Published: Sep 22, 2014 | Updated: Sep 23, 2014
By Elizabeth DeVita Raeburn, Contributing Writer, MedPage Today
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Action Points
Note that this large Swedish study suggested that several modifiable risk factors, including moderate alcohol intake and refraining from smoking, were associated with a dramatic reduction in risk of myocardial infarction in men.
Be aware that the risk factors were collected by self-report, and the design of this study precludes a true assessment of causality.

Adhering to a healthy diet and lifestyle could prevent as many as four out of five heart attacks in men, according to a population-based, prospective cohort study of Swedish men.

Practicing just two of five low-risk behaviors — a healthy diet and moderate alcohol consumption — was associated with a relative risk of 0.65 (95% CI: 0.48-0.87) for myocardial infarction (MI) compared with men who practiced none of the low-risk behaviors.

Following all five low-risk factors — refraining from smoking, being physically active and having no abdominal adiposity, in addition to the other two — was associated with a relative risk of 0.14 (95% CI: 0.04-0.43), wroteAgneta Åkesson, PhD, of the Karolinska Institute in Sweden and her co-authors online in The Journal of the American College of Cardiology.

“This combination of healthy behaviors, present in 1% of the men, could prevent 79% (95% CI: 34-93) of the MI events on the basis of the study population,” they said.

Programs that target men and encourage them to adhere to these behaviors — even just two of them — could have a large impact on the burden of disease, wrote Åkesson and her colleagues.

Each of the five lifestyle factors was inversely and independently associated with the risk of MI after adjustment for the other aspects of the low-risk profile, the authors said.

“This reduction in risk corresponded to 18% for the healthy diet, 11% for moderate alcohol consumption, 36% for no smoking, 3% for being physically active, and 12% for having a low abdominal circumference,” the authors wrote.

In an accompanying editorial, Dariush Mozaffarian, MD, DrPH of Tufts University, cited earlier research attesting to the risk reduction power of simple lifestyle factors, and went so far as to call for change. “It is time to prioritize these most basic and fundamental behaviors,” he said.

Medical educators, clinicians, health administrators and insurance providers should design a way to incorporate ways to target and measure dietary quality, physical activity, smoking and waist circumference into “every aspect of the health system,” wrote Mozaffarian.

“Patients should enter their doctor’s office and not simply ask ‘How are my blood pressure, cholesterol, and glucose levels?’ but also ask ‘How are my dietary habits, physical activity level, smoking, and waist measurement?'”

The study followed 20,721 Swedish men between the ages of 45 and 79 with no history of cancer, cardiovascular disease, diabetes, hypertension, or high cholesterol from 1997-2009. The men were asked to complete a detailed questionnaire addressing their diet and lifestyle at baseline in 1997.

The cohort was then linked to the Swedish National Inpatient and Cause of Death Registers, considered to be more than 99% complete, in order to identify subsequent incident cases of nonfatal and fatal MI in the study population. There were 1,361 incident cases of MI over the course of the study.

The authors defined the five low-risk behaviors as: being in the top quintile of the Recommended Food Score; consuming 10 to 30 g/day of alcohol; not smoking; walking or bicycling more than 40 minutes a day and exercising for at least an hour a week; and having a waist circumference of less than 95 centimeters.

The Healthy Food Score was developed for the National Health and Nutrition Examination Survey, and is highly predictive of mortality, the authors said. Points are given for servings per week of foods with beneficial effect on cardiovascular health, such as fruit, vegetables and whole grains, with a maximum score of 25.

Mozaffarian noted that the Healthy Food Score is based on higher intake of healthful foods, rather than lower intake of unhealthful ones. These results are consistent, he said, with earlier analyses that found that a lack of healthful foods, rather than excess of unhealthful ones, produced a larger burden of disease.

All associations between low risk diet and lifestyle factors were adjusted for age, education, marital status, family history of MI, aspirin use, energy intake and non-Recommended Food Score, which consisted of a score given frequency of nonrecommended foods such as red and processed meat, solid fats and full fat cheese.

Overall, men who followed a low-risk diet were less likely to smoke and live alone than those with lower scores of recommended foods, the authors said. They also tended to be more educated.

A separate analysis of 7,139 men with hypertension and high cholesterol identified at baseline also found a decrease in risk with “increasing adherence” to the low-risk behaviors defined in the study. However this result was hampered by low sample size, which led to “unstable” and “insignificant” estimates of risk, the authors said.

Of great importance, the authors said, is that these lifestyle behaviors are modifiable — people can change and adapt to low-risk behaviors. They cited an earlier study, in which men who adopted at least two healthy behaviors reduced their incidence of coronary heart disease by 27%.

Among the limitations of the study were measurement error due to self-report, which might have led to misclassification, and the small number of subjects in the study who followed all five behaviors and had MIs.