Diet and Health Guidelines to Lower Risk of Heart Disease

Presented by Janice Hermann, PhD, RD/LD

OCES Adult and Older Adult Nutrition Specialist

Cardiovascular DiseaseCardiovascular disease describes diseases of

the heart and blood vesselsCoronary heart diseaseStokeHypertensionCongestive heart failure

Cardiovascular DiseaseCoronary heart disease is the most common

form of cardiovascular diseaseUsually caused by atherosclerosis

Stroke is the second most common form of cardiovascular disease

AtherosclerosisThickening of the blood vessel walls due to

plaque formation (accumulation of lipids, smooth muscle cells, minerals and fibrous connective tissue)

Atherosclerosis DevelopmentInitiated by minimal but chronic injuries that

damage the blood vessel liningOxidized LDL cholesterol accumulates in blood

vessel wallBlood vessel damage causes inflammationImmune system responds sending white blood cellsWhite blood cells enter blood vessel wall, engulf LDL

cholesterol, forming foam cellsFoam cells visible as fatty deposits along blood vessel

wall, known as fatty streaks

Atherosclerosis DevelopmentSmooth muscle cells from blood vessel tissue

stimulated to divide, engulf LDL cholesterol and form fibrous connective tissue

Plaque accumulates calcium and cholesterol in lipid core can crystallize and harden

Sometimes the blood vessel may expand outward to accommodate the plaque volume; other times plaque narrows the blood vessel lumen

Atherosclerosis DevelopmentAtherosclerosis

DevelopmentInjuryOxidized LDL accumulatesDamage causes inflammationImmune system responds

with white blood cellsEngulf LDL cholesterol forming

foam cellsSmooth muscle proliferationLipid, mineral accumulationMaturation of lesion

Inflammation and InfectionAs mentioned plaque formation is initiated by

an inflammatory response to injuries that damage the blood vessel lining

There is also evidence that persistent infection may contribute to plaque formation

This has led to the use of markers indicating artery wall inflammationA promising marker is a protein known as C-

reactive protein (CRP), which is produced during the acute phase of inflammation

PlaquePlaque can exist in two forms:

A stable formHas a thicker barrier between its lipid core and the blood

vessel lumen Blood vessels that accommodate plaque only by narrowing

may impede blood flow, but generally have more stable plaqueAn unstable plaque

Has a thin barrier which is highly susceptible to rupture resulting in blood clot formation

Blood vessels that accommodate plaque by expanding are less likely to interfere with blood flow but generally have unstable plaque

Blood ClotsBlood clots can enlarge over time obstructing

blood flow or a clot may break free and travel through the circulatory system until it lodges in a narrowed artery and obstruct blood flow

When blood flow is obstructed the surrounding tissue is deprived of oxygen which results in cell deathHeart – heart attackBrain – strokeLung – pulmonary embolismKidney – acute renal failure

AneurysmAtherosclerosis also is a risk factor for

aneurysmsAn aneurysm is an abnormal enlargement within

the blood vesselPlaque can weaken the blood vessel wall, allowing

it to expand and balloon outAneurysms that go undetected can rupture and

lead to massive bleeding and death

Coronary Heart Disease Risk FactorsSome factors initiate atherosclerosis by:

Causing direct damage to the artery wallAllowing lipid materials to penetrate artery

surfaceOther factors promote progression of

atherosclerosis and related complications by inducing:Plaque ruptureBlood clotting

Coronary Heart Disease Risk FactorsNon modifiable risk factors:

Increasing ageGenderFamily history of premature heart disease

Modifiable risk factors:High LDL cholesterolLow HDL cholesterolHigh blood pressureDiabetesObesity (especially abdominal obesity)Physical inactivityCigarette smokingDiet high in saturated fat, trans fat, and cholesterol and

low in fruits, vegetables and whole grains

Preventing Coronary Heart DiseaseFor most people, preventing coronary heart

disease focuses on lowering modifiable risk factors

Studies have suggested that 80 to 90 percent of people with severe heart disease have at least one of the four classic risk factors:High LDL cholesterolHigh blood pressureDiabetesSmoking

