Estrogen Without Progesterone

Estrogen Without Progesterone Can Be Harmful

In the uterus

The tissues that line the uterus are programmed to die at some point and be replaced. This programmed cell death is called apoptosis. (Aypa-tosis) An excess of estrogen and a lack of enough progesterone will prevent this programmed cell death. This may be why supplementation with estrogen without progesterone can lead to cancer of the uterus.

In the breast

In the breast, estrogen helps form the duct cells and the milk-producing apparatus. Progesterone causes these cells to differentiate into milk-producing glands. If thers not enough progesterone, then the duct cells are not pushed into the well-differentiated glandular state and are more easily able to transform themselves into a cancer cell.

Cells in the breast are constantly being replaced. One gene known as BCL-2 blocks cell death and can lead to uncontrolled cell growth and cancer. Another gene known as P-53 prevents this cell overgrowth and subsequent cancer. Estrogen increases the activity of this growth-controlling BCL-2 gene whereas progesterone decreases its activity. Progesterone also increases the activity of the anti-cancer P-53 gene. By the way, lipoic acid is a suppletment that also increases the activity of the anti-cancer P-53 gene.

This may be why studies have shown that adequate progesterone levels decrease the risk of breast cancer. For instance, women who have had numbers of children have been exposed to a good deal of progesterone with their pregnancies, and subsequently they have a lot less breast cancer. (Recall, there are three estrogenic hormones, estriol, estrone, and estradiol. Estriol rises to very high levels in pregnancy. There is evidence that higher estriol levels protect women from breast cancer. So this may be another reason why pregnancy seems to protect a bit from breast cancer).