Study finds link between light pollution and an increased risk of Alzheimer’s disease

Excessive exposure to light pollution at night could increase the risk of Alzheimer’s disease, says US researchers.

Alzheimer’s disease affects over 940,000 people in the UK today, and this number is continuing to grow. The disease – which is a type of dementia – is associated with an ongoing decline in brain functioning. It causes memory loss and can also impact the way that you feel, speak and behave.

The disease is particularly common in people above the age of 65. In fact, 1 in 11 people aged 65 and over are living with dementia in the UK today. However, new research has suggested that some younger people may now also be at a higher risk of developing Alzheimer’s disease.

Light pollution at night time could be an important risk factor to investigate in relation to Alzheimer’s disease, according to a new study. Research published in Frontiers in Neuroscience determined that excessive exposure to light at night could increase the risk of the disease for people under the age of 65.

The study used data from satellites to determine the average night-time light intensity in the US states between the years 2012–2018, and gathered Medicare data to determine the prevalence of Alzheimer’s disease in those states. By comparing both data sets, researchers found that states with higher intensity of light pollution at night were positively associated with the prevalence of Alzheimer’s disease.

Additionally, researchers were able to say that, for people who were aged 65 and younger, the prevalence of Alzheimer’s disease had a stronger correlation with nighttime light pollution than other potential disease risk factors, like kidney disease and obesity.

What does this mean?

This is a breakthrough in understanding new risk factors of the disease, and who they affect. Previously, risks of Alzhiemer’s have always been associated with people over 65. However, now younger demographics are vulnerable.

Robin Voigt-Zuwala, Ph.D., an author of the study, said in the research: '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.'

'Additionally, younger people are more likely to live in urban areas and have lifestyles that may increase exposure to light at night,' she added.

While these findings may raise concerns, it is important to remember that this is a modifiable risk factor. This means that those at risk can decrease the amount of night-time light exposure that they’re receiving.

Symptoms of dementia

According to the NHS, those suffering may experience issues with :