All living creatures throughout evolution have developed biological clocks to better adapt to the 24 hour day called the Circadian Rhythm. These are called Circadian Clocks and they regulate physiology, metabolism, and behavior. In humans, many aspects of physiology are subject to circadian regulation. These include sleep-wake cycles, cognitive performance, cardiac and renal functions, digestion and detoxification. Overall, about 10% of all genes express in a Circadian manner. These peripheral genes, sometimes referred to as peripheral oscillators, are controlled by the master clock located in the brain.
It has been known for over 40 years that all humans have such a master clock built into their bodies, controlling numerous functions, such as when hormones are released, the level of one’s appetite, metabolic functions, mood, and cardiovascular health. The master clock regulates a myriad of cellular, physiological, and behavioral 24 hour rhythms. This master clock is located in the hypothalamus of the brain, at a spot called the superchiastmatic nucleus (SCN). This location is on top of the optic nerves, allowing it to sense light and dark!
There are also clocks in most of the cells of our bodies called peripheral clocks, and all are regulated by our genetics by what are called clock genes!
The discovery of clock genes has led to a revolution in our understanding of how Circadian Rhythms are generated in individual cells. Light signals detected by the eyes are interpreted by the SCN which then sends out synchronization signals to other cells of the body via hormone secretion, sympathetic innervation, and indirect cues such as body temperature, feeding times , and activity rhythms. The regulation of these clock genes is extraordinarily complex, involving many types of receptors and proteins for signaling, and also include hormone receptors such as glucocorticoids (like cortisol), thyroid, and estrogen.
Women with PCOS have documented dysfunction of their Circadian Rhythm systems. They simply do not keep proper time by the master clock in the brain, nor synchronize all the cells of the body as they should. Circadian disruption is associated with insulin resistance and obesity, as well as with intestinal problems, and mood and cognitive issues. A broken clock increases one’s risk for cancer, a heart attack, a stroke, and dementia. But do not get all stressed out! Over the upcoming months, I will take you through the issues of the Circadian Rhythm as they relate specifically to PCOS, discuss the special clocks within us all, and explain in-depth how they relate to gut health, sleep, mood, the immune system, the cardiovascular system and more!
So stay tuned! We have a great journey ahead of us, as we explore the nature of our biological rhythms, how we can work to get them working properly again, and aid you in your quest to return to a state of optimal health and happiness!
*This is a repost of a guest post Dr. Gersh orginally posted on PCOS Diva at: http://pcosdiva.com/2016/05/resetting-clock-series-part-1-circadian-rhythm/
