Light of your Night

You probably, like all of us, have lights in your home. And you probably turn the lights off before bed. That’s probably pretty unhealthy. Mommyblogs have discussed the blue-light exposure pretty extensively, but I’m here to 100% support their efforts.

Your body is a machine regulated in part by the light that you see. Blue light (mimicking the blue sky) wakes you up; darkness makes you drowsy and this sets the tone for your circadian rhythm.  At night, melatonin is released and this hormone makes you drowsy but is also ‘anti-cancer’; exposure to light during darkness (i.e. interrupted melatonin), “increases cancer progression via elimination of it suppression of tumor lineolic acid uptake.” In this study, Melatonin suppression resulting from exposure to light at night has been linked to an increased risk for diseases. This is hypothesized because melatonin receptors are located in “the central nervous system and in peripheral tissues including the heart, kidney, pancreatic islets, adrenal glands, stomach, and gonads.”

I’ve known about the anti-cancer effects of a dark room since I was young and I’ve diligently been sleeping in the darkest rooms possible since that age (because I’m a keener). But the story of melatonin requires not only a dark room but reduced exposure of light before bed:


Compared with dim light, exposure to room light before bedtime suppressed melatonin, resulting in a later melatonin onset in 99.0% of individuals and shortening melatonin duration by about 90 min. Also, exposure to room light during the usual hours of sleep suppressed melatonin by greater than 50% in most (85%) trials.”

Consider these two anecdotes: truly blind people have the lowest rates of cancer because their melatonin is never suppressed; and shift workers (i.e. those without steady cycles of darkness) may have more cancer.

So does this mean we are relegated to the dark ages of no indoor lights? There is a funky, but easy-fix solution: using blue-filtering goggles (like welders wear) but the efficacy is limited. One small study has reported self-reported increases in sleep quality following wearing amber tinted glasses after one week for 3 hours prior to sleep. Another, that from 9pm onward, amber glasses had a weak increase in sleep onset. And another, that amber glasses reduced light-induced melatonin suppression.

Is it the best solution ever? I guess you could change over all your light bulbs, turn off your computer and TV and phone at sundown. Or you wear the glasses. Your call. But this is really really important IMHO for those with cancer, and those in recovery.





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