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Too Much Estrogen
The most significant hormone imbalance in aging men is a decrease in free
testosterone, while estrogen levels remain the same or increase
precipitously. As men grow older, they experience a variety of disorders
relating to the dual effects of having too little testosterone and excess
estrogen. The result is a testosterone-estrogen imbalance that directly
causes many of the debilitating health problems associated with normal aging
One cause of hormone imbalance in men is that their testosterone is
increasingly converted to estrogen. One report showed that estrogen levels
of the average 54-year-old man are higher than those of the average
59-year-old woman (1, 5, 13-18, 48).
The reason that testosterone replacement therapy does not work by itself for
many men is that exogenously administered testosterone may convert
(aromatize) into even more estrogen, thus potentially worsening the hormone
imbalance problem in aging males (i.e., too much estrogen and not enough
free testosterone) (21, 26). Although there are studies that show that
testosterone replacement therapy does not increase estrogen beyond normal
reference ranges, we will show later how the standard laboratory reference
ranges do not adequately address the issue of estrogen overload (4, 8, 9,
17, 22-25, 27, 29-32).
Estrogen is an essential hormone for men, but too much of it causes a wide
range of health problems. The most dangerous acute effect of excess estrogen
and too little testosterone is an increased risk of heart attack or stroke
(39-43, 261-270). High levels of estrogen have been implicated as a cause of
benign prostatic hypertrophy (BPH) (35-44, 46, 47). One mechanism by which
nettle root extract works is to block the binding of growth-stimulating
estrogen to prostate cells (42-44, 48-50).
When there is too little testosterone present, estrogen attaches to
testosterone cell receptor sites throughout the body and creates many
problems in aging men. In youth, low amounts of estrogen are used to turn
off the powerful cell-stimulating effects of testosterone. As estrogen
levels increase with age, testosterone cell stimulation may be locked in the
"off" position, thus reducing sexual arousal and sensation and causing the
loss of libido so common in aging men (94, 99, 259).
High serum levels of estrogen also trick the brain into thinking that enough
testosterone is being produced, further slowing the natural production of
testosterone. This happens when estrogen saturates testosterone receptors in
the hypothalamus region of the brain. The saturated hypothalamus then stops
sending out a hormone to the pituitary gland to stimulate secretion of
luteinizing hormone that the gonads require to produce testosterone. High
estrogen can thus shut down the normal testicular production of testosterone
(1, 53, 54, 271-277).
One further complication of excess estrogen is that it increases the body's
production of sex hormone-binding globulin (SHBG). SHBG binds free
testosterone in the blood and makes it unavailable to cell receptor sites
(51, 52, 55, 56).
Based on the multiple deleterious effects of excess estrogen in men,
aggressive action should be taken to reduce estrogen to a safe range if a
blood test reveals elevated levels. We will discuss the appropriate blood
tests and steps that can be taken to lower estrogen levels later in this