We know that working too many hours on too little sleep can be dangerous. Teaching hospitals have the latest technology and the most up-to-date facilities, but they are also staffed by residents in training who may be working long swing shifts and haven't had a good night's sleep in days. Third shift factory workers have more accidents than their daytime counterparts, even when their shifts never change. There's something in our bodies that craves a regular amount of sleep during nighttime hours, even when modern life encourages us to fight against the clock to squeeze more into a 24-hour day. Scientists, called chronobiologists, at the University of California at San Diego's Center for Circadian Biology are studying how time affects our bodies and our health.
All across the UCSD campus, members of the Center for Circadian Biology—which does not have its own building— are researching these timekeeping functions. Among their findings: Genes that run our circadian rhythms are linked to metabolism and its control networks. Mess with one and you mess with the other. For example, eat too late in the evening, when your metabolic defenses have powered down, and your chances of growing obese balloon. In turn, that fat can also invade your liver and thus increase your likelihood of inflammation and cancer.
Our mental health is also at risk. Researchers have found that 70 percent of people with disorders that keep them from sleeping at the usual time—possibly due to a genetic abnormality—suffer from conditions like severe depression or anxiety. In fact, nearly two-thirds of bipolar sufferers report abnormal sleep cycles.
Already, doctors treating cancer have used chronobiology’s findings to better plan their treatments. For example, undergoing chemotherapy later in the day increases patients’ chances of avoiding nausea because stomach linings better repair themselves at that time.