AgeAging strongly associated with

atherosclerosis due to:Cumulative exposure to risk factorsDegeneration of blood vessels with age

Aging becomes a significant risk factor for:Men at age 45 or older,Women at age 55 or older as they reach

menopause

GenderGender difference in age of coronary heart

disease onset has been attributed to:A protective effect of estrogen in womenMen also tend to have other possible risk

factors:Higher homocysteine levelsHigher risk of iron overload

Ultimately, coronary heart disease kills as many women as men

Family HistoryFamily history of early coronary heart disease

in one’s immediate family members is an independent risk factor, independent of other risk factors

LDL cholesterolLDL cholesterol is easily oxidizedOxidized LDL cholesterol is actively taken up

and retained in the blood vessel wallOxidized LDL has other damaging effects:

Activate proliferation of smooth muscle cells involved in plaque formation

Induce vasoconstriction (increase blood pressure)Simulate blood clottingInhibit some normal protective functions of HDL

LDL cholesterolHigh levels of a variant form of LDL called

lipoprotein(a) has been found to accelerate progression atherosclerosis and double the risk of coronary heart diseaseAbnormally high levels are largely genetically

determined and have been associated with premature development of heart disease

LDL Cholesterol LevelsHigh LDL cholesterol ≥ 160 mg/dLRecommended LDL cholesterol < 100 mg/dL

HDL CholesterolHDL carries cholesterol from body cells to the

liver to be removed and thus protects against atherosclerosis

Low HDL cholesterol is a risk factor for coronary heart diseaseLow HDL cholesterol levels often coexist with other

risk factors such as high triglyceridesSome factors that increase coronary heart

disease risk such as obesity, smoking, inactivity and male gender also reduce HDL

HDL CholesterolLow HDL < 40 mg/dLRecommended HDL ≥ 60 mg/dL

Blood PressureThe stress of blood flow along the blood vessel

walls (shear stress) can cause mechanical damage within the blood vesselPlaque tends to develop at points where blood vessels

branch or bend disturbing blood flowHigh blood pressure intensifies the stress of blood

flow on arterial walls Plaque protruding inward can reduced blood flow

and raise blood pressure even furtherThus, hypertension and atherosclerosis become

mutually aggravating conditions

Blood PressureFor people over 50 years of age, a high

systolic blood pressure is more predictive of coronary heart disease risk than diastolic blood pressure

High blood pressure is ≥140/ ≥90 mm HgRecommended blood pressure is <120/<80

DiabetesHigh blood glucose can attach (glycate) to

proteins forming glycoproteinsThese proteins can damage blood vessels and

worsen atherosclerosisOther effects of diabetes promote blood clot

formation

DiabetesHigh fasting blood glucose is ≥ 126 mg/dLRecommended fasting blood glucose is < 100

mg/dLHigh 2 hr OGT blood glucose is ≥ 200 mg/dLRecommended 2 hr OGT blood glucose is

< 140 mg/dL

Obesity (Especially Abdominal)Obesity, especially abdominal obesity, increases

the risk of coronary heart disease by:Increasing blood pressureIncreasing insulin resistanceIncreasing risk of diabetesIncreasing LDL cholesterolIncreasing triglyceridesLowering HDL cholesterol Alters concentration and activity of blood clotting

factors promoting blood clotting

Obesity (Especially Abdominal)Overweight = BMI 25.0-29.9Obese = BMI ≥ 30Recommended BMI = 18.5 – 24.9Recommended waist circumference is:

Men: <102 cm (<40 in)Women: <88 cm (<35 in)

ObesityThe initial goal of a weight-loss program is no

more than 10% of original body weightFor some, avoiding additional weight gain

may be a desirable starting point

Physical InactivityPhysical inactivity can increase risk of:

