Diet, Nutrients, Vitamins & Cancer

Diet, Nutrients, Vitamins & Cancer

Many foods, especially fruits and vegetables, contain substances that help to prevent the formation of cancers or actively attack existing cancers. This seems to be one of the purposes of food and is a part of the economy of nature. For cancer prevention, a diet containing high-quality fruits and vegetables is essential. Ideally, fruit and vegetables should not only be free of herbicides, fungicides, pesticides, etc. but should also be grown on soil that has not been depleted of natural minerals and nutrients. A number of experts have pointed out that for cancer treatment rather than prevention, it may be too late for a dietary regime alone to result in a cure. Concentrated extracts should also be considered. However, to maintain or regain health, the importance of a whole food diet cannot be over-emphasized.

Woodlands Healing Research Center A good overview of nutrition and cancer.

Cornell University Scientific research papers concerning the influence of fruit and vegetables on cancer risk, etc.

American Institute for Cancer Research The cancer charity that fosters research on diet and cancer prevention, and educates the public about the results.

Phytochemicals as Nutriceuticals An excellent survey of the many beneficial substances found in plants.

Nutrition Journal – Nutrition and Cancer: A Review of the Evidence for an Anti-cancer Diet. An excellent review.

The Oncologist – Complementary and Alternative Therapies for Cancer. A good review of the options.

Cancer Active – Ten foods you should add back into your diet today.

Cancer Active – Twelve foods you should have in your diet to fight cancer.

Life Extension Foundation – An excellent review of many anti-cancer foods and supplements.

Many well-known vitamins and other antioxidants have been shown to help lessen the side effects of chemotherapy and radiotherapy. Some also possess anti-cancer properties. However, some antioxidants can inhibit the cytotoxic effect (and hence their ability to kill cancer cells) of chemotherapy drugs, while others can enhance their cytotoxic effect (such as vitamin E and 5FU). The subject is complex because there are so many antioxidants and so many chemotherapy drugs, and the full nature of all the interactions is unknown. So if you are intending to take vitamins and antioxidants along with chemotherapy, it is best to do further research and/or ask a medical professional who knows about these things.

Dietary supplements are a huge industry, and quality varies considerably, so it is important to get high-quality vitamins and antioxidants. Vitamins etc. that have been extracted or prepared in such a way as to maximize their bioavailability are preferable because the body is able to absorb greater quantities. There is little point in taking large doses of vitamins if most of them are never absorbed into the body or if they are simply excreted in your urine. What are antioxidants?

Moss Reports Dr Ralph Moss has studied this subject in detail and has many useful things to say on the use of antioxidants during chemotherapy and radiotherapy. Try searching his site for antioxidants. He has also written a well-considered report, Should patients undergoing radiation and chemotherapy take antioxidants? (It’s not free!)

The Simone Report – Nutrients and Cancer Treatment. Has some useful information on chemotherapy and antioxidants.

Gary Null et. al. Vitamin C & the Treatment of Cancer. A review of the research literature.

Arnold Gore A detailed study of antioxidants, cancer, chemotherapy, and radiation.

PubMed Dietary antioxidants during cancer chemotherapy: impact on chemotherapeutic effectiveness and development of side effects. A scientific and technical review of some of the known or suspected interactions.

Diet, Nutrients, Vitamins & Cancer

National Cancer Institute A factsheet on a vitamin E and selenium cancer prevention trial.

AnnieAppleSeedProject A review of some of the studies concerning the beneficial combination of antioxidants. See also.

Doctor’s Guide A report on the enhancing effect of Vitamin E on the colorectal cancer drug, 5FU.

Higher Nature UK supplier of high-quality nutritional supplements, with an advice line. Check out their True Food range of supplements with enhanced bioavailability.

Vitamin C High Intravenous Dose

Vitamin C, also known as ascorbic acid, was first suggested as a cancer treatment in 1976, by Linus Pauling, winner of the Nobel prize for chemistry in 1954 and the Nobel peace prize in 1964. His research showed that life expectancy in terminally ill cancer patients who were given 10gms of vitamin C per day was significantly increased, compared to those who were not. Various studies since then have produced similar results, with survival times being generally doubled. Other studies, however, have found no benefits, and have concluded that any positive benefits are those of a placebo. In practice, doctors who have used the method have found that it works with some patients and not with others. Why this should be so is presently unknown.

