蜜芽传媒

Over the years, a number of scientific studies have shown that nightshift workers are more likely to suffer or die of heart related illnesses - including heart attacks and stroke - but how working nights affects the heart hasn't been clear.

Now, new research has shown that each of the cells in our heart has an internal clock that changes their chemical composition through the day - anticipating our daily functions in a circadian rhythm. Scientists think that changing that rhythm with shift work can add extra stress on our hearts.

They say if people travel across time zones or change shift patterns they should trick their bodies into accepting the new times by making sure they get lots of light and a big meal at the start of their shift - and try to have a stretch of time with no food or light during their new 'night-time'.

Dr John O'Neil from the MRC Laboratory of Molecular Biology in Cambridge led the research team.

"How the heart beats is determined by two things, both signals from the brain, and then levels of Ions: sodium and potassium within each heart cell which triggers the heart beat. It's been known for donkey's years that signals from the brain change between day and night but everyone assumed sodium and potassium levels didn't change. But we were really surprised they actually changed by about 30% between morning and night and this seems to help the heart to beat faster when we're awake and actually need the heart to work harder."

(Photos: Night workers struggling through a shift. Credit: Getty Images)

Show less