Genetics is primarily responsible for the timing of a girl's first period, claim scientists at the Institute of Cancer Research, a college of the University of London.
This study contradicts the earlier claim that environment, lifestyle and diet played a bigger role in menarche, the time when periods begin. But this study has revealed that a girl's age of menarche was connected to that of her relatives that included her mother, older sister, grandmother and aunts. Interestingly, female relations from the father's side had a comparatively strong influence on the timing of a girl's first period.
The age at which periods begin is important as an early onset or late menopause could mean chronic diseases like breast cancer because of a longer exposure to the female sex hormones.
Researcher Danielle Morris of the ICR said 'The age at which a girl's mother or older sister began their periods is the strongest clue as to when she will start."
The study was carried out to identify those at high-risk of developing breast cancer. The findings could help women within families with an early menarche pursue lifestyles that help reduce the risk of breast cancer in later life.