lipids in heart disease & cancer by jennifer turley and joan thompson © 2013 cengage
TRANSCRIPT
Lipids in Heart Disease & Cancer
By Jennifer Turley and Joan ThompsonBy Jennifer Turley and Joan Thompson
© 2013 Cengage© 2013 Cengage
Presentation Overview
Lipids in Heart Disease• Incidence• Contributing factors• Prevention• Blood lipids• Dietary fat• Oxidation & antioxidants• Trans & omega 3 fatty
acids• Other factors
Lipids in Cancer• The cancer process• Diet & lifestyle &
disease risk• P:S ratio• Dietary lipids &
disease risk
Heart Disease
• #1 cause of death in America.• 1/3 die of atherosclerosis.• Myocardial infarction and stroke risk
increase with atherosclerosis.
DietRelated
Non-DietRelated
AlcoholRelated
De
ath
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Atherosclerosis
• Plaques: • Occlude arterial vessels. • Form from arterial wall injury. • Contain cholesterol (oxidized LDL), platelets, etc.
Hypertension
• Is high blood pressure.• Is a leading cause of arterial wall
injury. • Synergizes with atherosclerosis to
cause heart disease and stroke.
Blood Pressure Classification of Measurements
Category Systolic1 Conjunction Diastolic2
Optimal <120 and <80
Pre-hypertension 120-139 or 80-89
Stage 1 hypertension 140-159 or 90-99
Stage 2 hypertension ≥ 160 or ≥ 100
1 Systolic Blood Pressure in mm of mercury (Hg)2 Diastolic Blood Pressure in mm of mercury (Hg)
Reducing Blood Pressure
• DASH Diet (The Dietary Approach to Stop Hypertension)• Increase calcium, potassium and magnesium• Low-fat, fiber-rich, moderate protein &
carbohydrate
• Aerobic exercise
• Healthy Body Weight
Who is Dying of Heart Disease?
• 25-34 years: Men at 3X rate as Women• 35-44 years: Men at 2X rate as Women• 45-64 years: Women catching up to men• 65-75 years: Women catching up to men• 75-80 years: Women = Men
What are the Risk Factors?
• Elevated serum cholesterol• Genetics• Smoking tobacco & drinking alcohol• Hypertension• Diabetes• Obesity• Sedentary lifestyle• Stress• Male gender• Consuming a low fiber & high fat diet
How can it be prevented?
• Lifestyle changes• Less stress, no smoking
• Healthy diet • Healthy fats, nutritionally adequate
• Regular aerobic exercise• An hour a day
• All positively affect blood lipid values and blood pressure
Elevated Serum Cholesterol & Increased Deaths from Heart Disease
mg/dl total cholesterol
Blood Lipids
Serum Triglycerides• VLDL• CHYLOMICRONS
Serum Cholesterol• LDL (Bad, 77.5%)• HDL (Good, 17.5%)
IDL (Neutral, 5%)
Lipid Carrier Molecules
Serum Triglycerides
• Elevated levels are associated with heart disease.• High triglyceride levels thicken the blood causing
hypertriglyceridemia.• Triglycerides are packaged primarily in
Chylomicrons and Very Low Density Lipoproteins (VLDL).
• A fasting 12 hour blood test is needed to determine an accurate triglyceride level. • <150mg/dl is normal. • 450 mg/dl is like pumping ketchup, causes arterial
damage contributing to heart disease and stroke.
Serum Cholesterol
• Elevated levels are associated with atherosclerosis if 2 other risk factors exist.
• Cholesterol is packaged as Low Density Lipoproteins (LDL) and High Density Lipoprotein (HDL). Intermediate Density Lipoprotein (IDL) is present to a minor extent.
• HDL’s return cholesterol to the liver for synthesis of bile, hormones, and vitamins.
• LDL’s delivers cholesterol to tissue and therefore have a higher plaque effect.
Blood Cholesterol Levels & Disease Risk
Total Cholesterol< 200 mg/dl Desirable/Low Risk
200-239 mg/dl Borderline High Risk
≥ 240 mg/dl High Risk
LDL Cholesterol< 100 mg/dl Optimal
100-129 mg/dl Near optimal
130-159 mg/dl Borderline high
160-189 mg/dl High
≥ 190 mg/dl Very high
HDL Cholesterol< 40 Low (indicates risk)
> 60 High
Blood Cholesterol Levels & Disease Risk
Metabolic Syndrome: If Three or More of These Factors
– Fasting Blood Triglycerides: ≥150 mg/dl– HDL: <50 mg/dl ♀ <40 mg/dl ♂– Blood Pressure: ≥130/85 mm Hg1. Fasting Blood Glucose: ≥110 mg/dl2. Waist Circumference: >35” ♀ >40” ♂
Therapeutic Lifestyle Changes (TLC) DietSummary of the TLC Diet
Total FatSFAPUFAMUFATrans Fatty AcidsCarbohydratesProteinsCholesterolPlant stanols/sterolsSoluble FiberTotal Calories
25%-35% of Calories<7% of Calories≤10% of Calories≤20% of CaloriesAs low as possible50%-60% of Calories~15% of Calories<200 mg/day2 g/day10g-25g/dayBalance energy intake and expenditure to maintain desirable body weight and prevent weight gain. Expend 200 Calories/day in moderate physical activity.
