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The Mineral Selenium: A Powerful Anti-Cancer Substance
mineral selenium
Date: 1/20/2006 2:22:07 AM ( 18 y ) ... viewed 5488 times The Mineral Selenium: A Powerful Anti-Cancer Substance
The mineral selenium proves itself as powerful anti-cancer medicine
One of the most effective naturally occurring weapons against cancer is,
like most healthy things, something many of us are not getting enough of.
The mineral selenium has been shown in multiple studies to be an effective
tool in warding off various types of cancer, including breast, esophageal,
stomach, prostate, liver and bladder cancers. Not many people get the
recommended dose of 200 micrograms a day. Most Americans only get between 60
and 100 micrograms of selenium daily from dietary sources, according to the
Life Extension Foundation's Disease Prevention and Treatment. That means
daily supplements might be worth considering.
Selenium was first used in conventional medicine as a treatment for dandruff, but our understanding of the mineral has come a long way since then. Today, research shows selenium, especially when used in conjunction with vitamin C, vitamin E and beta-carotene, works to block chemical reactions that create free radicals in the body (which can damage DNA and cause degenerative change in cells, leading to cancer).
Selenium also helps stop damaged DNA molecules from reproducing. In other words, selenium acts to prevent tumors from developing. "It contributes towards the death of cancerous and pre-cancer cells. Their death appears to occur before they replicate, thus helping stop cancer before it gets started," says Dr. James Howenstine in A Physician's Guide to Natural Health Products That Work.
Selenium makes chemotherapy safer, more effective
In addition to preventing the onset of the disease, selenium has also been shown to aid in slowing cancer's progression in patients that already have it. According to the Life Extension Foundation, the use of selenium during chemotherapy in combination with vitamin A and vitamin E can reduce the toxicity of chemotherapy drugs. The mineral also helps "enhance the effectiveness of chemo, radiation, and hyperthermia while minimizing damage to the patient's normal cells; thus making therapy more of a 'selective toxin,'" says Patrick Quillin in Beating Cancer with Nutrition.
A 1996 study by Dr. Larry Clark of the University of Arizona showed just how effective selenium can be in protecting against cancer. In the study of 1,300 older people, the occurrence of cancer among those who took 200 micrograms of selenium daily for about seven years was reduced by 42 percent compared to those given a placebo. Cancer deaths for those taking the selenium were cut almost in half, according to the study that was published in the Journal of the American Medical Association.
While the study concluded the mineral helped protect against all types of cancer, it had particularly powerful impacts on prostate, colorectal and lung cancers. Jean Carper, in Miracle Cures, called Dr. Clark's findings an "unprecedented cancer intervention study" that "bumped up the respectability of using supplements against cancer several notches."
Food sources of selenium
Although too much selenium can actually be toxic to the system, research indicates the majority of the population is not getting enough of the essential mineral. So, how can we up our intake of selenium and help our bodies fight cancer? The good news is there are some good dietary sources of selenium: Mushrooms, egg yolks, seafood, poultry and kidney, liver and muscle meats contain the mineral. Vegetables -- garlic, onions, broccoli, asparagus, tomatoes and others -- as well as whole grains and seeds can also be good sources of selenium.
However, because the amount of selenium in vegetables and grains depends on the selenium content in the soil in which they are grown, it can be hard for average consumers to know how much of the mineral they are actually getting in their diets. "The selenium content of food is largely dependent on the content of volcanic ash in the soil on which the food was grown, with higher volcanic ash content yielding higher selenium levels. Soil that is irrigated by seawater, such as much of California's cropland, also contains higher levels of selenium," says Sue Gebo in What's Left to Eat. Gebo adds that, in general, soil in the western United States is richer in selenium than soil in the eastern part of the country.
Accordingly, geography can have a significant impact on diet. In Antioxidants Against Cancer, author Ralph Moss PhD, says one theory for why cancer rates are so high in Linxian, China, dubbed "the 'world capital' of cancer," is that the soil is deficient in the essential minerals selenium and zinc. In Earl Mindell's Supplement Bible, Earl Mindell RPh PhD, suggests part of the reason American men are five times more likely than Japanese men to die from prostate cancer could be because, in general, "the Asian diet contains four times the amount of selenium as the average American diet."
