Women who are ‘morning people’ are less likely to develop breast cancer than those who are sharpest in the evening، a study suggests، daily mail reported.
Research involving more than 400،000 women found ‘larks’ have a breast cancer risk up to 48 per cent lower than ‘night owls’.
The scientists، led by the University of Bristol، also showed women who slept longer than the recommended seven to eight hours a night increased their chances of a diagnosis by 20 per cent for each extra hour spent asleep. One explanation may be that those who function better in the morning have slept better and woken earlier.
And those who are sharper in the evening may have had more disrupted sleep، which could affect the risk of cancer.
The researchers believe staying awake later may also have an impact on a woman’s body clock، increasing the risk further. This echoes previous studies which found night-shift workers and those exposed to more artificial light at night are at greater risk of cancer.
The research team، who presented their findings at the National Cancer Research Institute conference in Glasgow، analysed women’s genes and asked them whether they were a morning or an evening person.
Dr Rebecca Richmond، from Bristol، said: ‘We would like to do further work to investigate the mechanisms underpinning these results، as the estimates obtained are based on questions related to morning or evening preference rather than actually whether people get up earlier or later in the day.
‘It may not be the case that changing your habits changes your risk of breast cancer. It may be more complex than that.’
Dr Emma Pennery، of the Breast Cancer Care charity، said: ‘Changing your sleeping habits is not as easily done as other proven risk-reducing choices، as they’re often part and parcel with jobs، parenting or other health conditions.’