Cancer-and-Vitamin-D Background Links
February 7, 2004
This January, 2004, Dartmouth Medical School study concludes that "The nutrients calcium and vitamin D work in tandem, not separately, to reduce the risk of colorectal cancer."
"The new analysis found that calcium supplements prevented adenomas only among poeple with higher-than-average baseline vitamin D levels, and serum vitamin D levels were associated with reduced adenoma recurrence only among those taking calcium supplements. The authors write that 'further investigation is needed to understand the mechanistic basis of the vitamin D/calcium interaction and to clarify the amount of intake of each nutrient required.'"
CNN.com - Study- Vitamin D cuts colon cancer risk - Dec. 9, 2003
A diet rich in vitamin D appears to protect people from developing potentially cancerous growths in the colon, a study of more than 3,100 veterans has found. Patients who consumed the amount of vitamin D contained in daily servings of milk and fish were 40 percent less likely to develop polyps than those who got little or no vitamin D. The study also confirmed previous research that found that cereal fiber and regular use of pain relievers such as aspirin and ibuprofen reduce the risk of advanced polyps and that smoking, heavy drinking and a family history of polyps raise the risk.
Diets high in calcium have been linked with a reduced colon cancer risk, and vitamin D is needed to help the body absorb calcium. But evidence about any protective effect from vitamin D alone is sparse, said Dr. David Lieberman, the lead author and a gastroenterologist at the Portland, Ore., Veterans Affairs Medical Center. Study participants filled out detailed health questionnaires before their exams asking about diet, family medical history and lifestyle habits. Participants were not asked about exposure to sunlight, which interacts with chemicals in the skin to produce vitamin D and is a major source of the vitamin. Participants who reported consuming more than 645 international units of vitamin D daily were 40 percent less likely to have advanced polyps than those who consumed little or none of the vitamin. Experts generally recommend about 200 to 800 IUs of vitamin D a day for adults. Food sources of vitamin D include some types of fish and fortified milk. For example, one tablespoon of cod liver oil has 1,360 IUs; 31/2 ounces of salmon have 360 IUs; and a cup of fortified milk contains 100 IUs.
CNN.com - Health - Vitamin D being studied as anti-cancer drug ...
Because the vitamin is toxic in high doses, taking calcium from the bone and moving it to the blood and urine, scientists had to alter the vitamin for the trials. The natural vitamin would not be safe at the dosage researchers believe would be necessary for cancer prevention. After 20 weeks, the most promising version of the vitamin had reduced the incidence of tumors by 28 percent and the number of tumors by 63 percent. It will be several steps yet before the compound can be tested in humans.
Moment in the sun enough for vitamin D: Cancer Council. 29/3/2003. ...
The Cancer Council of New South Wales (CCNSW) says as little as 10 minutes exposure to the sun three times a week is enough to maintain healthy Vitamin D levels.
2003- Vitamin D and Cancer
Karina Kelly from ABC TV’s “Catalyst” program investigates.
KELLY : Medical experts around the world are talking about a new epidemic – a health concern that may be dramatically increasing the risk of cancer, hypertension and even diabetes in our community and in this sunburnt country, it seems amazing that it’s caused by a lack of sunlight.
PROFESSOR TERRY DIAMOND : The problem is a huge problem.
PROFESSOR PHILIP SAMBROOK : This is crazy. How can this happen in sunny Australia.
PROFESSOR REBECCA MASON : Yes, even in sunny Australia there is a significant problem.
KELLY : .And the cause is something that’s been right under our noses for nearly a century. The lack of a common vitamin – vitamin D.
HOLICK : I believe that the public health problem for vitamin D deficiency is quite significant. I would estimate minimum 25 per cent of adults in the United States, Europe and probably even in Australia are vitamin D deficient.
KELLY : But how much of a problem is vitamin D deficiency? According to Professor Michael Holick it’s a killer.
HOLICK : For example, in Europe it’s estimated that 25 per cent of women that die of breast cancer may not have died of breast cancer if they would have maintained adequate vitamin D levels throughout their life and have had some sun exposure.
KELLY : Most of the vitamin D used by our bodies is made by our skin when it’s exposed to sunlight. We’ve known for the best part of a century that sunlight makes vitamin D and that means healthy bones, but science is now revealing that vitamin D is much more vital to our survival than we could possibly have imagined.
