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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 Disease Cardiovascular disease describes diseases of the heart and blood vessels Coronary heart disease Stoke Hypertension Congestive heart failure Cardiovascular Disease Coronary heart disease is the most common form of cardiovascular disease Usually caused by atherosclerosis Stroke is the second most common form of cardiovascular disease Atherosclerosis Thickening of the blood vessel walls due to plaque formation (accumulation of lipids, smooth muscle cells, minerals and fibrous connective tissue) Atherosclerosis Development Initiated by minimal but chronic injuries that damage the blood vessel lining Oxidized LDL cholesterol accumulates in blood vessel wall Blood vessel damage causes inflammation Immune system responds sending white blood cells White blood cells enter blood vessel wall, engulf LDL cholesterol, forming foam cells Foam cells visible as fatty deposits along blood vessel wall, known as fatty streaks Atherosclerosis Development Smooth 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 Development Atherosclerosis Development Injury Oxidized LDL accumulates Damage causes inflammation Immune system responds with white blood cells Engulf LDL cholesterol forming foam cells Smooth muscle proliferation Lipid, mineral accumulation Maturation of lesion Inflammation and Infection As 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 inflammation A promising marker is a protein known as C- reactive protein (CRP), which is produced during the acute phase of inflammation Plaque Plaque can exist in two forms: A stable form Has 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 plaque An 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 Clots Blood 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 death Heart – heart attack Brain – stroke Lung – pulmonary embolism Kidney – acute renal failure Aneurysm Atherosclerosis also is a risk factor for aneurysms An aneurysm is an abnormal enlargement within the blood vessel Plaque can weaken the blood vessel wall, allowing it to expand and balloon out Aneurysms that go undetected can rupture and lead to massive bleeding and death Coronary Heart Disease Risk Factors Some factors initiate atherosclerosis by: Causing direct damage to the artery wall Allowing lipid materials to penetrate artery surface Other factors promote progression of atherosclerosis and related complications by inducing: Plaque rupture Blood clotting Coronary Heart Disease Risk Factors Non modifiable risk factors: Increasing age Gender Family history of premature heart disease Modifiable risk factors: High LDL cholesterol Low HDL cholesterol High blood pressure Diabetes Obesity (especially abdominal obesity) Physical inactivity Cigarette smoking Diet high in saturated fat, trans fat, and cholesterol and low in fruits, vegetables and whole grains Preventing Coronary Heart Disease For 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 cholesterol High blood pressure Diabetes Smoking Age Aging strongly associated with atherosclerosis due to: Cumulative exposure to risk factors Degeneration 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 Gender Gender difference in age of coronary heart disease onset has been attributed to: A protective effect of estrogen in women Men also tend to have other possible risk factors: Higher homocysteine levels Higher risk of iron overload Ultimately, coronary heart disease kills as many women as men Family History Family history of early coronary heart disease in one’s immediate family members is an independent risk factor, independent of other risk factors LDL cholesterol LDL cholesterol is easily oxidized Oxidized LDL cholesterol is actively taken up and retained in the blood vessel wall Oxidized LDL has other damaging effects: Activate proliferation of smooth muscle cells involved in plaque formation Induce vasoconstriction (increase blood pressure) Simulate blood clotting Inhibit some normal protective functions of HDL LDL cholesterol High levels of a variant form of LDL called lipoprotein(a) has been found to accelerate progression atherosclerosis and double the risk of coronary heart disease Abnormally high levels are largely genetically determined and have been associated with premature development of heart disease LDL Cholesterol Levels High LDL cholesterol ≥ 160 mg/dL Recommended LDL cholesterol < 100 mg/dL HDL Cholesterol HDL 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 disease Low HDL cholesterol levels often coexist with other risk factors such as high triglycerides Some factors that increase coronary heart disease risk such as obesity, smoking, inactivity and male gender also reduce HDL HDL Cholesterol Low HDL < 40 mg/dL Recommended HDL ≥ 60 mg/dL Blood Pressure The stress of blood flow along the blood vessel walls (shear stress) can cause mechanical damage within the blood vessel Plaque tends to develop at points where blood vessels branch or bend disturbing