Prevention

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Prevention

 

Heart failure is the cumulative result of structural and functional abnormalities in which the heart gradually loses the ability to pump sufficient blood to meet the body’s metabolic requirements. Consequently, the risk factors for heart failure are closely associated with those for cardiovascular disease. Although many conditions may lead to heart failure, an understanding of the respective responsibility of the precipitating causes in the development of heart failure is critical for prevention strategies.

 

How can heart failure prevention best be achieved?

 

Since heart failure develops from cardiovascular disease, preventing cardiovascular disease, when possible, should be the first step in our endeavor to prevent heart failure. It follows, that our next step in preventing heart failure is to prevent or delay the onset of heart failure in patients with cardiovascular disease. The control of lifestyle factors such as the use of  tobacco, dietary habits, body weight, physical activity, and psychosocial stress, serve as an important starting point for the primary prevention of heart failure.

 

  • Discontinue all tobacco use and avoid exposure to second-hand smoke. Smoking is a well-recognized cause of a multitude of diseases and is the single largest preventable cause of disease and premature death. Smokers have a 47% increased risk of developing heart failure compared to non-smokers.1
  • Nutritional status is an important determinant of chronic disease risk, especially cardiovascular disease. The optimal cardio-protective diet remains elusive. However, data from epidemiologic research and clinical trials have provided clear guidelines by which the inception and progression of cardiovascular disease may be influenced. The characteristics of a healthy heart diet are as follows:

1.      There is growing evidence that dietary habits, particularly the composition of dietary fatty acids and carbohydrates, influence the development and progression of heart failure.2  Saturated fatty acids should account for  no more than 10% of total energy intake.3  Studies have shown that substituting polyunsaturated fats from vegetable oils for full-fat dairy products and fatty red meats lowers the risk of cardiovascular disease. Research also shows that replacement of saturated fat by carbohydrates, especially refined carbohydrates and added sugars, increases the risk of insulin resistance and diabetes, risk factors for cardiovascular disease.4

2.      In food processing, trans fatty acids are formed as a result of adding hydrogen to liquid oils to make them semisolid and increase their shelf life. These fatty acids are commonly found in bakery products, fast foods, packaged snacks, and margarines. Smaller amounts are consumed in ruminant fat in dairy and meat products.5Trans fat has been demonstrated to increase total cholesterol  and decrease HDL cholesterol levels. In controlled trials, substituting 1% of energy intake from trans fatty acids with saturated, monounsaturated, or polyunsaturated fatty acids decreases the total cholesterol/HDL cholesterol ration by 0.31, 0.54, and 0.67, respectively.3 In prospective cohort studies, it has been demonstrated that each 2% energy replacement of trans fatty acids with saturated, monounsaturated, or polyunsaturated fatty acids resulted in a 17%, 21%, or 24% lower risk of developing coronary heart disease.6 Given that trans fatty acids have no known nutritional value beyond their energy content, it is currently recommended that < 1% of total energy intake be derived from trans fatty acids.3

3.      Excess dietary salt has long been recognized as a contributing factor to the development of hypertension. It had been shown that even a reduction of as little as 1 gram per day of salt intake reduces systolic blood pressure by 3.1 mmHg in hypertensive individuals and 1.6 mmHg in normotensive  individuals. In healthy individuals, dietary salt intake should be limited to < 5 grams/day.3

4.      The increased consumption of dietary fiber has been shown to lower the risk of cardiovascular disease. Dietary fiber comprises a broad class of indigestible plant compounds such as cellulose, hemicellulose and pectin. Based on physical properties and physiological roles, dietary fiber is classified as either soluble fiber or insoluble fiber. Important dietary sources of fiber include wholegrain products, legumes, nuts, fruits and vegetables. The cardio-protective benefits of increased dietary fiber include:7;8 

·         lower plasma total cholesterol, triglycerides, and apolipoprotein B

·         higher HDL cholesterol

·         improved triglyceride levels

·         improved postprandial glucose

·         improved insulin sensitivity

·         blood pressure reduction

                        Current recommendations are for a dietary fiber intake of between 30-45 grams/day.3

