Jetting off without the jet lag

Everyone hates the jet lag — the nighttime insomnia, loss of appetite, decreased alertness, and depressed mood — that accompanies travel to locations in different time zones. The symptoms of jet lag are caused by misalignment of a person's internal body clock (also known as the circadian clock) and external time. Now, Gregor Eichele and colleagues, at the Max Planck Institute for Biophysical Chemistry, Germany, have provided new insight into the molecular mechanisms responsible for resetting the internal circadian system in the mouse. One of their key observations indicates that modulating the speed with which the adrenal gland shifts its rhythmic production of glucocorticoid hormones to the new light/dark cycle (the equivalent of the new time zone when considering human travel) regulates the resetting of the entire internal body clock. The authors suggest that their data point to new potential therapies to overcome jet lag. In an accompanying commentary, Mary Harrington, at Smith College, Northampton, discusses how these data have implications not only for those who suffer jet lag but also for those who perform rotating shift work, which has been linked to many serious health problems, including breast cancer, stroke, and cardiovascular disease. She also cautions that it will be important to determine whether treatments for jet lag that allow the body clock to shift rapidly are actually better for one's health than the slower adjustments that occur naturally.

Source: Journal of Clinical Investigation