The bright city lights may be calling, but they are also increasing our risk of Alzheimer’s disease.
New research out of the United States has found that outdoor light at night could be a significant risk factor in the most common form of dementia.
Rush University Associate Professor Robin Voight-Zuwala said while light pollution had been associated with increased risk of some disorders and diseases, this was the first time it had been associated with Alzheimer’s disease.
“Our research shows that there is an association between Alzheimer’s disease prevalence and exposure to light at night, particularly in those under the age of 65,” Associate Professor Voight-Zuwala said.
She said researchers studied light pollution maps across 48 states in the US, incorporated medical data associated with Alzheimer’s disease risk factors and divided the groups by light intensity.
“(We) found that light intensity was correlated with Alzheimer’s disease prevalence even when some well-established disease factors were not.”
Associate Professor Voight-Zuwala said while the cause was unknown, higher nighttime light intensity was associated with a greater Alzheimer’s disease prevalence than any other risk factor examined in the study for those under the age of 65, suggesting younger people may be more sensitive to the effects of light exposure at night.
She said exposure to light influences the body’s natural sleep-wake pattern, which was called a circadian rhythm.
“Exposure to light at night can disrupt a person’s circadian rhythm, which can promote inflammation and make a person less resilient and more prone to disease.
“The good news is that simple changes can be made with minimal effort to reduce exposure to light at night, such as adding black out curtains or sleeping with an eye mask.”
