24-Hour Lighting May Disrupt Newborn's Bio-Clock

Mouse study suggests it could have negative long-term effects

MONDAY, Aug. 21, 2006 (HealthDay News) -- Constant exposure to the lights in neonatal intensive care units could upset the development of premature babies' biological clocks, a new study suggests

The study found that exposing baby mice to constant light prevented the master biological clock in their brains from developing properly. That could have long-term behavioral consequences, the U.S. researchers say.

They noted that about 14 million low-weight babies are born worldwide each year and are exposed to artificial lighting in hospitals.

"We are interested in the effects of light on biological clocks, because they regulate our physiology extensively and also have an important effect on our mood. This study suggests that cycling the lights in NICUs may be better than constant lighting for premature babies from the perspective of developing their internal clocks," study head Douglas McMahon, professor of biological sciences at Vanderbilt University in Nashville, Tenn., said in a prepared statement.

The study was expected to be published Monday in the journal Pediatric Research.

The findings in this study of baby mice help explain the results of several previous studies, the researchers said. One of those studies found that babies in neonatal units with day/night cyclic lighting tended to begin sleeping through the night more quickly than babies in units with constant lighting.

Other studies found that babies in units with day/night cyclic lighting gained weight faster than babies in units with constant lighting.

More information

The Society for Neuroscience has more about biological clocks.

SOURCE: Vanderbilt University, news release, Aug. 21, 2006
Consumer News