Obeying the clock yields benefits for metabolism

摘要

While we can't choose our parents, we certainly can choose our friends. And just as we choose our friends, it is also a rite of passage that we break the rules that our parents set, even those that provide healthful benefits. In fact, one of the most common patterns to change with entry into adulthood is the adherence to a "normal" bedtime and disruption in the alignment between periods of activity and sleep with the natural day-night cycle. Indeed, the clock that we learn to disobey is an internal genetically programmed timepiece with near 24-h precision that originally evolved to enable the earliest forms of life on Earth to accurately anticipate the rising and setting of the sun. Importantly, there may even have been a survival benefit to this clock because, at least in plants, misalignment of endogenous period length of the clock with the environmental light cycle reduces survival and diminishes reproduction (1). Interestingly, it has recently been suspected that alignment between behavioral cycles and the light-dark cycle may also provide health benefits to humans, since at clinical and epidemio-logical levels, a strong correlation has emerged between chronic sleep and cir-cadian disruption and metabolic disease (2).