Perhaps the most frequently cited, yet underachieved, recommendation for the prevention of cardiovascular disease is to implement healthy lifestyle habits. The INTERHEART study showed that healthy diet patterns, regular exercise, and moderate alcohol intake are associated with a significantly lower risk of coronary heart disease (CHD).¹ Populations that follow a Mediterranean-type diet have reduced rates of CHD, cancer, and total mortality.² An intensive lifestyle plan of diet and exercise also significantly reduces the incidence of diabetes in subjects with impaired fasting glucose.³

The Health Professionals Follow-Up Study (HPFS) discussed in this issue of Cardiology Review confirmed these findings by showing that men with an evidence-based, calculated, low-risk profile had nearly a 90% lower risk of CHD than men with a high-risk profile when followed over 20 years. Most importantly, this study showed that 57% of the CHD events in this high-risk cohort could have been prevented with adherence to the 5 defined healthy lifestyle factors, even if subjects were taking medications for hypertension and cholesterol. This information alone is probably not surprising to most clinicians; however, the enlightening data from this study is that men who adopted ≥ 2 additional low-risk lifestyle factors had a 27% lower risk of CHD compared with men who made no changes during the follow-up period. Although it is not clear which 2 combinations of the 5 factors are best to achieve this result (one would hope that smoking cessation is 1 of them!), the data show that favorable alterations in poor lifestyle habits can reduce the risk of CHD as much as, if not more than, has been shown with primary prevention drug treatments for hypertension and dyslipidemia and with aspirin prophylaxis.

The most difficult lifestyle habits to change are diet and exercise, and the disturbing increase in obesity in the United States is tied to this problem. To complicate matters, many opinions exist about the best diet to follow and include the Dietary Approaches to Stop Hypertension (DASH) diet, the US Department of Agriculture Food Pyramid, and diets designed to be low fat, high fat (with monounsaturated and omega-3 fatty acids), and high protein-low carbohydrate. Although caloric restriction, rather than diet type, is more important for weight management, the multitude of diet options is confusing to both patients and their health care providers. It certainly does not help us to convince our female patients that reducing fat intake (predominantly saturated fat) and increasing intake of fruits, vegetables, and grains is important when the Women’s Health Initiative (WHI) showed no beneficial effects on cardiovascular disease outcomes with this diet over 8 years.⁴ Nevertheless, the diet that is advocated by both the WHI and the American Heart Association⁵ was the basis for determining the diet score that was one of the low-risk healthy lifestyle factors of the HPFS, and it is the most sensible to recommend.

Exercise has consistently been shown to improve cardiovascular risk factors, reduce the incidence of diabetes, and be associated with reduced all-cause mortality compared with a sedentary lifestyle. Encouraging our patients to adopt the recommended 30 minutes of moderate-intensity exercise on most, if not all, days of the week remains a big challenge.

With the new therapies available to help with smoking cessation and with local government policies that prohibit smoking in public places, it may become easier to reduce the prevalence of cigarette smoking and passive smoking exposure in the future.⁶ We hope that research in the pharmaceutical control of obesity, combined with help from the food industry and the government, along with better consumer education, engaged physician involvement, and enhanced reimbursement for lifestyle change consultations from health care providers, will reduce the obesity epidemic in the United States. The take-home message from the HPFS is that most CHD risk can be prevented with lifelong adherence to healthy lifestyle factors and that changing a few of the “unhealthy” factors can significantly reduce CHD risk, even if we prescribe medications for hypertension and dyslipidemia.

References
1. Yusuf S, Hawken S, Ounpuu S, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. 2004; 364(9438): 937-952.

2. Trichopoulo A, Costacou T, Bamia C, et al. Adherence to a Mediterranean diet and survival in a Greek population. N Engl J Med. 2003; 348(26): 2599-2609.

3. Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002; 346(6): 393-403.

4. Howard BM, Van Horn L, Hsia J, et al. Low-fat dietary pattern and risk of cardiovascular disease: the Women’s Health Initiative randomized controlled dietary modification trial. JAMA. 2006; 295(6):655.

5. Lichtenetein AH, Appel LJ, Brands M, et al. Summary of American Heart Association diet and lifestyle recommendations revision 2006. Arterioscler Thromb Vase Biol. 2006; 26(10):2186-2191.

6. Bartecchi C, Alsever RN, Nevin-Woods C, et al. Reduction in the incidence of acute myocardial infarction associated with a city-wide smoking ordinance. Circulation. 2006; 114(14):1490-1496.