Melatonin Improves DNA Damage Repair Capacity in Night Shift Workers

TUESDAY, Feb. 25, 2025 (HealthDay News) — For night shift workers, melatonin supplementation seems to improve oxidative DNA damage repair capacity, according to a study published online Feb. 24 in Occupational & Environmental Medicine.

Umaimah Zanif, from the British Columbia Cancer Research Institute in Vancouver, Canada, and colleagues examined whether melatonin supplementation would improve oxidative DNA damage repair among night shift workers in a parallel-arm randomized placebo-controlled trial involving 40 night shift workers. Supplements were consumed before day sleep during a four-week period. Creatinine-adjusted 8-hydroxy-2″-deoxyguanosine (8-OH-dG) measured in urine was an indicator of oxidative DNA damage repair capacity, with higher concentrations indicative of better repair.

The researchers observed a borderline statistically significant 1.8-fold increase in urinary 8-OH-dG excretion during day sleep in association with the melatonin intervention (95 percent confidence interval, 1.0 to 3.2; P = 0.06). During the subsequent night shift, there was no statistically significant difference in 8-OH-dG excretion (melatonin versus placebo excretion ratio, 0.9; 95 percent confidence interval, 0.6 to 1.5; P = 0.7).

“Assessing long-term efficacy is critical since those who work night shifts for many years would need to consistently consume melatonin supplements over that time frame to maximize the potential cancer prevention benefits,” the authors write.

Abstract/Full Text