Transcript: The Role of Vitamin C in the Treatment of Terminal Cancer
Studies in the 70’s showed an extraordinary survival gain in terminal cancer patients with vitamin C, a simple, relatively nontoxic therapy. So, no wonder it got a lot of attention, especially when reported by a world-renowned scientist, Linus Pauling. But studies like this in the 1980’s found no such benefit. So, alas, they were left with the inevitable conclusion that the apparent positive results in the original study were the product of bias rather than treatment effectiveness. In the 1990’s, though, an alternative explanation arose. The disappointing 80’s research only used oral vitamin C, whereas the apparently successful 70’s experiments also gave vitamin C intravenously, and we didn’t realize until the 90’s that the same dose given IV can lead to dramatically higher levels in the bloodstream than if taken orally. So, maybe high dose vitamin C does help in terminal cancer, but maybe only when given intravenously.
Encouraging case reports continued to be published. Here, there was a regression, remission, and cure documented in individual cases of advanced kidney cancer, bladder cancer, and lymphoma. But that was three success stories out of how many? If it was three out of a hundred, or even three out of a thousand, well ok, if the treatment is sufficiently nontoxic. But there’s evidence that IV vitamin C is widely used in the alternative medicine world, as in 86% of 172 practitioners surveyed. Just those 172 practitioners alone treated about 10,000 patients a year. And you ask the manufacturers, and they’re selling hundreds of thousands of vials of this stuff in the U.S. Now, it’s not all being used for cancer, but presumably at least thousands of cancer patients are being treated every year with IV vitamin C, making the publication of three remarkable case reports seem less impressive. So, no matter how amazing these cases seemed, it’s possible the cancers just spontaneously regressed all on their own, and it was just a coincidence that it happened after they were given vitamin C. To know for sure, you have to put it to the test.
To date, there have been some small pilot studies, and the results so far have been disappointing. The good news is that even insane doses of IV vitamin C seem remarkably safe, but failed, in this study of two dozen patients, to demonstrate anticancer activity. Similar small studies have been published, all the way through to the present with tantalizing but inconclusive results. What we do know is that the present state of cancer treatment is unsatisfactory. People have this perception that chemotherapy will significantly enhance their chances for a cure, but put all our cancer-killing chemo together and the overall contribution to 5-year survival is on the order of 2%. All those side-effects for 2.1%, at a cost of maybe $100,000 per patient per year. So, it may be worth looking deeper into therapies likes IV vitamin C. However, the lack of financial reward, since vitamin C can’t be patented and sold for $100,000, and bias against alternative medicine could dissuade conventional investigators and funding agencies from seriously considering this approach.
So, decades later what can we conclude? After trials which have included at least 1,600 patients over 33 years, we have to conclude that we still do not know whether vitamin C has any clinically significant antitumor activity. Although there is currently no definitive evidence of benefit, the Mayo Clinic randomized controlled trials do not negate the potential benefit based on what we now know about oral versus IV routes of administration. So, we’re kind of back at square one: does it work or not? There are highly polarized views on both sides, but everyone’s working off the same incomplete data. What we need are carefully controlled clinical trials. The question, though, is what do we do until then?
If it was completely nontoxic, then one could argue what have you got to lose, but it’s not; it’s only relatively nontoxic. For example, there have been rare but serious cases of kidney injury reported. After all, if it’s so safe, why did our bodies evolve to so tightly control against excess absorption? It can also be expensive and time-consuming. Each infusion can cost one to two hundred dollars out of pocket, which can be quite a boon for alternative medicine practitioners. About 90% of the millions of doses of vitamin C being dispensed are in for-profit arrangements; so, there’s financial pressures pushing in both directions.
Given the relative safety and expense, though, if controlled studies even find a small benefit, it would be worthwhile. And if they don’t, the vitamin C question can be put to rest once and for all, but in cancer treatment, we don’t have the luxury of jettisoning possibly effective relatively nontoxic treatments. We should revisit promising avenues, without prejudice, and with open minds.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
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