A study conducted among 400 000 women in the UK Biobank looked at approximately 450 biomarkers and found that earlier risers are less likely to develop breast cancer than those who up stay up late at night.
As reported by Sarah Knapton from the
Telegraph, the research was funded by Cancer Research UK and the Medical Research Council and presented at the NCRI Cancer Conference in Glasgow on 5 November.
Out of the 400 000 women, 2,740 were breast cancer survivors and 149 064 were disease free. Researchers then mapped the genetic variations between the earlier risers and the night owls and compared it with that to the risk of developing cancer.
The morning people had a reduced risk of more than 40%, compared to the night owls. The study also found women who slept longer than the recommended seven to eight hours had a 20 per cent increased risk of breast cancer for every additional hour slept.
“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,”. In other words, it may not be the case that changing your habits changes your risk of breast cancer; it may be more complex than that. said Rebecca Richmond, a research fellow in the Cancer Research U.K. Integrative Cancer Epidemiology Program at the University of Bristol.
“However, the findings of a protective effect of morning preference on breast cancer risk in our study are consistent with previous research highlighting a role for night shift work and exposure to ‘light-at-night’ as risk factors for breast cancer.
“We also found some evidence for a causal effect of increased sleep duration and sleep fragmentation on breast cancer, assessed using objective measurements of sleep obtained from movement monitors worn by around 85,000 UK Biobank participants.”
The researchers believe their findings have implications for policy-makers and employers. Dr Richmond said: “These findings have potential policy implications for influencing sleep habits of the general population in order to improve health and reduce risk of breast cancer among women.”
Dr Richmond and her colleagues are planning to investigate the mechanisms underlying the effects of different sleep characteristics on the risk of developing breast cancer. “We would like to use genetic data from large populations to further understand how disrupting the body’s natural body clock can contribute to breast cancer risk,” she said.