A recent study has discovered a new risk factor for Alzheimer's: light at night. Experts recommend simple measures to protect yourself.
Various studies have already shown that factors such as unhealthy diet, stress, lack of sleep, obesity and even intestinal inflammation can promote Alzheimer's. Now researchers from the USA have identified another risk factor. Their study, which was recently published in the journal “Frontiers in Science”, provides the first evidence that nighttime light could increase the risk of Alzheimer's – especially in younger people.
Researchers at Rush University Medical Center in Chicago investigated the effects of so-called light pollution at night on the body – and found an increase in Alzheimer's cases. To do this, they analyzed the “Light Pollution Maps” (satellite data on light pollution) of 48 US states and compared them with medical data on risk factors for Alzheimer's.
The result: In people over 65, the occurrence of Alzheimer's was more closely linked to high levels of light pollution than to other disease factors such as alcohol abuse, chronic kidney disease, depression or obesity. Risk factors such as diabetes, high blood pressure and strokes, on the other hand, were more closely linked to Alzheimer's than light pollution.
Surprisingly, however, a different picture emerged among those under 65: Among them, greater light exposure during the night was associated with a greater prevalence of Alzheimer's disease – compared to all other risk factors studied.
The results suggest that younger people are particularly sensitive to the effects of nighttime light exposure. The researchers are not yet able to say exactly why this is the case. They offer a possible explanation: artificial light disrupts the day-night rhythm, sleep as such and also hormone levels. According to study author Robin Voigt-Zuwala, there are individual differences in light sensitivity. She believes that certain gene types could play a role by influencing the body's response to biological stressors. These stressors could in turn lead to an increased susceptibility to Alzheimer's.
According to the scientist, there are simple measures that can protect against light pollution: “Blackout curtains and face masks can help.” She also recommends reducing the amount of blue light inside buildings and also paying attention to warm light.
According to researchers, more than 80 percent of the world's population is affected by light pollution. This includes, for example, the lighting of streets and facades, billboards and car lights – in other words, everything that illuminates the otherwise dark night.
This not only has adverse effects on plants and animals, but also has serious health consequences for us humans. Sleep disorders and an increased risk of diseases such as obesity, depression and cancer were previously known. The connection now described with Alzheimer's is new.