HOLICK : We think now that being able to maintain adequate vitamin D levels may be important for decreasing your risk of getting prostate cancer and breast cancer and colon cancer. There’s some evidence that in young children if they’re fortified with vitamin D from one year of age on, it can reduce by 80 per cent their risk of getting type 1 diabetes.
KELLY : And the list doesn’t end there. Michael Holick has treated patients with mild hypertension simply by putting them on a sunbed three times a week. After a month, the patients blood pressure had returned to normal and their blood levels of vitamin D had doubled.
KELLY : Rebecca Mason and her team have been looking at skin cells and what happens to them in the presence of vitamin D.
MASON : What we find is that the Vitamin D treatment markedly increases cell survival and it also reduces the DNA damage in the surviving cells.
HOLICK : Red staining reveals the amount of cancer causing genetic damage produced by ultra violet light. Unprotected by vitamin D, these cells have deteriorated markedly, but the cells treated with Vitamin D fared much better and while Vitamin D protects healthy cells, Rebecca Mason’s experiments are showing that it has the opposite effect on cancer cells - it kills them.
MASON : The Vitamin D compound actually enhances tumour cell death, so in normal cells protection from stress induced death cancer cells increased cell death and that’s, you know, a very nice system to have evolved with.
KELLY : Terry Diamond works with patients
who’s Vitamin D levels have hit rock bottom, for them no amount of sunlight
will fix the problem. Without massive doses of Vitamin D, they risk serious bone
DIAMOND : We know from studies, published studies, that if you correct the vitamin D deficiency in a high risk population group, you can reduce the risk of hip fractures by 25 to 40 per cent.
KELLY : In the future, knowing your vitamin D status may be as important as knowing your cholesterol levels and a simple blood test is all you need. So courtesy of the latest science, you can sit back and enjoy getting a bit of sun on your body – guilt free.
HOLICK : It’s not that you should avoid sunlight at all cost, but really consider sunlight your friend and what you don’t want to do is don’t overdo it. You never want to burn and in fact, you really don’t need more than 20 or 25 per cent of the amount of sunlight that would in fact cause a mild sunburn.
Vitamin D and Multiple Sclerosis
ACS (American Cancer Society) Search for Vitamin D
This is the American Cancer Society search page for "vitamin D".
HHMI News- Vitamin D May Be Crucial in Preventing Colon Cancer
New studies by researchers at the Howard Hughes Medical Institute indicate that vitamin D protects against colon cancer by helping to detoxify cancer-triggering chemicals that are released during the digestion of high-fat foods. The studies show that a specific type of bile acid, called lithocholic acid (LCA), which is a known carcinogen, activates the vitamin D receptor. When the vitamin D receptor is switched on, it triggers other proteins that detoxify the bile acid.
MEDLINEplus- Too Much Vitamin D UPS Prostate Cancer Risk
Men who had the least amount of vitamin D circulating in their blood were 50 percent more likely to have prostate cancer than men whose blood contained an average amount of vitamin D. Among men with the most vitamin D -- around twice the blood levels as men with an average amount -- the risk of prostate cancer increased by 70 percent. Vitamin D is linked to a number of health benefits, so people who are deficient in the vitamin should make sure to boost their intake, the authors, led by Dr. Pentti Tuohimaa of the University of Tampere in Finland, write. However, "our study suggests that moderately high levels of vitamin D for long periods may have adverse effects on prostate cancer risk," they note. Consequently, for people looking to use vitamin D to help them reduce their risk of prostate cancer, "very high serum vitamin D may not be the appropriate goal," Tuohimaa and colleagues add.
During the current study, the largest to date on prostate cancer risk and vitamin D, Tuohimaa and colleagues measured the amount of vitamin D in blood samples from 622 men with prostate cancer and 1,451 men who were cancer-free. All participants were from Finland, Norway or Sweden. In general, men who had high or low levels of vitamin D in their blood were more likely to have prostate cancer than men carrying around an average amount of vitamin D in their bodies.
Prostate Cancer Center - Vitamin D
Clearing the Colon- Vitamin D May Help Prevent Cancer
We’ve known for some time that eating a high-fat diet increases a person’s risk of developing colon cancer, but a new study published in the May 17 issue of Science suggests that Vitamin D may help lower that risk. The protective power, they found, is that Vitamin D detoxifies the colon of potentially cancer-causing waste produced by excess fat.