5.   Increased consumption of fruits and vegetables, especially green leafy  vegetables and vitamin C-rich fruits and vegetables, is associated with a reduced risk of chronic disease, including a lower risk of morbidity and mortality from cardiovascular disease.9 The cardio-protective effects of fruit  and vegetable intake appear to be dose related. A cross-sectional study found that many of the benefits of fruit and vegetable intake increased proportionally by the  number of servings.10 Joshipura et al.9 reported that each 1 serving/day increase in intake of fruits or vegetables was associated with a 4% lower risk for coronary heart disease. Current recommendations are for the consumption of at least 200 grams (2-3 servings) of fresh fruit and 200 grams (2-3 servings) of fresh vegetables per day.3

6.   Substantial evidence exists to support moderate alcohol consumption, compared to no or heavy alcohol consumption, as part of a cardio-protective diet.  All types of alcohol appear to provide some degree of protection against the occurrence of cardiovascular disease, although research suggests that red wine is more protective than other forms.11 Current recommendations are that consumption of alcoholic beverages be limited to two glasses per day (20 grams of alcohol) for men and one glass per day (10 grams of alcohol) for women.3 However, it is noted that recommendations for alcohol consumption be made with caution, citing the serious risks of heavy alcohol consumption, including addiction, accidents, liver disease, some forms of cancer, as well as psychiatric and social problems.11

7.   The regular and adequate consumption of cardio-protective functional foods  should be included as part of a heart-healthy diet. The European Commission’s Concerted Action on Functional Food Science in Europe has recommended the following working definition for functional foods: “a food can be regarded as ʻfunctionalʼ if it is satisfactorily demonstrated to affect beneficially one or more target functions in the body, beyond adequate nutritional effects, in a way that is relevant to either an improved state of health and well-being and/or reduction of risk of disease.

Functional foods must remain foods and they must demonstrate their effects in  amounts that can normally be expected to be consumed in the diet; they are not   pills or capsules, but part of a normal food pattern.”12 The potential mechanisms by which functional foods may influence the prevention of cardiovascular disease include:13

·         lowering blood lipid levels

·         improving arterial compliance

·         reducing low-density lipoprotein oxidation

·         decreasing plaque formation

·         scavenging free radicals

·         inhibiting platelet aggregation

Functional foods offer significant potential for the prevention and treatment of cardiovascular diseases. These foods include the following:

·         soybeans

·         oats

·         psyllium

·         flaxseed

·         fish

·         grapes and grape juice

·         nuts

·         tea

·         dark chocolate

8.  Moderate intensity physical activity and aerobic exercise is associated with a reduced risk for cardiovascular morbidity and mortality.3 The mechanisms underlying the benefits of regular physical activity on cardiovascular disease are multifaceted and include:14

·         improved lipid profile, insulin-resistance, and glycemic control

·         lowered blood pressure

·         reduced obesity and adiposity

·         improved regulation on endothelial function

·         reduced inflammation

·         decreased thrombotic tendency

·         decreased myocardial oxygen demands during exercise and improved myocardial oxygen supply

9.   Numerous reports indicate that overweight and obesity foreshadow metabolic and cardiovascular consequences, rendering individuals at substantially higher risk for type 2 diabetes as well as cardiovascular disease morbidity and mortality.15-17 Obesity is of critical importance in the development and progression of cardiovascular disease, and subsequent heart failure, because it exerts its effects on risk by negatively impacting many of the other risk factors associated with cardiovascular disease.17 Potential adverse effects of increasing body weight on other risk factors for cardiovascular disease include:3;17

·         increases in insulin resistance leading to glucose intolerance and type 2 diabetes

·         increased blood pressure

·         increased inflammation

·         promotion of a thrombotic state

·         increased serum triglyceride

·         increased LDL cholesterol

·         increased apolipoprotein B

·         decreased HDL cholesterol

·         increased incidence of atrial fibrillation

·         increased risk for obstructive sleep apnea

·         increased incidence of metabolic syndrome

 10.  The importance of elevated blood pressure lies in the fact that it represents a major risk factor for coronary heart disease, stroke, atherosclerosis and peripheral vascular disease. Guidelines aimed at assisting physicians at selecting the best management strategies for the treatment of hypertension recommend that all patients diagnosed with hypertension should be treated, initially by non-pharmacological means and, if necessary, with pharmacological antihypertensive therapy.18

