For those of you who can’t get enough of flying around the globe for business, here is a timely reminder to take it easy. A US study has shown that jet-lagged mice die younger.

Tests on more than 100 mice at the University of Virginia showed that old mice forced to live on a confusing schedule of light and darkness, simulating rotating shifts or international travel, died sooner than those on gentler schedules. One group had its light/dark cycle shifted forward by six hours. A second group had its schedule shifted back by six hours, and the third group’s schedule was unaltered.

The study found that 83 percent of old mice survived under the normal schedule, 68 percent lived after eight weeks of shifting steadily backward, but fewer than half – 47 percent – survived when the lights regularly came on six hours earlier. When they sped up the schedule, changing the light schedule every four days, even more mice died. Time to grab the melatonin, folks.