Sleep for a few hours will be short-lived?

In the end we need to sleep much during the day and often sleepy head venting or Monday morning it is always difficult to get out of bed if it is the case, you will conclude that: my lack of sleep!Lack of sleep brought harm, I believe we are all familiar: the lack of energy, unresponsive, memory loss, reduced immunity and even premature aging body。
The most common argument is that an adult should have the sleep time is 7-8 hours, but an experiment at the University of California, the United States has come to a sensational conclusion: sleep eight hours a day will make you die faster。
Zaoshuizaoqi good sleep for a few hours will be short-lived?The experimental six-year period, jointly conducted by the University of California San Diego School of Pharmacy and the American Cancer Society。 They range from 102-year-old and 30-year-old target of one million of age were observed。 In this experiment, the subject's age, medical history, health, etc. have been taken into account, they are now with their physical condition similar objects for comparison。
Only six or seven hours of sleep a day who sleep more than eight hours a day than, or less than four hours of people is much lower mortality rate。 Wherein the person slept 7 hours per day lowest mortality, and even human sleep five hours, this factor should be less than eight hours of sleep enough people。