Circadian rhythms: More than blocking blue light at night

A common approach for people experiencing sleep problems is blocking blue light at night. Blue light is a signal that helps set our circadian rhythm by synchronizing our master clock to the environment.

But many require further help. In fact, most do. That’s because circadian rhythms are about a lot more than just blocking blue light at night.

Every individual cell has it’s own circadian rhythm. For best results, you need to synchronize the trillions of cellular clocks in your body together.

To do this, you need to pay attention to light, feeding, physical activity, social connected-ness, nutrition, and anything that affects body temperature.

All these signals are important, and simply addressing blue light at night while ignoring these other factors leads to poor results.

Let there be light, during the day…and fiber

In addition to avoiding blue light at night, getting adequate light during the day is important. In a pair of experiments, researchers found that getting adequate light during the day prevented the disrupting effects of blue light at night on melatonin.(1, 2)

It’s important to point out that these studies used artificial light during the day, which is substantially less effective than regular ole sunlight.

Another recent paper found blue blocking glasses at night may not be the ideal way to address light. There’s a natural day-to-night transition in color from from yellow to blue that also plays a role.

In mice, this signals through a different set of receptors than blue light that we also have. So simply blocking via blue blockers may present a conflicting signal because it negatively effects these receptors.

Finally, a recent paper found that prebiotic supplementation can help prevent light-induced disruption of circadian rhythms in mice fed a high fat diet(Junk food, not keto). This likely occurs through the generation of butyrate, which affects genetic expression.

Blue light at night fiber

With circadian rhythms, the goal is to build a robust rhythm. You can’t do that by simply blocking blue light at night and time-restricted eating.


There’s no doubt that blocking blue light at night using blue blocking glasses provides benefits for those ignoring their light environment. But there’s a lot more to your light environment than just artificial blue light at night.

In addition, other factors unrelated to light help build a strong, stable circadian rhythm. Paying attention to these other factors is important, particularly if you deviate from your light environment from time to time.

To get the most out of your circadian endeavors, and to prevent a single night or 2 out from compromising your results, pay attention to light throughout the day, feeding times, physical activity, nutrition, and body temperature rhythms. Your results will be infinitely better.

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