This is kinda like circadian rhythms’ second Nobel Prize. Technically it was LED lights back in 2014, but if you don’t see the connection, I have failed.
Melatonin plays a pivitol role in circadian entrainment. Literally thousands of papers published about it every year.
THIS IS WHY YOU NEED BLUE BLOCKERS: A single night light exposure acutely alters hormonal and metabolic responses in healthy participants (Albreiki et al., 2017)
They had the participants sleep in either dim (<5 lux) or bright (>500 lux) light and monitored them from bedtime for 24 hours. >500 lux is about as bright as an overcast day, so they weren’t blasting them with 10000 lux LED light devices, although there was a pretty good spike in the blue zone:
[side note: similar effects have been seen with much less light; ~200 lux can lower melatonin by about half]
Prior to the test meal on the following day, everything was already haywire. After the bright light night, insulin increased (NS) enough to lower free fatty acids (P<0.05), but not enough to bring glucose (NS) down to the dim light condition. And yeah, huge difference in melatonin.
After a standardized meal, the bright light group had higher insulin AUC (P<00.01) and glucose (P<0.05), and lower free fatty acids (P<0.01). And that was just one night!
They had no melatonin to sensitize the system. Gravitas.
It’s hard to get around this, even with supps: “Melatonin content was found to range from -83% to +478% of the labelled content. Additionally, lot-to-lot variable within a particular product varied by as much as 465%. This variability did not appear to be correlated with manufacturer or product type” (Erland and Saxena, 2017)
But if you absolutely must, for jet lag or something, I usually check with Labdoor who ranked Puritan’s Pride, Nature Made, and NOW Foods as the top 3. Labdoor is looking for quality control, not conducting sleep studies… although melatonin supps fared pretty well over at Examine.com (but they still agree that darkness and/or blue blockers should be first line).
Three bucks a month for access to all articles and there are many other options. And it’s ad-free.
If you’re on the fence considering it, try it out, you can cancel at any time! Also, there is a limited number of positions remaining at the $3 level.
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