The Case for Sleep Medicine
By GAYLE GREENE
The risks of sleeping pills are real, as I well know, having taken them for three decades. But so are the risks of chronic sleep loss. As the pioneering sleep scientist William Dement has argued, sleep is “the most important predictor of how long you will live — perhaps more important than smoking, exercise or high blood pressure.”
Sleep deprivation ratchets up the stress system, leaving you more susceptible to even relatively mild sources of strain. When University of Chicago researchers led by Eve Van Cauter deprived young, healthy people of a few hours of sleep for six nights, they produced in them the hormonal profiles of much older people: higher levels of stress hormones and lower levels of growth hormone (essential to cell repair). The study’s participants developed hormonal imbalances conducive to weight gain and levels of insulin resistance like those of people with diabetes.
Loss of sleep also compromises immune resistance and leaves you more vulnerable to everything from the common cold to cancer. In a University of Chicago study led by Karine Spiegel, participants whose sleep was restricted to four hours a night for six nights had, when vaccinated for influenza, less than half the immune response of those who had slept well. Michael Irwin and colleagues at the University of California, Los Angeles found that even modest sleep loss — only one night, between 3 and 6 a.m. — significantly reduced white blood cell activity, a crucial line of defense against infection and cancer.