Unfortunately, the answer appears to be yes. And the habit, although it’s so ever-present it may be more of an environmental thing than a habit… is artificial light known as blue light. You’ve probably heard a lot about the risks and damage blue light is known to do to people’s health, but this is a new one… increasing a person’s risk of colon cancer by 60%.
The main problem with blue light stems from the fact that it is high-energy visible light (HEV) and is different than the UV (ultraviolet light) that comes from the sun. Blue light is able to reach the retina of your eyes, while UV light is blocked by your cornea and crystalline lens in your eyes from reaching the retina. So the UV light can do surface damage if you’re exposed to it too long (like getting a sunburn if in the sun too long), but since blue light is able to penetrate further, it can impact your health below the surface.
Previous studies have reported that artificial light — especially blue light— has been linked to numerous health problems including sleep disorders, obesity, and increased risks of some cancers — especially in night-shift workers.
But now a study has found a connection between blue light and colorectal cancer. Researchers from the Barcelona Institute of Global Health (ISGlobal) conducted an analysis of any association between nighttime exposure to outdoor artificial light and colorectal cancer. The researchers compared data from about 2,000 adults in Barcelona and Madrid. In order to make their findings as clear as possible, they excluded data from night-shift workers since night-shift work is already linked to colon cancer. They then estimated each person’s probable nighttime exposure to artificial light based on information from the International Space Station (ISS).
The results from those adults in both cities showed that the people with the highest exposures to outdoor blue light had a huge 60% higher risk of developing colon cancer than those with less exposure to blue light. They found no such link between full-spectrum light exposure and colon cancer.
But why would blue light be connected to colon cancer? The researchers explained it by the fact that nighttime exposure to artificial light — especially blue light— can interfere with the body’s production and secretion of melatonin. And since melatonin has been found in other studies to reduce or inhibit colon cancer migration and metastasis and to have “anticancer activity” it’s fairly easy to see why blocking melatonin could result to colorectal cancer.
So what can you do about it? Choose light bulbs with a warm tone, limit screen time at night and make use of blue filtering options on your electronics… computers, tablets, phones, etc. Most of them have such options available…. Often found in “settings” and if not there, consult your manual, “google” it online, or ask someone younger than you!
Some people will wonder if taking melatonin supplements would help… we are not aware of any studies on that particular question, and we are lay people and can’t even speculate whether it would help, but we would caution NOT to use it for that purpose. Melatonin is loved by a lot of people as an aid for sleeping better, but whether it would have any impact on this blue light problem and colon cancer we don’t know, but it would seem far better to just limit your nighttime exposure to blue light, than to take the chance that you can count on melatonin supplements to protect you from it — it isn’t worth the risk, so the best idea is to limit blue light., rather than try supplementation and find out it didn’t work for this.