Many people gobble big doses of vitamin C in hopes of boosting their immune system and warding off illness. But new research shows that in people with cancer, the vitamin may do more harm than good.
Researchers at Memorial Sloan-Kettering Cancer Center in New York studied the effects of vitamin C on cancer cells. As it turns out, the vitamin seems to protect not just healthy cells, but cancer cells, too. The findings were published today in the journal Cancer Research.
“The use of vitamin C supplements could have the potential to reduce the ability of patients to respond to therapy,” said Dr. Mark Heaney, an associate attending physician at the cancer center, in a press release.
Dr. Heaney and his colleagues tested five different chemotherapy drugs on cancer cells in the laboratory. Some of the cells were first treated with vitamin C. In every case, including a test of the powerful new cancer drug Gleevec, chemotherapy did not work as well if cells had been exposed to vitamin C. The chemotherapy agents killed 30 to 70 percent fewer cancer cells when the cells were treated with the vitamin.
A second set of experiments implanted cancer cells in mice. They found that the tumors grew more rapidly in mice that were given cancer cells pretreated with vitamin C.
The researchers found that just like healthy cells, cancer cells also benefit from vitamin C. The vitamin appeared to repair a cancer cell’s damaged mitochondria, the energy center of cells. When the mitochondria is injured, it sends signals that force the cell to die, but vitamin C interrupts that process.
“Vitamin C appears to protect the mitochondria from extensive damage, thus saving the cell,” Dr. Heaney said. “And whether directly or not, all anticancer drugs work to disrupt the mitochondria to push cell death.”
Dr. Heaney measured the buildup of vitamin C levels in cells and said that the levels of vitamin C used in the experiments were similar to those that would result if a patient took large doses of the vitamin in supplement form. Earlier research at the cancer center showed that vitamin C seems to accumulate within cancer cells more than in normal cells.
Patients should eat a healthy diet that includes foods rich in vitamin C, Dr. Heaney said, but it’s the large doses of vitamin C in tablet form that are worrisome.
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From 1 to 25 of 96 Comments
Is it okay for someone who is fighting cancer to take a regular multivitamin? Has this been studied?
— HeronThat whirring noise you hear is Dr. Linus Pauling spinning in his grave.
See http://www.quackwatch.org/01QuackeryRelatedTopics/pauling.html
but also: http://lpi.oregonstate.edu/infocenter/vitamins/vitaminC/
— Rob L, N Myrtle Beach SCwell…this just shows we should be advocating a healthy diet
— tim hunterand large doses of Vitamin C to avoid cancer in the first place
Hmm. Vitamin C is not patentable. Could this have something to do with the findings?
— RuthThis is old news. What needs to be tested is whether an antioxidant-free diet is superior in cancer patients receiving chemotherapy.
— MarkIt’s amazing that medicine’s prejudice against vitamin supplement takes the confirmation that Vitamin C aids cell repair to consider its use as a supplement by otherwise healthy people “worrisome,” because it also aids cancer cells.
While heeding the advice that one shouldn’t take the vitamin if diagnosed with cancer, it seems that everyone else should be ENCOURAGED to take Vitamin C supplements in reasonably sized doses to ward off the damage that every day brings to every cell as we age and are exposed to pollution and stress.
Most of us don’t eat enough really good food to get all the vitamins and minerals we need, even if we are active enough to burn a substantial amount of calories without inviting obesity. I’ll bet if the medical establishment ever did a study of hose that take reasonable vitamin supplements and exercise vs those that exercise and take none, the first would come out significantly healthier on any number of scores.
Of course, these same doctors who pooh-pooh any kind of vitamin supplementation are all too ready with expensive and often toxic drugs at the first cough, and especially with older people, rarely encourage the vigorous exercise that the again body thrives on. Ah,well.
— wiegandRuth:
Are you suggesting that a scientist is being paid off by some pharmaceutical company, or perhaps a cabal of companies, to discredit vitamin C, and then as a result the scientist faked the results of his test?
If you are not suggesting such a ridiculous scenario, then the answer to your question would be, No, this could not have anything to do with the findings.
— BobbyDoes this information mean that the C deficiency state of
— Blairscurvy is a preferable condition for an individual with cancer? C is essential for collegen integrity and detoxification. Might the cancer treatments have an even harsher
impact on overall health and survival of the individual?
A very wise man once told me that when something doesn’t make sense to follow the money.
Far be it for me to infer that the Medical Industrial Complex is keeping an army of experts gainfully employed by NOT finding a cure for cancer, but it seems strange that any solution to cancer which does not involve expensive drugs or doctor-supervised treatments couldn’t possibly ever help.
I could provide countless examples but the studies at Duke and by Dr Fernando Dimeo in Berlin clearly show that exercise and a nutritious diet are far more effective in treating depression than the pills pushed upon us by Big Pharma (Prozac et al). But only one of these paths leads to tens of billions of dollars.
— Peter ParkerI think we need to stop using the antiquated term “vitamin.”
The semantic reality is that there are a significant number of people who believe that if a substance is called a “vitamin,” it must be vital for one’s health and, by extension, taking large doses prevent or treat a disease. We know that excess doses of water soluble vitamins are mostly excreted by the body, although some accumulation is possible, predisposing individuals to complications (kidney stones, eg). Fat soluble vitamins are even more dangerous: they are more difficult for the body to excrete. Consequently, the threshold of toxicity for vitamins A, D, E and K is much lower. Add to that the propensity for certain vitamins to interfere with medications (this is true for AIDS medications, as well as certain cancer medications), and you’ve got a dangerous situation.
If we stop calling vitamins “vitamins” and call them by their chemical names, I believe fewer people will abuse them.
