The study documented sleep habits including the use of sleeping
pills of more than a million men and women ranging in age
from 30 to 102. Surprisingly, people who reported themselves
insomniacs were not found to have any increased risk of mortality,
but the use of sleeping pills was associated with an increased
mortality of 25 percent.
The average American sleeps six and a half hours a
night, said Daniel F. Kripke, a professor of psychiatry
at UCSD, and the head of the research group. People
who sleep five, six, or seven hours are perfectly safe.
However, the National Sleep Foundation, which recommends
eight hours of sleep, challenged the study. Although
sizable, the study population [friends and relatives of American
Cancer Society volunteers] is not a random sample and does
not represent the entire population, said an NSF representative.
The NSF argues that the study does not identify geographic
and racial factors of the study group.
The idea that sleeping less will lead to longer life cannot
yet be proven; In fact, some other studies seem to contradict
A new study presented at the annual meeting of the American
Diabetes Society suggests that healthy young people who regularly
sleep less than 6.5 hours a night had greater insulin resistance
than people who have 7.5 to 8.5 hours of sleep at night, according
to an online article published by About.com. Insulin resistance
is the condition that often leads to Type 2 diabetes. Less
sleep in this case could increase the risk of mortality.
Students must not use these findings of either study as a
rationalization for study shortcomings. These studies do not
mean that we need less or more sleep. A higher risk for accidents
and weakening of the immune system are still associated with
inadequate sleep. However, these studies might eventually
change the notion of adequate sleep equals eight hours.