Oestrogen and Breast Cancer Risk

Natural oestrogen is the female hormone produced mainly by the ovaries in women. This production increases in your early teens and this is when your periods start – this is called the Menarche. Young women/teenagers are starting their periods at a younger age than they used to. In the Victorian era it was quite common for periods to start at age 16 and although this can still be a normal age for some, many now start at age 11 or 12. This is due to a more healthy lifestyle, better nutrition and less malnourishment, less disease and infections (often as a result of immunisation programmes, clean water, good nutrition attributes of more affluent societies).

As you get older your ovaries slow down and stop working and the amount of oestrogen produced by the ovaries is significantly reduced. As a result your periods stop. This is called Menopause. The average age of menopause in the UK is between 45 and 55. Although this age has not changed significantly, there are some women whose menopause is after 55.

Due to periods starting earlier, women are exposed to natural oestrogen from a younger age and over a longer  timespan and this could be a factor increasing the risk of breast cancer.