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- <head><title>Estrogen and Osteoporosis</title></head>
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- <h1>
- Estrogen and Osteoporosis
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-
- The government declared victory in the war on cancer, though the age-specific death rate from cancer keeps
- increasing. In the equally well publicized effort to prevent disability and death from osteoporosis, no one is
- declaring victory, because the only trend in its incidence that has been reported is an increase. The
- estrogen-promoting culture tells us that this is because of the aging of the population, but the age corrected
- numbers still show a great increase--for example, in Finland between 1970 and 1995, the number of women (for a
- given population of women older than 60) breaking their forearm because of osteoporosis more than doubled
- (Palvanen, et al., 1998). That this happened during a time when the use of estrogen had become much more common
- doesn't present a good argument for the protective effects of estrogen treatment. (And during this period there
- was a large increase in the consumption of estrogenic soy products.) Recently our local newspaper had a story at
- the bottom of the front page reporting that lean women who used estrogen and synthetic progestins had an 80%
- higher rate of breast cancer. Several days later, across the top of the front page, there was a rebuttal
- article, quoting some doctors including a "world class expert on hormone replacement therapy" and a woman who
- has taken Premarin for forty years and urges everyone to take it. The "protection against osteoporosis" and
- against heart disease, they said, must be weighed against a trifle such as the 80% increase in cancer. It
- appeared that the newspaper was apologizing for reporting a fact that could make millions of women nervous. (Jan
- 26, Register-Guard). Medical magazines, like the mass media, don't like to miss any opportunity to inform the
- public about the importance of using estrogen to prevent osteoporosis. Their attention to the bone-protective
- effect of progesterone has been noticeably less than their mad campaign to sell estrogen, despite the evidence
- that progesterone can promote bone rebuilding, rather than just slowing its loss. Although I have spoken about
- progesterone and osteoporosis frequently in the last 25 years, I have only occasionally considered what estrogen
- does to bones; generally, I described estrogen as a stress-promoting and age-promoting hormone. In the 1970s,
- pointing out progesterone's protective antagonism to excessive amounts of other hormones, and that the catabolic
- glucocorticoids tend to increase with aging, I began referring to progesterone as the "anticatabolic" hormone
- that should be used to prevent stress-induced atrophy of skin, bones, brain, etc. A former editor of Yearbook of
- Endocrinology had reviewed a series of studies showing that excess prolactin can cause osteoporosis. Then, he
- presented a group of studies showing how estrogen promotes the secretion of prolactin, and can cause
- hyperprolactinemia. In that review, he wryly wondered how something that increases something that causes
- osteoporosis could prevent osteoporosis. Women have a higher incidence of osteoporosis than men do. Young women
- have thinner more delicate bones than young men. The women who break bones in old age are generally the women
- who had the thinnest bones in youth. Menstrual irregularities, and luteal defects, that involve relatively high
- estrogen and low progesterone, increase bone loss. Fatter women are less likely to break bones than thinner
- women. Insulin, which causes the formation of fat, also stimulates bone growth. Estrogen however, increases the
- level of free fatty acids in the blood, indicating that it antagonizes insulin (insulin decreases the level of
- free fatty acids), and the fatty acids themselves strongly oppose the effects of insulin. Estrogen dominance is
- widely thought to predispose women to diabetes. Between the ages of 20 and 40, there is a very considerable
- increase in the blood level of estrogen in women. However, bone loss begins around the age of 23, and progesses
- through the years when estrogen levels are rising. Osteoarthritis, which involves degeneration of the bones
- around joints, is strongly associated with high levels of estrogen, and can be produced in animals with estrogen
- treatment. Thirty years ago, when people were already claiming that estrogen would prevent or cure osteoporosis,
- endocrinologists pointed out that there was no x-ray evidence to support the claim. Estrogen can cause a
- positive calcium balance, the retention of more calcium than is excreted, and the estrogen promoters argued that
- this showed it was being stored in the bones, but the endocrine physiologists showed that estrogen causes the
- retention of calcium by soft tissues. There are many reasons for not wanting calcium to accumulate in the soft
- tissues; this occurs normally in aging and stress. Then, it was discovered that, although estrogen doesn't
- improve the activity of the cells that build bone, it can reduce the activity of the cells that remove bone, the
- osteoclasts. The osteoclast is a type of phagocytic cell, and is considered to be a macrophage, the type of cell
- that can be found in any organ, which can eat any sort of particle, and which secretes substances (cytokines,