Another reason it seems to be difficult for Americans to get enough selenium is the processing many of our foods go through before they make it onto grocery store shelves. Mindell points out, for example, that processing wheat into white flour strips it of a great deal of its selenium. One way to get more selenium in your diet might be to eat more organically grown foods, which some studies have shown to contain more selenium as well as higher levels of beta carotene and vitamin E. These two work together with selenium in cancer prevention, according to Alternative Medicine author Burton Goldberg.
Perhaps a more surefire way to boost your selenium intake is to add supplements to your diet. Mindell advocates the use of supplements, saying, "To me, taking selenium supplements, in addition to eating selenium-rich foods, is good insurance against disease." However, for those who oppose taking pills, Dr. Andrew Weil in Ask Dr. Weil says eating just one shelled Brazil nut -- grown in the selenium-rich soil of central Brazil -- provides 120 micrograms of the mineral, getting you that much closer to the daily target of 200 micrograms.
Although extremely high doses of selenium can have toxic effects, most people are not at risk for such an overdose, and could, in fact, use more of the mineral. Simply adding more selenium-rich foods, such as organically grown vegetables and fruits to your diet, along with supplements, can help reduce your risk of cancer. And another positive side effect of selenium, according to Eat and Heal, by the Editors of FC&A Medical Publishing, is that it can actually improve your mood. Those editors write, "People who don't eat enough selenium-rich foods tend to be grumpier than people with a high dietary intake, according to recent research." So, go ahead and crack a Brazil nut open and smile.
The experts speak on selenium and cancer
Selenium Mechanisms
There are several possible mechanisms for the protective effect of selenium. Selenium activates an enzyme in the body called gluthathione peroxidase that protects against the formation of free radicals—those loose molecular cannons that can damage DNA. In this situation, selenium may work interchangeably (and in synergy) with vitamin E. In test tube studies, selenium inhibited tumor growth and regulated the natural life span of cells, ensuring that they died when they were supposed to instead of turning "immortal" and hence malignant. Because of this particular action, the University of Arizona researchers say that selenium could be effective within a fairly short time frame.
Numerous studies suggest that an inverse association exists between selenium levels and cancer incidence (Hocman, 1988; Willett and Stampfer, 1986; Milner, 1985). Associations appear to be particularly strong with cancers that are also associated with high-fat, low-fiber diets (i.e., breast, colon, prostrate, etc.). The mechanism for selenium's reported protective effects is likely due to its function in antioxidant synthesis. Glutathione peroxidase, the primary enzyme that converts hydrogen peroxide to water (and thus prevents lipid peroxidation) is selenium-dependent. Inhibition of lipid or bile acid oxidation may account for its protective role (reviewed by Linder 1991:496-7). Selenium may also act as an immune stimulant. Selenium deficiency inhibits macrophage-mediated tumor destruction, and inhibits tumor necrosis factor-alpha production in animals (Kiremidjian-Schumacher et al., 1992). Dietary supplementation with selenium produced the opposite effects.
The safest antioxidants are vitamin C, vitamin E, selenium, and beta-carotene. Together, they block the chemical reactions that create free radicals, which can damage DNA and promote a variety of degenerative changes in cells. Chemotherapy and radiation generate free radicals; that is how they kill dividing cells.
At the Yunnan Tin Corporation in China there is a very high rate of lung cancer among the miners. Forty healthy miners were given selenium supplements for a year. The selenium, which increased in their blood, boosted a key detoxifying enzyme system while simultaneously decreasing dangerous lipid peroxide levels by nearly 75 percent. It also protected against cancer-causing substances and ultraviolet radiation. Doctors at the Chinese Academy of Medical Sciences concluded that selenium supplements were a safe and effective food supplement for people.
