Those fatty snacks you turn to as comfort food during stressful times may wind up doing worse damage to your arteries than usual, according to a new study.
Researchers at Ohio State University found that short periods of psychological stress cause the body to take longer to clear fats from the bloodstream, offering one physical reason why stress has been linked to heart disease.
"If a person has a high-fat snack or meal during a time of stress, that fat is going to be circulating in the blood for a longer period of time," said Catherine Stoney, a professor of psychology and co-author of the report. It appears in the current issue of the journal Psychophysiology.
"That means it may be more likely to be deposited in the arteries, where it can contribute to heart disease," Stoney added.
The study involved 70 middle-aged, healthy, non-smoking volunteers, divided equally between men and women. Half were between the ages of 40 and 48, and the rest were between 54 and 61, to consider the effects on both premenopausal and post-menopausal women.
Each volunteer was tested twice, with the sessions taking place within three days. During both, an IV was inserted into a vein, and a solution containing triglycerides (fats) equal to about 100 calories was injected to mimic what would happen a few hours after eating a fatty meal.
During one test, volunteers simply rested and their triglyceride levels were checked continuously for 40 minutes. In the other test, volunteers got the same setup, but then went through 40 minutes of stressful activities. They ranged from having to prepare and give a videotaped speech to dealing with difficult word problems and doing an exercise involving accurately drawing mirror images.
In all 70 subjects, triglyceride levels declined more quickly in the restful situation than when they were doing the stressful tests. On average, fat levels fell by 2.8 percent per minute during the stressful sessions, compared with 3.2 percent a minute during the restful sessions.
In some people, the difference in fat-clearing rates during stressful and restful times was dramatic, while in others, the difference was small, reflecting individual differences in how people metabolize fat, Stoney said.
But the consistency of effect was still striking. "During stress, people are not metabolizing fat as rapidly and efficiently," she said.
At restful times, the study also found, women cleared fats more quickly than men did. But the researchers found no difference in the rates of clearance during stress.
They also found no difference in fat-clearance rates among women who had undergone menopause, or between post-menopausal women who were or were not taking hormone-replacement therapy.
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