- hormone-like proteins) that modify the functions of other cells. When estrogen was found to impair the activity
- of this kind of cell, there wasn't much known about macrophage cytokines. With the clear evidence that estrogen
- inhibits the osteoclasts without activating the bone-building osteoblasts, estrogen was said to "prevent bone
- loss," and from that point on we never heard again about estrogen promoting a positive calcium balance. Calcium
- retention by soft tissues has come to be an accepted marker of tissue aging, tissue damage, excitotoxicity, and
- degeneration. Positive calcium balance had been the essence of the argument for using estrogen to prevent
- osteoporosis: "Women are like chickens, estrogen makes them store calcium in their bones." But if everyone now
- recognizes that calcium isn't being stored in bones, it's better for the estrogen industry if we forget about
- the clearly established positive calcium balance produced by estrogen. The toxic effects of excessive
- intracellular calcium (decreased respiration and increased excitation) are opposed by magnesium. Both thyroid
- and progesterone improve magnesium retention. Estrogen dominance is often associated with magnesium deficiency,
- which can be an important factor in osteoporosis (Abraham and Grewal, 1990; Muneyyirci-Delale, et al., 1999). As
- part of the campaign to get women to use estrogen, an x-ray (bone density) test was devised which can supposedly
- measure changes in the mineral content of bone. However, it happens that fat and water interfere with the
- measurements. Estrogen changes the fat and water content of tissues. By chance, the distortions produced by fat
- and water happen to be such that estrogen could appear to be increasing the density of a bone, when it is really
- just altering the soft tissues. Ultrasound measurements can provide very accurate measurements of bone density,
- without the fat and water artifacts that can produce misleading results in the x-ray procedure, and don't expose
- the patient to radiation, but the ultrasound method is seldom used. In recent years, there has been quite a lot
- of research into the effects of the macrophage cytokines. Immune therapy for cancer was considered quackery when
- Lawrence Burton identified some substances in blood serum that could cause massive tumors in rodents to
- disappear in just a few hours. One of the serum factors was called Tumor Necrosis Factor, TNF. An official
- committee was formed to evaluate his work, but it reported that there was nothing to it. A member of the
- committee later became known as "the authority" on tumor necrosis factor, which was thought to have great
- potential as an anticancer drug. However, used by itself, TNF killed only a few cancers, but it damaged every
- organ of the body, usually causing the tissues to waste away. Other names, lymphotoxin and cachectin, reflected
- its toxic actions on healthy tissues. Aging involves many changes that tend to increase the inflammatory
- reaction, and generally the level of TNF increases with aging. Although cancer, heart failure, AIDS, and extreme
- hormone deficiency (from loss of the pituitary or thyroid gland, for example) can cause cachexia of an extreme
- and rapid sort, ordinary aging is itself a type of cachexia. Progeria, or premature aging, is a kind of wasting
- disease that causes a child's tissues (including bones) to atrophy, and to change in many of the ways that would
- normally occur in extreme old age. Recent studies have found that both men and women lose minerals from their
- bones at the rate of about 1% per year. Although men have lower estrogen in youth than women do, their bones are
- much heavier. During aging, as their bones get thinner, men's estrogen levels keep rising. Besides having weaker
- bones, old people have weaker muscles, and are more likely to injure themselves in a fall because their muscles
- don't react as well. Muscle loss occurs at about the rate of 1% per year. Women's muscles, like their bones, are
- normally smaller than men's, and estrogen contributes significantly to these differences. TNF can produce very
- rapid loss of tissue including bone, and in general, it rises with aging. Some of the people who like to say
- that "osteoporosis is caused by estrogen deficiency" know about the destructive actions of TNF, and argue that
- it rises at menopause "because of estrogen deficiency." There are very good reasons for rejecting that argument;
- the experiments sometimes seem to have been designed purely for propaganda purposes, using toxic levels of
- estrogen for a specific result. One researcher noted that the effects of estrogen on cells in vitro are
- biphasic: Low doses increased TNF, high doses decreased TNF. Everyone knows that unphysiologically high doses
- (50 or 100 or more times above the physiological level of around 0.25 micrograms per liter) of estrogen are
- toxic to cells, producing functional and structural changes, and even rapid death. So, when a researcher who
- wants to show estrogen's "bone protective" effect of lowering TNF adds a lethal dose of estrogen to his cell
- culture, he can conclude that "estrogen inhibits TNF production." But the result is no more interesting than the
- observation that a large dose of cyanide inhibits breathing. TNF is produced by endotoxin, and estrogen
- increases the amount of endotoxin in the blood. Even without endotoxin, though, estrogen can stimulate the
- production of TNF. Lactic acid and unsaturated fats and hypoxia can stimulate increased formation of TNF.
