What Melatonin Does To Your DNA

Spoiler: it’s good

What dreams may come, when we have shuffled off this deoxyribonucleic coil,

…must indeed give us pause!

Researchers (Dr. Umaimah Zanif et al.) did a randomized, placebo-controlled trial of 40 night-shift workers tested whether taking 3mg of melatonin daily for 4 weeks before daytime sleep (because: night-shift workers) could improve the body’s ability to repair oxidative DNA damage.

Why Dr. Zanif and her team investigated melatonin: melatonin normally rises at night and helps regulate sleep and circadian rhythms, but overnight work suppresses melatonin production, which can reduce the body’s capacity to repair oxidative DNA damage, and could be one mechanism linking long-term night-shift work to a higher cancer risk.

Quick note about the participants: all workers had performed at least two consecutive night shifts per week for at least 6 months, with shifts lasting at least 7 hours, and none had sleep disorders or major chronic illnesses.

Of course, that’s not to say it’s only night workers who are affected—it’s relevant for anyone with disrupted sleep. But night workers make for a clear, consistent demographic in which to study these matters.

You may be wondering how DNA repair was measured: the team measured urinary 8-hydroxy-2′-deoxyguanosine (8-OH-dG), a marker of oxidative DNA damage repair capacity, with higher levels interpreted as greater DNA repair activity.

The results, in numbers:

• Main finding: during daytime sleep after night-shift work, the melatonin group showed approximately 1.8 times higher urinary 8-OH-dG levels than the placebo group, suggesting improved oxidative DNA repair capacity.
• Statistical analysis: the increase was described as borderline statistically significant, with a 95% confidence interval of 1.0 to 3.2 and a p-value of 0.06.
• One more thing: no significant difference between groups was observed during the subsequent overnight work period, suggesting the benefit occurred specifically during sleep rather than throughout the entire day.

In other words, restoring melatonin signaling can counter some of the biological stress caused by circadian disruption in general and night work as a top-tier example of that.

You can read the paper in full, here: Melatonin supplementation and oxidative DNA damage repair capacity among night shift workers: a randomised placebo-controlled trial

We’ve also written a bit about melatonin before, including:

• Melatonin: A Safe, Natural Sleep Aid?
• Melatonin Supplementation & Your Heart
• Melatonin vs Lupus!

Want more options?

Some sleep aids can help, but many are harmful and/or do not really work as such; here’s a rundown of examples of those: Safe Effective Sleep Aids For Seniors?

Want to learn more?

For a much more in-depth treatment of the topic of sleep in general, you might like this book that we reviewed a while back:

Why We Sleep – by Dr Matthew Walker

Basically, if you will read only one book on sleep, that’s the book.

Sweet dreams!