The Dangers of Age-Related Hormone Decline
By the time a woman enters menopause, she may have already experienced two decades of hormonal imbalance. During the postmenopausal period, when sex hormone levels decrease significantly, aging women are at increased risk of the following diseases: heart disease, osteoporosis, Alzheimer’s, dementia, among others.
Heart disease. According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading killer of American women (CDC 2012). The risk for postmenopausal women is equal to that seen in men. Menopause can cause elevations in blood pressure, low-density lipoprotein (LDL) cholesterol, total cholesterol, triglycerides, as well as homocysteine levels, C-reactive protein, and interleukin-6 (an inflammatory cytokine), which are all associated with estrogen deficiency (Cushman 2003; Davison 2003; Dijsselbloem 2004). At the same time, high-density lipoprotein (HDL) cholesterol levels drop significantly. Estrogenic activities are vital for maintaining the integrity of the vascular endothelium, where atherosclerotic changes begin (Arnal 2009). Finally, lack of estrogen replacement in the postmenopausal state may predispose women to forms of cardiac muscle disease that are only now beginning to be understood (Kuo 2010).
Osteoporosis. Hormone deficiencies (beginning as early as age 30) are clearly associated with bone loss and osteoporosis. By the time women reach age 50, they are at a significantly increased risk of an osteoporotic bone fracture. Estrogen deficiency results in increased production of pro-inflammatory cytokines, which cause increased bone breakdown and inflammation (Weitzmann 2006). Combined estrogen and androgen (i.e., natural or synthetic) therapy has been shown to increase BMD more than estrogen therapy alone (Notelovitz 2002).
Alzheimer's and dementia. Hormone loss is associated with neuronal degeneration and increased risk of dementia, Alzheimer’s disease, and Parkinson’s disease (Amtul 2010; Rocca 2008). Estrogen stimulates degradation of beta-amyloid protein (noted to accumulate in the brain of Alzheimer's disease patients) by up-regulating production of protective proteins (Liang 2010). Deficiencies in pregnenolone and DHEA, which are both neuroprotective hormones, are also linked to reduced memory and brain cell death associated with Alzheimer's disease (Vallée 2001; Yao 2002). These two hormones play an important role in regulating neurotransmitter systems that are involved in learning, stress, depression, addiction, and many other vital functions (Vallée 2001).
Progesterone's Balancing Act
In a healthy young woman, progesterone serves as a counterweight to estrogen during the menstrual cycle. Estrogen levels rise during the first half of the cycle and progesterone levels rise in the middle. Progesterone's job is two-fold: 1) to prepare the uterus for implantation with a healthy fertilized egg, and 2) to support the early stage of pregnancy. If no implantation occurs, progesterone levels drop until another cycle begins.
Studies have shown that progesterone has anti-proliferative effects on breast cancer and leukemia cells (Formby 1998; Hayden 2009; Hilton 2010). Breast cancer is 5.4 times more common in pre-menopausal women with low progesterone levels than with favorable levels (Cowan 1981). Data suggest that while bioidentical (i.e., natural) progesterone does not increase risk of breast cancer, synthetic progestins used in conventional HRT do (Campagnoli 2005).
Natural progesterone has also demonstrated neuroprotective properties. One study called for more attention to progesterone as a “potent neurotrophic agent that may play an important role in reducing or preventing motor, cognitive, and sensory impairments [in both men and women]” (Stein 2005).