Editorial in journal Sleep cites evidence of longer life with 6 to 7 hours sleep

The best survival rate is experienced by people who sleep 7 hours, rather than 8 or more, or less than 4.5 hours, according to an editorial in the February 2004 issue of the journal SLEEP by Daniel F. Kripke, M.D., professor of psychiatry, University of California, San Diego (UCSD) School of Medicine.*

The editorial, titled "Do We Sleep Too Much?" comments on a study by A. Tamakoshi and Y. Ohno in the same issue of the journal**, as well as the results of two other studies: the Nurses' Health Study (NHS) in the Archives of Internal Medicine (2003;163:205-209), and the Cancer Prevention Study II by Kripke, that was reported in the Archives of General Psychiatry (2002; 59: 131-136).***

See the web sites below for a synopsis of current articles in SLEEP and a news release about the 2002 Kripke study that surveyed more than one million adults.

* http://www.journalsleep.org/Editorials2004/SleepTooMuch.pdf
** http://www.journalsleep.org/citation/sleepdata.asp?citationid=2317
*** http://health.ucsd.edu/news/2002/02_08_Kripke.html

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