The notion that being stressed out on the job causes high blood pressure doesn’t hold up, according to a new analysis of studies involving more than 100,000 people.

“There’s no doubt that in the moment stress raises blood pressure,” the study’s author, Dr. Samuel J. Mann of Weill Cornell Medical College in New York, told Reuters Health. But there’s virtually no evidence, he said, that such stress leads to chronic high blood pressure, or hypertension. “They’ve been trying to prove that for 40 years.”

While job stress can certainly affect health in some ways, he added, blood pressure isn’t one of them. “There’s a robust relationship between job stress and things like tension headaches, anxiety, depression,” Mann said. “If somebody is having all that and having headaches every day, can’t sleep and is anxious, then that’s a person who should change his job.”

Mann conducted his review after the 2003 publication of a well-designed study by French researchers that found no link between job stress and hypertension.

In the current analysis, he looked at 48 studies claiming to support such an association. Many, Mann found, had serious flaws -for example, only basing the findings on diastolic pressure (the lower number in a blood pressure reading) rather than systolic pressure.

Others only found a stress-hypertension association in a small subgroup of individuals studied, and such subgroups varied from study to study. Still others looked at several variables measuring stress and found only one of them was linked, weakly, with hypertension, and played up this finding rather than the negative ones.

“After decades of research,” Mann concludes in his report in Current Hypertension Reviews, “the evidence for a relationship between job stress and blood pressure is weak.”

Studies have tied stress to heart disease, Mann noted, but hypertension is not likely to be the contributing link. Instead, he added, stress might boost high blood pressure risk by leading people to overeat, gain weight and abuse alcohol.

While Mann says he’s not categorically denying that job stress could cause hypertension in some people, it’s role is likely small. About 40 percent of hypertension is due to genetics, and another 40 percent to overweight, poor diet, salt intake and lack of exercise - leaving about 20 percent available for other causes, he explained.

“If somebody has hypertension and they don’t like their job, medically there’s no reason to tell them to quit their job because it adversely affects their blood pressure.”

SOURCE: Current Hypertension Reviews, May 2006.