Numerous mechanisms have been explored to explain the modulation of carcinogenesis by selenium (Medina 1986, El-Bayoumy 1991). The best characterized function of selenium in mammalian cells is as a component of the seleno- enzyme, glutathione peroxi-dase. This enzyme is localized in the cytosol and mitochondrial matrix, and it eliminates organic peroxides from the cell (Medina 1986). However, available evidence suggests that the prevention of carcinogenesis by selenium is not related to its function in glutathione peroxidase (Medina 1986). Other seleno- proteins have been identified, but their impact on carcinogenesis is not defined (Medina 1986). There is some evidence that selenium may alter the metabolism of carcinogens or the interaction of chemical carcinogens with DNA, but there is considerable controversy in the literature (Medina 1986). Additional mechanistic studies suggest that selenium may alter cell proliferation and/or immunologic responses (Medina 1986, El-Bayoumy 1991). Further research is needed to understand the mechanisms whereby selenium prevents cancer.
Selenium is needed to produce glutathione peroxidase, an antioxidant enzyme that protects the body from free radical damage. It is also important in preventing cancer and cardiomegaly an enlargement of the heart that causes premature aging and early death.
The best known functions of selenium at nutritionally adequate, but not at excessive, levels are its role as a part of the enzyme glutathione peroxidase and its interaction with heavy metals. Glutathione peroxidase destroys hydroperoxides and lipoperoxides, thereby protecting the constituents of the cells against free radical damage. Ip and Sinha (1981) have shown that selenium, through its function in glutathione peroxidase, could well be involved in protecting against cancer induced by high intakes of fat, especially polyunsaturated fatty acids. Glutathione peroxidase activity in human blood increases with increasing selenium intakes, but reaches a plateau at intakes well below those customary in the United States (Thomson and Robinson, 1980). Thus, if the antitumorigenic effect of selenium is mediated through its function in glutathione peroxidase, attempts to increase the enzyme activity by selenium supplementation, superimposed on an adequate diet in the United States, would not be successful. The second function of selenium is to protect against acute and chronic toxicity of certain heavy metals. Although selenium is known to interact with cadmium and mercury, the mechanism of action is not known. Selenium does not cause an increased elimination of the toxic elements, but, rather, an increased accumulation in some nontoxic form (National Academy of Sciences, 1971). It is conceivable that carcinogenic effects of these, and perhaps other heavy metals, could be counteracted by selenium, in a manner similar to its protection against their general toxicity.
Selenium's main function in the body is to convert hydrogen peroxide to water, which is important for cellular health. Herbal Medicine Healing Cancer by Donald R Yance Jr, page 193 All of the body's tissues contain selenium, but it is most plentiful in the liver, kidneys, spleen, pancreas, and testes. Selenium works synergistically with vitamin E to protect tissues and cell membranes, aid in the production of antibodies, and help maintain a healthy heart and liver
Selenium is a mineral with anticancer activity. But the anticancer effects of selenium are greatly reduced when there is an insufficient intake of vitamin E. Rats who receive a normal amount of vitamin E in their diets showed a 45 percent decrease in tumors when they were given selenium. But they only had a 25 percent decrease if their diet was low in vitamin E. In fact, vitamin E was considered more important than selenium in decreasing "oxidant stress" to the fat of the breast.
Selenium—An essential trace mineral found in fruits and vegetables, selenium helps the body produce functional glutathione peroxidase, an enzyme essential for detoxification. Low dietary levels of selenium have been correlated with a higher incidence of cancer; accordingly, supplementation of this nutrient acts as a deterrent against cancer in general.
Red clover is also rich in calcium, manganese, and selenium, which is a key cancer-fighting antioxidant. I munch the flower heads, but not everyone likes them. Some people dry the flower heads, turn them into a powder, and add them to soups.
A particularly worthy form of selenium is Se-methylselenocysteine, currently available and attracting positive attention. This is the form of selenium found naturally in plants such as broccoli and garlic. A suggested selenium dosage (as a preventive) is 200 mcg a day. The optimal dose for the cancer patient is unknown at this time, but suggestions have ranged from 200-400 mcg a day. Depending upon the selenium content of the soil, foods considered to be good sources of selenium include Brazil nuts, grains, onions, tomatoes, broccoli, chicken, eggs, garlic, liver, seafood, and wheat germ. Americans typically get from 60-100 mcg of selenium a day from dietary sources.
