Disruptions in circadian rhythms not only cause sleep disorders, but could also put you at risk of these five health conditions

Your body knows exactly when to sleep, wake up, eat, exercise, focus on work, rest and sleep again. You might call it discipline, routine or simply how you lead your life, but this internal body clock is something that not only every human but every mammal on planet earth has. It’s known as the circadian rhythm and until a century ago, it depended largely on sunlight. What is the circadian rhythm? A study published in the journal Anesthesiology in 2015 reveals that our circadian rhythms depended on sunlight as the only source of light for thousands of years, but this changed with the invention of electrical lighting about 200 years ago. Since then, our dependence on electrical lights and gadgets that emit such light has increased exponentially (and quite creatively too), and this has led to disruptions in our natural circadian rhythms. [caption id=“attachment_8490161” align=“alignnone” width=“640”] Representational image. Unsplash@Alexandra Gorn[/caption] As per this study, and many others, disruptions in circadian rhythms can have immense effects on not just your sleep-wake cycle but also the molecular biology of individual cells and even organ systems in your body. Another study published in Biological Rhythm Research in 2016 explains how disruptions in circadian rhythms can affect your immune function, metabolism, cognitive abilities and social as well as occupational behaviour. Health consequences of disrupted circadian rhythms Clearly then, prolonged and habitual disruptions in circadian rhythms can affect your health in a big way, and these effects may not be immediately visible. This highlights the need for understanding exactly which health problems you’re at an increased risk of and what they entail. 1. Sleep disorders: According to the US National Sleep Foundation, disrupted circadian rhythms can affect melatonin production in your body, which, in turn, can lead to sleep disorders like insomnia, shift workers disorder (SWD), jet lag disorder, hypersomnia and nightmares. 2. Mental health disorders: A recent study in Translational Psychiatry says that disruptions in sleep cycles and the secretion of cortisol and melatonin are linked to mood disorders. Another study in The Lancet Psychiatry in 2018 found that circadian rhythm disruptions can also increase the risks of major depressive disorder and bipolar disorder. 3. Neurodegenerative disorders: Circadian rhythm disruptions over a long period of time affects how the hypothalamus functions, and this can lead to neurodegeneration over time. A new study in JAMA Neurology found that circadian rhythm disruption in elderly individuals is likely an early warning sign of Parkinson’s disease. A similar link between circadian rhythm and Alzheimer’s has also been underlined by researchers. 4. Obesity: Circadian rhythm is linked to both sleep and metabolism, so it’s inevitable that any disruptions in the former will lead to issues in the latter. A study in the Journal of Obesity and Metabolic Syndrome in 2018 indicates that disrupted sleep-wake cycles also affect the circadian food intake timings, which alters the glucose and energy metabolism in the body. This is a huge contributing factor to greater weight gain and obesity. 5. Heart disease: Growing evidence shows that circadian rhythms are intrinsically linked to cardiovascular functions. A study published in Frontiers in Pharmacology in 2015 showed that the onset of many cardiovascular diseases like myocardial infarction, stroke, arrhythmia and sudden cardiac death is linked to the circadian clock of the body, especially through endothelial function, platelet aggregation and thrombus formation. For more information, read our article on How to fall asleep. Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.