COLUMBUS, Ohio -- A new study has found that mild psychological stress can temporarily increase blood levels of a chemical associated with the development of heart disease.
The study of 34 middle-aged women found that brief periods of stress increased blood levels of the amino acid homocysteine. Research over the past 20 years has found that an even moderately elevated level of homocysteine is a risk factor for heart disease in both men and women.
"This is the first study to show that behavioral factors may influence homocysteine levels," said Catherine Stoney, author of the study and a professor of psychology at Ohio State University.
"We knew that psychological stress plays a role in cardiovascular disease. These findings suggests homocysteine may be one mechanism for the stress effect."
The study will be published May 14 in the journal Life Sciences. Homocysteine is a dietary byproduct of animal protein. Normally, it is broken down in the bloodstream by folic acid and the B vitamins. "People who have deficiencies in folic acid and the B vitamins have higher sustained levels of homocysteine and are at increased risk for cardiovascular disease," Stoney said.
This study involved 34 women between the ages of 40 and 63. Half were pre-menopausal and half were post-menopausal.
For the study, the participants came to Ohio State's General Clinical Research Center in the morning after an overnight fast. Researchers inserted a catheter into their arms to collect blood during the experiment.
During the experiment, the women were given two stress-inducing tests. In one test, they had to continuously and rapidly subtract 17s from a four-digit number. In the other test, the participants had to give a videotaped speech about an anger-provoking, hypothetical event. Blood samples were taken before, during and after the stress-causing tests.