Selenium Anti-Cancer Effects
Some forms of cancer are the result of free radical oxidation that destroys or damages the part of the DNA that regulates cell multiplication. When that happens, the cells can begin to multiply abnormally, damaging the healthy tissue until your whole body is invaded by these wildly proliferating cells. Since selenium can protect you from free radical oxidation, one way to minimize your risk of developing this type of cancer is to eat selenium-rich foods like whole grains or their products with each meal. If you already have cancer, selenium may be useful in slowing its progression. A way to get it in even more concentrated doses than in foods is to take brewer's yeast or supplements
Laboratory studies have shown that selenium can inhibit the growth of
breast, cervical, colon, and skin cancer.
Regular intake of yellow and green vegetables, as well as foods containing
calcium, selenium and other micro-nutrients, lowers the risk of colon
cancer.
Selenium is protective against many types of cancers, promotes apoptosis, is
a powerful antioxidant, and improves quality of life during aggressive
cancer therapies According to P.D. Whanger (professor of agricultural
chemistry), nearly 200 animal studies have been conducted to evaluate the
effects of supernutritional levels of selenium on experimental
carcinogenesis using chemical, viral, and transplantable tumor models. Two
thirds of the studies found that high levels of selenium reduced the
development of tumors at least moderately (14-35% compared to controls) and,
in most cases, significantly (by more than 35%) (Whanger 1998).
Selenium has been used in combination with vitamin A and vitamin E to reduce
the toxicity of chemotherapy drugs, particularly Adriamycin (Faure et al.
1996; Vanella et al. 1997). The synergistic effect of vitamin E and selenium
together to enhance the immune system is greater than either alone. A new
form of selenium is Se-methylselenocysteine (SeMC), a naturally occurring
selenium compound found to be an effective chemopreventive agent. SeMC is a
selenoamino acid that is synthesized by plants such as garlic and broccoli.
SeMC has been shown to induce apoptosis in certain ovarian cancer cells (Yeo
et al. 2002) and to be effective against breast cancer cell growth both in
vivo and in vitro (Sinha et al. 1999). SeMC has also demonstrated
significant anticarcinogenic activity against mammary tumorigenesis (Sinha
et al. 1997). Moreover, a study has demonstrated that SeMC is one of the
most effective selenium chemopreventive compounds, inducing apoptosis in
leukemia HL-60 cell lines (Jung et al. 2001a). Some of the most impressive
data suggest that exposure to SeMC blocks clonal expansion of premalignant
lesions at an early stage. This is achieved by simultaneously modulating
certain molecular pathways that are responsible for inhibiting cell
proliferation and enhancing apoptosis (Ip et al. 2001). Unlike
selenomethionine, which is incorporated into protein in place of methionine,
SeMC is not incorporated into any protein, thereby offering a completely
bioavailable compound for preventing cancer. Therefore, 200<400 mcg of SeMC
a day is suggested for cancer patients. Please note that selenium also
possesses antioxidant properties, so its use before, during, or immediately
after chemotherapy could theoretically inhibit the actions of certain
chemotherapy drugs.
Scientists have confirmed that vitamins C and E along with the mineral
selenium afford some prostate cancer prevention. This is not surprising to
anyone who understands diet, biochemistry, and how antioxidants work.
Glutathione peroxidase destroys free radicals and superoxides. Its name
means that it destroys peroxides (the potent oxidants that form in tissues)
and uses glutathione as a helper. Glutathione requires selenium to function;
and wherever selenium is at work, vitamin E can't be far away because they
function together.
For prostate cancer management, stay on a low fat diet, eat tomato products
often, take a multivitamin, vitamins C, E and selenium.
Men with higher intakes of antioxi-dants such as vitamin C, vitamin E, and
the trace mineral selenium have lower levels of prostate cancer.
Selenium Statistics
In a December 1996 article in the Journal of the American Medical
Association, Dr. Larry Clark presented evidence that supplemental selenium
could reduce cancer death rates by as much as 50%. 1,312 patients were given
200 mcg. of selenium daily. The patients receiving selenium had a rise of
67% in their blood selenium level.
