch

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Herbal Precautions◦ “Natural” does not mean beneficial or safe.

◦ Herbs are not drugs; they are dietary supplements ????

◦ Lack of information and discrepancies True identification of herbs Purity of herbal preparations Appropriate uses and contraindications of herbs Effectiveness of herbs Variability of herbs Accuracy of labels Safe dosages of herbs Interactions of herbs with medicines and other herbs Adverse reactions and toxicity levels of herbs

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Internet Precautions

• Advertising and marketing of their own products

– Introduces a bias?

• Quotations from researchers and physicians

– May be taken out of context

– Not accurately reported – research efforts are complex

• Increased access to products

– Places a strain on resources

– Potentially adulterated

– Are you getting what you pay for?

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The Consumer’s Perspective

• People may seek alternative medicine

– because it is more in line with their beliefs about health and life

• Use alternate therapies

– in addition to conventional therapies

• Selecting reliable practitioners means

– checking out training,

– qualifications and

– licenses.

• Keep physicians informed

– Potential drug-herb interactions is well-recognised

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Any Questions?

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BMS208 Human Nutrition Topic18: Diet and Health Brian Spurrell.

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