Lifestyle may affect sudden cardiac death risk

Researchers have identified one more reason for women to stay fit, eat healthy, abstain from smoking, and maintain their weight: those who do so might be less likely to die from sudden cardiac death.

The new study, published in the Journal of the American Medical Association, found that each positive lifestyle choice - a Mediterranean-style diet, a healthy weight, not smoking, and exercise - was linked to a smaller chance of sudden cardiac death, and added together, the factors were tied to a 92 percent reduced risk.

"The more you adhere to this healthy lifestyle, the better you are in terms of your risk of sudden cardiac death," said Dr. Stephanie Chiuve from Brigham and Women's Hospital in Boston and the lead author of the study.

Sudden cardiac death is responsible for half of all cardiac deaths, with about 250,000 to 310,000 cases occurring annually in the U.S., the authors write.

Chiuve's study, which was funded by the National Institutes of Health and the American Heart Association, did not look at how long women stuck to each of the healthier lifestyle factors, nor was it able to prove that healthy living is actually responsible for the drop in sudden cardiac death risk.

Unlike a heart attack, which is caused by a blood vessel blockage, sudden cardiac death is related to a malfunctioning of the electrical rhythm of the heart.

Chiuve and her colleagues looked at results from the Nurses' Health Study, in which more than 81,000 women periodically answered surveys about health and lifestyle.

During the 26 years of the study, 321 women suffered sudden cardiac death at an average age of 72.

Women who ate a diet closest to the Mediterranean diet, which has a high proportion of vegetables, fruits, nuts, omega-3 fats, and fish, along with moderate amounts of alcohol and small amounts of red meat, had the lowest risk of sudden cardiac death - 40 percent less than women whose diets least resembled the Mediterranean diet.

Weight was tied to a similar effect on risk. Normal-weight women were 56 percent less likely to suffer sudden cardiac death compared to obese women.

Exercise was also linked with a smaller chance of sudden cardiac death, and the more the women exercised, the smaller their risk. At least 30 minutes a day of exercise brought the risk of sudden cardiac death down by 28 percent.

Smoking was the biggest risk factor. Women who had never smoked were 75 percent less likely to suffer sudden cardiac death than women who smoked at least 25 cigarettes per day.

The researchers concluded that 81 percent of cases of sudden cardiac death were due to unhealthy lifestyles.

Chiuve said the results are important for understanding who is at risk for sudden cardiac death. Most people are flagged as being at high risk because of other health problems, such as having had a heart attack in the past.