Blue light increases chance of bowel cancer by as much as 60 per cent

By - World Healthcare Journal

A study conducted by researchers at the Barcelona Institute for Global Health has found that artificial light, commonly known as ‘blue light’, emitted at night increases the risk of developing bowel cancer.

This is not the first time that blue light has been linked to cancer by experts; previously it has been linked with increased chances of being diagnosed with breast and prostate cancer.

Experts believe that blue light may disrupt the body's circadian rhythm, which in turn affects hormone levels. Both breast and prostate cancers are hormone-related.

Of 2,000 adults in Barcelona and Madrid, 660 bowel cancer sufferers were selected to participate in the study, while the rest were randomly selected. By examining images from the International Space Station, researchers were able to determine the level of blue light at night time in areas across the two Spanish cities.

However, the way people behaved at night was not captured by the satellite images, due to the commonly used rolling shutter in Spain and other Mediterranean countries. Night workers were also exempt from these studies.

Bowel cancer, also known as colorectal or colon cancer, affects more than 250,000 people in the UK, and is the second most common cause of cancer death.

"Using the same methodology as the previous study, we decided to analyse the relationship between exposure to artificial light and colorectal cancer, the third most common type of cancer worldwide after lung and breast cancer. ” said study coordinator Dr Manolis Kogevinas of the Barcelona Institute for Global Health.

Researchers found that residents in both cities, who lived in areas with the highest exposure to blue light, had a 60 per cent higher risk of developing colon cancer than those who were less exposed. Dr Kogevinas said blue light is emitted by most white LED lamps, tablets and mobile phone screens.

Blue light releases a lot of energy, but close exposure over a long period of time can suppress melatonin levels in the human body. Melatonin plays a crucial role in regulating day-night cycles and has several other key functions.

In 2018, the Barcelona Institute for Global Health of Spain established a link among 4,000 people in 11 regions between heavy exposure to LED lighting and double the risk of prostate cancer. It also confirmed there was a one and a half times higher chance of breast cancer.

The research has come as health chiefs caution that LED street lights may disrupt people's sleep and damage eyesight. Public Health England has raised similar concerns about the increasing use of LED lights on new cars.