It has been suggested that the high dose acts as an immuno-booster, stimulating the body’s defenses to attack cancer. This may be so, but in vitro studies published in the Proceedings of the National Academy of Sciences (2005) have also indicated that a high dosage of vitamin C results in the formation of hydrogen peroxide, which kills cancer cells. Normal cells remain unaffected by vitamin C at any concentration. Phase I clinical trials are presently underway to test the efficacy of the treatment.

Proponents of the method have pointed out that studies showing no benefit from the treatment used oral rather than intravenous administration. The suggested dose of vitamin C as a cancer treatment is 32gms or more per day. Because doses higher than 3-6 gms per day can cause irritation to the gastrointestinal tract, it has to be administered as an intravenous infusion in a saline medium. This, of course, can only be done by a competent doctor. Side effects are generally minimal, with some dizziness during administration. It cannot be used in cases where there is fluid on the lungs, heart, or peritoneum.

Physorg News report of scientific studies. Vitamin C: Possible cancer-killing promise.”

BBC News Report Vitamin C helps to fight cancer.Proceedings of the National Academy of Sciences Pharmacologic ascorbic acid concentrations selectively kill cancer cells: Action as a pro-drug to deliver hydrogen peroxide to tissues, (September 20, 2005).

Annals of Internal Medicine Vitamin C pharmacokinetics: implications for oral and intravenous use,” (April 6, 2004)

Linus Pauling Institute: Is Vitamin C Harmful to Cancer Patients?” (2000)

Linus Pauling Institute: A useful overview of the biological functions of vitamin C.

Dove Clinic A good article from UK cancer specialist, Dr Julian Kenyon.

Vitamin D

An increasing number of studies have demonstrated that vitamin D is involved in the body’s natural protection against cancer. It is found in a number of food substances and is produced naturally in the skin in response to sunlight. Since the amount of sunlight in wintertime in northern and southern latitudes, together with an indoor lifestyle, produces insufficient vitamin D for the body’s requirements, the consumption of vitamin D in foods or supplements is essential. Note, however, that high doses of vitamin D are toxic, causing a build-up of blood calcium, which can lead to death. The latest recommended daily dose is 1000 IU (international units).

Office of Dietary Supplements, National Institute of Health An excellent overview of vitamin D.

Nutrition Science News Vitamin D as a defense against cancer.

BUPA Health News Vitamin D, sunlight, and cancer.

Food Consumer Vitamin D may lower cancer risk. A new report of the findings was published in the February 2006 issue of The American Journal of Public Health.

American Journal of Public Health Publisher of the latest vitamin D and cancer report. At the time of writing, the February 2006 edition is not yet online, but this is where you can find it.

Vitamin B17, Amygdalin & Laetrile

Among the many vitamins shown to exhibit anti-cancer properties is vitamin B17, also called amygdalin, and found in a number of fruits and vegetables (including wheatgrass), but especially fruit pips and kernels such as apple pips and apricot kernels (the richest source). However, caution is required, since one of the metabolites of B17 is cyanide, although it is claimed that B17 is metabolized safely. Laetrile is the trade name for the synthesized compound, laevo-mandelonitrile-beta-glucuronoside, patented in the US, which is a close relative of B17. In popular practice, the names laetrile and amygdalin get used interchangeably. The scientific evidence concerning the positive anti-cancer benefits of B17 is mixed. Some claim it to be the universal preventative and remedy against cancer and the subject of a massive cover-up. Others describe the claims as fraudulent. In practice, doctors using the treatment have found that like practically all cancer treatments, conventional or otherwise it has benefits for some patients, but not for others. Intravenous infusion is also more effective than oral administration.

Cancer Cure Foundation Laetrile and information on vitamin B17.

