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Nutrition and Heart Disease. Unit 19. Diet and Heart Disease. Diets high in saturated fat and trans fat are a major risk factor for heart disease Other risk factors can also be modified Except age, sex, genetic tendencies. Declining Rates of Heart Disease.
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Nutrition and Heart Disease Unit 19
Diet and Heart Disease • Diets high in saturated fat and trans fat are a major risk factor for heart disease • Other risk factors can also be modified • Except age, sex, genetic tendencies
Declining Rates of Heart Disease • In the US, deaths from heart disease have dropped since the 1950s • Lower cholesterol levels • Reduced smoking • Improved blood pressure • Advances in medical care
A Big Health Problem • Heart disease still causes 1 of 4 deaths
Heart Disease • Heart disease (coronary heart disease) • Disorder that results when circulation of blood to parts of the heart is inadequate • Usually due to narrowing of arteries caused by buildup of plaque, which causes atherosclerosis
Key Terms • Plaque • Deposits of cholesterol, other fats, calcium, and cell minerals in the lining of the inner wall of arteries • Atherosclerosis • “Hardening of the arteries” due to plaque buildup
Heart Disease • Narrowing of arteries by 50% or more can cause chest pain (angina) • A heart attack occurs when an artery leading to the heart is completely blocked
Blood flow to the base of the heart blocked by ruptured plaque deposit or blood clot Heart Attack
Other Effects • Atherosclerosis can also block arteries in the legs, neck, brain, and other body parts • Cardiovascular disease • Disorders related to plaque buildup in arteries of the heart, brain, and other organs and tissues
What Causes Atherosclerosis? • High blood cholesterol levels and chronic inflammation in the inner walls of arteries work together to increase atherosclerosis
Key Terms • Chronic inflammation • Inflammation that lasts weeks to years • Inflammation • First response of the body’s immune system to infection or irritation • Triggers release of substances that promote oxidation and other harmful reactions
Cholesterol and Heart Disease • Generally, the higher the blood cholesterol level, the more plaque builds up • Diets high in saturated fat and cholesterol raise blood cholesterol • Trans fat raises cholesterol levels more than saturated fat
HDL and LDL Cholesterol • Cholesterol in blood is bound to proteins, forming lipoproteins • HDL (high density lipoprotein) lowers blood cholesterol levels (“good cholesterol”) • LDL (low density lipoprotein) raises blood cholesterol levels (“bad cholesterol”)
Understanding HDL and LDL • High HDL protects against heart disease • >40 mg/dL in men; >50 mg/dL in women • Moves cholesterol from blood to liver • High LDL increases risk of heart disease • Forms plaque in arteries
Triglycerides and Heart Disease • Triglycerides in blood are attached to very-low-density lipoproteins (VLDL) • High blood triglyceride levels increase risk of heart disease, metabolic syndrome, and type 2 diabetes
Genetics and Blood Cholesterol • Genetic traits influence the way diet and exercise affect blood lipid levels • Nutritional deprivation early in life can permanently modify functions of certain genes, such as those that affect HDL levels
Inflammation and Heart Disease • LDL cholesterol can enter the endothelium of artery walls and cause chronic inflammation • Inflammation oxidizes LDL cholesterol, which damages artery walls and forms plaque • Endothelium • Layer of cells lining the inside of blood vessels
Inflammation and Heart Disease • Antioxidants stop or repair effects of oxidation, and lower inflammation • Antioxidants are found mainly in plant foods • Phytochemicals in fruits and vegetables • Vitamins C and E • Selenium and beta-carotene
High LDL cholesterol Low HDL cholesterol High saturated, trans fat, cholesterol diet Family history Diet low in vegetables, fruit, whole grain Elevated inflammation High triglycerides Hypertension Smoking Inactivity Obesity Diabetes Age (men>45, women>55) Who’s at Risk?
Risks for Women • Diabetes, obesity, high triglyceride levels, and age are stronger risk factors in women • LDL cholesterol levels are weaker predictors • Risk increases after menopause
Managing Heart Disease • Dietary and lifestyle changes: • Reduce high blood pressure and body weight • Reduce inflammation • Stop smoking • Improve blood lipid profiles • Improve overall health
Key Terms • Plant stanols and sterols • Substances in corn, wheat, oats, rye, olives, wood, and some other plants • Similar in structure to cholesterol but not absorbed by the body • Decrease cholesterol absorption
Other Factors • Exercise and weight loss lower LDL-cholesterol and raise HDL-cholesterol • Moderate alcohol consumption increases HDL-cholesterol • Cholesterol-lowering drugs may be prescribed
Current food recommendations for dietary treatment of heart disease Heart-Healthy Foods
EPA and DHA form anti-inflammatory chemicals Antioxidants, weight loss, and exercise also reduce inflammation Chronic Inflammation and Oxidation
Statins • Statins are drugs that reduce cholesterol production in the liver • Lipitor, Vytorin, Zetia, Crestor • Reduce heart attacks, strokes 30-40% • Side effects • Muscle pain and weakness • Liver disease, kidney failure
Looking Toward the Future • Escalating rates of child and adolescent obesity in the US will lead to a 5-16% increase in heart disease by 2035 • Changes are needed in diet and lifestyle, quality of foods in stores and restaurants, and consumer awareness