Sleeping Yourself Healthy

Disruption of our natural circadian rhythm, the internal biological clock that numerous epidemiological studies suggest we all have programmed into us to a considerable degree, may lead to increased risk of diabetes and obesity. In an attempt to reach beyond these epidemiological accounts, a newer study actually examined humans in a controlled lab environment over a prolonged period, and systematically altered the timing of sleep, mimicking modern day disruptions like shift work or recurrent jet lag.

The study was conducted using 21 healthy participants, who were housed  in a completely controlled environment for nearly six weeks. The researchers controlled how many hours of sleep participants got, when they slept, their daily activities and diet. Participants started with getting optimal sleep—approximately 10 hours per night—in order to establish an effective baseline.

This was followed by three weeks of 5.6 hours of sleep per 24-hour period, and with sleep occurring at all times of day and night. Consequently, there were many days when participants were trying to “force” sleep at unusual times within their internal circadian cycle. The study closed with the participants having nine nights of recovery sleep at their usual time.

Results indicated that prolonged sleep restriction combined with simultaneous circadian disruption decreased the participants’ resting metabolic rate. Moreover, during this period, glucose concentrations in the blood increased after meals as a result of decreased insulin secretion by the pancreas. According to the researchers, an altered resting metabolic rate such as this could translate into a yearly weight gain of over 10 pounds if diet and activity remain unchanged, while consistently increased glucose concentration and poor insulin secretion could lead to an increased risk for diabetes.

“We think these results support the findings from studies showing that, in people with a pre-diabetic condition, shift workers who stay awake at night are much more likely to progress to full-on diabetes than day workers,” said Orfeu M. Buxton, PhD, Brigham and Women’s Hospital, and lead study author. “The evidence is clear that getting enough sleep is important for health, and that sleep should be at night for best effect.”

Those of us who have trouble getting to sleep or getting enough sleep are advised to begin unwinding well in advance of our planned bedtime–turning off televisions, computers and other electronic stimuli in exchange for a little light reading, preferably in a reclined position. If sleep is especially problematic, a naturally-based supplement might help to reassert the circadian rhythm we’re all born with.