Why We are Losing the War on Cancer Dr Ralph Moss’ interesting story of his struggle with the Memorial Sloan-Kettering Cancer Center in New York regarding laetrile. The story of vitamin B17. A UK information site, offering a useful downloadable guide to B17.

Offshore Pharmacy A good review of the positive side of the case for laetrile or B17.

The Cancer Cure Foundation A balanced view of the controversy.

National Cancer Institute A brief overview.

Whale A networking page with many links to sites concerning laetrile. Check out, especially, the Dr Manners interview.

NineMSN News & Current Affairs “Vitamin B17: Cancer Cure or Con?” A news report examining the controversy.

1Cure4Cancer is A site that emotively presents the evidence in the form of hyped-up claims and conspiracy theories. Links to sales sites for vitamin B17.

Apricot Powder – A US vendor of apricot kernels and amygdalin.

Bayho – A US vendor of apricot kernels.

Quackwatch: A detailed debunking of the claims surrounding B17 by dedicated debunkers, together with the history of the treatment.

Folic Acid and Folate – Vitamin B9

Folate and folic acid are B vitamins, referred to specifically as vitamin B9. Although the names are often used interchangeably, folate is the form actually found naturally in many foods, including dark leafy greens such as spinach, beetroot, mustard greens, asparagus, avocado, Brussels sprouts, broccoli, turnip and other root vegetables, peas, chickpeas, lentils, kidney beans, white beans, lima beans, mung beans, soya beans, oranges, brewer’s yeast, whole grains, wheat germ, bulgur wheat, orange juice, and milk. Some of these – such as spinach and broccoli, are better sources than others.

Folic acid is the form used as a dietary supplement and is rarely found in foods or the human body. The body is able to absorb folic acid about twice as easily as folate. Largely because folate deficiency around the time of conception can result in birth defects, all-grain products in the USA 1998, such as pasta, bread, and cereals, have been fortified with folic acid. Similar statutory requirements are also in place in a number of European countries. The recommended daily adult requirement of folate is at least 400 micrograms, a quantity now obtained by many people in the US and Europe (though not the UK), through the addition of folic acid to grain products.

Because folate is involved in the synthesis of RNA, and the repair and functioning of DNA, its deficiency can result in DNA damage that can lead to cancer. Several studies have associated low levels of folate in the blood with an increased risk of cancer. Other studies have reported that diets low in folate are associated with an increased risk of breast, colon, and pancreatic cancer, while diets high in folate are linked with a decreased risk of breast and colorectal cancer. Research has also shown that the risk is further reduced when folic acid is taken along with other nutrients, such as methionine, and vitamins B6 and B12, which help the body utilize folate. On the other hand, alcohol interferes with the absorption and metabolism of folate, and studies have shown that alcohol consumption, even as little as one drink a day, significantly increases the risk of both colon and breast cancer. That studies have been conducted on particular forms of cancer does not mean that other forms of cancer are unaffected by the concentration of dietary folate. It is simply the best way to obtain meaningful data from such trials.

Epidemiological studies linking diet to cancer risk do not prove a direct cause, and the conservative view is that megadoses of folic acid supplements are inadvisable as a means of reducing cancer risk. On the other hand, studies have shown that those with a family history of colon cancer reduce their risk of getting the disease by long-term use of multivitamin tablets containing folic acid. Folate is also destroyed by overcooking, and being water-soluble, is leached into the water when boiling vegetables. Steaming your vegetables is a better option.

Because folate is required for rapid cell division, including cancer cells, some cancer drugs, such as methotrexate, are designed to interfere with folate metabolism. It is important, therefore, for anyone taking methotrexate to seek their oncologist’s advice concerning the use of folic acid supplements. Because folate is better utilized by the body when in conjunction with vitamins B6 and B12, it is advisable for those taking a folic acid supplement to combine it with a B-complex supplement. Also, it seems inadvisable for patients with cancer to take high doses of folic acid, since this will only supply the tumor with more of the folate it requires for proliferation.

Folate’s integral part in cellular metabolism underlies studies showing that folate deficiency is also related to miscarriage, heart disease, Alzheimer’s disease, osteoporosis, depression, cancer, cervical dysplasia, inflammatory bowel disease, burns, and male infertility.