The patients receiving selenium had a 67% decrease in cancer of the
prostate, a 58 percent decrease in colon or rectal cancer and a 45% decrease
in lung cancer. This suggests that possibly up to 100,000 lives a year might
be saved in the USA by the simple addition of selenium to the diet.
An article in the Journal of the American Medical Association (JAMA) by
Clark et al. (1996) showed that 200 mcg of supplemental selenium a day
reduced overall cancer mortality by 50% in humans compared to a placebo
group not receiving supplemental selenium. This 9-year study demonstrated
that a low-cost mineral supplement could cut the risk of dying from cancer
in half in certain individuals.
In a recent five-year study of nearly 30,000 rural Chinese people,
researchers from the NCI found that daily doses of these three nutrients
reduced cancer deaths by 13%.
But what if you already have cancer? Again, the research shows a
prolongation of lifespan with proper supplementation. In a study in Cancer
Letters (Evangelou et al. 1997), animals with malignant tumors given high
doses of vitamins C and E and selenium manifested a significant prolongation
of the mean survival time. Complete remission of tumors developed in 16.8%
of the animals.
Dr. Raymond Shamberger was also among the first to discover the link between
low selenium content in the soil and increasing numbers of deaths from
cancer. In 1976, he pointed out that the cities and states with high
selenium content in the soil also had significantly lower rates of cancer,
especially of the digestive and urinary systems.
A Powerful Antioxidant "selenium is a crucial mineral in the battle against
prostate cancer," says Dr. Schachter. In one study of hundreds of men, a
daily intake of 200 micrograms of selenium cut the incidence of prostate
cancer by 60 percent.
The statistics for breast cancer are particularly striking. "The higher the
selenium, the lower the breast cancer," said Prof. Ladas. Similar
associations have been found with leukemia, as well as cancers of the
intestines, rectum, ovary, prostate, lung, pancreas, skin and bladder. In
Yugoslavia, scientists studied 33 patients with breast cancer. These women
had selenium levels in their bloodstream only half those of healthy
volunteers.
Although the study failed to show the effectiveness of selenium in altering
the course of either basal or squamous cell carcinoma, selenium impacted the
incidence of other types of malignancies with amazing success (Clark et al.
1996). The overall reduction in cancer incidence was 37% in the
selenium-supplemented group; a 50% reduction in cancer mortality was
observed over a 10-year period. The following are the site-specific
reductions in cancer incidence observed in the study: colon-rectal cancers
(58%), lung cancer (46%), and prostate cancer (63%). A selenium deficiency
appears to increase the risk of prostate cancer fourfold to fivefold. It was
determined that, as the male population ages, selenium levels decrease,
paralleling an increase in prostate cancer (Brooks et al. 2001).
In a study published in the journal of the National Cancer Institute, the
relationship between serum levels of selenium and the development of upper
digestive tract cancer was explored (Mark et al, 2000). The relative risk of
esophageal cancer was 0.56 in individuals in the highest quartile of
selenium level compared with those in the lowest quartile. The corresponding
relative risk of gastric cardia cancer was 0.47. Based on the data, the
researchers calculate that 26.4% of esophageal and gastric cardia cancers
are attributable to low selenium levels.
Selenium Recommendations
The Recommended Daily Allowance (RDA) is 50 to 100 micrograms (not
milligrams) but few people get even that much. Selenium is so important that
I believe that practically every adult should take a 200 microgram selenium
supplement every day. This is readily available in health food stores at a
minimal price. Organic selenium derived from yeast may be better absorbed
man the mineral form, sodium selenite. Very high doses of either can be
toxic, however, and should only be taken under a doctor's prescription. To
summarize: selenium has a strong ability to prevent cancers, especially of
the internal organs. There is no evidence that selenium interferes with
chemotherapy, radiation or a combination of both. On the contrary, there is
evidence that it decreases the side effects of such treatments
The supplements that I'd recommend for cancer prevention are the
antioxidants: vitamins C and E, beta-carotene, and the mineral selenium.
Moderate doses of zinc, beta-carotene, selenium and vitamin E are safe and
inexpensive. I believe these results are valid and are an accurate
reflection of what antioxidants can do. The finding that two terrible
cancers could be prevented by a few pennies worth of supplements received
little attention in the mainstream media.
