Lipids in Heart Disease and Cancer

By Jennifer Turley and Joan Thompson

© 2016 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.

AtherosclerosisPlaques:

• 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

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

AHA

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 RiskNCEP ATP III

Metabolic Syndrome: If Three or More of These Factors :1. Fasting Blood Triglycerides: ≥150 mg/dl2. HDL: <50 mg/dl ♀ <40 mg/dl ♂3. Blood Pressure: ≥130/85 mm Hg4. Fasting Blood Glucose: ≥110 mg/dl5. 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

Oxidation of Fat• 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.

Antioxidants• 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

Vitamin E is best

food vs. supplements

dilemma

Hydrogenation of Fat, Part 1

• 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, Part 2

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

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.

80% TFA intake is from processed foods & 20% from animal products

Omega-3 Fatty Acids Heart Healthy

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 recommendations

• 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•Scallops

To 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 cysteine & methionine metabolism.

• Elevated levels of homocysteine cause arterial wall damage & contribute to heart disease.

• Folic acid (folate), B6 & B12 function as cofactors for the enzymes driving the inter conversion of cysteine & methionine, thus adequate intakes prevent hyperhomocystemia.

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)

Some Summary Points 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).

Some Summary PointsHow 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