blood flow High blood pressure intensifies the stress of blood flow on arterial walls Plaque protruding inward can reduced blood flow and raise blood pressure even further Thus, hypertension and atherosclerosis become mutually aggravating conditions Blood Pressure For 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 Hg Recommended blood pressure is <120/<80 Diabetes High blood glucose can attach (glycate) to proteins forming glycoproteins These proteins can damage blood vessels and worsen atherosclerosis Other effects of diabetes promote blood clot formation Diabetes High fasting blood glucose is ≥ 126 mg/dL Recommended fasting blood glucose is < 100 mg/dL High 2 hr OGT blood glucose is ≥ 200 mg/dL Recommended 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 pressure Increasing insulin resistance Increasing risk of diabetes Increasing LDL cholesterol Increasing triglycerides Lowering HDL cholesterol Alters concentration and activity of blood clotting factors promoting blood clotting Obesity (Especially Abdominal) Overweight = BMI 25.0-29.9 Obese = BMI ≥ 30 Recommended BMI = 18.5 – 24.9 Recommended waist circumference is: Men: <102 cm (<40 in) Women: <88 cm (<35 in) Obesity The initial goal of a weight-loss program is no more than 10% of original body weight For some, avoiding additional weight gain may be a desirable starting point Physical Inactivity Physical inactivity can increase risk of: Low HDL cholesterol Obesity which can increase the risk of: Diabetes High blood pressure Regular physical activity can lower coronary heart disease risk: Increase HDL Lower LDL cholesterol Lower triglycerides Promote weight loss Improve insulin sensitivity Lower blood pressure Strengthen heart muscles Physical Activity Aerobic activities help the heart the most Goal is to expend at least 2,000 calories in physical activity per week Dietary Guidelines physical activity recommendations: For substantial health benefits 150 minutes of moderate-intensity per week or 75 minutes of vigorous-intensity per week For additional health benefits 300 minutes of moderate-intensity per week or 150 minutes of vigorous-intensity per week Cigarette Smoking Substances in smoke: Induce vasoconstriction Increase blood pressure Damage blood vessels Injure blood vessel walls Increase oxidative stress Promote LDL cholesterol oxidation Damage platelets Promote blood clotting Decrease oxygen carrying capacity of blood Promote lipid accumulation in blood vessel walls Cigarette Smoking Passive smoke has similar effects Recommendations 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 Diet A 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 cholesterol Low in nutrients that decrease coronary heart disease risk such as fiber, omega-3 fatty acids, and antioxidants Saturated Fat Saturated fat has the strongest effect of all lipids on blood LDL cholesterol levels Clinical trials suggest every 1% increase in calories from saturated fat raises LDL cholesterol 2% Saturated Fat Replacing saturated fat with monounsaturated or polyunsaturated fats can lower LDL cholesterol levels Polyunsaturated fats have a slightly greater effect on lowering LDL cholesterol, but can also promote a slight reduction in HDL cholesterol Saturated Fat Average American diet provides 11% of total calories from saturated fat Main sources of saturated fat are whole-milk products, high fat meats, and baked goods Recommendations 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 Fat Replacing saturated fats with carbohydrates can also reduce LDL cholesterol but may lower HDL cholesterol and raise triglycerides This 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 Fat Dietary Guidelines recommendations are: Total fat 20 to 35% total calories Saturated fat < 10% total calories Saturated Fat - Tropical Oils Although, liquid a room temperature, tropical oils are highly saturated Coconut oil (92% saturated) Palm kernel (82% saturated) Palm oils (50% saturated) Saturated Fat - Steric Acid Stearic 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 Fats Process 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 Fat Trans fat result from hydrogenation of vegetable oils Unsaturated bonds change from a cis to trans configuration Trans fats are unsaturated, but they can raise LDL cholesterol When trans fats replace saturated fats in the diet they can lower HDL cholesterol Trans Fat Most sources of trans fats are products made with partially hydrogenated oils Baked goods like crackers, cookies, and doughnuts, and fried foods like french fries and fried chicken Soft margarines and other products are now available with little, or no, trans fat Current trans fat intakes average about 2.6% of calories Dietary Guideline recommendations are to keep trans fat intake as low as possible Dietary Cholesterol Although saturated fat is the main culprit in raising blood cholesterol, dietary cholesterol plays a part Dietary cholesterol also raise LDL cholesterol, but not as much as saturated fat Dietary Cholesterol