Examples of Food in a 2200 Calorie One Day TLC Diet
GrainsVegetablesFruits Low Fat DairyLean Meat/Fish/AlternativesEggsOils
7 ounce equivalents with ½ whole grains3 cup equivalents 2 cup equivalents 3 cup equivalents6 ounce equivalents, soy protein may replace some animal product<2 yolks/week 6 teaspoon equivalents
Dietary Fat & Lipoproteins• SFA:
Increase LDL
• PUFA :Decrease LDL & HDL
• MUFA:Decrease LDL
• Cholesterol: Can Increase LDL
• Phospholipids:Not indicated in heart disease
Fatty Acid Composition of Common Fats
• The double bonds of polyunsaturated fatty acids are targets for oxidation (damage by oxygen species).
• The double bond breaks with oxidation generating lipid fragments that are very sticky. (-CH2CH=CHCH2- to CH2CHO + CH2CHO).
• The sticky fragments contribute to atherosclerotic plaque formation.
Oxidation of Fat
• Antioxidants: Prevent oxidation reactions, react with oxygen radical species directly, & prevent heart disease
• Antioxidants vitamins include: vitamin E (alpha-tocopherol), vitamin C (L-ascorbic acid), beta-carotene (provitamin A)
• Minerals with antioxidant cofactor functions include: Zinc, Copper, & Iron
Antioxidants
• Trans fatty acids levels are high in processed foods containing partially hydrogenated oils.
• The double bonds from PUFA & MUFA are removed by hydrogenation (adding hydrogen).
• The fatty acid becomes more saturated. • Is used in the process of making
margarine.• The softer the margarine the less trans fat. • Stick margarine & shortening are highly
hydrogenated and partially hydrogenated.
Hydrogenation of Fat
Hydrogenation of Fat
H+ H+H+ H+ H+
H+ H+H+
Unsaturation Saturation
+H2
spotlight
Partial Hydrogenation of Fat
• Is done in the food industry.• Many of the double bonds from
PUFA & MUFA are removed and many can be chemically modified to a trans fatty acid (TFA) configuration.
• TFAs contribute to heart disease.
Cis vs. Trans Fatty Acids
• Cis: • The naturally occurring configuration in PUFA &
MUFA.• Hydrogen atoms are on the same side of the double
bond in the fatty acid Carbon chain.
• Trans: • Form during the partial hydrogenation process. • A chemical “Fluke”• Hydrogen atoms are on the opposite side of the
double bond in the fatty acid Carbon chain.
The Chemical Structure of Cis & Trans Fatty Acids
spotlight
Trans Fatty Acids are Detrimental to Health
• TFAs contribute to heart disease by increasing LDL & decreasing HDL cholesterol & increasing triglycerides.
• An intake of 2-3% of energy from TFAs has greater than predicted negative effects from the marked adverse blood lipid changes. TFAs may also contribute to inflammation, endothelial cell dysfunction, and diabetes (insulin resistance).
• Intake should be < 1% of energy to as low as possible.
Consumer Keys for Avoiding Trans Fatty Acids
• Read the nutrition facts panel. TFA free is defined as ≤0.5 gm/serving.
• Avoid foods with partially hydrogenated oils in the ingredient list (such as cookies, chips, doughnuts) on the food label.
• Bake with vegetable oils.• Use margarines that are soft. Choose margarines
that are trans fatty acid free.• Avoid deep-fat fried foods like french fries, corn
chips, doughnuts, & chicken nuggets.• Avoid high meat and dairy product intake as a
natural TFA source from bacterial action on unsaturated fatty acids in the ruminants stomach.
Omega-3 Fatty Acids Heart Healthy
Alpha-Linolenic AcidAn Omega-3 fatty acid
Omega carbon
Omega carbon
Linoleic AcidAn Omega-6 fatty acid
How Do Omega-3 Fatty Acids Work?
• They affect the synthesis of eicosanoid hormone like compounds such as prostaglandins & leukotrienes.
• The compounds produced from omega 3 fatty acids:• Decrease blood clotting (prevent plaque build-up) • Decrease blood pressure (prevent atherosclerosis) • Decrease blood total cholesterol, LDL cholesterol, &
triglycerides & increase HDL cholesterol) • Decrease inflammation (prevent arthritis, asthma)• Increase immunity (prevent cancer)
American Heart Association omega 3 fatty acid recommend
• Consume 0.5-1.8 grams of omega-3 fatty acids per day as fatty fish or supplements.• The omega-3 fatty acids in fish are called
EPA & DHA.