Low HDL cholesterolObesitywhich can increase the risk of:DiabetesHigh blood pressure

Regular physical activity can lower coronary heart disease risk:Increase HDLLower LDL cholesterolLower triglyceridesPromote weight lossImprove insulin sensitivityLower blood pressureStrengthen heart muscles

Physical ActivityAerobic activities help the heart the mostGoal is to expend at least 2,000 calories in

physical activity per weekDietary Guidelines physical activity

recommendations:For substantial health benefits

150 minutes of moderate-intensity per week or75 minutes of vigorous-intensity per week

For additional health benefits300 minutes of moderate-intensity per week or 150 minutes of vigorous-intensity per week

Cigarette SmokingSubstances in smoke:

Induce vasoconstrictionIncrease blood pressure

Damage blood vesselsInjure blood vessel walls

Increase oxidative stressPromote LDL cholesterol oxidation

Damage plateletsPromote blood clotting

Decrease oxygen carrying capacity of bloodPromote lipid accumulation in blood vessel walls

Cigarette SmokingPassive smoke has similar effectsRecommendations are to not start smoking

or to quit smoking and to avoid second hand smoke

Quitting smoking can improve coronary heart disease risk almost immediately, and people who stop smoking can eventually reverse the damage from smoking

DietA diet high in saturated fat, trans fat, and

cholesterol and low in fruits and vegetables, and whole grains is associated with increased coronary heart disease risk, even more than might be expected based on risk factors such as LDL cholesterol alone High in nutrients that increase coronary heart disease

risk such as saturated fat, trans fat and cholesterolLow in nutrients that decrease coronary heart disease

risk such as fiber, omega-3 fatty acids, and antioxidants

Saturated FatSaturated fat has the strongest effect of all

lipids on blood LDL cholesterol levelsClinical trials suggest every 1% increase in calories

from saturated fat raises LDL cholesterol 2%

Saturated FatReplacing saturated fat with

monounsaturated or polyunsaturated fats can lower LDL cholesterol levelsPolyunsaturated fats have a slightly greater effect

on lowering LDL cholesterol, but can also promote a slight reduction in HDL cholesterol

Saturated FatAverage American diet provides 11% of total

calories from saturated fatMain sources of saturated fat are whole-milk

products, high fat meats, and baked goodsRecommendations are to choose lean meats or

fish, use fat-free or low-fat milk products, limit snack foods and bakery products high in saturated fat

Saturated FatReplacing saturated fats with carbohydrates

can also reduce LDL cholesterol but may lower HDL cholesterol and raise triglyceridesThis effect can be offset somewhat by limiting

added sugars and including fiber-rich foods; generous amounts of whole grains, legumes, fruits and vegetables

DRI recommended carbohydrate intake is 45-65% of total calories

Saturated FatDietary Guidelines recommendations are:

Total fat20 to 35% total calories

Saturated fat< 10% total calories

Saturated Fat - Tropical OilsAlthough, liquid a room temperature, tropical

oils are highly saturatedCoconut oil (92% saturated)Palm kernel (82% saturated)Palm oils (50% saturated)

Saturated Fat - Steric AcidStearic acid is a saturated fatty acid that is

mainly in animal products, and some plant foods like chocolate

Studies have shown saturated fatty acids raise blood cholesterol

However, other studies show that some saturated fatty acids like stearic acid may not affect or ay even lower total blood cholesterol

Further research is needed

Saturated Fat - Hydrogenated FatsProcess of hydrogenation changes a liquid oil,

naturally high in unsaturated fatty acids, to a more solid and more saturated fat