All Refer Health – A brief overview.

The Doctor Will See You Now – A useful overview with a historical perspective.

Office of Dietary Supplements – A full overview in layman’s language, including a table of foods containing folate.

University of Maryland Medical Center – Another excellent in-depth overview, including details of its protection against various ailments.

Wikipedia – An overview from this online encyclopedia.

Linus Pauling Institute – An in-depth overview for the more scientifically minded.

American Cancer Society – A useful overview, and a report concerning the role of folate in reducing the risk of breast cancer.

American Cancer Society – “Folate Reduces Risk of Colon Cancer For People with Family History.”

Vegetarian Nutrition – “Folate and Colorectal Cancer: Is There a Connection?” A review of some of the studies, up to the late 1990s.

Inositol & IP-6 (Inositol Hexaphosphate)

IP-6 is a combination of the carbohydrate, inositol, with six phosphate molecules. Present in almost all mammalian cells, it is an antioxidant and a member of the vitamin B6 family. Found especially in sesame seeds, beans, and cereals (especially corn, oats, and rice), IP-6 is thought to regulate cell function, including proliferation and differentiation. Back in the mid-1980s, pathology professor, Dr A. M. Shamsuddin, and his colleagues at the University of Maryland School of Medicine found that IP-6 slowed or stopped the growth of human liver cancer cells in cell culture, and shrank existing tumors in mice. According to Dr Shamsuddin, IP-6 inhibits the proliferation of cancer cells, often causing them to revert to normality. Other animal studies, largely with colon, lung, and breast cancers, have confirmed the cancer-inhibiting properties of IP-6.

Clinical trials on human beings have yet to be conducted, although in cell culture studies IP-6 has been shown to inhibit the growth of human prostate cancer cells and adenocarcinoma. Since the publication of the original research, IP-6 has moved in and out of medical favor. Because IP-6 also binds to important minerals such as calcium, magnesium, copper, iron, and zinc (a process known as chelation) in the stomach, preventing their bodily utilization, the conservative view is that its use as a supplement must be considered experimental, and it should be taken under appropriate medical supervision. A high-fiber diet is said to provide a sufficient supply of IP-6.

On the other hand, since iron is used by cancer cells as a primary growth factor, a substance that actively chelates iron from cancer cells is of positive benefit. IP-6 does not remove iron from red blood cells because the iron is tightly bound to the hemoglobin molecule. Dr Shamsuddin, author of IP-6: Nature’s Revolutionary Cancer Fighter (1998), says that studies have shown the excessive chelation worries to be unfounded. He also maintains that IP-6 holds promise for the prevention and treatment of high cholesterol and lipid levels, kidney stones, and maybe even as an immune booster. He also observes that studies show that simply eating large quantities of fiber is a less effective weapon against cancer than eating foods that are especially high in IP-6. Taking IP-6 as a supplement is still more effective.

As a nutritional supplement, IP-6 works best when combined with inositol, because the two together form IP-3, which is actually the compound responsible for much of the anti-cancerous effects of IP-6. Despite concerns over the excessive chelation of essential minerals, no toxic side effects have been reported. However, IP-6 can cause flatulence and gastrointestinal discomfort. P-6) and Inositol: From Laboratory to Clinic. A presentation by Ivana Vucenik and A.M. Shamsuddin

Annie Appleseed Project – Links to a number of IP-6 research studies.

Broccoli & Tomatoes

Studies have shown that eating tomatoes and broccoli lowers the risk of prostate and breast cancer. The carotenoid, lycopene, the red substance in tomatoes, also appears to have potential benefits in treating oral, oesophageal, lung, stomach, colorectal, pancreatic, bladder, cervical, and some other forms of cancer. There is also evidence that lycopene by itself is not as effective as whole tomatoes because of synergistic reactions with other tomato substances. Cooked and concentrated forms of tomato are the best sources of lycopene. So it seems like its a good idea to make your diet rich in broccoli as well as sun-dried organic tomatoes in oil, dried tomato powder, or other organic tomato concentrates, especially tomato paste and tomato sauce. Further details concerning the anti-cancer substances in broccoli and other brassicas are given in the section on indole-3-carbinol, and on tomatoes in the section on lycopene.

