Researchers at University of Bristol found that women who are "morning people" are 40 to 48 percent less likely to develop breast cancer than women who are most active in the evening and go to sleep later - about one fewer case of breast cancer among every 100 morning larks as among the same number of night owls. The research also suggested that for women who slept longer than the recommended seven to eight hours per night, the risk of being diagnosed increased by 20 per cent per additional hour slept.
Cancer risks associated with a person's body clock and sleep patterns have been reported in previous research and the United Kingdom researchers wanted to explore sleep traits in more detail, as well as any genetic factors underlying this.
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. Still more studies must be done to understand the connection between waking up earlier or later in the day and breast cancer diagnosis.
Attendees of the event included hundreds of family members, sports teams, friends, and even those valiant survivors affected by breast cancer; most wearing sashes to signify their defeat against the cause.More news: Jeff Sessions Has Been Fired
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She tells the BBC: "We still need to get at what makes an evening person more at risk than a morning person... we need to unpick the relationship".
Dan Damon has been speaking to one of the researchers, Professor Richard Martin - an expert in cancer epidemiology from the University of Bristol.
"Previous research has looked at the impact of shift work, but this is showing there may be a risk factor for all women". Does the body clock affect hormone levels to alter cancer risk, or the immune system, or metabolism? The World Health Organization already says disruption to people's body clocks because of shift work is probably linked to cancer risk.More news: Bryce Harper rejected contract offer from Nationals
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Those that were found to have the genes of a morning person had a lower chance of getting breast cancer.
The findings have been published on researchers' website bioRxiv but have not yet gone through scientific peer review. "This study provides further evidence to suggest disrupted sleep patterns may have a role in cancer development", Kirwan said in a meeting news release.
"In terms of the implications of the research, it supports existing evidence that sleep patterns influence cancer risk, but it remains unclear how individual preferences for early or late rising interact with actual sleep behaviours", Moorthie wrote in an email.More news: Web pioneer wants new 'contract' for internet