United States: According to new findings of a study in Frontiers in Neuroscience, exposure to outdoor light at night may increase a person’s chance of developing Alzheimer’s disease (AD).
More about the finding
According to Dr. Robin Voigt-Zuwala, an associate professor at Rush University Medical Center in Chicago and the first author of the study, “We show that, in the U.S., there is a positive association between AD prevalence and exposure to light at night, particularly in those under the age of 65,” as Fox News reported.
“Nightly light pollution, a modifiable environmental factor, may be an important risk factor for AD,” Voigt-Zuwala said.
According to experts, some of the common types of artificial light sources include street lamps, cars, traffic signs, offices, and any other building with artificial lights on.
About the study
In the study, researchers analyzed light pollution maps across the country, ranking each state’s “nighttime intensity data.” They then looked at the corresponding levels of Alzheimer’s disease.
Thus, the study showed that for people aged 65 years old and older, light pollution can be an even greater threat than such conditions as obesity, depression, alcohol dependence, chronic kidney disease, etc.
The following risk factors were considered, and it was observed that while light pollution posed a threat to the age group, the following risks surpassed the impacts: hypertension, diabetes, and stroke.
The exception is that people under 65 years old seem to be affected by the exposure to lighting at night as it boosted the attack rate of Alzheimer’s more than any other risk factor.
According to Voigt-Zuwala, “Certain genotypes, which influence early-onset AD, impact the response to biological stressors, which could account for increased vulnerability to the effects of nighttime light exposure,” Fox News reported.
“Additionally, younger people are more likely to live in urban areas and have lifestyles that may increase exposure to light at night,” he added.
Risks of light pollution
Earlier research indicates that light pollution is rising at a rate of approximately 10 percent per year and affects 80 percent of the human population, with the night sky becoming brighter.
It is established that light contamination alters the biological clock and decreases the levels of melatonin, which results in sleep disturbances.
Lack of sleep, in the same respect, is known to cause other diseases, including neurodegenerative diseases such as Alzheimer’s disease.
Another experiment conducted and published in the American Journal of Preventive Medicine stated that getting five hours of sleep can increase the chance of dementia by 30 percent for citizens who are above fifty years old.
Sleep-related disorders
Sleep-related movement disorders are described as a group of parasomnias, maximum of which are characterized by abnormal movements during sleep, according to the above-mentioned study, and it was established that adults having such disorders are nearly four times more likely to be diagnosed with dementia.
According to Dr. Earnest Lee Murray, who is a board-certified neurologist at Jackson-Madison County General Hospital in Jackson, Tennessee, and was not part of the study said that the environmental factors could affect the occurrence of dementia such as Alzheimer’s.
“We have known for some time that the lack of quality sleep has detrimental health effects, and this includes an increased risk of developing cognitive difficulties later in life,” he added.
The doctor also noted that the brain generally depends upon a circadian rhythm in order to restore itself during sleep.
Murray said, “Constant light exposure disrupts this circadian rhythm and limits the amount of time the brain is in the deeper, restorative stages of sleep.”