A connection between Vitamin D and colon cancer makes sense because the colon contains many Vitamin D receptors. In previous studies, the binding of Vitamin D to its receptors has been shown to aid in digestion by regulating calcium levels. Researchers from the University of Texas speculated, though, that this binding action provided additional benefit--perhaps protecting against colon cancer. In the Science report, the researchers explained that when the enzymes in the colon break down fats in the food we eat, a toxic acid called lithocholic acid is produced as a by-product.
Did you know that 90 percent of colorectal cancer is preventable? Click here to learn more about colorectal cancer and how you can reduce your risk.
Cancer Advisors - Matching Patients with Clinical Trials - Help ...
Does Calcium Cure Cancer- Is Calcium A Treatment For Breast Cancer
For instance, some evidence points to a prostate, breast and colon cancer belt in the United States, which lies in northern latitudes under more cloud cover than other regions during the year. Rates for these cancers are two to three times higher than in sunnier areas.
Black human skin is thicker than white skin and thus transmits only about 40 percent of the UV rays for vitamin D production. Darkly pigmented individuals who live in sunny equatorial climates experience a higher mortality rate (not incidence) from breast and prostate cancer when they move to geographic areas that are deprived of sunlight exposure in winter months. The rate of increase varies, and researchers hesitate to quote figures because many migrant black populations also have poor nutrition and deficient health care that confound statistics somewhat.
Does Calcium Cure Cancer- Is Calcium A Treatment For Breast Cancer ...
Vitamin D Key to Colon Cancer
"The current American diet can provide more fat on a daily basis than a human being was ever meant to handle," Mangelsdorf says in a press release.
Vitamin D and Breast Cancer, Notre Dame Magazine, spring 2002
Testing High Dose Vitamin D for Prostate Cancer
The researchers are hoping to permanently arrest prostate tumors using Calcitriol (Rocaltrol).
"We don't really expect to eradicate the disease -- that would be great, but we hope to stop it in its tracks," Beer said. If the study shows that long-term use of vitamin D poses no risk, patients could theoretically stay on this treatment the rest of their lives to keep the cancer from progressing.
Research Page- Vitamin D Receptor Gene and Breast Cancer Risk
Identifies two Vitamin D Receptor genetic types among Latinas. Women possessing two of the highest vitamin D genes have one-third the breast cancer risk of women who inherit two copies of the less-protective gene. Women may be at risk for breast cancer on the strength of both their genotype and their serum vitamin D levels.
African-American women may have a third type, which supports the highest vitamin D levels of all.
Cancer, The World Health Network
This page contains a number of links to other articles.
The Vitamin D Controversy and the Sun- Dispelling the Myth
ACS -- Calcium
This article observes that the recommended daily intake of calcium is 1,000 mg. a day for men and women 19-50, and 1,200 mg. a day for those who are older than 50. Dietary sources of calcium are broccoli, greens, legumes (beans), nuts, seeds, and canned fish with bones, such as salmon and sardines. "Calcium's role in preventing or slowing the growth of cancer has only become a notable subject of research within the last 10 to 15 years."
Calcium may lead to high blood pressure and perhaps, to colorectal cancer. "The researchers found that calcium supplements moderately reduced the recurrence of colorectal adenomas."
"A Harvard University study also showed indirect evidence that excessive levels of dietary or supplemental calcium should be avoided to reduce the risk of advanced prostate cancer."
ACS -- Vitamin D Has Role in Colon Cancer Prevention
Vitamin D may be more important to colon cancer prevention than previously believed, according to a study published in the Journal of the American Medical Association (Vol. 290, No. 22: 2959-2967). The study examined people with no symptoms of colon cancer to determine what role diet, exercise, smoking, and other behaviors played in the development or not of colon polyps, small growths in the colon that can turn into cancer if they aren't removed.
"Higher levels of vitamin D were associated with a lower risk of serious colon polyps," said lead study researcher David Lieberman, MD, chief of gastroenterology at the Portland Veterans Affairs (VA) Medical Center and Oregon Health Sciences University. "There have been some studies suggesting this, but our data are compelling." Men who consumed more vitamin D in their diet each day were less likely to develop colon polyps, and men who consumed the most of the vitamin (more than 645 IUs, or international units) daily reduced their risk the most. However, too much vitamin D can cause nausea, constipation, weakness, and other problems, so Lieberman cautioned against overdoing it.
