Reading an iPad or Kindle in bed may increase cancer risk
Reading an iPad or a Kindle before bed instead of a printed book can cause sleep deprivation and increase the risk of cancer, scientists have warned.
It disrupts normal sleep patterns and can lead to waking up earlier and drowsiness the following day, a study claims.
The light from the devices suppresses the hormone melatonin, low levels of which have been linked to increased risk of breast, prostate, and bowel cancer, scientists in Boston have warned.
Dr Anne-Marie Chang, who led the study, said the body's normal rhythms "were interrupted by the short-wavelength enriched light, otherwise known as blue light, from these electronic devices.
"Participants reading a light-emitting eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock and reduced next-morning alertness than when reading a printed book," she said.
Dr Chang said the light of e-readers had an "extremely powerful effect" on sleep patterns.
She pointed to the newly identified link between night lights and cancer.
"The results of this study are of particular concern, given recent evidence linking chronic suppression of melatonin secretion by nocturnal light exposure with the increased risk of breast cancer." (© Daily Telegraph, London)