Cold weather may have no correlation to heart-related deaths during winter months, according to a new study.
Recent research published in the Journal of the American Heart Association analyzed trends in heart-related deaths in New Zealand, where Christmas occurs during the summer season when death rates are usually at a seasonal low – allowing researchers to separate any winter effect from a holiday effect.

 “Spikes in deaths from natural causes during Christmas and New Year’s Day has been previously established in the United States,” said Josh Knight, B.Sc., study author and research fellow at the University of Melbourne in Australia. “However, the Christmas holiday period (Dec. 25 to Jan. 7) in the U.S. falls within the coldest period of the year when death rates are already seasonally high due to low temperatures and influenza.”

Deaths occurring in a 25-year period between 1988 and 2013 were studied. There were a total of 738,409 deaths with 197,109 being heart-related.

Researchers discovered a 4.2 percent rise in heart-related deaths occurring away from a hospital from Dec. 25 and Jan. 7. In addition, the average of a cardiac death was 76.2 years compared with compared with 77.1 years during other times of the year.

Emotional stress, changes in diet and alcohol consumption, lower numbers of hospital staff and changes in the physical environment (for example visiting relatives) were theorized as causes in the increase.

Researchers also said patients may be more reluctant to seek medical care.

 “The Christmas holiday period is a common time for travel within New Zealand, with people frequently holidaying away from their main medical facilities,” Knight said. “This could contribute to delays in both seeking treatment, due to a lack of familiarity with nearby medical facilities, and due to geographic isolation from appropriate medical care in emergency situations.”

Another explanation may have to do with a terminally ill patients’ will to live and hold off death for a day that is important to them, researchers stated.

“The ability of individuals to modify their date of death based on dates of significance has been both confirmed and refuted in other studies. However, it remains a possible explanation for this holiday effect,” Knight said.

The study did not track daily temperatures and New Zealand has an island climate, which almost eliminates the extremes of temperature that have been associated with heart-related death rates in previous studies.