Indole-3-Carbinol (I3C) & Isocyanates

Isocyanates are formed from the breakdown of various sulfur-containing compounds known as glucosinolates, found in cruciferous vegetables. Different crucifers contain different glucosinolates, resulting in different isocyanates. Crucifers include brassicas such as broccoli, cauliflower, cabbage, Brussels sprouts, collard greens, mustard, kale, kohlrabi, rutabaga, turnips, bok choy, and Chinese cabbage. Other cruciferous vegetables are radish, horseradish, garden cress, watercress, wasabi, and arugula. Epidemiological studies have shown that diets high in cruciferous vegetables are associated with a reduced risk of several forms of cancer. However, crucifers are high in other anti-cancer compounds, such as vitamin C, carotenoids, selenium, folate, and fiber.

I3C is an isocyanate derived from the breakdown of glucobrassicin, a glucosinolate found in a number of common brassicas, the highest concentrations being present in Brussels sprouts, garden cress, mustard greens, and turnip. I3C can combine in the acidic environment of the stomach to form other compounds, such as 3,3’di-diindolylmethane (DIM).

Cell culture studies have shown I3C and DIM to induce apoptosis (cell death) in the prostate, breast, and cervical cancer cells. There is also some cell culture evidence that they can inhibit the spread of cancer cells into normal tissue, as well as the angiogenesis (growth of new blood vessels) required by tumors for rapid growth. It is also possible that I3C is effective against other forms of cancer. One cell culture study has shown that I3C inhibits the proliferation of human colon cancer cells.

In animal studies, I3C has been shown to inhibit the development of cancer when given before or simultaneously with a carcinogen. However, in some instances, I3C promotes the development of cancer when given after a carcinogen. These paradoxical results have led some experts to advise against the use of I3C and DIM supplements as cancer preventative supplements until they are better understood.

Preliminary human trials show that I3C supplementation is helpful in treating conditions related to human papillomaviruses (HPV) infection, such as the pre-cancerous cervical intra-epithelial neoplasia (CIN, also called cervical dysplasia) and recurrent respiratory papillomatosis (RRP). In one trial, 30 women with pre-cancerous CIN were given 12 weeks of I3C supplementation or a placebo. Complete regression of CIN was found in 50% of the women taking 200 mg per day and 44% of the women taking 400 mg per day. None of the women who took a placebo experienced a complete regression. Both I3C and DIM are known to affect estrogen metabolism, helping its elimination from the body. I3C has also been shown in cell culture studies to boost the production of certain proteins that inhibit the formation of breast and prostate cancer by repairing damaged DNA.

Two forms of breast cancer are commonly described – those that depend on estrogen for their growth, and those that do not. I3C inhibits the proliferation of both kinds of breast cancer cells, while the commonly used breast cancer drug, Tamoxifen, only inhibits the proliferation of the estrogen-dependent form. In cell culture studies, a combination of Tamoxifen with I3C functions better against breast cancer cells than either of the two alone.

Broadly speaking, the effect of I3C and DIM supplements on the risk of other cancers is unknown. Moreover, since little I3C and DIM reach internal bodily tissues after oral intake, it is uncertain whether I3C and DIM supplementation have any effect on cancer risk. High doses (800 mg/day) of I3C and DIM supplements have been associated with disequilibrium and tremor, which disappears on reduction of the dose. Other minor side effects, such as skin rash, have also been reported. There is also the possibility that I3C and DIM supplements may indirectly help in the metabolism and elimination of many drugs, perhaps decreasing their efficacy.

The breakdown of glucobrassicin to I3C is mediated by an enzyme also found in brassicas, but which is deactivated by boiling. Being water-soluble, glucosinolates are also leached into cooking water by boiling. The means of brassica consumption, therefore, has an effect on their efficacy in an anti-cancer role.

Other resources:
Complementary and Alternative Cancer Treatment
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