Circadian rhythms refer to the body’s natural 24-hour cycle of physical, mental, and behavioral changes that respond to light and darkness.
They can affect many bodily functions, including sleep patterns, hormone release, appetite, digestion, and even body temperature.
Medical News Today recently reported on a study that found reducing exposure to light at night could cut a person’s risk of diabetes.
“People who perform shift work for many years are at greatly increased risk of type 2 diabetes. One of the possible reasons for this is disruption of the body’s circadian rhythms by mistimed environmental signals,” Andrew Phillips, associate professor in the College of Medicine and Public Health at Flinders University in Australia and senior author of the study, told Medical News Today. “Light is an easily modifiable environmental factor, which has underappreciated effects on human health.”
The influence of light on our circadian rhythms has now been found to have more potentially detrimental effects.
Frontiers reports on how light pollution could increase the risk of Alzheimer’s disease. Here’s the start of the story:
80% of the world’s population are exposed to excessive or inappropriate use of artificial light outdoors, dubbed light pollution. Light exposure at night can lead to many health problems, including disrupted circadian rhythms and subsequent sleep problems – a known risk factor for neurodegenerative diseases. Researchers have now found that exposure to light at night could increase the prevalence of Alzheimer’s disease, especially in a younger population.
In some places around the globe, the lights never go off. Streetlights, roadway lighting, and illuminated signs can deter crime, make roads safer, and enhance landscaping. Undisrupted light, however, comes with ecological, behavioral, and health consequences.
In the US, some states have legislation in place to reduce light pollution; however, levels of light at night remain high in many parts of the country. Now, researchers there have investigated correlations between outside nightly light pollution and Alzheimer’s disease (AD).
“We show that in the US there is a positive association between AD prevalence and exposure to light at night, particularly in those under the age of 65,” said first author of the Frontiers in Neuroscience study, Dr Robin Voigt-Zuwala, an associate professor at Rush University Medical Center. “Nightly light pollution – a modifiable environmental factor – may be an important risk factor for AD.”