The National Academy of Sciences advises that no more than 150 micrograms of
selenium be taken orally daily. But Revici's "bivalent negative selenium"< a
combination of the mineral with various organic substances, such as the
fatty acids of sesame oil to one million micrograms, have been injected (in the treatment of drug addiction), apparently without any ill effects. In the treatment of cancer
the dosage is generally about 10,000 micrograms, still nearly one hundred
times the National Academy of Science's recommended dose.
But in the meantime, I will continue to take my 200 micrograms of selenium a
day selenium has been associated with toxicity, so don't go overboard. If you're
not fond of popping pills, you can get 120 micrograms of selenium in just
one Brazil nut. Buy the shelled kind Brazil where the soil is richest in the mineral. Other good sources are tuna
fish, seafood, wheat germ, and bran.
While everyone needs selenium on an everyday basis, there are certain
situations in which the human need for selenium may be increased, or in
which additional selenium may be helpful in the treatment of a disease. If
you are a male, your selenium needs are greater than if you are female. If
you suffer from heart disease or muscular disorders, additional selenium may
help you. The same can be said if you suffer from cataracts, diabetes,
cystic fibrosis, liver necrosis, iron deficiency anemia, joint problems,
heavy metal poisoning, or cancer.
Now, Dr. Mark A. Nelson, a professor and researcher at the Arizona Cancer
Center, says, "The Nutritional Prevention of Cancer (NPC) Trial tripled the
intake and suggests that higher levels of selenium may be necessary for
cancer prevention." Until nutritionists conduct more research, though, no
one can recommend the best, safest amount you should get. Experts warn
selenium is a toxic mineral, which means too much of it, especially from
supplements, is unsafe.
Doctors at the Chinese Academy of Medical Sciences concluded that selenium
supplements were a safe and effective food supplement for people. There have
also been a number of reports of selenium's toxicity or even its alleged
ability to cause cancer. There is no question that excess selenium in the
soil (in the form of its compounds, selenite or selenate) can kill grazing
animals and could probably in sufficiently large doses kill humans as well.
The symptoms of selenium poisoning are readily apparent without a doctor's
assistance, according to Dr. Gerhard Schrauzer, a world expert on the topic.
These symptoms include a heavy garlic odor, pallor, nervousness, depression,
a metallic taste, skin eruptions, irritability, discolored teeth and hair
loss. There is some doubt about the carcinogenicity studies. For instance,
one study showed toxic effects for inorganic, but not organic, forms of the
mineral.
General / History of Selenium
Selenium (Se) is a metal that is chemically similar to sulfur. It was first
discovered in 1817 and because of its silvery color was named for Selene,
the ancient goddess of the moon. Selenium is an essential component of two
important antioxidant enzymes and is also the helpmate of vitamin E.
Initially, selenium's importance in human health was underrated. In fact,
its main use in conventional medicine was as a treatment for dandruff!
Strange as it may seem, toenail levels of selenium are considered a good
indicator of long-term selenium intake. They found that the people whose
toenails had the highest levels of selenium had half of the rate of lung
cancer compared with those whose toe-nails were low in selenium.
Aside from Revici's work, little has been done to investigate the use of
this mineral as a cancer treatment. In 1911, Prof. August von Wasserrman
achieved growth inhibition, shrinkage and eventually the disappearance of
tumors by injecting selenium directly into mouse tumors. Four years later,
two doctors caused the shrinkage and the eventual disappearance of small
tumors in cancer patients, although larger tumors failed to respond.
Dr. Gerbhard Schauzer, a biochemist at the University of California in San
Diego, S believes that if every woman in America began taking selenium
supplements today or followed a diet high in selenium, the breast cancer
rate in this country would decline drastically in a few years.
Asia has considerable quantities of selenium in its soil, making the Asian
diet rich in the mineral; not surprisingly, cancer and heart disease occur
considerably less often in Asian cultures than in the West.