— famdocVitamin D seems more promising and all you have to do is let the sun shine on your skin to get it.
http://www.vitamindcouncil.org/cancerMain.shtml
— john#4, Ruth
It is called paranoia.
— ArrowVitamin C is bad???? Well, maybe if the FDA and others would heed the findings of Krebs, they’d realize that B17, found in apricot pits and many other food stuffs, attacks cancerous cells and cancerous cells alone.
— too droll to trollHey Ruth, post #4…this is science, not politics….but don’t quit your job in the health food store as yet, because there are still many fools that can be hoodwinked
— tomA couple of points: The study only seems to show that taking large doses of vitamin protects the cancer cells against those highly destructive anti-cancer drugs (and that it also helps *normal* cells, a point which is at least equally significant). It doesn’t at all indicate that taking vitamin C is bad for you or that it encourages cancer. It also has no bearing on Pauling’s work with the IV use of vitamin C as a cancer treatment which recently studies appear to support. (note the *IV*, oral vitamin doesn’t seem to be effective).
— Lee H.For some reason, there’s this feeling out there that anything “natural” has to be good, and more is always better. Example: people have actually died from drinking too much water (even totally pure water).
We have hopefully learned our lessons with megadoses of vitamin E causing heart attacks and megadoses of vitamin A causing osteoporosis.
Anyone who is taking megadoses of vitamin C should now have more reason than ever to stop.
Multivitamins for those who can’t get enough of the vitamins in the diet are safe, but megadoses are proving to be dangerous!!
— jackThis findings are just one more example of how supposedly “first-class” researchers haven’t done their homework. It is well-known (among serious vitamin researchers) that the effects of vitamin C on cancer are absolutely dose related. It takes relatively high doses of vitamin C to have anti-cancer effects and low doses do protect all cells, including cancer cells.
— DrColeDuh, Vit C is an antioxidant. Many chemotherapeutic agents affect redox status. Will the researchers then get another paper published when they “discover” that cellular membranes have Vit E? Vit E and C work in concert. Also, these are just cell culture studies. Doesn’t the body maintain homeostasis of Vit C and get rid of excess? Their claims of going from culture studies to human studies are a bit far reaching. As a scientist, I get tired of this kind of stuff - far reaching implications. Do the studies in mice or rats and then try to put fear into the public. Otherwise, this is just another paper that may not correlate to true in vivo situations. Thanks!
— AnnelisAs far as I remember,it was during the 80s that doctors advocating the use of Vitamin C were aware of a possible interference with chemo drugs,but did not know the mechanism of this interaction.However,it seems to me that moderate dosis of supplements are still very helpful for good health,I remember a study at the Rockefeller University where the contents of Viamin C in oranges was examined,some of them contained up to 90 mgs,others None!,so much for a “healthy diet”!!!
— AlbertoWho did the research, who sponosered the study? I am sure some HUGE Pharma company did??
I agree with Tim Hunter take Vit C all the time
— PAll along, a major problem with cancer treatment has been that it affects healthy cells as well as cancer cells. It is easy to accept that what benefits healthy cells would benefit cancer cells too. I bet vitamin C isn’t even the only one. More research is needed to find out in what other ways we are helping cancer cells.
— SusannaRob L
You seem to have misunderstood the article. Pauling proposed that Vitamin C played an important role in the health of the body. In the 50s and 60s, the medical establishment declared that 30mg. was all that was necessary for good health. Megadoses were always controversial. My doctor knows I take 1000mg. of Vitamin C, and have since Pauling. During my last visit, he told me to cut back to 500mg. This would have been a megadose back in the 60s. I get a cold about every six, or seven years. The article shows that people in cancer therapy should not take Vitamin C supplements. It reconfirms that Paul was right about the protection of cells by Vitamin C. However, a balace diet is still the best protection. Don’t you wish everybody could affort to eat right?
— sullivanI am a big proponent of vit C to fight cancer along with a macrobiotic diet and other vitamins and herbs and sea vegetables, I’ve seen it work miracles. But recently while doing some research for a friend I found information about the pawpaw fruit and that it lowers the bodies energy level on a cellular level to 50 micro units. Cancer operates at a higher speed 75 micro units (this is why a PET scan works the cancer cells uptake the glucose quicker and show up on the scans while normal cells don’t)
So the pawpaw starves the cancer of energy, in the same article it talked of other substances, Vit C being being one that speed up the cells’ energy levels and thus might not be good to take in large doses when fighting cancer. I was surprised and dismayed but it might be true. I stlll take 2000 units a day in Vit C and when my sister had cancer she took 6,000 a day and her doctor was shocked and said he had never seen anyone heal so fast from surgery. She also, in a month’s time, had a spontaneous remission, she had been given 2 months to live with stage 4 sarcoma. A miracle. So it is hard for me to say what the truth is, but I would find a pawpaw tree…
— itsaboutimeThis article and the many responses prove only one thing to me - we really haven’t the slightest clue, but we are all very invested in asserting that we do.
— ElteegeePeople are being very conspiratorial about this. Megadose vitamins are a billion dollar business as well, people, just as “big pharma.” The final word is in on beta carotene supplements, long theorized to prevent cancer — it turns out they have no effect at all, or if they do, a slightly positive association.
The “magic bullet” of a mega-dose will not work; Vitamins are important for health and wellness, but only in the context of a wide variety of other phytochemicals that come with a healthy diet high in vegetables and fruits.
Other than that, there are a lot of comments here from people a bit angry to hear news they don’t like. I recommend lowering the paranoia defenses and reading further and more widely.
And try to get away from the “magic bullets”; the Linus Pauling method (if x is good, 1000x is even better) does not apply, it turns out, to delicate systems like the human body.
— S.D.