Estrogen and Disease
Facts about estrogen and cardiovascular disease:
Physicians now know that estrogen helps protect women against heart disease, which is critical as more American women die of heart disease than any other disease. When a woman's body is producing estrogen, her risk of having a heart attack is much lower than a man's. However, by the time a woman is 65 years old, her risk of heart attack equals a man's because she no longer produces estrogen.
How does estrogen protect against heart disease?
There are several ways that estrogen protects the body from heart disease. First, it reduces the body's total cholesterol level by regulating the amount of cholesterol produced by the liver. This, in turn, raises the high-density lipoprotein (HDL) level, commonly referred to as the "good" cholesterol, and lowers the low-density lipoprotein (LDL) level, or "bad" cholesterol. (The LDL is the cholesterol that builds up in the arteries, increasing the risk of heart attack, while HDL helps to prevent blockage from occurring in the arteries.)
Several clinical studies over the past 15 years have shown that women who use estrogen after menopause significantly reduce their risk of developing and dying from heart disease. A 1991 study showed that estrogen replacement reduced the risk of death from cardiovascular disease by almost 50 percent, with actual overall deaths reduced by 40 percent. Some researchers believe this is because of estrogen's ability to maintain HDL and LDL levels at healthier, premenopausal levels. In most cases, this protection lasts for as long as the woman is taking estrogen.
Facts about estrogen and stroke:
Today, there is growing evidence that estrogen replacement therapy may decrease the incidence of stroke, another deadly disease that affects many elderly women. Most strokes are caused by the same type of arterial disease that causes heart attacks. One study showed that estrogen replacement therapy decreased the incidence of stroke by 30 to 40 percent in postmenopausal women. Further research in this area continues.
Facts about estrogen and Alzheimer's disease:
Estrogen is important to the building and maintenance of nerve networks in the brain from early on in life. Several studies are now pointing to the fact that estrogen may offer protection against Alzheimer's disease in postmenopausal women. One study conducted on almost 90,000 postmenopausal women found that those taking estrogen had a significantly longer life and by the time of their deaths, the women on estrogen had a 40 percent lower incidence of Alzheimer's disease. In another related study, estrogen was also associated with a significantly decreased occurrence of the disease. In addition, those women who did develop Alzheimer's disease and were on estrogen replacement therapy seemed to have a milder form of the disease. Additional studies are being conducted to determine just what the protective nature of estrogen is in its relationship with Alzheimer's disease.
Facts about estrogen and osteoporosis:
Women are four times more likely to develop osteoporosis than men. Estrogen deficiency is one significant cause of accelerated bone loss in women during and after menopause, and is the major cause of bone fractures in postmenopausal women.
How does menopause affect osteoporosis?
Bone mass reduction accelerates during menopause - demonstrating a clear relationship between the level of estrogen in a woman's body and the speed at which osteoporosis develops. After menopause, a woman's risk for osteoporosis is greatly increased. The sudden loss of estrogen leads to bone loss of between 2 and 5 percent for at least five to ten years after menopause.
Preventing osteoporosis:
Bone loss generally begins after age 35. It is important for women of all ages to build bone mass with weight-bearing exercises such as walking, running, and lifting weights. Physicians also recommend diets rich in calcium and vitamin D. In addition, it is generally recommended that women take in at least 1,000 mg of calcium before menopause and 1,500 mg after menopause.
Estrogen replacement therapy and non-hormonal medications may help prevent osteoporosis, although these medications cannot reverse bone loss once it has occurred.
