Approximately one in every 10 American women between the ages of 45 and 64 years of age has some form of heart disease, and this statistic increases to one in five after age 65. This significant rise in heart disease is believed to be at least partially due to the reduced estrogen levels women experience as they go through menopause. As women’s estrogen production dwindles, their risk of heart disease rises dramatically, eventually becoming the same as men’s risk.
Because women tend to develop heart disease later in life than men, they also tend to have a longer exposure to high cholesterol levels and a thicker buildup of plaque in their blood vessels when their heart disease hits.
Estrogen therapy lowers cardiovascular risk, according to Dr. Jonathan Wright. As stated earlier, it seems to increase blood levels of “good” HDL cholesterol and decrease levels of “bad” LDL cholesterol. However, estrogen is often prescribed as Prempro, in combination with progestin (medroxyprogesterone acetate or MPA), as referenced in the WHI study above. Studies have consistently shown that estrogen alone is more effective in increasing HDL than when combined with progestin.
In Commonsense Guide to a Healthy Heart, Dr. John Lee argues that supplements of bioidentical progesterone (i.e., not progestin) may be more critical for heart health among perimenopausal women than estrogen. He says that “Postmenopausal women with sufficient body fat produce estrogen sufficient for all known body functions excluding pregnancy. The fall in estrogen levels is negligible compared to the almost complete absence of progesterone which commonly begins to fall ten years or so before actual menopause.”
Progesterone protects the heart in many ways, including its ability to reduce high blood pressure. For example, during pregnancy, the high levels of progesterone protect against constriction of blood vessels. Hyperactivity of the blood vessels, which can lead to pain and the development of strokes, is one aspect of cardiovascular disease that is frequently overlooked.
However, Dr. Lee is adamant that the effects of bioidentical progesterone and the more common progestin (medroxyprogesterone acetate or MPA) on the heart and blood vessels are very different. He states that “MPA is a synthetic (foreign) compound and is simply not progesterone, a compound natural to human metabolism.”
Dr. Lee cites research that concludes that “progesterone protects against coronary artery spasm and MPA increases the risk of serious unrelenting coronary artery spasm.” Another well known study using rhesus monkeys demonstrated that progestin (i.e., synthetic, not bioidentical progesterone) dramatically increases spasm in the blood vessels of the heart, while progesterone does not. (See Spasms and the Effects of Magnesium below.) Studies also indicate that “MPA correlated with reduced coronary artery flow whereas progesterone correlated with improved coronary artery flow.”
Dr. Lee summarizes his treatment philosophy by stating that “progesterone inhibits the changes that cause cholesterol to become harmful to arteries, and that progestins and estrogens do not have the same effect. In other words, progesterone is uniquely protective of arteries.”