Despite scientists knowing of an internal body clock for many years, the general populace is still out of the loop when it comes to the importance of this clock. This internal clock is called the circadian rhythm, and modern research is beginning to uncover its importance in many bodily functions. Generally speaking, the circadian rhythm is simply a twenty-four-hour loop that is endogenously regulated but can be affected by external factors like daylight and temperature. Researchers like Kanyan Xu are leading the effort in investigating the effects of the circadian rhythm on our metabolism. This link has been covered in the New York Times by writer Anahad O’Connor, and he elaborates on the connection between the circadian rhythm and time-restrictive eating, also commonly known as time-restrictive fasting. The benefits of time-restrictive fasting are becoming very trendy in pop-science culture, as it is becoming a popular option for dieting. While the sensationalized claims of “eat anything you want for an eight-hour window and lose weight” commonly seen with trending times is overblown, the scientifically proven effects of time-restrictive fasting are undeniable.
In his study, Kanyan Xu argues that the circadian clock of Drosophila is “regulated by clocks in digestive/metabolic tissues”(Xu et al., 2008) and also by “neuronal clocks” (Xu et al., 2008). Put more plainly, these tissues, specifically those found in the fat body, regulate our circadian clocks. When these tissues were removed, animal tended to “display increased food consumption but have decreased levels of glycogen and a higher sensitivity to starvation.”(Xu et al., 2008). He also presents neuronal clocks as another moderator of the circadian rhythm and suggests the interplay between the digestive tissues and the neurons “provide effective energy homeostasis.”(Xu et al., 2008). The results of his study confirm these proposals while also finding interesting links between the circadian clock and feeding rhythms. They confirmed flies feed in a rhythmic fashion even in complete darkness. He also states: “A number of environmental stimuli such as temperature, light, and food availability exhibit rhythmic patterns, which vary in a circadian or seasonal fashion.”(Xu., 2008). Importantly, these environmental factors can be easily controlled by humans and this revelation begins to show how humans can take control of their feeding habits and circadian clocks. Finally, Xu’s findings “indicate the importance of connections between different clocks in regulating behavioral rhythms and other physiological functions.”(Xu et al., 2008). The importance of this finding is that our circadian clocks are not simply determined by a few groups of cells, but rather exist as a combination of inputs from a vast amount of cell groups, including digestive cells and neurons. Xu then links his studies to the mammalian SCN which serves as a “main clock” to coordinate the other clocks to light. This connection to mammals and their responsiveness to light serves as a preview to what is discussed in the New York Times article.
In his article, Anahad O’Connor details the work done by Satchin Panda, Courtney Peterson, and Paolo Sassone-Corsi about the circadian clock and its relation to weight gain in humans. He begins by introducing the concept discussed Xu’s study, saying: “our bodies function optimally when we align our eating patterns with our circadian rhythms”(O'Connor, Anahad. “When We Eat, or Don't Eat, May Be Critical for Health.” The New York Times, 24 July 2018). He then lists the struggles that come with eating against the grain of our internal clocks, saying weight gain becomes far more likely. O’Connor lists the common issues found in the average eating schedule, saying most people overload their calories towards the end of the day, and eat within a fifteen-hour window. He then gets a contribution from Dr. Satchin Panda of the Salk Institute who proposes “people improve their metabolic health when they eat their meals in a daily 8- to 10-hour window”(O'Connor, Anahad. “When We Eat, or Don't Eat, May Be Critical for Health.” The New York Times, 24 July 2018). Thus, most people eat across a far larger time window than they should per day, and this could be a contributing factor to rising weight gain across the world. Dr. Panda then describes the evolutionary origins of the circadian rhythm. O’Connor then speaks to Dr. Courtney Peterson from the University of Alabama at Birmingham about the benefits of “consuming the bulk of your food earlier in the day”(O'Connor, Anahad. “When We Eat, or Don't Eat, May Be Critical for Health.” The New York Times, 24 July 2018). O’Connor then elaborates on the negative symptoms associated with working a night shift, specifically “obesity, diabetes, some cancers and heart disease.”(O'Connor, Anahad. “When We Eat, or Don't Eat, May Be Critical for Health.” The New York Times, 24 July 2018). He then describes a human experiment by Dr. Peterson in which two groups of men had their eating patterns controlled and monitored. One group had a twelve-hour window and the other had a six-hour period beginning in the morning. The results were very promising, “On the time-restricted regimen, the men had lower insulin, reduced levels of oxidative stress, less nighttime hunger and significantly lower blood pressure.”(O'Connor, Anahad. “When We Eat, or Don't Eat, May Be Critical for Health.” The New York Times, 24 July 2018). O’Connor then concludes the piece by summarizing the main argument, eating a large breakfast followed by progressively smaller meals.
The findings presented in Xu’s study and O’Connor’s article come to similar conclusions. While studied in different species, the studies presented in the New York Times showed similar results to the healthy, rhythmic eating flies seen in Xu’s study. Just as Xu’s study found deregulating the clocks led to abnormal and sometimes unhealthy phenotypes, humans who eat without a rhythm over a long time period are more susceptible to serious health complications. The findings in each of these studies benefit each other as well. The controlled deregulation of the smaller clocks in humans could be done with technological advancements and more research to be sure its ethical. These findings can also contribute to general mammalian circadian studies as they can further test the adverse health effects to understand why they are ocurring. Overall I believe a shift towards a circadian focused diet would help in the general health of the world. The amount of scientific backing that the healthiest option is eating your largest meal early is becoming overwhelming. Studies like Dr. Xu’s and Dr. Peterson’s display the risks of breaking the circadian clocks feeding patterns, while also showing the positives of adopting a time-restrictive diet.
Works Cited
O'Connor, Anahad. “When We Eat, or Don't Eat, May Be Critical for Health.” The New York Times, 24 July 2018, www.nytimes.com/2018/07/24/well/when-we-eat-or-dont-eat-may-be-critical-for-health.html.
Xu, Kanyan et al. “Regulation of feeding and metabolism by neuronal and peripheral clocks in Drosophila” Cell metabolism vol. 8,4 (2008): 289-300. https://www.cell.com/cell-metabolism/fulltext/S1550-4131(08)00290-8?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1550413108002908%3Fshowall%3Dtrue
No comments:
Post a Comment