- Estrogen increases production of nitric oxide systemically, and nitric oxide can stimulate TNF formation. How
- does TNF work, to produce tissue damage and wasting? It causes cells to take up too much calcium, which makes
- them hypermetabolic before it kills them. It increases formation of nitric oxide and carbon monoxide, blocking
- respiration. TNF can cause a 19.5 fold increased in the enzyme which produces carbon monoxide (Rizzardini, et
- al., 1993), which blocks respiration. All of the normal conditions associated with high estrogen also are found
- to involve increased production of TNF, and treatment of animals with estrogen clearly increases their TNF.
- Premature ovarian failure (with low estrogen levels) leads to reduced TNF, as does treatment with antiestrogens.
- If bone resorption is significantly regulated by TNF, then it should be concluded that increased estrogenic
- influence will tend to produce osteoporosis. Tamoxifen, which has some estrogenic effects, including the
- inhibition of osteoclasts, can kill osteoclasts when the dose is high enough. The inhibition of osteoclast
- activity by either estrogen or tamoxifen is probably a toxic action, that has been characterized as "beneficial"
- by the estrogen industry simply because they didn't have any better argument for getting women to use their
- products. Some types of dementia, such as Alzheimer's disease, involve a life-long process of degeneration of
- the brain, with an inflammatory component, that probably makes them comparable to osteoporosis and
- muscle-wasting. (In the brain, the microglia, which are similar to macrophages, and the astrocytes, can produce
- TNF.) The importance of the inflammatory process in Alzheimer's disease was appreciated when it was noticed that
- people who used aspirin regularly had a low incidence of that dementia. Aspirin inhibits the formation of TNF,
- and aspirin has been found to retard bone loss. In the case of osteoporosis (A. Murrillo-Uribe, 1999), as in
- Alzheimer's disease, the incidence is two or three times as high in women as in men. In both Alzheimer's disease
- and osteoporosis, the estrogen industry is arguing that the problems are caused by a suddenly developing
- estrogen deficiency, rather than by prolonged exposure to estrogen. Similar arguments were made fifty years ago
- regarding the nature of the menopause itself--that it was caused by a sudden decrease in estrogen production.
- The evidence that has accumulated in the last forty years has decisively settled that argument: Menopause is the
- result of prolonged exposure to estrogen. (Even one large dose destroys certain areas in the brain, and chronic,
- natural levels damage the nerves that regulate the pituitary. Overactivity of the pituitary leads to many other
- features of aging.) The links between estrogen and TNF appear to be essential factors in aging and its diseases.
- Each of these substances has its constructive, but limited, place in normal physiology, but as excitatory
- factors, they must operate within the appropriate constraints. The basic constraint is that resources, including
- energy and oxygen, must be available to terminate their excitatory actions. Adequate oxygen, a generous supply
- of carbon dioxide, saturated fats, thyroid, and progesterone restrain TNF, while optimizing other cytokines and
- immune functions, including thymic protection. In the development of the organism and its adaptive functions,
- there are patterned processes, functional systems, that can clarify the interactions of growth and atrophy. The
- respiratory production of energy and carbon dioxide, and the respiratory defect in which lactic acid is
- produced, correspond to successful adaptation, and to stressful/excitotoxic maladaptation, respectively.
- Excitotoxicity, and Meerson's work on the protective functions of the antistress hormones, have to be understood
- in this framework. This framework integrates the understanding of cancer metabolism with the other stress
- metabolisms, and with the metabolism of normal growth. Unsaturated fats, iron, and lactic acid are closely
- related to the actions and regulation of TNF, and therefore they strongly influence the nature of stress and the
- rate of aging. The fact that cancer depends on the presence of polyunsaturated fats probably relates to the
- constructive and destructive actions of TNF: The destructive effects such as multiple organ failure/congestive
- heart failure/shock-lung, etc., apparently involve arachidonic acid and its metabolites, which are based on the
- so-called essential fatty acids. When oxygen and the correct nutrients are available, the hypermetabolism
- produced by TNF could be reparative (K. Fukushima, et al., 1999), rather than destructive. Stimulation in the
- presence of oxygen produces carbon dioxide, allowing cells to excrete calcium and to deposit it in bones, but
- stimulation in the absence of oxygen produces lactic acid and causes cellular calcium uptake. It is in this
- context that the therapeutic effects of saturated fats, carbon dioxide, progesterone, and thyroid can be
- understood. They restore stability to a system that has been stimulated beyond its capacity to adapt without
- injury.
-
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