Send your comments and tips to firstname.lastname@example.org
Beth Israel Deaconess Medical Ctr.
Boston Medical Center
Brigham and Women's Hospital
Cambridge Health Alliance
Caritas St. Elizabeth's Medical Ctr.
Children's Hospital Boston
Dana-Farber Cancer Institute
Joslin Diabetes Center
Mass. General Hospital
Mass. Health Law
New England Baptist Hospital
Short White Coat
Tufts-New England Medical Center
UMass Memorial Medical Center
University of Massachusetts
VA Medical Centers
A Healthy Blog
Running A Hospital
Nature Network Boston
SciBos - Corie Lok's blog
Nurse at small
Dr. Gwenn Is In
Healthy Children blog
Other Globe Blogs
Elizabeth Cooney is a health reporter for the Worcester Telegram & Gazette.
Boston Globe Health and Science staff:
Karen Weintraub, Deputy Health and Science Editor, and Gideon Gil, Health and Science Editor.
Short White Coat blogger Ishani Ganguli
Short White Coat blogger Jennifer Srygley
Monday, May 14, 2007
Bright lights, big sleep for Mars -- and Earth, too
Two bursts of bright light in the evening help the brain's clock adapt to a longer day, sleep researchers at Brigham and Women's Hospital report, something important for astronauts traveling to Mars but also for earthbound travelers, shift workers or other people whose internal clocks are out of synch.
"Utilization of bright-light exposure could work whether you're going to Mars or Los Angeles," Dr. Charles Czeisler, chief of sleep medicine at Brigham and Women's Hospital, said in an interview.
Czeisler, Dr. Richard E. Kronauer of Harvard and colleagues from the University of Lyon and the University of Colorado conducted a study for NASA's National Space Biomedical Research Institute that appears in today's Proceedings of the National Academy of Sciences.
They set out to solve the problem of what could be perpetual jet lag-like fatigue on an eventual year-and-a-half-long mission to Mars, a plan announced by President Bush in 2004. The Martian day is 39 minutes and 35 seconds longer than a day on Earth -- which doesn't seem like much at first, but adds up to more than four hours in just one week.
The researchers sequestered 12 healthy people in rooms with no time cues for 65 days. First they observed their individual internal clocks, finding a range of differences in the timing of when their bodies released melatonin. Some people were releasing the sleep-promoting hormone as much as five hours before bedtime while for others it was an hour ahead.
"This may explain why some individuals feel so tired in the evening," Czeisler said. "It's as if people are in different time zones, like England and Boston. Their internal clocks are spread out over many time zones.
Over the next 30 days, the participants were exposed to a longer day under varying amounts of light. Those who got two 45-minute sessions of bright light in the evening were able to adapt their sleep/wake cycles to a longer-than-24-hour day.
"These results suggest that people could be treated for sleep disorders" in this way, Czeisler said.