IT’S HARDER To heal AT NIGHT
Researchers have found that our body clocks allow us to repair injuries better in the day
Circadian rhythm, better known as our body clock, is the cycle that keeps us ticking. During a 24-hour cycle it helps to drive multiple processes in the body, from hormone secretion and sleeping patterns to metabolism. And researchers at the Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge have discovered that this cycle can affect the healing of wounds such as cuts and burns.
Dr John O’neill, the senior author of the study, said, “This is the first time that the circadian clock within individual skin cells has been shown to determine how effectively they respond to injuries.”
The study found that, on average, burns that occurred at night took 60 per cent longer to heal than burns that happened during the body clock daytime cycle. Nighttime burns (sustained between 8pm and 8am) healed around 28 days later as opposed to that of 17 days if a burn was sustained during the day (between 8am and 8pm). The study drew these conclusions after analysing data from 118 patient records from all major burns units in England and Wales.
The reasoning behind the differences in healing time is due to how long it takes for skin cells to move to the site of the wound and begin repairs, a process that occurs more quickly during the daytime. This is driven by increased activity of the proteins within the cell, in particular actin filaments, which act like a muscle within the cell.
In a statement, Dr Ned Hoyle, the lead author of the study, said, “We’ve shown that the daily cycles in our body clock control how well cells can repair damaged tissue by affecting an essential protein called actin. Efficient repair of our skin is critical to preventing infection, and when healing goes wrong wounds can become chronic or excessive scarring can occur. Further research into the link between body clocks and wound healing may help us to develop drugs that prevent defective wound healing or even help us to improve surgery outcomes.”