A short night's sleep can leave you groggy and unhappy the next day, but a lifetime of short nights can have graver consequences. We are living in a 24/7 society, and sleep deprivation has become an epidemic, especially for teens and the workforce.
Now there is substantial evidence that sleep deprivation is associated with increased risk for diabetes, obesity and other chronic illnesses. Considering that chronic diseases are the leading causes of death and disability in the U.S., we should stop treating sleep as a sacrificial luxury and instead insist on it as an essential part of a healthy lifestyle.
How much sleep is enough? The National Sleep Foundation recommends that adults get seven to nine hours of sleep each day. Children need even more. Yet, according to the CDC website "nearly 30 percent of adults reported an average of 6 hours or less of sleep per day," (National Health Interview Survey data, 2005-2007), and less than one-third of high school students in 2009 said they slept at least eight hours on an average school night.
I recently co-authored a study with other researchers at the Harvard School of Public Health, Brigham and Women's Hospital and Harvard Medical School that looked at rotating night shift workers -- a group of people whose work schedule puts them constantly at odds with their natural circadian sleep rhythms. This is the hormonal, light-sensitive rhythm that cycles within us, nudging us to sleep at nighttime and prodding us awake at sunrise. Our large study showed that women who worked rotating night shifts for three to nine years had a 20 percent increased risk for Type 2 diabetes. Women who did shift work for 10 to 19 years experienced a 40 percent increased risk. Women who did shift work for more than 20 years faced an even higher increased risk -- 58 percent.
Our research has suggested that people who do shift work tend to smoke, eat unhealthy diets and exercise less. They also are more likely to experience sleep deprivation. Shift workers battle their circadian rhythms, which influences blood pressure, heart rates and blood sugar regulation. If disrupted by sleep deprivation, these functions can be impaired. That's the reason why shift work has been associated with long-term increased risk of hypertension, diabetes, and even cardiovascular disease.
With almost 15 million Americans working full time on evening, night, rotating or other irregular schedules, shift work is not going away and has become indispensable in some sectors. But the increased health risks these workers face offer us all lessons in chronic illness prevention.
• We need to encourage worksite health education that emphasizes the importance of sleep, healthy diet and exercise, as well as the early detection and management of risk factors that contribute to chronic illnesses. These approaches would be particularly important for shift workers, whom we should treat as a high-risk group for obesity and diabetes.
• We need to stop equating sleep deprivation with productivity. In fact, we sacrifice sleep to watch TV, spend time at the computer and play video games. Evidence suggests that sleep deprivation can induce hunger hormones that boost our appetites. When we are fatigued and hungry, we tend to eat high-calorie and sugary foods.
• We need to fund more sleep studies, which can help us better understand the role of sleep in physical and mental health and develop preventive strategies.
• And we need to balance our work schedules and personal lives and be regimented about adhering to healthy behaviors.
Increasing the quantity and quality of our sleep hours may be an important strategy for reducing risk for diabetes, obesity and other chronic diseases. On Sunday, March 11, when we "spring" forward and lose an hour of sleep due to daylight saving time, keep in mind that one step toward protecting your health may be no farther than your pillow.
Dr. Frank Hu will be participating in a live webcast event, "Fighting the Clock: How America's Sleep Deficit is Damaging Longterm Health," on Tuesday, March 6, from 2 p.m. - 3 p.m. ET. The event is presented by The Forum at Harvard School of Public Health in collaboration with The Huffington Post and can be watched at www.ForumHSPH.org and at huffingtonpost.com/healthy-living.
For more by Frank B. Hu, M.D., Ph.D., click here.
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