Melatonin pills could help repair DNA damage due to night shift work, study finds

New Delhi: Melatonin supplements could boost the body’s ability to repair DNA damage related to night shift work, potentially lowering cancer risk among this group of workers, a study has suggested.

However, researchers, including those from the British Columbia Cancer Research Institute in Canada, cautioned that data from larger studies are needed before melatonin can be recommended for long-term use.

Normal production of the melatonin hormone, which is linked with one’s body clock and daylight, is suppressed among night shift workers. Melatonin supplements are considered a ‘physiological support’ to help the brain restore the quality, structure, and pattern of sleep.

Researchers explained that producing lower levels of melatonin compromises the body’s ability to repair DNA damage caused by everyday biological processes, potentially increasing the risk of certain cancers among night shift workers.

The findings, published in the journal Occupational and Environmental Medicine, "suggest that melatonin supplementation may improve oxidative DNA damage repair capacity among night shift workers." For the study, the researchers looked at 40 night shift workers, most of whom were employed in healthcare.

Half the participants were randomly assigned a three-milligram melatonin pill (taken with food an hour before sleeping during the day) for about a month, while the other half were randomly assigned a placebo pill on the same schedule.

All the participants worked at least two consecutive night shifts every week, lasting seven hours each night, for a minimum of six months. None had sleep disorders or long-term conditions, the researchers said.

Urine samples were collected during the second day of the night-shift-day-sleep routine -- once before starting the trial and once near the end of the four week-period.

Analysis revealed 80 per cent higher levels of '8-OH-dG' -- a molecule that indicates one's capacity to repair DNA damage -- in the urine samples of night shift workers who were taking melatonin supplements.

The researchers explained that most of the 8-OH-dG is removed from DNA as part of the repair process and excreted into urine, where its levels are measured -- therefore, higher levels mean a better capacity for DNA repair.

The study's results suggested that better repair might be occurring among those taking the melatonin supplement, compared to those taking the dummy pill, the authors said.

"Increased oxidative DNA damage due to diminished DNA repair capacity is a compelling mechanism that may contribute to the carcinogenicity of night shift work," they wrote.

However, they cautioned that larger-scale studies examining long-term impacts of melatonin pills are required, results from which would help determine if supplementation could be viable for lowering cancer risk among night shift workers.

Doctors strictly advise melatonin supplements for those working irregular shifts and crossing time zones, among whom day-and-night differentiation is affected.

However, the supplements are not sedatives or sleep-inducing drugs and consulting with medical experts, including psychiatrists, is recommended before one considers melatonin pills for resolving sleep-related issues.