Sleep Less or Sleep More

Sat, Aug 1, 2009

Sleep SecretsSleepLessOrMore

The following information may surprise you: the study conducted by University of California, San Diego (UCSD) reports very unusual results, which still have no final scientific explanation. Here is a publication of UCSD School of Medicine News: (the article below has been formatted for better reading)

Sleep less, live longer? Or sleep more, live longer? None of the above!

Here what study says:

  • It’s a common belief that 8 hours of sleep is required for optimal health.
  • A 6-year study of more than 1,000,000 adults ages 30 to 102 has shown that people who get only 6 to 7 hours sleep a night have a lower death rate.
  • Individuals who sleep 8 hours or more, or less than 4 hours a night, show to have a significantly increased death rate compared to those who averaged 6 to 7 hours.
  • Researchers indicated the highest mortality rates with long-duration sleep, the study could not explain the causes or reasons for this association.

Dr. Daniel F. Kripke, M.D., a UCSD professor of psychiatry who specializes in sleep research said the following:

  • We don’t know if long sleep periods lead to death.
  • Additional studies are needed to determine if setting your alarm clock earlier will actually improve your health.
  • Individuals who now average 6.5 hours of sleep a night, can be reassured that this is a safe amount of sleep.
  • From a health standpoint, there is no reason to sleep longer.”





Daniel F. Kripke, M.D., in his sleep lab at UCSD

The study, which addressed sleep issues, also indicated that participants who reported occasional bouts of insomnia did not have an increased mortality rate, but those individuals who took sleeping pills were more likely to die sooner. Here what he said:

  • “Insomnia is not synonymous with short sleep.”
  • “Patients commonly complain of insomnia when their sleep durations are well within the range of people without sleep symptoms.”
  • “Previous sleep studies have indicated that both short- and long-duration sleep had higher mortality rates”
  • “However, none of those studies were large enough to distinguish the difference between 7 and 8 hours a night, until now.”

With 1.1 million participants, this study was the first large-scale population study of sleep to also take into consideration the following variables, such as:

  • age
  • diet
  • exercise
  • previous health problems
  • risk factors such as smoking
  • longevity among the participants.

Although the study was conducted from 1982-88, the sleep results have not been available until recently due to the length of time required to input and analyze the vast amount and variety of data from the 1.1 million participants.

The figures above indicate hours of sleep for men (left) and women (right). The hazard ratio, the top bar graph, indicates the mortality risk while the bottom graph shows the percentage of subjects associated with the reported number of hours sleep.

The results of the study is astonishing:

  • The best survival rates were found among those who slept 7 hours per night.
  • The study showed that a group sleeping 8 hours were 12 percent more likely to die within the six-year period than those sleeping 7 hours, other factors being equal.
  • Even those with as little as 5 hours sleep lived longer than participants with 8 hours or more per night.
  • The mean age for women in the study was 57, while the mean age for men was 58.
  • Within the six year period, 5.1 percent of the women had died and 9.4 percent of the men.
  • The causes of death resembled the distribution for the general population.

Source: Data came from the American Cancer Society with analysis supported by the National Institutes of Health.


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