The importance of relaxation and the severity of seasonal affective disorders was brought to light in a recent nationwide study in Sweden. The study started out as a mission to explain why heart attack incidence rates vary over time, and the results linked an increased risk with times most people would associate with high stress.
Researchers examined data from 156,000 people experiencing myocardial infarction, AKA a heart attack, and looked at the data in the context of seasons and stress. All of the data were obtained from Swedish hospitals between 2006 and 2013. Their mind findings were this:
- Heart attack rates are higher during winter holidays and on Mondays year-round
- Heart attack rates are lower during the summer, especially the month of July, and on weekends year-round
"This is the first study that investigates these culturally defined time-periods in the Swedish population,” said first author John Wallert, a PhD student. “Our study seems to suggest that psychosocial demands on behavior influences basal biological systems, even to such an extent that they may be potential triggers for [heart attack].”
Myocardial infarction, or heart attack, is caused by a blockage in the coronary arteries that prevents blood flow from reaching the heart. When blood reaches the heart, this massive muscle then uses blood to send oxygen and nutrients to the body’s tissues. When this flow is inhibited, the tissues starve.
The Centers for Disease Control and Prevention (CDC) estimate that every year around 735,000 Americans have a heart attack.
“We have to remember that this is an observational study and be cautious with our conclusions,” Wallert said. “The systematic variation in MI rates is likely multifactorial.”
Scientists aren’t going to suggest disrupting the traditional work week based on the study’s results, but the findings still offer an interesting spin on stress and a person’s risk of heart attack.
“How we in society have agreed on periods of work and rest is actually quite well aligned with our predisposed, internal biological clock, the circadian rhythm,” Wallert explained. “This and other findings might have a bearing on future public health and clinical policy.”
The present study was published in the American Heart Journal.
Sources: CDC, Uppsala University