People get cholesterol in two ways: Liver production About 1,000 mg/day Foods also contain cholesterol Average intake 331 mg/day men and 211 mg/day women Animal products (egg yolk, meat, poultry, fish seafood, whole milk dairy products) contain cholesterol Plant foods (fruits, vegetables, grains, nuts and seeds) do not contain cholesterol Dietary Cholesterol Dietary Guideline recommendations are: Limit dietary cholesterol intake to < 300 mg/day Soluble Fiber When 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 tract May also influence the liver’s production of cholesterol by other means Soluble Fiber Dietary sources of soluble fiber include oats, barley, legumes, and fruits The soluble fiber from psyllium seed husks is also effective for lowering cholesterol levels Fiber Dietary fiber intake in the United States averages about 15 g/day Many organizations recommend dietary fiber intake should be 20 – 30 g/day DRI for fiber is 14 g/1,000 calories Would be 28 g for a typical 2,000 calorie diet Omega-3 Fatty Acids Fatty fish are high in two omega-3 fatty acids: Eicosapentaenoic acid (EPA) Docosahexaenoic acid (DHA) Fatty fish Mackerel Lake trout Herring Sardines Albacore tuna Salmon Omega-3 Fatty Acids Omega-3 fatty acids may be beneficial by: Suppressing inflammatory response Reducing blood clotting time Stabilizing heart rhythm Lowering 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 supplements Not all studies with fish oil supplements have reported positive outcomes Omega-3 Fatty Acids Omega-3 fatty acids found in flaxseeds and other land plants have lesser or different effects than omega-3 fatty acids from marine sources Although 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 Antioxidants Oxidized LDL is especially atherogenic Epidemiological 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 Antioxidants Controlled 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 Alcohol Coronary heart disease risk is lower for people who drink moderate amounts than nondrinkers Moderate amounts of alcohol has favorable effects on: HDL cholesterol levels Atherosclerosis Inflammation Blood clotting activity Alcohol Moderate intake defined as: 1 drink for women or 2 drinks for men/day One drink is: 1 ½ fl oz of 80 proof 1 fl oz 100 proof 4 fl oz wine 12 fl oz beer Alcohol Too much alcohol: Raise blood pressure Raise blood triglycerides Contribute to obesity Associated with certain types of cancer Gastrointestinal tract Liver Breast Ovarian For these reasons, nondrinkers are not encouraged to start drinking in an effort to decrease coronary heart disease risk Soy Several 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 fats Approximately 25 grams of soy protein daily appears to be needed for significant benefit Whether the LDL lowering effect is due to soy protein alone or to other components of soy, such as isoflavone or sapoinins, remains unclear Plant Sterols Plant 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 carotenoids Unknown if eating more fruits and vegetables could compensate Plant Sterols Plant sterols are extracted from soybeans and pine-tree oils They 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 body Use of folate, B6 and B12 supplements to reduce coronary heart disease risk is not recommended Recommendations are to get enough folate, B6 and B12 in the diet from fruits and green leafy vegetables Emerging Coronary Heart Disease Risk Factors There are other emerging physiological factors that appear to influence coronary heart disease risk: Metabolic syndrome Hypertriglyceridemia Homocysteine Iron Overload Metabolic Syndrome Metabolic 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/dl HDL < 40 mg/dl in men or < 50 mg/dl in women Blood pressure ≥ 135/85 mm Hg Serum glucose ≥ 110 mg/dl Metabolic Syndrome Each 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 Syndrome Recommendations 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 Triglycerides Whether high triglycerides are an independent risk factor for coronary heart disease remains debatable High triglycerides is common in people with metabolic syndrome and diabetes High triglycerides are associated with low HDL Overweight, sedentary lifestyle, and cigarette smoking all may raise triglyceride levels Dietary factors that influence triglycerides the most are high intakes of carbohydrate (≥60% of total calories) and alcohol Triglycerides High blood triglycerides is ≥ 200 mg/dL Recommended blood triglycerides is < 150 mg/dL Triglycerides High blood triglycerides is ≥ 200 mg/dL Recommended blood triglycerides is < 150 mg/dL Homocysteine High homocysteine related to atherosclerosis and coronary heart disease risk Damage blood vessel walls Increase oxidative stress Increase 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 Overload Iron overload, more common in men, is associated with increase coronary heart disease risk Iron overload increases oxidative stress More research is needed to understand iron’s role in coronary heart disease