The ill-effects of chronic stress—which range from psychological to physical health problems—are well documented in the scientific literature. And it makes intuitive sense that living under a dull but constant threat of terrorist attack would likely count as a chronic stressor. But until now, no one had tested this hypothesis on a large scale.
Now, a new study examining around 17,300 people living in Israel has confirmed that fear of terrorists does take a toll on health. Specifically, terrorism fear is linked to increased heart rates and a greater chance of death, the Economic Times reports.
The study participants underwent annual health examines from 2002 to 2013. During the exams, they were evaluated for stress using both physical proxies such as heart rate and levels of stress-related chemicals in their blood and through self-reported questionnaires.
Around four percent of the participants suffered from frequent stress due to the threat of terrorist attacks that manifested as physical symptoms, the Economic Times reports. At those times, their resting heart rate was higher, increasing from about 60 beats per minute to up to 80 beats per minute. Elevated heart rate is a known predictor of stroke and heart attack, the Times points out. The researchers also found that people who were afraid of terrorist attacks had elevated levels of inflammation, which is also linked to increased risk of a heart attack, and lower levels of acetylcholine, a neurotransmitter that helps suppress overkill inflammatory responses.
"We found that fear of terrorism and existential anxiety may disrupt the control processes using acetylcholine, causing a chronic accelerated heart rate," lead author and molecular neuroscientist Hermona Soreq said in a statement. "Together with inflammation, these changes are associated with increased risk of heart attack and stroke."