More good news for those smug early risers who can get up at the crack of dawn to do yoga before work: You're less likely to develop breast cancer than night owls. The study also found that women who sleep more than seven to eight hours have a 20% increased risk for each additional hour after that that they slept.
"Our findings are based on questions related to morning or evening preference rather than actually whether people get up earlier or later in the day", said Rebecca Richmond, of the University of Bristol.
'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.
"However, the findings of a protective effect of morning preference on breast cancer risk in our study are consistent with previous research...", Richmond noted.
Dr. Sowmiya Moorthie, senior policy analyst in epidemiology at PHG Foundation, who was not involved in the research, added that the study's major strength is the use of "multiple approaches to examine the links between sleep traits and breast cancer, which allows the researchers to demonstrate consistency in their findings". Still more studies must be done to understand the connection between waking up earlier or later in the day and breast cancer diagnosis.
Researchers also looked at results from nearly 229,000 women signed up to an global genetic study carried out by the Breast Cancer Association Consortium. They used a clever new way of analysing data - called Mendelian randomisation. The Breast Cancer Walk, which centered at the Manhattanville College Campus and directed its way up to SUNY Purchase, totaled five kilometers.More news: North Korea 'really angry' at USA as tensions rise
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'.
The Medifem Multi-Specialist Hospital & Fertility Centre has rounded up a series of activities put together to mark Breast Cancer Awareness campaign in October.
"The authors do not show any biological mechanism by which sleep timing preference could influence breast cancer risk".
"We know already that night shift work is associated with worse mental and physical health".
The data showed that women who were morning types, also known as "larks, ' had a reduced risk of breast cancer compared with those who were evening types, or 'owls".
However, cancer experts say modifying your sleep patterns probably won't have a significant impact on your cancer risk.