The effects of oestrogen dominance on breast health
The effects of oestrogen in the body are supposed to be balanced, or opposed by the hormone progesterone. Progesterone is a hormone made by the ovaries in the second half of the menstrual cycle, after ovulation. After ovulation the ovarian follicle changes into what is known as the corpus luteum, which secretes progesterone until day one of the menstrual cycle, which is when bleeding begins. Some progesterone is also made in the adrenal glands. Progesterone is made out of the steroid hormone pregnenalone, and it is the precursor to several hormones, including cortisol, oestrogen and the male hormones testosterone and androstenedione.
Where oestrogen acts like a fertiliser on hormone sensitive tissues, progesterone acts like a lawn mower. While oestrogen stimulates breast cells to grow and divide, progesterone causes them to mature. Progesterone protects the breasts and uterus from potentially harmful effects of excess oestrogen. Unfortunately, progesterone deficiency is extremely common in today’s women; there are several reasons for this. If ovulation does not occur, the ovary cannot produce progesterone in the second half of the menstrual cycle. Ovulation can be inhibited by high insulin levels (causing polycystic ovarian syndrome), stress, nutritional deficiencies and endocrine disruptors (chemicals that behave like oestrogen). If you are chronically stressed, you will convert much of your progesterone to cortisol. This can cause menstrual problems and promote weight gain around your torso.
Oestrogen dominance describes a condition where not enough progesterone is being produced relative to oestrogen. You can have high, normal or low levels of oestrogen, but if you are not producing adequate progesterone to counteract oestrogen, you are said to suffer with oestrogen dominance. Women with oestrogen dominance are more likely to suffer with painful breasts or breast lumps, particularly in the week before menstruation.