Published: Thu, November 08, 2018
Medicine | By Brett Sutton

Morning people 'less likely to develop breast cancer'

Morning people 'less likely to develop breast cancer'

A University of Bristol study has found a link between early risers and a lower risk of breast cancer.

The study found that a preference for mornings reduced the risk of breast cancer by 40 per cent compared with being an evening type.

The data also showed that women who slept longer than the recommended seven to eight hours a night had a 20 percent increased risk of breast cancer for each 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.

In other words, it is at present unknown whether it is your genetic body clock itself, or living out of sync with it - for instance, forcing yourself to get up early for work if you are a lark - which affects your breast cancer risk.

Around one in seven women in the United Kingdom will develop breast cancer during their lifetime, and well-known risk factors include smoking, alcohol, age and family history.

"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 participants", she added.

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.


"The authors do not show any biological mechanism by which sleep timing preference could influence breast cancer risk".

"Previous research has looked at the impact of shift work, but this is showing there may be a risk factor for all women".

Dan Damon has been speaking to one of the researchers, Professor Richard Martin - an expert in cancer epidemiology from the University of Bristol.

The study was funded by Cancer Research UK and the Medical Research Council. "Another limitation is that sleep timing preference (chronotype) is self-reported, and the investigation did not specifically recruit individuals with different sleep patterns, such as night-shift workers", Burgess wrote in the comments of the study.

The American Cancer Society says 45% of cancer deaths in the United States are linked to modifiable risk factors, such as cigarette smoke, excess body weight, eating red and processed meat and physical inactivity.

"We know that sleep is important generally for health", said Richmond.

Being a morning person is partly down to genetics, so this lowered risk does make some sense.

About the NCRI Cancer ConferenceThe NCRI Cancer Conference is the UK's largest forum showcasing the latest advances in cancer research.

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