ACS -- Vitamin D Protects Against Colon Cancer
"We've known for a long time that high-animal fat, Western-style diets, and colon cancer go hand-in-hand," said study author David Mangelsdorf, PhD, a Howard Hughes Medical Institute investigator at the University of Texas Southwestern Medical Center in Dallas. "We also know that vitamin D is protective for colon cancer."
In Western countries, colon cancer has been linked to diets high in red meat and animal fat. To digest these foods, the body makes lithocholic acid. Mangelsdorf says it is probably one of the most toxic compounds that the body naturally makes. "If you inject lithocholic acid into an animal's colon, they'll get colon cancer," he said. Humans have evolved to deal with this acid by detoxifying it. What surprised Mangelsdorf and his colleagues is that the body uses the vitamin D receptor — which is normally thought of as a way to help the body maintain normal levels of calcium — to do it. Both vitamin D and lithocholic acid can attach to the receptor and switch on a detoxifying gene. Colon cancer patients have been found to have high concentrations of lithocholic acid, he said.
Vitamin D deficiency is also associated with colon cancer. "If you didn't have enough vitamin D in your diet, the vitamin D receptor wouldn't be functioning at its optimum," Mangelsdorf said.
According to the National Institutes of Health, people aged 19-50 need 200 IUs daily (in either their diet or in supplements) for adequate nutrition, while people between 51 and 69 should get 400 IUs each day. People 70 and older need 600 IUs of vitamin D each day, but no one should consume more than 2,000 IU a day. The Institute of Medicine's Food and Nutrition Board recommends an upper limit of 2,000 IUs of vitamin D for most children and adults, and no more than 1,000 IUs for babies under 12 months. Too much vitamin D causes too much calcium in the blood, leading to kidney and bone problems, buildup of calcium in muscles, and heart trouble. Researchers hope to eventually find another substance that will trigger the protective effects of the vitamin D receptor without endangering the body.
Cereal fiber was another important dietary factor for colon cancer prevention. People who ate more than 4 grams per day had a significantly lower risk of colon polyps. Exercise, calcium, and multivitamins also had a small benefit. Taking NSAIDs had a significant protective effect. Men who took NSAIDs daily were only two-thirds as likely to get colon polyps as men who did not take the drugs. Other studies have also suggested these drugs can help prevent colon cancer, but because they can cause side effects including ulcers and stomach bleeding, experts say it's too soon to recommend them as a routine method of prevention.
"These data support relatively simple and safe recommendations that may reduce the risk of colon cancer," said Lieberman. "Stop smoking, reduce alcohol and red meat consumption, take a multivitamin, exercise regularly, and consume vitamin D, calcium, and cereal fiber in your diet."
Regular screening for colon cancer is also important, he noted, especially for people who have a relative who had the disease. In this study, people with a family history of colon cancer had a 66% greater risk of developing colon polyps.
Colon polyp risk factors
ACS -- Study- Calcium May Reduce Risk Of Colon Cancer
A new study by the American Cancer Society shows calcium may lower the risk of colon cancer slightly for both men and women, while vitamin D might help cut risk in men. The effect seemed to be strongest in people who took supplements, rather than getting these nutrients from foods. However, researchers said it is still too early to change recommendations about how much calcium or vitamin D to take in order to reduce colon cancer risk. “Overall recommendations are tricky,” said lead researcher Marji McCullough, senior epidemiologist at the American Cancer Society, “because very high calcium and/or dairy intake has been found in some studies to increase prostate and possibly ovarian cancer risk.”
McCullough and her colleagues studied more than 60,000 men and more than 66,000 women who were already participating in an ACS study of nutrition and cancer prevention. The participants were all between 50 and 74-years old when they enrolled in the study in 1992 and 1993. They were asked about their diet and supplement intake at the time they enrolled. The researchers used these questionnaires to estimate different nutrient intakes, including calcium and vitamin D. People who took calcium supplements had about a 30% lower risk of developing colon cancer than people who did not take supplements. In addition, men who got the most vitamin D also had a lower cancer risk. The protective effects were not seen in women, however. The researchers couldn’t fully explain this result, but said it might be due to the lower number of cancers in the group of women studied, or possibly to some aspect of sex hormone metabolism that is not yet understood.
