Combination of Healthy Lifestyle Factors Protects the Heart
Overall, those who are at greatest risk for having a sudden cardiac arrest (SCA) are those who have pre-existing cardiovascular disease. But for some, SCA can happen in those who appear healthy and have no known heart disease or other risk factors. This is why it is vitally important to maintain a healthful lifestyle that includes activities that protect the heart, such as not smoking, exercising regularly, having a low body weight and eating a healthy diet.
Smoking, Weight are Greatest Contributors to Heart Risks
Stephanie E. Chiuve ScD of Brigham and Women’s Hospital and Harvard Medical School proved this correlation by using data collected as part of the Nurses’ Health Study which examined health and lifestyle factors for over 80,000 women between June 1984 and June 2010. The women were surveyed using questionnaires every two to four years during the study period. During the 26 years of follow-up, there were 321 cases of Sudden Cardiac Death (SCD) among the women in the study.
Women who were considered low-risk in four specific areas had a 92% lower risk of SCD when compared to women who were not in the low-risk categories for any of the four factors. Low risk was defined as not smoking, having a body mass index (BMI) of less than 25, exercise duration of 30 minutes per day or longer, and consuming a diet that closely related to the Mediterranean-style diet which emphasizes fruits, vegetables, legumes, whole grains, and fish.
Even just modifying one of these factors into the low-risk category was protective against SCD. Smoking was the biggest contributory risk factor overall. Women who had never smoked were 75% less likely to suffer cardiac death than women who smoked at least 25 cigarettes a day. The second greatest risk factor was weight – normal weight women were 56% less likely to suffer SCD compared to obese women.
Sudden cardiac arrest is a condition in which the heart suddenly and unexpectedly stops beating. Death occurring within one hour after symptom onset without evidence of circulatory collapse (ie: heart attack) is considered sudden cardiac death. There are about 250,000 to 310,000 cases each year of SCD in the US.
Ventricular fibrillation (V-fib), a type of heart arrhythmia, causes most SCAs. Coronary heart disease, severe physical stress, certain inherited disorders and structural changes to the heart can cause the arrhythmias that lead to sudden cardiac arrest. The risk of SCA increases with age. Men are two to three times more likely to have conditions leading to SCA than women.
“The primary prevention of SCD remains a major public health challenge because most SCD occurs among individuals not identified as high risk,” the authors write. “In this cohort of female nurses, adherence to an overall healthy lifestyle was associated with a lower risk of SCD and may be an effective strategy for the prevention of SCD.”
S. E. Chiuve, T. T. Fung, K. M. Rexrode, D. Spiegelman, J. E. Manson, M. J. Stampfer, C. M. Albert. Adherence to a Low-Risk, Healthy Lifestyle and Risk of Sudden Cardiac Death Among Women. JAMA: The Journal of the American Medical Association, 2011; 306 (1): 62 DOI:10.1001/jama.2011.907