Germana Carillo While light pollution is associated with an increased risk of some disorders and diseases, this is the first time it has been linked to Alzheimer's disease
Long-term exposure to serious light pollution could provide a significant possibility of contracting Alzheimer’s disease, especially in people below age 65. Conventionally, it was viewed as a disease restricted to old age.
That was the conclusion from a study published in the journal Frontiers in Neuroscience by scientists at the Rush University Medical Center. The researchers held that the risk of Alzheimer’s is more widespread among the youth exposed to nighttime light pollution; the brighter the night light, the stronger the chance of the disease.
Robin Voigt-Zuwala led the research team, which assessed light pollution maps across 48 States of America, comparing these with medical data about known variables and risk factors associated with Alzheimer’s disease.
The study
For this research, the scientists divided the participants into five groups with regard to light intensity levels. However, for each group, they found that light intensity was associated with the prevalence of Alzheimer’s disease even when all the factors of the disease were not fully established.
It is important to note that in individuals under 65, higher nighttime light intensity carries a greater prevalence of Alzheimer’s than any other risk factor examined in the study. So, light exposure during the night may be more sensitive to its effects in younger people.
“Some of them have a genetic predisposition that can affect early-onset AD, and the same genes might be causing vulnerability to light at night in general,” Voigt-Zuwala said. Plus, younger people tend to be living more in cities and having lifestyles which could lead to increasing light exposure at night.
Reducing light exposure
The body has a natural sleep-wake cycle called the circadian rhythm steered by exposure to light.
How exposure to nighttime light disrupts one’s circadian rhythm can also breed inflammation and make him or her less resilient against diseases.
Luckily, nighttime light exposure can be minimized with very easy modifications that involve barely any effort, including hanging up blackout curtains or sleeping with an eye mask.
The researchers did point out that their findings apply to only a segment of the population, and that additional tests are necessary to come up with a clearer understanding of the link between Alzheimer’s and evening outdoor light.
