Sleep Deprivation and Interruptions Can Impact Gene Function

According to a recent survey conducted by the National Sleep Foundation, almost half of Americans between the ages of 13 and 64 report that they either never or almost never get a full night’s sleep during the work or school week. As is the case with many people who do shift work, travel for business, or have disrupted sleep schedules for other reasons (such as college students), the solution that many of these sleep deprived people turn to is daytime naps that they believe compensate for their lack of sleep. Some companies are even setting up nap rooms to allow their workers to take short breaks to offset their late night hours. Unfortunately, a new study is revealing that this kind of disrupted sleep schedule may be doing a tremendous amount of unseen physical damage. A new report out of the Sleep Research Centre at the University of Surrey in the United Kingdom has been written with a focus on understanding the impact of sleep deprivation and sleep disruptions. The study indicated that any kind of disrupted sleep pattern, and especially ones that involved napping during the day and keeping late hours at night can actually impact the way that your genes function. These results should be of particular interest to shift workers, hard-driven workaholics, business travelers who chronically cross multiple time zones, and college students. The test was conducted over a three-day period. Researchers created intervals during which they disrupted the study participants’ sleep and then took blood samples for analysis so that they could look into what kind of effect the sleep patterns would have on the genes. They found that in one third of participants, the genes showed a negative impact.  The study was conducted in a special sleep lab that utilized lights to manipulate bedtimes by four hours each day until all participants were out of sync with their natural biological clock by twelve hours. This achieved the same physical effect as jet lag or shift work. The blood tests showed a decrease in gene expression. Research has already shown that disrupted gene expression impacts circadian rhythms, metabolism, immune response, inflammation and stress. The genes are responsible for releasing information about when to manufacture the proteins that control all of the body’s chemical signals, so when they are not functioning properly, there are direct health implications. The study was published in a journal called Proceedings of the National Academy of Sciences (PNAS), and scientists are optimistic that its results will help solve some of the mysteries regarding the relationship between sleep deprivation and interruption and the negative health effects that they had already been linked with, including diabetes, cancer, heart disease and obesity. It is well established that shift workers and others who suffer from chronic sleep deprivation have a high risk for stroke and early death. It has also been proven that establishing a regimented sleep routine can improve health and help people with weight loss. Similarly, lack of exposure to enough light has been linked to early death and mental health disorders such as depression.  With the results of this study, the link may now be explained. According to Derk-Jan Dijk, leader researcher, director of the Sleep Research Centre and professor of Sleep and Physiology, “This research may help us to understand the negative health outcomes associated with shift work, jet lag, and other conditions in which the rhythms of our genes are disrupted.” Other similar studies and statements support these findings, including a statemet issued last year by the American Medical Association (AMA) warning of the physical impact caused by nighttime electric light. The policy statement linked problems with sleep patterns directly to light exposure at night and other related health problems, saying that the lights disrupted circadian rhythms and that it seemed to be having a “direct link to human health, such as cell cycle regulation, DNA damage response, and metabolism.” This statement came shortly after the publication of research that indicated that those who worked shift work at night under bright electric lights ran a higher risk of being diagnosed with breast cancer. According to research published in  Chronobiology International, scientists from the Danish Cancer Society and Yale University determined that they had found biological changes impacting gene expression in women who performed shift work. The exact same gene expression was found in women with breast cancer. And as long ago as 2007 the International Agency for Research on Cancer warned that working late shifts was likely a “human carcinogen.” The study that was conducted in the United Kingdom was small as compared to the other studies cited here, as well as studies previously conducted by the same researchers. However, the results gleaned from the 22 subjects in this most recent study were similar to larger studies done in the past. There is no doubt that long work days, disrupted exposure to natural light and overexposure to electric light, and disrupted sleep patterns are taking an extreme toll on human health. Unfortunately, despite the increasing evidence that these activities are creating very real and possibly irreversible health risks, there is little likelihood that any of the phenomena behind these activities are likely to come to a halt. Business people will continue to have to travel to distant continents, factories will continue to operate 24 hours a day, and college students will continue to stay up late and then nap during the day. Though it seems counterintuitive to think that medical science will need to come up with a solution for the damage that has been done rather than having people change their behavior patterns, it is probably the only way to put a stop to any physical damage being done.