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The body's internal clock is naturally aligned with the day-night cycle but circadian rhythms can be altered by exposure to light at night, lack of daylight from travel, work, electronic devices, or an underlying problem. During the day, exposure to light causes the internal clock to send signals that generate alertness and help keep us awake and active. As night falls, the internal clock begins the production of melatonin, which promotes sleep.

We must maintain a healthy circadian rhythm by maintaining a consistent sleep schedule, exposing ourselves to light, and exercising daily. The use of artificial light in our homes and electronic devices has led more people to report less sleep at night, as well as irregular sleep patterns. During sleep, our cells use the rest period to repair damaged cells and regenerate new cells after apoptosis.

Abnormal circadian rhythms as a potential carcinogen, which has increased focus on defining the underlying mechanisms of circadian disruption-induced tumorigenesis.

The CLOCK gene (Circadian Locomotor Output Cycles Kaput) is one of the circadian clock genes and is considered a fundamental regulatory gene of the circadian rhythm, responsible for mediating several biological processes. Therefore, abnormal expression of CLOCK affects its role in the circadian clock and its more general function as a direct regulator of gene expression. This dysfunction can lead to serious pathological effects, including cancer.

Circadian rhythm disruption has been shown to be associated with an increased risk of developing obesity and obesity-related diseases and is closely related to tumorigenesis in breast cancer, prostate cancer, colorectal cancer, pancreatic adenocarcinoma, liver, lung cancer, kidney cancer and others associated with elevated lipid levels and attenuated lipid signaling, inflammatory responses, insulin resistance and adipokines.

An alteration of the biological clock has been detected in obesity, which causes an increase in the expression of inflammatory cytokines, which is aggravated by the disease itself. Furthermore, disruption of the circadian rhythm could contribute to metabolic dysfunction of adipose tissue, thus increasing the risk of developing cardiometabolic diseases.

The interplay between circadian rhythm and cancer involves the regulation of cell division, DNA repair, immune function, hormonal balance, and the potential for chronotherapy. Circadian rhythm disturbances can promote abnormal cell development and tumor metastasis, possibly due to immune system imbalances and hormonal fluctuations.

Dysfunctions in the 24-hour circadian rhythm are a common occurrence in older adults and are more severe in people with age-related neurodegenerative diseases, including dementias related to Alzheimer's disease and Parkinson's disease. Manifestations differ depending on the type and severity of the neurodegenerative disease and, for some patients, occur before the onset of typical clinical symptoms of neurodegeneration.

https://www.sleepfoundation.org/circadian-rhythm (2023).----

https://link.springer.com/article/10.1007/s10549-022-06792-0 (2023).---

https://www.sciencedirect.com/science/article/pii/S1044579X23000366 (2023).---

https://undergradsciencejournals.okstate.edu/index.php/MRCMB/article/view/17654 (2023).--

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10069698/ (2023).---

https://www.mdpi.com/2072-6694/15/2/408 (2023).--

https://www.tandfonline.com/doi/abs/10.1080/13813455.2021.1988110 (2024).--

https://www.mdpi.com/1422-0067/25/11/5846 (2024).--

https://www.nature.com/articles/s43018-024-00759-4 (2024).--

https://link.springer.com/chapter/10.1007/978-981-99-3746-2_25 (2024).--

https://www.nature.com/articles/s41420-024-01960-1 (2024).--

https://www.sciencedirect.com/science/article/abs/pii/S0167488924001253 (2024).--

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This is why obesity is a disease of light more than it is due to food:

https://romanshapoval.substack.com/p/thelightdiet

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