Risk started to decrease with as little as 700 milligrams of total calcium –-from food and supplements -- a day, and taking more than 1200 milligrams a day did not seem to give any greater protection. But the greatest reduction in risk was seen in people whose calcium came primarily from supplements rather than from diet. The researchers recommended further study to determine the optimal dose of calcium for colon cancer protection. Until then, people should consult their doctors about whether they need to take a calcium or vitamin D supplement.
ACS -- Prostate Cancer Rates in African-American Men Studied
A genetic difference and lower levels of D vitamin may contribute to the higher rates of prostate cancer in African-American men, according to a study reported in the Dec. 20 Journal of the National Cancer Institute. Researchers led by Elizabeth A. Platz, ScD, MPH, of the department of epidemiology at the Harvard School of Public Health, evaluated 45,410 male health professionals. They followed these men, who were ages 40 to 75, for 10 years beginning in 1986. The group included 491 African Americans, 817 Asian Americans, 42,984 white Americans, and 1,128 men who had reported an unspecified ancestry.
Results of the study add to a growing body of evidence that African-American men have a greater risk of developing prostate cancer than any other racial group with 1.8 times more prostate cancer than white or Asian men. Although the reasons for the higher risk are still unclear, the major finding of this study was that it was not caused by any socioeconomic differences. The study authors also report that lower levels of D vitamin in African-American men warrants further study as a possible risk factor. "Vitamin D may also influence the risk of prostate cancer. The active form of vitamin D can inhibit the growth of prostatic epithelial cells and African-American men had lower levels [of vitamin D]," they write. "Because circulating [vitamin D] levels are determined, in part, by sun exposure, our observation is consistent with the hypothesis that individuals with more skin pigmentation tend to have lower levels."
ACS -- Milk And Dairy Products May Lower Young Women's ...
Do milk or dairy products affect a woman's breast cancer risk? A report in the Journal of the National Cancer Institute (Vol. 94, No. 17: 1301-1311) found that the answer may depend on whether she is premenopausal or postmenopausal.
The study, written by Myung-Hee Shin and colleagues from the Harvard School of Public Health and Harvard School of Medicine in Boston, looked at information from a group of 121,700 nurses who lived in 11 states and were followed as part of the Nurses' Health study, begun in 1976. The nurses were surveyed on a regular basis about risk factors for heart and blood vessel diseases, and for cancer. Beginning in 1980, they were asked questions about their diets. Information on more than 88,600 women was reviewed for this particular study.
"In conclusion, high intakes of dairy products, especially low-fat dairy and skim/low-fat milk, may be associated with a modest reduction in the risk of breast cancer in premenopausal women but not in postmenopausal women," the authors wrote.
ACS -- Scan Shows Prostate Cancer Treatment-related Bone Loss
The researchers found that most of the 41 men studied had low levels of vitamin D and dietary calcium before they even began Androgen Deprivation Therapy. These levels were below the Recommended Daily Allowance (RDA) of 800 mg/day. Smith says levels of Vitamin D and calcium intakes below the RDA are associated with low bone density.
ACS -- Calcium Found to Reduce Colon Cancer Risk
If an ounce of prevention is worth a pound of cure, Americans might try adding calcium to their diets. It can cut the risk of developing colon cancer in half, said researchers in the March 20 Journal of the National Cancer Institute (Vol. 94, No. 6: 437-446). The authors, Kana Wu, MD, and colleagues from the Harvard School of Public Health and the Harvard School of Medicine, reported on the diets and habits of 150,000 female nurses and male health professionals (including groups such as dentists, podiatrists, and pharmacists among others, but not physicians). Although earlier studies weren’t clear as to whether calcium helped to prevent colon cancer, a new look at better data shows that people who increase the amount of calcium in their diet can cut their risk.
The authors found that calcium seemed to work if the people in the study took in a certain amount, or threshold, of calcium every day. That included both dairy products and calcium pills. Taking more calcium didn’t cut the risk any further.
So how good is calcium? If calcium intake from all sources was considered, there was a 40% to 50% lower risk of distal, or left-sided, colon cancer in people taking over 700 mg of calcium a day. That means their risk was cut by almost half, compared to those who took in 500 mg or less calcium a day. For the greatest benefit to women, they had to be “steady” consumers of milk over time.