Additional Benefits of Selenium
Antioxidants, like beta carotene, vitamin C, vitamin E, and selenium appear
to enhance the effectiveness of chemo, radiation, and hyperthermia while
minimizing damage to the patient's normal cells; thus making therapy more of
a "selective toxin." An optimally nourished cancer patient can better
tolerate the rigors of cytotoxic therapy.
Patients with advanced rectal cancer were treated with a combination of
selenium, the drug 5-FU, and radiation. Scientists reported a protective
effect of selenium on quality of life.
Selenium-deficient animals have more heart damage from the chemo drug,
adriamycin.43 Supplements of selenium and vitamin E in humans did not reduce
the efficacy of the chemo drugs against ovarian and cervical cancer. Animals
with implanted tumors who were then treated with selenium and cisplatin
(chemo drug) had reduced toxicity to the drug with no change in anti-cancer
activity. Selenium supplements helped repair DNA damage from a carcinogen in
animals. Selenium was selectively toxic to human leukemia cells in culture.
While most nutritionists agree on the importance of growth (proliferative)
nutrients, few nutritionists respect the importance for anti-proliferative
nutrients. For every force in the body, there must be an opposing force to
regulate that mechanism. There are agents that cause fluid loss from the
kidneys (diuresis) and other agents that stem this fluid loss when it is
excessive (anti-diuretic hormone). Just as there is a need for nutrients to
augment growth, there is a need for nutrients to control excessive growth
and shut down the process. Selenium, fish oil, garlic, Cat's claw, Maitake
D-fraction, vitamin E succinate, vitamin K, quercetin, genistein, and bovine
cartilage all may assist the cancer patient in this manner.
Vitamin E and selenium supplements in animals helped to reduce the heart
toxicity from adriamycin. Selenium and vitamin E supplements were given to
41 women undergoing cytotoxic therapy for ovarian and cervical cancers, with
a resulting drop in the toxicity-related rise in creatine kinase.
One of the foremost selenium investigators, Gerhard Schrauzer of the
University of California at San Diego, says: Apart from its functions as an
essential micronutrient, selenium also appears to have other physiological
functions in which it acts as a physiological resistance factor [emphasis
added]. Its cancer protecting effects fall into this category. In addition,
selenium protects against free radicals, mutagens, toxic heavy metals and
certain bacterial, fungal and viral pathogens. The selenium requirement
increases under stress, just as the requirement for certain vitamins
increases during infections. Selenium, according to Schrauzer, is most
effective as a form of nutritional cancer prophylaxis. In animal research,
its protective effect is greater the earlier in life it is given, and its
shielding effect against virally induced cancer disappears if the nutrient
is no longer fed to the animal. Nevertheless, selenium does have an effect
on slowing the rate of growth of established spontaneous or transplanted
breast tumors in animals, and in reversing the development of some malignant
cell lines when used at pharmacological levels. Further, selenium has shown
a general capacity to stimulate the immune system in several animal models,
which may add to its anticancer effects. It is of special relevance to
cancer patients undergoing chemotherapy that selenium "has by now been shown
to prevent or retard tumorigenesis induced by virtually all the major known
carcinogens," probably, Schrauzer believes, "by modulating the rate of cell
division."
Just as selenium protects you against toxic metal poisoning, it can also
protect you against radiation, whether you are exposed to it through the
environment or more directly through medical treatments. A particularly
effective form of selenium for this purpose is selenoaminoacid compounds
(selenium plus amino acids). Selenium also protects you against compounds
called epoxides, as it breaks them down. What are epoxides? Formed when an
enzyme named aryl hydrocarbon hydroxylase binds with a carcinogenic
substance, epoxides could be called the immediate cause of cancer. The
carcinogens cause your body to produce them, and then cancer may ensue.
Reports from Germany indicate that selenium supplementation in patients
undergoing radiation therapy for rectal cancer improved quality of life and
reduced the appearance of secondary cancers (Hehr et al. 1997) It appears
that selenium acts as an immunologic response modifier, normalizing every
component of the immune system
Macrophages body clear of tumor cells. Also, since they produce interferon, they can
help eliminate the viruses that cause some forms of cancer. But to do their
job properly, they need adequate selenium.
