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Published on: December 11, 2020
Melatonin supplementation and oxidative DNA damage repair capacity among night shift workers: a randomised
Umaimah Zanif1, Agnes S Lai1, Jaclyn Parks1
1Cancer Control Research, BC Cancer Research Institute, Vancouver, British Columbia, Canada.
Objectives:
A decreased ability to repair oxidative DNA damage, due to melatonin suppression, is a compelling mechanism by which night shift workers are at an increased risk of cancer. We sought to determine if melatonin supplementation would improve oxidative DNA damage repair among night shift workers.
Methods:
We conducted a parallel-arm randomised placebo-controlled trial of melatonin supplementation among 40 night shift workers. Supplements were consumed before engaging in day sleep over a 4-week period. All urine excreted during a representative day sleep and night work period before and during the intervention period was collected for measurement of creatinine-adjusted 8-hydroxy-2'-deoxyguanosine (8-OH-dG) as an indicator of oxidative DNA damage repair capacity, with higher concentrations indicating better repair. Linear regression models were used to analyse the association between ln-transformed 8-OH-dG concentration and intervention status during day sleep and night work.
Results:
The melatonin intervention was associated with a borderline statistically significant 1.8-fold increase in urinary 8-OH-dG excretion during day sleep (95% CI 1.0, 3.2, p=0.06). No statistically significant difference in 8-OH-dG excretion was observed during the subsequent night shift (melatonin vs placebo excretion ratio=0.9; 95% CI 0.6, 1.5; p=0.7).
Conclusions:
Our results suggest that melatonin supplementation improves oxidative DNA damage repair capacity among night shift workers. Future larger-scale trials are needed to evaluate the impact of varying doses of melatonin supplements and examine the impacts of longer-term use of melatonin supplements by night shift workers.
Insights
Melatonin supplements may enhance the body's ability to repair oxidative DNA damage in night shift workers. This study found improved DNA repair capacity during sleep periods after melatonin supplementation.
Area of Science:
- Biomedical Science
- Occupational Health
- Molecular Biology
Background:
- Night shift work is associated with increased cancer risk, potentially due to impaired oxidative DNA damage repair linked to melatonin suppression.
- Melatonin plays a crucial role in cellular repair mechanisms, and its suppression in shift workers may compromise DNA integrity.
Purpose of the Study:
- To investigate whether melatonin supplementation can improve the capacity for oxidative DNA damage repair in night shift workers.
- To assess the impact of melatonin on 8-hydroxy-2'-deoxyguanosine (8-OH-dG) levels, a biomarker for oxidative DNA damage repair.
Main Methods:
- A 4-week, parallel-arm, randomized placebo-controlled trial involving 40 night shift workers.
- Urine samples were collected during day sleep and night work periods to measure creatinine-adjusted 8-OH-dG levels.
- Linear regression models analyzed the association between melatonin intervention and 8-OH-dG concentrations.
Main Results:
- Melatonin supplementation showed a borderline statistically significant 1.8-fold increase in urinary 8-OH-dG excretion during day sleep (p=0.06).
- No significant difference in 8-OH-dG excretion was found during the subsequent night shift between the melatonin and placebo groups (p=0.7).
Conclusions:
- The findings suggest that melatonin supplementation may enhance oxidative DNA damage repair capacity in night shift workers, particularly during sleep.
- Larger-scale studies are recommended to explore optimal melatonin dosages and the effects of long-term supplementation in this population.
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