But, the decreased risk only applied to cancers in left side of the colon. There was no decreased risk for cancers in the right side of the colon. Left-sided colon cancers are more common, but are more often diagnosed at earlier stages than right-sided colon cancers, which may not show signs or symptoms until late in the disease. There were more findings: calcium only helped people who did not take aspirin. And, taking vitamin D with the calcium was the key to reaping the benefits. Milk and many calcium tablets already contain vitamin D.
That means increasing the amount of calcium in the diet, usually with more dairy foods, or taking a calcium supplement can help. And, for people who take aspirin on a daily basis, increasing calcium intake doesn’t lower risk any further.
ACS -- What Vitamins Should You Take-
Recommends folic acid, B12 and other B-vitamins, vitamin E (?), and selenium. Vitamins A and C have shown no benefit in preventing or treating cancer.
Several studies from around the world have found that people who consumed higher levels of garlic had a lower risk of certain types of cancers. In particular, human studies have suggested that garlic may play a protective role in stomach, prostate, and colorectal cancers, but have failed to demonstrate an effect in breast and lung cancer. Laboratory studies suggest garlic may be of benefit in reducing tumor growth. An oil-soluble sulfur compound in processed garlic has been shown to kill human colon cancer cells in mice. Another compound found in aged garlic extract has also been shown to kill rapidly growing tumor cells. Significant antitumor activity was also found by injections of garlic into carcinoma of the bladder in mice.
Although widely prescribed for reducing blood cholesterol, a well-controlled study published in a major medical journal concluded that garlic therapy was not effective for treating high cholesterol.
Studies suggest that diets rich in tomato intake may account for a reduction in the risk of several different types of cancer. The strongest evidence is for a protective effect against cancers of the lung, stomach, and prostate gland. There may also be a protective benefit against cancers of the cervix, breast, oral cavity, pancreas, colorectum, and esophagus.
Population studies from many countries have shown that the risk of developing some cancers are lower in people who either have diets high in tomato products or have higher levels of lycopene in their blood. A population-based case-control study recently found that lycopene from tomato-based foods was associated with a small reduction in risk for prostate cancer. However, a direct relationship has not yet been proven. Other compounds in tomatoes or those diets high in tomato products, either acting alone or with lycopene, may be responsible for the protective effects currently associated with lycopene.
Since interest in lycopene is relatively recent, there have only been a few experimental studies on the role of lycopene in preventing or treating cancer. One animal study found that lycopene treatment reduced the growth of brain tumors. Another animal study showed that chronic intake of lycopene considerably suppressed breast tumor growth. The application of this study to human disease is cautioned since 95% of human breast cancers do not have the same characteristics that mice have. Lycopene has also been shown to interfere with the growth of many different human cancer cell lines in the laboratory, especially those that grow in response to insulin-like growth factor I. Animal and laboratory studies may show a certain substance holds promise as a beneficial treatment, but further studies are necessary to determine if the results apply to humans.
Results of a small clinical study presented at the 1999 annual meeting of the American Association for Cancer Research suggested that lycopene supplements may benefit those with prostate cancer. Among 15 men who had taken two capsules of lycopene every day for about three weeks before surgery, five had smaller, less advanced lesions and the cancer was less likely to have spread beyond the prostate than the men who received a placebo (inactive substance). Although these results are encouraging, this was a very small study. Also, the daily dose of the lycopene supplements equaled the amount of lycopene in about four pounds of tomatoes. More research is needed to find out whether lycopene treatment before surgery has any impact on long-term survival, whether continuing treatment after surgery is helpful, and what doses are most effective.
Modified Citrus Pectin
One animal study found that MCP inhibits the prostate cancer received MCP orally and were found to have a much lower risk of the tumor spreading to the lungs.
A second study examined the effects of MCP on lung metastases from melanoma cells. Researchers injected mice with melanoma cells that were given MCP and found that they developed significantly fewer metastatic lung tumors than mice who didn't receive the drug. When lung tumors did develop in MCP-treated mice, they tended to be smaller than those which formed in untreated animals.
The results from these two studies appear to show that MCP makes it difficult for cancer cells that break off from the main tumor to join together and form colonies in other organs. However, the study results also showed that MCP had no effect on the main tumor and that it may only be useful for preventing or slowing the growth of metastatic tumors that are in the very early stages of development. Animal and laboratory studies may show a certain substance holds promise as a beneficial treatment, but further studies are necessary to determine if the results apply to humans.
