Eating at the right time of day: An underappreciated lifestyle therapy for hypertension?
Daily cycles of light and dark due to the rotation of the earth around its axis have dictated how life has evolved on Earth. Organisms have thus developed the ability to predict these 24-h cycles by developing an endogenous circadian clock, which is entrained to external cues. In mammals, circadian rhythms are controlled and generated by the central or master circadian clock located in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus in the brain . This master clock consists of multiple single-cell circadian oscillators that are synchronized to 24 h by environmental factors, primarily dark/light and also temperature and food. The retina perceives the dark/light cycle information and transmits this signal to the SCN via the retinohypothalamic tract. The SCN then transmits these inputs to peripheral oscillators located outside the SCN. Such peripheral oscillators exist in nearly all peripheral tissues such as liver, adipose, pancreas, muscle and blood. Therefore, circadian rhythms have been described for virtually all physiological and biochemical processes, including behavioural ones .