Some of the known natural compounds that can reduce insulin resistance
include omega-3 fatty acids, curcumin, flavonoids, selenium, and vitamin E.
Dietary risk factors must be managed. Therefore, besides restricting dietary
sugars, individuals should eat an adequate amount of fruits and vegetables
because phytochemicals in fruits and vegetables act as potent anticancer
agents.
Selenium can prevent solar damage, pigmentation and dark spots, but because
the selenium content of soil varies across the country, not everyone is
getting enough to be beneficial," says Dr. Burke, citing the Southeast in
particular as an area deficient in selenium. To quench the free radicals
caused by sun exposure and to prevent skin damage, Dr. Burke recommends
daily supplements of 50 to 200 micrograms of selenium in the form of
1-selenomethionine, depending on where you live and your family history of
cancer. Selenium can be toxic in doses exceeding 100 micrograms, so if you'd
like to try this therapy to protect your skin, you should discuss it with
your doctor.
The importance of selenium to cardiovascular health was demonstrated in the
provinces of China where the mineral was deficient. This correlation can be
seen throughout the world. Ray Shamberger, M.D., and Charles Willis, M.D.,
of the Cleveland Clinic in Ohio, reported in 1976 that people who live in
low-selenium areas have three times more heart disease than those living in
areas where the soil and water are rich in the mineral.
Selenium also appears to help stimulate antibody formation in response to
vaccines. This immunostimulating effect is also enhanced by vitamin E; the
presence of these two nutrients can increase antibody formation by 20-30
times, as shown by research.
Selenium may also aid in protein synthesis, growth and development, and
fertility, especially in the male. It has been shown to improve sperm
production and motility. Thus, selenium may prevent male infertility;
however, we do not know whether selenium deficiency will actually cause male
infertility. These are only some of the conjectures about other selenium
functions.
Selenium Interactions
Certain metals such as lead, cadmium, arsenic, mercury and silver block the
action of selenium. . . . Recent laboratory experiments have shown that high
doses of zinc block the action of selenium. Therefore, one has to be careful
about taking excessive amounts of zinc (over 20 milligrams per day from diet
and supplements) while taking selenium [emphasis added].
I think the selenium and saffron complement one another. Selensaff, a
product made by Scientific Botanicals (see Resources), is used in cancer
therapy to create a redox effect enhancing both oxygen uptake and the excretion of oxygen waste.
Zinc is important because it is an antagonist to selenium and may in itself enhance
or inhibit different tumors. Selenium in minute quantities is essential to
human health. According to Prasad, among the minerals, "only selenium has
been shown to have a role in cancer prevention":
Vitamin E and selenium protected animals against the potent carcinogenic
effects of DMBA from tobacco.
Selenium acts as an antioxidant and strengthens the body's immune defense
system. Thus, many of the effects which are produced by vitamin E deficiency
can be reversed or prevented by selenium. Some laboratory experiments have
suggested that the combination of vitamin E and selenium is more effective
in preventing cancer than either of them alone.
However, one experiment has demonstrated increased susceptibility to
DMBA-induced tumors when selenium deficiency was aggravated by high dietary
levels of polyunsatu-rated fatty acids, and protection by a physiological
supplement of selenium (0.1 pg/g) to the diet (Ip and Sinha, 1981). The
interpretation of these results is further complicated because of the varied
protocols used in these experiments and the knowledge that selenium
interacts with many other nutrients, such as heavy metals in the diet.
In some experiments, dietary zinc exceeding nutritional requirements has
been shown to suppress chemically induced tumors in rats and hamsters, but
when given in drinking water it counteracts the protective effect of
selenium in mice...While the evidence on the effect of zinc on tumor
development is complex, it strongly suggests that, in general, one should be
cautious about taking zinc supplements if one has cancer. And since selenium
has a wide spectrum of demonstrable anticancer effects, cancer patients
should be particularly cautious with zinc, since it is a selenium
antagonist. I have seen many cancer patients taking moderately large amounts
of zinc as part of a comprehensive megavitamin nutritional supplement
program. In view of the available scientific evidence, this is another
critical example of an area where uninformed nutritional supplementation may
do harm.
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