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BMS208 Human
Nutrition
Topic18: Diet and Health
Brian Spurrell
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.
Objectives
2
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.
Objectives
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• 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.
Nutrition and Infectious Diseases
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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
Nutrition and Infectious Diseases
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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
Nutrition and Infectious Diseases
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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.
Nutrition and Infectious Diseases
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Nutrients affecting
immunity
Protein
Fatty acids
Vitamin A
Vitamin E
Vitamin B6
Folate
Vitamin C
Iron
Zinc
Selenium
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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.
Nutrition and Infectious Diseases
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The Top 10 Killers!
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• 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.
Nutrition and Chronic Diseases
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13
Some
cancers
Atherosclerosis
Hypertension
Obesity
Gallbladder
disease
Stroke and
heart attack
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.
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• 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.
Cardiovascular Disease
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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.
Cardiovascular Disease
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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.
Cardiovascular Disease
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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
Cardiovascular Disease
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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
Cardiovascular 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)
Cardiovascular Disease
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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)
Cardiovascular Disease
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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!
Cardiovascular Disease
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• Risk Factors for Coronary Heart Disease
– 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
Cardiovascular Disease
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• Risk Factors for Coronary Heart Disease
– Diabetes
• Risk similar to people with established CHD
• CHD risk equivalents
Cardiovascular Disease
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Cardiovascular Disease
• Risk Factors for Coronary Heart Disease
– 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
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• Risk Factors for Coronary Heart Disease
– 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.
Cardiovascular Disease
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• Risk Factors for Coronary Heart Disease
– 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!
Cardiovascular Disease
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• Risk Factors for Coronary Heart Disease
– Metabolic Syndrome
• Also called Syndrome X or
• insulin resistance syndrome
– Insulin resistance is a risk factor
Cardiovascular Disease
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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)
Cardiovascular Disease
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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.
Cardiovascular Disease
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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.
Cardiovascular Disease
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• Hypertension with accompanying atherosclerosis can
cause heart attacks and strokes.
• Weight control is the most effective dietary strategy for
treating hypertension.
Hypertension
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• 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.
Hypertension
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• 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.
Hypertension
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• 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??
Hypertension
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• 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.
Hypertension
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• Treatment of Hypertension
– Drug Therapy
• Diuretics and antihypertensive agents
– Increase urinary output => lose potassium
– Watch potassium levels
Hypertension
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• 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.
Diabetes Mellitus
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• 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
Diabetes Mellitus
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• 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
Diabetes Mellitus
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• 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.
Diabetes Mellitus
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• Complications of Diabetes
– Diseases of the Nerves
• Neuropathy
• Hands and feet
• Careful of injuries and infections
• Gangrene may develop and amputation may be
required.
Diabetes Mellitus
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• 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.
Diabetes Mellitus
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Diabetes Mellitus
• Recommendations for Diabetes
– 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
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Diabetes Mellitus
• Recommendations for Diabetes
– 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.
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• Recommendations for Diabetes
– Recommendations for Type 2 Diabetes
• Moderate weight loss is helpful (4.5 – 9.0 kg).
• Regular, long-term physical activity
Diabetes Mellitus
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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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Normal cells
Malignant cells
Normal
cells
Initiation
Promotion
Mutagens alter the
DNA in a cell and
induce abnormal
cell division.
W&R, Fig. 18-7, p. 643
Further tumour
development
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).
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Cancer
• How Cancer Develops
– 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.
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Cancer
• How Cancer Develops
– 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
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Cancer
• How Cancer Develops
– 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
• How Cancer Develops
– 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.
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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
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• 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.
Recommendations for Chronic
Diseases
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• Some factors to manage them.
– Physical activity
– Moderate weight loss
• Benefits
– Improved blood glucose
– Lower blood lipids
– Lower blood pressure
Chronic disease states
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Complementary and Alternative
Medicine
Highlight 18
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• 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.
Complementary and Alternative
Medicine
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• 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.
Defining Complementary and
Alternative Medicine
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 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
Examples
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• 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 –
Examples
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• 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
Examples
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• 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
Examples
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 Little research
 folklore, 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.
Sound Research, Loud
Controversy
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• 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
Nutrition-Related Alternative
Therapies
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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
Nutrition-Related Alternative
Therapies
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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
Nutrition-Related Alternative
Therapies
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• 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?
Internet Precautions
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• 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
The Consumer’s Perspective
74
Any Questions?
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