What are phytoestrogens?
Actions of phytoestrogens
Plants are authentic chemical plants, since during the process of
growth and maturation synthesize thousands of different substances.
In fact, until recently, most of the drugs were obtained from plants
and, even today, such as caffeine, cocaine and morphine continue
obtaining them.
Plant foods also contain many different chemicals; some are known by the names of carbohydrate, protein, fat and vitamins , ie nutrients called because they are necessary for normal metabolism of the organism. Besides these components, these foods contain other substances, known as the phytochemicals and nutrients are not considered. Many have no known activity in the body, but can have other harmful actions ( cholesterol , purine, oxalic acid, anti-nutrients, etc.) and also beneficial actions.
Most of the effects of phytochemicals has not been studied in depth,
although currently being investigated very actively in this field. It is thought that many of them may have beneficial effects, especially in the prevention of some diseases such as arteriosclerosis and cancer.
A special type of phytochemicals found in soybeans and derivatives
thereof such as tofu and some whole grain cereal or flax seeds, are
phytoestrogens.
Phytoestrogens in several different substances as isoflavones,
coumestans, lignans or genistein sharing a similar chemical structure to
estrogen included.
These substances have an important, though considerably weaker,
antioxidant activity and similar actions that estrogen or female sex
hormones.
This peculiar "hormonal" action gives phytoestrogens some very
interesting features in the prevention and treatment of some diseases,
which have probably been the most studied phytochemicals.
These substances have an important, though considerably weaker,
antioxidant activity and similar actions that estrogen or female sex
hormones.
This peculiar "hormonal" action gives phytoestrogens some very
interesting features in the prevention and treatment of some diseases,
which have probably been the most studied phytochemicals.
Phytoestrogens and breast cancer
A phytoestrogens have several beneficial actions attributed to them,
and perhaps most important is the possibility of reducing the risk of
breast cancer. It has long been known that populations with high intake of soy, such as China and Japan, have a small risk of developing breast cancer
, but when they migrate to countries like the United States this risk
increases to two generations to equal the of the American population.
This change in the risk of breast cancer was attributed for many years
to lower consumption of fat in these residents in Asia populations, but
recent epidemiological studies have ruled this out, increasing the
hypothesis that soy consumption, because it contains phytoestrogens may
lower this risk.
It has been shown in repeated experiments on animals that
phytoestrogens prevent or reduce the development of breast cancer, but
experimental tumors in animals are quite different tumors in people and
although, today, do not have clear demonstration that phytoestrogens
decrease the risk of breast cancer, studies in laboratory animals and
epidemiological studies in different populations support this
hypothesis. In any case, a diet with soy or its derivatives is healthy without harmful effects on populations who consume diet.
Although there is no clear scientific evidence, macrobiotic diets that
include foods from soybeans and their derivatives, have been linked to
lower incidence of breast, prostate and colon, and even better response to treatment of some tumors. This effect has also been attributed to phytoestrogens.
Phytoestrogens and prostate cancer
Prostate cancer with clinical manifestations also has a frequency 10-15 times higher in the US than in Japan.
Soy Phytoestrogens inhibit the growth of cells of prostate cancer and
decrease in crops precancerous lesions in the prostate of mice and rats.
In patients with this cancer with metastases, estrogens are used to
slow their growth, so it is suspected that phytoestrogens can also help
reduce the appearance of this tumor and control its progression.
Some epidemiological studies in Asian populations was found that tofu consumption reduces the risk of prostate cancer.
Phytoestrogens and osteoporosis
Estrogens (female sex hormones) play an important role in the
deposition of calcium in the bone, and soy phytoestrogens, by a similar
action may favor the calcium content in the bone and prevent osteoporosis in women.
Ipriflavone is a synthetic substance with similar chemical structure
and phytoestrogens that when metabolized in the body to produce
identical phytoestrogens soy. This substance increases bone calcification, so it is thought that phytoestrogens may also share this effect.
In rats it has also been shown to increase bone calcium phytoestrogens
with estrogen-like potency and postmenopausal women in studies also
demonstrate an increase in bone calcium content consumption with about
40 grams of soy protein. This amount is slightly elevated and elusive taking natural foods from soybeans.
Phytoestrogens and menopause symptoms
Soy derivatives have also been shown useful in the treatment of hot flashes experienced by some patients after menopause , in whom the symptoms but do not eliminate reduce their frequency.
Although phytoestrogens can be helpful in these cases, and also enjoy
the aura of "natural remedy" remember that the greatest effect in
preventing hot flashes and osteoporosis is achieved by administration of
estrogens, which are obtained from natural source such as mare's urine.
Phytoestrogens and cholesterol
Phytoestrogens also exert a favorable effect on cholesterol and
descending the level of LDL (bad) cholesterol and raise the HDL (good
cholesterol) and also in monkeys prevent the development of
arteriosclerosis.
Other effects of phytoestrogens
The only adverse effect found in animals ingesting large amounts of phytoestrogens is a decrease in fertility.
This effect has not been detected in humans and in fact the Chinese and
Japanese populations, taking larger amounts of phytoestrogens, are not
characterized by lower fertility.
Although most studies indicate that soy, tofu and other products
derived from it may have these benefits, probably mediated by
phytoestrogens, there is sufficient scientific evidence to recommend the
use of phytoestrogen supplements or soy extracts.
These products, like vitamins, it is best to take them into the natural
form of the foods that are not within the envelope of a capsule.
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