The Surprising Danger of Artificial Light at Night

Dear Natural Health Solutions Reader,

Sedentary lifestyles… Processed food… Isolation… Synthetic drugs…

There are many ways our lives diverge from those of our ancestors — and that have made us less healthy as a result.

But one of the most recent dramatic changes of modern life gets far too little attention: the huge increase in artificial light at night (what researchers refer to with the friendly-sounding acronym ALAN).

Consider that it has been barely 100 years — an eye blink in evolutionary time scales — since we began flooding the night with light.

(And “flood” is the appropriate word. My wife and walked to a grocery store last night, and I literally refused to go in. There was enough ghastly, blinding fluorescent light blasting out of the windows of the place to make me remain resolutely in the parking lot, admiring the lovely moon.)

This tendency to turn night into day has obvious downsides.

Yes, as our sleep-regulating hormones, melatonin and serotonin, are thrown out of whack, we suffer exhaustion…

But a couple of recent studies by researchers from Israel’s University of Haifa compared night satellite images of more than 80 countries, with a goal of figuring out what else that rascal ALAN might being doing to us.

The worrisome results…

ALAN May Make Us Fat

As it turns out, 70 percent of the countries with higher-than-average ALAN also have high rates of obesity.¹

Researchers determined this after they adjusted for confounders such as national wealth and typical caloric intake.

Why does ALAN correlate with obesity? The study wasn’t designed to find causation, but other studies have shown that chronic sleep deprivation can skew hormones in the direction of increased hunger and weight gain — via the same biochemistry that gives cannabis users “the munchies.”²

Bad as this was, there was an even more concerning downside of life in the highly illuminated countries…

ALAN May Give Us Cancer

In another study, the researchers looked at ALAN and breast cancer rates.³ The analysis showed that highly illuminated countries also tended to have higher rates of the deadly disease, but the correlation was strong only in certain regions, such as Western Europe.

In Southeast Asia and parts of the Middle East, surprisingly, there were “relatively low breast cancer rates against a backdrop of relatively high artificial light at night levels,” the researchers concluded.

They stated that this anomaly requires more research.

Another worrisome observation — the type and amount of ALAN has changed over the last several years.

Blue-white light, the kind emitted by LED fixtures, has dramatically increased. That’s bad news, as blueshifted light from computer screens, and possibly other sources, has been shown to be especially harmful to melatonin production.⁴

Bottom Line

Blasting our retinas and skin with five, six, or seven hours of ALAN each night is profoundly unnatural.

So it’s not a bit surprising that our hormonal balance gets thrown out of whack, resulting in cascading problems, including immune system dysfunction, increased lipogenesis (fat formation), and higher incidence of cancerous malignancies.

I’m generally an easygoing guy, but I absolutely insistent both in my home and at work that light at night be kept to a minimum. We use low-wattage incandescent bulbs (these little beauties are great) wherever possible, and I have installed f.lux on every device with a screen that we own.

Also, while we have no evolutionary experience with ALAN, we have a great deal of it with FLAN — firelight at night. Human beings tamed fire about 350,000 years ago — plenty of time for us to adapt to this pleasant source of illumination and to benefit from it.⁵

Whether it is from candles or a crackling wood stove, FLAN is my favorite source of nighttime illumination. For the sake of your health, in whatever manner fits your lifestyle, I urge you to make it yours as well.

Sincerely,

Brad Lemley
Editor, Natural Health Solutions

Citations

1. Rybnikova NA, Haim A, Portnov BA. Does artificial light-at-night exposure contribute to the worldwide obesity pandemic?. Int J Obes (Lond). 2016

2. Hanlon EC, Tasali E, Leproult R, et al. Sleep Restriction Enhances the Daily Rhythm of Circulating Levels of Endocannabinoid 2-Arachidonoylglycerol. Sleep. 2016

3. Rybnikova N, Haim A, Portnov BA. Artificial Light at Night (ALAN) and breast cancer incidence worldwide: A revisit of earlier findings with analysis of current trends. Chronobiol Int. 2015

4. Oh JH, Yoo H, Park HK, Do YR. Analysis of circadian properties and healthy levels of blue light from smartphones at night. Sci Rep. 2015

5. Ron Shimelmitz, et. al. The emergence of habitual fire use 350,000 years ago. Journal of Human Evolution. Dec. 2014