Researchers from Rush University Medical Center in Chicago have discovered a link between light pollution at night and the risk of developing Alzheimer’s disease. The study, published in Frontiers in Neuroscience, suggests that exposure to artificial light during the night could be one of the environmental factors contributing to Alzheimer’s.
What is Alzheimer’s Disease?
Alzheimer’s is the most common form of dementia, a group of conditions that lead to memory loss and cognitive decline. It happens when harmful plaques and tangles form in the brain, affecting neurons responsible for memory and thinking.
In the early stages, people with Alzheimer’s may become forgetful. As the disease progresses, they experience confusion, lose their sense of direction, and struggle with everyday tasks. According to the World Health Organization (WHO), over 55 million people globally suffer from dementia, with Alzheimer’s making up about 75% of these cases. In India, it’s estimated that between 3 and 9 million people live with the disease. Unfortunately, there is still no cure for Alzheimer’s, although recent drugs may help slow down its progress.
The Study on Light Pollution
Earlier studies have shown that several factors, such as genetics, health conditions, and environmental influences, can raise the risk of Alzheimer’s. This new study adds light pollution to the list, showing that exposure to artificial light at night may contribute to the disease.
The researchers used satellite data to measure light pollution levels across the US and combined it with health data from Medicare reports on Alzheimer’s prevalence. They also included other factors known to increase Alzheimer’s risk, such as diabetes, hypertension (high blood pressure), and depression.
While some of these health conditions had a stronger link to Alzheimer’s than light pollution, the study found that light exposure was still a significant factor. Surprisingly, night-time light pollution had a stronger connection to Alzheimer’s than other common risk factors like alcohol abuse, chronic kidney disease, heart failure, and obesity. The researchers also discovered that the link between light pollution and Alzheimer’s was even more pronounced in younger patients, especially those under 65 who had early-onset Alzheimer’s.
How Light Pollution Affects the Brain?
One of the study’s authors, Robin Voigt, explained that exposure to artificial light at night disrupts the body’s natural sleep-wake cycle, known as circadian rhythms. Poor sleep, in turn, can increase the risk of developing Alzheimer’s. The disruption of circadian rhythms has also been linked to other conditions that increase Alzheimer’s risk, such as obesity, diabetes, and depression.
A Growing Problem
Around 80% of the world’s population is exposed to light pollution, mostly from streetlights, building lights, and other sources. While these lights are often seen as beneficial for safety, more research is showing their negative impacts on both humans and the environment. This new study adds to the growing evidence that night-time light pollution is not as harmless as it seems and should be a concern for policymakers.
The findings call attention to the need for better awareness and regulations on light pollution, especially as we continue to learn more about its potential health risks.