SOURCE: Hebrew University of Jerusalem, news release, Dec. 22, 2014
TUESDAY, Dec. 23, 2014 (HealthDay News) -- Long-term fear of terrorists may damage your heart and increase your risk for an early death, a new study from Israel suggests.
Conducted by researchers from the Hebrew University of Jerusalem, the study involved 17,300 Israelis. In Israel, the threat of war and terrorism has been a part of life for more than 60 years.
"We wanted to test whether fear of terrorism can predict an increase in pulse rate and increased risk of death," study author Hermona Soreq, a professor of molecular neuroscience, said in a university news release.
The researchers used data from annual checkups, including blood tests, heart rate and stress tests results, to examine how the participants' health changed between 2002 and 2013.
The participants also completed questionnaires, which provided clues to their psychological, occupational and physical well-being.
Resting heart rate wasn't only influenced by fitness level and immune system response, the researchers found. Fear of terror played a significant role in annual increases in the participants' heart rate, according to the study published Dec. 22 in the Proceedings of the National Academy of Sciences.
About 4 percent of participants had a heightened fear of terror that predicted a rise in their resting heart rate. In some cases, participants living in fear had resting heart rates of up to 80 beats per minute -- much faster than a normal heartbeat of 60 beats per minute.
An elevated resting heart rate increases the risk of death from heart disease or death from any cause, the researchers explained. Usually, resting heart rates drop each year as people age. Those whose heart rate continues to rise are more likely to experience a heart attack or stroke, they said.
The researchers also considered the effects of chronic fear on acetylcholine -- a neurotransmitter involved in the body's responses to stress that dampens the inflammatory response. Using a blood test, they found that constant fear of terror inhibits this neurotransmitter, leaving the body more vulnerable to heart attack.
"We found that fear of terrorism and existential anxiety may disrupt the control processes using acetylcholine, causing a chronic accelerated heart rate. Together with inflammation, these changes are associated with increased risk of heart attack and stroke," Soreq said.
People fearful of attack who had elevated heart rates also had higher levels of C-reactive protein, a biomarker for inflammation.
The researchers suggested their findings could help doctors identify people who could benefit from early, preventive treatment, such as anti-inflammatory medication or exercise.
The American Psychological Association provides more information on the long-term effects of terror.