Omega-3 Fatty Acids
The evidence from the few clinical studies published in peer-reviewed medical journals is mixed. A limited study conducted at Harvard Medical Center suggested that one of the omega-3 fatty acids limited the recurrence of colon cancer. A preliminary study of omega-3s published in the Journal of the National Cancer Institute said that even though there appears to be a biological reason for omega-3s to fight cancer, clinical findings didn't prove that fish oil containing omega-3 fatty acids prevented cancer or its recurrence. A clinical study published recently in the journal Cancer concluded that omega-3 fatty acids seemed to prolong the survival of people with cancer who were also severely malnourished.
In societies that consume a lot of fish, researchers have noticed links between high intake of omega-3s and lower rates of breast cancer. For example, a study of people who live on the typical Mediterranean diet, which tends to contain high amounts of omega-3 fatty acids, concluded that the food they eat may offer some protection against heart disease and cancer. But the evidence is not conclusive and the subject needs further study. One researcher found evidence that major depression and cardiovascular disease were associated with low levels of omega-3 fatty acids which implied that omega-3s may possess the ability to maintain steady heart rates, therefore reducing the risk of sudden cardiac death.
Research is also focusing on the role of omega-3 fatty acids in relation to omega-6 fatty acids. Omega-6 is another essential fatty acid, and it can be found in many vegetable oils (corn, safflower, and sunflower), cereals, snack foods, and baked goods. Some researchers believe one of the reasons why Americans suffer high rates of cardiovascular disease and certain cancers, may be due to an imbalance in the ratio of omega-3 to omega-6 fatty acids. Ideally, the ratio of omega-3 to omega-6 fatty acids in the human body is 1-to-1. However, because the typical American diet is low in omega-3s and high in omega-6s, many people have 10 to 20 times more omega-6 fatty acids than omega-3 fatty acids in their systems. Studies show that women with breast cancer have 2 to 5 times more omega-6 fatty acids than omega-3 fatty acids in their systems.
Laboratory experiments suggest that omega-3 fatty acids may delay or reduce tumor development in animals. Other laboratory evidence shows that the balance between omega-3 and omega-6 fatty acid levels plays a role in the formation of breast cancer. One laboratory experiment, however, showed that both omega-3 and omega-6 fatty acids may promote the spread of colon cancer. Animal and laboratory studies may show that a substance has certain effects, but further studies are necessary to determine if the results apply to humans.
Not enough is known about omega-3 fatty acids to determine if they are safe in large quantities or in the presence of other drugs. Omega-3s may increase total blood cholesterol and inhibit blood clotting. People who take anticoagulant drugs or aspirin should not consume additional amounts of omega-3 due to the risk of excessive bleeding.
The source of omega-3 fatty acids may be a health concern. Because of pollution, many fish caught in the wild contain toxins absorbed from pollution. Experts recommend varying the type of fish eaten to reduce the chances of ingesting poisonous substances. Swordfish and shark, for instance, both of which are high in omega-3 fatty acids, may also contain high levels of mercury. Farm-raised fish tend to carry fewer toxins than fish in the wild.
Isoflavones in soy have been found to have protective effects against breast and prostate cancer in laboratory, animal, population, and case control studies. Randomized clinical trials are needed to understand how these findings apply to cancer prevention in humans. Results of research on the effects of consuming isoflavones on colon cancer risk have been mixed. Human studies on individual soy components are currently underway.
Researchers believe that the isoflavones in soy (such as genistein and daidzein) possibly play a role in reducing the risk of cancer. A number of laboratory and animal experiments and population studies have found that soy isoflavones have the potential to reduce the risk of developing several types of cancer including breast, prostate, and colon cancer. However, these results have not yet been reflected in human clinical trials, so no definite conclusions can be made.
There is enough evidence, scientists believe, for phytoestrogens to be used in clinical trials as potential chemopreventive agents (to prevent the development of cancer) or as an addition to breast or prostate cancer treatment. Human studies sponsored by the National Cancer Institute (NCI) are currently underway.
A review of research on the effects of vegetarian diets among Seventh-Day Adventists, whose religious doctrine advises against eating animal flesh, was presented to the National Institutes of Health (NIH). The report stated that Seventh-Day Adventists experienced less heart disease and fewer cases of some cancers than the general population. On average, Seventh-Day Adventist males had lower-than-average serum cholesterol levels and blood pressure and their overall cancer death rate was about half that of the general population. . The report cautioned that abstinence from tobacco and alcohol may have contributed to some of the health effects associated with vegetarian diets in the Seventh-Day Adventist community. In Great Britain, a 17-year population study that followed 11,000 vegetarians and health-conscious people, concluded that the daily consumption of fresh fruit was associated with a significant reduction in mortality from ischemic heart disease, cerebrovascular disease (stroke), and all causes of death combined. Another population study found a diet rich in grains, cereals, and nuts protected against prostate cancer.
