A man sleeps peacefully inside a dark bedroom cube, protected from the light pollution outside.

When True Darkness Is a Friend to Bladder Cancer

You may have read some recent research asserting a link between bright outdoor streetlights and colorectal cancer.

A Barcelona-based research team found that nighttime exposure to blue spectrum light cast by outdoor artificial lighting could increase this type of cancer. Most research on light exposure and cancer risk focuses on specific conditions experienced by people who work at night (shift workers). These people develop chronic circadian rhythm disruption because of chronic overnight exposure to bright light, which may increase their risk for developing colorectal, breast, or prostate cancer.1-3

Different types of light exposure

But now research seems to point at all light exposure at night—including the kind inside and outside your home—as a potential hazard. One study showed a link between sleeping spaces brightly illuminated by artificial outdoor lighting and higher rates of both prostate and breast cancer.4 Is there any connection between light pollution and bladder cancer? And how can seeking “true” darkness at bedtime help you during your bladder cancer treatment?

Does light pollution cause cancer?

Science consistently confirms links between nighttime light exposure and cancer risk. For instance, if you sleep in a space that’s lit by exterior streetlamps, you’re experiencing a kind of light pollution that’s fast becoming the norm in urban communities.5 Medical scientists now refer to light pollution—basically, an environmental carcinogen —as artificial light at night, or ALAN.6-7

Just think of all the ways that you might experience ALAN:8

  • Shift work
  • Baby lights
  • TVs, computers, handheld devices
  • Streetlights
  • Emergency lights

Where has "true" darkness gone?

It’s no surprise that photos of the Earth taken from space show a startling new 21st-century reality—“true” darkness is disappearing.5 Unfortunately, it’s this “true” darkness you need to maintain healthy circadian rhythms.

Why? Animal research continues to show chronic circadian disruption, caused by ALAN, leads to the development and spread of cancer.5 After all, ALAN limits the brain’s ability to produce and secrete melatonin.1,7

The benefits of melatonin

Did you know that melatonin, while known as the “sleep” hormone, also boosts your immune function?9 More importantly, melatonin is known for its anti-cancer functions.10

It’s not a stretch to conclude that shortages of melatonin may leave anyone at higher risk for developing cancer, and research continues to prove this out.7

In fact, melatonin is already commonly used in combination with chemotherapy, radiotherapy, tumor vaccination, and immunotherapy to assist in regulating the immune system defense against cancer cells.10

But does ALAN cause bladder cancer?

Current research hasn’t studied any links between ALAN and bladder cancer.

In fact, one South Korean study ruled out associations between ALAN and a wide variety of other cancers, including bladder cancer.11

But bladder cancer, the ninth most common cancer worldwide (the sixth most common among men), is still associated with many of the same circadian disruptors as other more common forms of cancer.12

Meanwhile, one Canadian study found shift workers, who live with chronic circadian disruption, at higher risk for bladder cancer due to low melatonin levels, so it’s hard to deny that light exposure at night can raise other's risks, but more research needs to happen.13

Maybe the better question is:

If you have bladder cancer, how might ALAN and melatonin impact your therapy and recovery?

Melatonin for bladder cancer

Lab researchers have noted a decrease in urinary levels of melatonin among bladder cancer patients.14

Some studies propose more routine screening for melatonin levels in these patients through urine tests.

Why not? Knowing you’re getting enough may actually reduce anxiety about sleep. Research suggests that those who actively measure their levels through urinalysis end up sleeping better.15

Reclaim your “true” darkness

You already generate your own melatonin as part of your sleep-wake cycle.

For this reason alone, it makes sense to seek consistent, adequate, high-quality sleep while living with and treating bladder cancer.

This means sleeping in a very dark room at night. An eye mask or blackout drapes, shades, or blinds can protect you from ALAN caused by the artificial illumination found outdoors in more urban locations.

Any melatonin supplement you receive as part of your treatment regimen will help.

In fact, if you aren’t taking a melatonin supplement, you may want to ask your oncologist about the possibility of adding it to your treatment plan.

Melatonin for the win

Melatonin reinforces immune function, circadian rhythms, and good sleep patterns.

It makes sense that getting a good night of sleep—ideally in “true” darkness—may be one of your best strategies for successful treatment of and recovery from bladder cancer. Not only can a sleeping space kept in “true” darkness help fulfill this strategy, but doing so will boost your immune system in your fight against cancer.16

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The BladderCancer.net team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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