The greater the degree of hydrogenation, the more saturated the fat becomes

Trans FatTrans fat result from hydrogenation of

vegetable oilsUnsaturated bonds change from a cis to trans

configuration Trans fats are unsaturated, but they can raise

LDL cholesterolWhen trans fats replace saturated fats in the

diet they can lower HDL cholesterol

Trans FatMost sources of trans fats are products made with

partially hydrogenated oilsBaked goods like crackers, cookies, and doughnuts, and

fried foods like french fries and fried chickenSoft margarines and other products are now available

with little, or no, trans fatCurrent trans fat intakes average about 2.6% of

caloriesDietary Guideline recommendations are to keep

trans fat intake as low as possible

Dietary CholesterolAlthough saturated fat is the main culprit in

raising blood cholesterol, dietary cholesterol plays a partDietary cholesterol also raise LDL cholesterol, but

not as much as saturated fat

Dietary CholesterolPeople get cholesterol in two ways:

Liver productionAbout 1,000 mg/day

Foods also contain cholesterolAverage intake 331 mg/day men and 211 mg/day

womenAnimal products (egg yolk, meat, poultry, fish seafood,

whole milk dairy products) contain cholesterolPlant foods (fruits, vegetables, grains, nuts and seeds) do

not contain cholesterol

Dietary CholesterolDietary Guideline recommendations are:

Limit dietary cholesterol intake to < 300 mg/day

Soluble FiberWhen eaten as part of a diet low in saturated

fat, trans fat and cholesterol, soluble fiber has been shown to help lower blood cholesterol

Soluble fibers can:Reduce cholesterol and bile absorption by binding

them in the intestinal tractMay also influence the liver’s production of

cholesterol by other means

Soluble FiberDietary sources of soluble fiber include oats,

barley, legumes, and fruitsThe soluble fiber from psyllium seed husks is

also effective for lowering cholesterol levels

FiberDietary fiber intake in the United States

averages about 15 g/day Many organizations recommend dietary fiber

intake should be 20 – 30 g/dayDRI for fiber is 14 g/1,000 calories

Would be 28 g for a typical 2,000 calorie diet

Omega-3 Fatty AcidsFatty fish are high in two omega-3 fatty acids:

Eicosapentaenoic acid (EPA)Docosahexaenoic acid (DHA)

Fatty fishMackerelLake troutHerringSardinesAlbacore tunaSalmon

Omega-3 Fatty AcidsOmega-3 fatty acids may be beneficial by:

Suppressing inflammatory responseReducing blood clotting timeStabilizing heart rhythmLowering triglyceride levels

Large intakes of EPA and DHA, however, may raise LDL cholesterol in some people

Increasing omega-3 fatty acids through foods is preferred to supplementsNot all studies with fish oil supplements have

reported positive outcomes

Omega-3 Fatty AcidsOmega-3 fatty acids found in flaxseeds and

other land plants have lesser or different effects than omega-3 fatty acids from marine sourcesAlthough limited evidence suggests these plant

sources of omega-3 fatty acids may lower coronary heart disease risk, more research is needed to confirm their benefits

AntioxidantsOxidized LDL is especially atherogenicEpidemiological studies suggest an

association between diets rich in antioxidants (fruits, vegetables and whole grains) and lower coronary heart disease risk

However, antioxidant rich diets are often linked with a healthy lifestyle and lower body weight making it difficult to determine which factor is responsible for the effect

AntioxidantsControlled trials with single antioxidant

supplements (vitamin C and E), combinations, or multivitamins have produced results too weak or inconsistent to conclude that they offer any significant benefit for preventing coronary heart disease, and several studies have suggested possible harm

Recommendations are to eat a diet rich in fruits, vegetables and whole grains

AlcoholCoronary heart disease risk is lower for

people who drink moderate amounts than nondrinkers

Moderate amounts of alcohol has favorable effects on:HDL cholesterol levelsAtherosclerosisInflammationBlood clotting activity

AlcoholModerate intake defined as:

1 drink for women or 2 drinks for men/dayOne drink is:

1 ½ fl oz of 80 proof1 fl oz 100 proof4 fl oz wine12 fl oz beer

AlcoholToo much alcohol:

Raise blood pressureRaise blood triglyceridesContribute to obesityAssociated with certain types of cancer

