A study published Thursday casts doubt on the widely held belief that the grief of losing a loved one can shorten the lives of surviving relatives.

The research, conducted in Israel, found that parents who lose a son to war or accidential death go on to lead full lifespans despite their grief."These findings raise questions about the effect of grief as a death-provoking factor," wrote Dr. Itzhak Levav and colleagues from Hadassah Medical Organization and Hebrew University in Jerusalem.

An editorial published with the study in the New England Journal of Medicine concluded that the stress of grief is unlikely to cause illness in most people.

Some studies have found that when a spouse dies, the surviving husband or wife is also at risk of an untimely death. However, this could result from a lifetime of sharing the same hazards, such as smoking or poor diet, rather than grief.