Waking up early in the morning may prevent your risk of developing breast cancer than those sleeping late, according to a study.
Breast cancer is the most common cancer among women worldwide impacting 2.1 million women each year and also leads cancer-related deaths among women.
Sleep traits — rising up early than going to bed late — could have a direct effect on risk of developing breast cancer, according to the study published by The BMJ.
In addition, those who sleep more than the recommended 7-8 hours a night also showed potential harmful effect.
Previous studies have shown a link between night shift work and risk of breast cancer. The reason identified was the disruption in the internal body clock.
For the new study, an international team led by research from the University of Bristol in the UK, analysed the potential effects of sleep habits on breast cancer risk.
They examined data of 4,09,167 women, from two high quality resources, using a technique called Mendelian randomisation, and analysed genetic variants associated with three particular sleep traits:
The results showed early risers had a slightly lower risk of breast cancer (one less woman per 100) than those in the evening preference. Little evidence was seen for sleep duration and insomnia symptoms.
However, the effect is likely to be smaller than that of other known risk factors for breast cancer, such as BMI and alcohol intake, the researchers stressed
The study “provides strong evidence for a direct effect of chronotype on breast cancer risk” and “have potential implications for influencing sleep habits of the general population in order to improve health,” the researchers said.
According to Eva Schernhammer, a professor from the University of Vienna, the study prompts the need to explore how the stresses on our biological clock can be reduced.
Moreover, it “could also help to align working hours with chronotype — to more closely match externally imposed timing with individual diurnal preference, especially in the working population,” she added, in a linked editorial.
The findings also “offer a tremendous opportunity for preserving good health, achieving healthy ageing, and, more specifically, for developing new personalised strategies for reducing the risk of chronic diseases associated with the circadian system,” Schernhammer said.