Women who carry excess body fat have an increasing incidence of cancer and this is due to the fact that they produce more oestrogen. Oestrogen production is higher when there is excessive body fat because oestrogen can also be made in adipose tissue. This is true even after the menopause. Oestrogen leads to proliferation of certain cells and when this goes awry it can lead to cancer. This can occur in the uterus, breast , endometrium and other tissues.
Carrying excess weight can also decrease the number of a protein, called sex hormone binding globulin (SHBG), that bind oestrogen in the blood and render it inert. So aswll as producing more oestrogen, a woman with excess body fat also has more ‘free’ and less ‘bound’ oestrogen in the blood .
Oestrogen is an essential hormone for women and a lack of it causes menopuse symptoms and loss of fertility. It is also natural for oestrogen levels to fall after the menopause but it is having higher than normal levels of oestrogen for long periods of time that could lead to certain cancers.