Gastrointestinal tractLiverBreastOvarian

For these reasons, nondrinkers are not encouraged to start drinking in an effort to decrease coronary heart disease risk

SoySeveral studies have shown diets low in

saturated fat and cholesterol and high in soy protein can reduce LDL cholesterol levels, especially when soy protein replaces foods that contain animal fatsApproximately 25 grams of soy protein daily

appears to be needed for significant benefitWhether the LDL lowering effect is due to soy

protein alone or to other components of soy, such as isoflavone or sapoinins, remains unclear

Plant SterolsPlant sterols can lower blood cholesterol

Reduce intestinal absorption of cholesterol, both dietary cholesterol and cholesterol in bile

Clinical trials have shown a little more than one tablespoon of margarine daily (containing about 2 grams of plant sterols) can lower LDL cholesterol by 6-15% without lowering HDL cholesterol

One concern is plant sterols may also reduce absorption and blood levels of carotenoidsUnknown if eating more fruits and vegetables could

compensate

Plant SterolsPlant sterols are extracted from soybeans and

pine-tree oilsThey can be hydrogenated to produce plant

stanols, which are compounds typically found in commercial products

Food manufacturers have designed margarines, cheese, and other products with added plant sterols

Folate acid, B6 and B12

High homocysteine levels related to atherosclerosis and coronary heart disease risk

Folate, B6 and B12 help break down and lower homocysteine in the bodyUse of folate, B6 and B12 supplements to reduce

coronary heart disease risk is not recommendedRecommendations are to get enough folate, B6 and

B12 in the diet from fruits and green leafy vegetables

Emerging Coronary Heart DiseaseRisk FactorsThere are other emerging physiological

factors that appear to influence coronary heart disease risk: Metabolic syndromeHypertriglyceridemiaHomocysteineIron Overload

Metabolic SyndromeMetabolic syndrome is a condition of having

three or more of the following abnormalities:Abdominal obesity

Waist circumference > 40 inches (men)Waist circumference > 35 inches (women)

Serum triglycerides ≥ 150 mg/dlHDL < 40 mg/dl in men or < 50 mg/dl in womenBlood pressure ≥ 135/85 mm HgSerum glucose ≥ 110 mg/dl

Metabolic SyndromeEach of these factors increases the likelihood

of developing coronary heart disease independently, but when they occur together, they elevate risk synergistically

Estimates are that approximately 24% of the population have metabolic syndrome

Metabolic SyndromeRecommendations for people with metabolic

syndrome are:Weight loss to achieve BMI less than 25 to support

reduced abdominal obesity, reduce triglycerides, and reduce blood pressure

Increased physical activity to support weight loss, glucose control, reduce triglycerides, reduce blood pressure and increase HDL cholesterol

Healthy eating habits that support weight loss, glucose control, reduce blood pressure and reduce triglycerides

TriglyceridesWhether high triglycerides are an

independent risk factor for coronary heart disease remains debatableHigh triglycerides is common in people with

metabolic syndrome and diabetesHigh triglycerides are associated with low HDLOverweight, sedentary lifestyle, and cigarette

smoking all may raise triglyceride levelsDietary factors that influence triglycerides the

most are high intakes of carbohydrate (≥60% of total calories) and alcohol

TriglyceridesHigh blood triglycerides is ≥ 200 mg/dLRecommended blood triglycerides is < 150

mg/dL

Triglycerides High blood triglycerides is ≥ 200 mg/dLRecommended blood triglycerides is < 150

mg/dL

HomocysteineHigh homocysteine related to atherosclerosis

and coronary heart disease riskDamage blood vessel wallsIncrease oxidative stressIncrease blood clotting activity

Uncertain whether harmful effects caused by homocysteine or something associated with it

Folate, B6 and B12 help break down homocysteine in the body

Iron OverloadIron overload, more common in men, is

associated with increase coronary heart disease risk

Iron overload increases oxidative stressMore research is needed to understand iron’s

role in coronary heart disease