In 1991, two nutritionists studying the benefits and risks of vegetarian diets reported that vegetarians are not necessarily healthier than non-vegetarians and that well-planned omnivorous diets (animal and vegetable products) can provide health benefits as well. They also pointed out that since many vegetarians adopt a healthier lifestyle--more physical exercise and no smoking--this factor may help improve their overall health.
Although preliminary studies involving small numbers of patients suggest certain anticancer benefits of CoQ10 supplements, the amount of evidence is minimal. More studies are needed with larger groups of patients to compare to conventional cancer treatments.
A review of 25 small human studies by the University of Texas reported mixed results for the use of CoQ10 as a cancer treatment. In one study involving 43 breast and prostate cancer patients, deaths were significantly lower among those who received a CoQ10 supplement with vitamins and minerals compared with those that received no CoQ10. In another study of 32 women with breast cancer that had spread to the lymph nodes and who were treated with a nutritional supplement program of vitamins, minerals, essential fatty acids, and CoQ10, all survived at least 24 months and had stable disease.
Low levels of CoQ10 have been associated with heart damage and chemotherapy treatment for cancer. One randomized clinical trial and four controlled studies found that for people who received CoQ10, there were some protective effects against heart damage related to chemotherapy. No scientific clinical research was found related to pain, weight loss, or increased appetite.
Few serious reactions to CoQ10 have been reported. Side effects may include headache, heartburn, and fatigue. Very high doses may cause involuntary muscle movements. Some users report mild diarrhea and skin reactions. Little is known about dosage or consequences of long-term use of CoQ10 supplements. There have been reports that CoQ10 may interact with anticoagulant (blood thinning) medications and pose a risk for prolonged bleeding.
It's very difficult to draw any conclusions from vitamin E studies because most of them seem to have been conducted using dl-alpha-tocopherol. The problem with dl-alpha-tocopherol is
If vitamin E occurs naturally with at least these eight components, surely nature has some compelling reasons to include all eight components. Consequently, when studies are conducted that don't replicate natural vitamin E, I'm led to wonder how realistic they are.
ACS -- Vitamin C
Many scientific studies of the protective effects of vitamin C have shown that consuming a diet high in fruits and vegetables (containing vitamin C) significantly reduces the risk of developing cancers of the pancreas, esophagus, larynx, mouth, stomach, colon and rectum, breast, cervix, and lungs. Many of these studies show that a high intake of vitamin C from dietary sources has about a twofold protective effect when compared to a low intake of the vitamin.
However, observational studies and recent experimental trials of vitamin C supplements have not shown the same strong protective effects against formation of cancer. Apparently, vitamin C is most beneficial when consumed naturally in fruits and vegetables because of the other active ingredients in the food.
The 2000 NAS report stated that there is not enough evidence to support claims that taking high doses of antioxidants (such as vitamins C and E, selenium, and beta carotene) can prevent chronic diseases. Some scientists believe that taking high doses of antioxidant vitamins may actually interfere with the effectiveness of radiation and some chemotherapy drugs. No studies have yet been done in humans to test this theory. However, a recent review suggests that a combination of antioxidant vitamin supplements together with diet and lifestyle changes may actually improve the effectiveness of standard and experimental cancer therapies. More research is needed to evaluate the effects.
Like vitamin E, vitamin C occurs as a part of a bioflavenoid complex.
ACS -- What's New in Prostate Cancer Research and Treatment ...
ACS -- Low Calorie Diet May Help Reduce Prostate Cancer ...
Can Prostate Cancer Be Prevented?
Limit intake of red meats.
5 or more servings of fruits and vegetables each day.
Bread, cereals, grin products, rice, pasta, and beans are also recommended..
Cooked tomato products.
Selenium (no more than 400 mcg. a day).
Avoid vitamin A,
Vitamin E (full-spectrum?)
Proscar (finisteride) led to 25% fewer prostate cancers, but those that occurred were more aggressive.