The National Institute of General Medical Sciences defines the circadian rhythm by our behavioral changes that follow a twenty-four-hour cycle heavily influenced by light and dark periods (NHS.GOV). Whether these changes are physical, mental, or behavioral, our circadian rhythm is critical for our survival as a species. The most important way of maintaining an efficient circadian rhythm pattern is by having a consistent sleep schedule, as explained by the scientists at Rensselaer Polytechnic Institute. Your body can adequately enter Delta (slow-wave) sleep by having a consistent sleep schedule. This sleep cycle is the most crucial out of them all, for it is when your body achieves maximum restoration and when your mind can sufficiently rest.
But what else does our body’s circadian rhythm do for us? Well, scientists at the Rensselaer Polytechnic Institute have uncovered a possible correlation between Alzheimer’s disease symptoms and our circadian rhythm. Essentially, they have discovered that “the circadian system is composed of a core set of clock proteins that anticipate the day/night cycle by causing daily oscillations in the levels of enzymes and hormones, ultimately affecting physiological parameters such as the immune response” (RPI). Furthermore, diseases such as Alzheimer’s and diabetes become far more prevalent when the circadian rhythm is interrupted.
So then, what exactly happens on the molecular level? How does disruption of the circadian rhythm influence diseases such as Alzheimer’s? As we’ve learned through the Immune System unit, macrophages engulf unwanted foreign invaders, which is one of the most critical aspects of our immune system. In the case of Alzheimer’s, one telltale is the formation of extracellular clumps of AB42, the 42 amino acid form of amyloid-β, around the brain which macrophages would typically engulf through phagocytosis (NIH.GOV). Further, “the researchers noticed oscillations in enzymes that help to make two proteins on the macrophage cell surface — heparan sulfate proteoglycan and chondroitin sulfate proteoglycan- both of which are known to play a role in regulating clearance of AB42” (RPI). As explained in the previous paragraph, if a disruption of the circadian rhythm affects our body’s immune response, this indeed entails that a disease like Alzheimer’s would only worsen over time, assuming that no regulation of the circadian rhythm would take place.
The findings seem promising, especially for a disease like Alzheimer’s which has no known cure yet. Only medicines that reduce symptoms are currently in circulation which just isn’t sufficient especially since Alzheimer’s is a prominent issue within older citizens. If scientists are able to further utilize this knowledge to help prevent Alzheimer’s from reaching high severity, then hopefully the lives of many will be improved and Alzheimer’s can be a disease of the past!