• Consume 1.5-3.0 grams alpha-linolenic acid (an omega-3 fatty acid) per day.• Plant sources of omega-three fatty acids flax
seed, walnuts, & canola oil.
Omega-3 Fatty Acids in Fish
• Best Sources:• Salmon• Herring• Mackerel• Tuna• Whitefish
• Good Sources:• Cod• Flounder• Halibut• Mahi Mahi• Orange Roughy• Sea Bass• Clams• ScallopsTo avoid mercury contamination,
eat fish that live closer to the surface and have a shorter lifespan.
Homocysteine in Heart Disease
• Homocysteine is an amino acid intermediate of Homocysteine is an amino acid intermediate of cysteine & methionine metabolism.cysteine & methionine metabolism.
• Elevated levels of homocysteine cause arterial Elevated levels of homocysteine cause arterial wall damage & contribute to heart disease. wall damage & contribute to heart disease.
• Folic acid (folate), BFolic acid (folate), B66 & B & B1212 function as cofactors function as cofactors for the enzymes driving the inter conversion of for the enzymes driving the inter conversion of cysteine & methionine, thus adequate intakes cysteine & methionine, thus adequate intakes prevent prevent hyperhomocystemiahyperhomocystemia. .
methionine
homocysteine
cysteine
Other Factors in Heart Disease
• High doses of Niacin: Increases HDL, decreases LDL.
• Statin type cholesterol lowering drugs: Reduce the synthesis of cholesterol in the liver.
• Cholesterol absorption inhibitor drugs.• Benecol spreads: Contain plant stanol esters that
reduce the absorption of cholesterol in the digestive tract.
• Wine: Reduces blood viscosity. Red wine and/or grape juice increases HDL.
• Alcohol: 1 serving per day decreases risk of a cardiovascular accident. It is an anticoagulant.
• Aerobic Activity: Increases HDL, decreases LDL.• Soluble Fiber: Decreases LDL.• Soy Protein: Increases HDL, decreases LDL.
Lipids in Cancer
• Cancer is the 2nd leading cause of death in Americans.
• It is characterized by uncontrolled cell growth.
• It occurs through a process of initiation, promotion, and progression.
Carcinogenesis
Cancer Risk
• Increased Cancer Risk by Lifestyle Practices – Smoking tobacco, UV light, Obesity,
Sedentary Lifestyle
• Increased Cancer Risk by Dietary Practices – ~ 45% of all cancer deaths are diet-related– Low F&V, antioxidant nutrient, & fiber intake– High total fat and PUFA, sodium intake– P:S ≥3:1 + high fat diet = cancer risk – P:S ≤0.33:1 (or ≤1:3) + high fat diet = heart
disease risk
Sample P:S Ratio Calculation
• Kathy ate a high fat diet.– 104 gm PUFA & 30 gm SFA
• What is her P:S ratio? 104 ÷ 30 = 3.47. This # is placed in the P
position of the ratio– The S position is always assigned the # 1
• The P:S is 3.47:1• Is the ratio increasing disease risk?
– This P:S ratio is increasing risk for cancer– Remember that you do want enough PUFA to
get your essential (linoleic and alpha-linolenic) fatty acid needs met.
Dietary Lipids & Disease Risk
Dietary Factor Heart Disease Cancer
Low fat intake(20-25% of total Calories)
Prevents disease
Prevents disease
Moderate fat intake(25-35% of total Calories)
Does not contribute to disease
Does not contribute to disease
High fat intake (>35% of total Calories)
Contributes to disease
Contributes to disease
Fatty Acids & Disease Risk
High SFALow MUFALow PUFA
Increases total blood cholesterol, LDL (is not ideal)
Is associated with heart disease(is atherogenic)
Low SFALow MUFAHigh PUFA
Decreases total blood cholesterol, HDL & LDL (is not ideal)
Increases cancer risk (is tumorgenic)
Low SFAHigh MUFAAdequate PUFA
Decreases total blood cholesterol, LDL(is ideal)
Is not associated with cancer or heart disease risk (is not tumorgenic or atherogenic)
Summary How to prevent heart disease
• Avoid dietary cholesterol & saturated fat.• Avoid hydrogenated or partially
hydrogenated fat (trans-fatty acids).• Consume MUFA and omega 3 fatty acids.• Protect PUFA, MUFA, & LDL with
antioxidants. • Consume adequate folate to prevent
hyperhomocystemia.• Consume soluble fiber, soy, and plant
stanols/sterols.• Avoid cigarette smoking.• Exercise (especially aerobic).
SummaryHow to prevent cancer
• Choose to eat mostly plant foods.– Eat plenty & a variety of whole
grains, fruits, & vegetables!• Avoid high fat diets especially saturated
fat & omega-6 fatty acids.• Consume an antioxidant-rich diet.• Practice all aspects of a sound diet:
Calorie control, adequacy, balance, moderation, and variety.
References for this presentation are the same as those for this topic found in module 3 of the textbook