 Diet and lifestyle play an important role in maintaining a healthy blood pressure and the prevention of hypertension. The Dietary Approaches to Stop Hypertension (DASH) trial demonstrated that a diet rich in fruits and vegetables, low-fat dairy products, and with reduced saturated and total fat intake can reduce the systolic and diastolic blood pressure of both non-hypertensive and hypertensive adults.19 In many cases, where nutritional and lifestyle recommendations are closely followed, one can prevent the progression of pre-hypertension to more serious classifications of hypertension. Hypertension is classified in stages based on the risk of developing cardiovascular disease  (Table 9).3

 

Table 9. Classification of blood pressure levels in untreated adults (adapted from Perk et al.)3

 

11.  Management of psychosocial stress

 

 

Aggressive implementation of nutrition- and lifestyle-based cardiovascular disease prevention strategies could prevent a significant proportion of the cardiovascular events and strokes that are otherwise expected to occur in the U.S. and other Western countries in the future.

 

 

Reference List

1.   Bui AL, Horwich TB, Fonarow GC. Epidemiology and risk profile of heart failure. Nature Reviews Cardiology 2011;8:30-41.

2.   Stanley WC, Dabkowski ER, Ribeiro RF, O’Connell KA. Dietary Fat and Heart Failure: Moving From Lipotoxicity to Lipoprotection. Circulation Research 2012;110:764-776.

3.   Perk J, De Backer G, Gohlke H et al. European Guidelines on cardiovascular disease prevention in clinical practice (version 2012): The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of nine societies and by invited experts). Atherosclerosis 2012;223:1-68.

4.   Astrup A, Dyerberg J+, Elwood P et al. The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010? The American Journal of Clinical Nutrition 2011;93:684-688.

5.   Mozaffarian D, Rimm EB, King IB et al. trans Fatty acids and systemic inflammation in heart failure. The American Journal of Clinical Nutrition 2004;80:1521-1525.

6.   Mozaffarian D, Clarke R. Quantitative effects on cardiovascular risk factors and coronary heart disease risk of replacing partially hydrogenated vegetable oils with other fats and oils. Eur J Clin Nutr 2009;63:S22-S33.

7.   Finks SW, Airee A, Chow SL et al. Key Articles of Dietary Interventions that Influence Cardiovascular Mortality. Pharmacotherapy 2012;32:e54-e87.

8.   Sanchez-Muniz FJ. Dietary fibre and cardiovascular health. Nutr.Hosp. 2012;27:31-45.

9.   Peterson J, Dwyer J, Adlercreutz H et al. Dietary lignans: physiology and potential for cardiovascular disease risk reduction. NUTR REV 2010;68:571-603.

10.   Mirmiran P, Noori N, Zavareh MB, Azizi F. Fruit and vegetable consumption and risk factors for cardiovascular disease. Metabolism 2009;58:460-468.

11.   Bhupathiraju SN, Tucker KL. Coronary heart disease prevention: Nutrients, foods, and dietary patterns. Clinica Chimica Acta 2011;412:1493-1514.

12.   Scientific Concepts of Functional Foods in Europe Consensus Document. British Journal of Nutrition 1999;81:S1-S27.

13.   Hasler CM, Kundrat S, Wool D. Functional foods and cardiovascular disease. Current Atherosclerosis Reports 2000;2:467-475.

14.   Scrutinio D. The potential od lifestyle changes for improving the clinical outcome of patients with coronary heart disease: mechanisms of benefit and clinical results. Reviews on Recent Clinical Trials 2010;5:1-13.

15.   Chen YT, Vaccarino V, Williams CS et al. Risk factors for heart failure in the elderly: a prospective community-based study. The American Journal of Medicine 1999;106:605-612.

16.   Kenchaiah S, Evans JC, Levy D et al. Obesity and the Risk of Heart Failure. New England Journal of Medicine 2002;347:305-313.

17.   Zalesin KC, Franklin BA, Miller WM, Peterson ED, McCullough PA. Impact of oesity on cardiovascular disease. Med Clin N Am 2011;95:919-937.

18.   Suter PM, Sierro C, Vetter W. Nutritional factors in the control of blood pressure and hypertension. Nutrition in Clinical Care 2002;5:9-19.

19.   Appel LJ, Moore TJ, Obarzanek E et al. A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure. New England Journal of Medicine 1997;336:1117-1124.