Nearly 50 years after Nobel Prize-winning chemist Linus Pauling and Scottish physician Ewan Cameron first suggested that high doses of vitamin C could treat cancer, the therapy is finally on track for approval as an alternative to chemotherapy. It's now reached the second stage of the process, which involves tests for safety and effectiveness; if all goes well, it could be available in cancer wards in just a few years' time.
The delay has been blamed on the results of previous studies that failed to reproduce the successes that Pauling and Cameron had achieved even in cases of terminal cancer. But bizarrely, those other researchers hadn't properly followed the duo's protocols. Instead of giving high doses of the vitamin intravenously (IV), they used oral vitamin C supplements instead.
Two of the most influential studies, conducted by researchers at the prestigious Mayo Clinic in Rochester, Minnesota, pretty much stopped any further research in its tracks when they were published in 1979 and 1985. The second trial was carried out because the first one had been criticized for using oral vitamin C, but it then followed exactly the same approach and came to the same conclusion—that the vitamin didn't work.
Since then, only two trials and 35 studies or case reports have been published of high-dose IV vitamin C therapy for cancer, say researchers at the Canadian College of Naturopathic Medicine in Toronto. Their review of 39 reports (from those 37 studies) concluded that the therapy might improve survival, reduce tumour mass and, as a bonus, lessen the worst toxic effects of chemotherapy.1
These findings were similar to the responses Pauling and Cameron had observed. In fact, Pauling became interested in the therapy in 1971, after seeing the results Cameron was achieving at his hospital in Scotland with the use of 10-g infusions of vitamin C in patients with untreatable, terminal cancer. When their progress was compared with those of other end-stage patients being given the usual treatments, his patients were found to be living six years longer than the conventionally treated group.
The importance of the IV method can be explained by the metabolic peculiarities of vitamin C (also called 'ascorbic acid' or 'ascorbate'): the body can only take up less than half the dose of more than 1 g of the vitamin when taken orally, and this absorption rate continues to fall as the dose increases. Pauling and Cameron were seeing positive results, with amounts of 10 g or more being fully absorbed, but only when the vitamin was given intravenously. A later study by the US National Institute of Diabetes and Digestive and Kidney Diseases discovered that high-dose IV vitamin C (IVC) resulted in 25 times the blood plasma concentrations as with the same dose taken as a supplement by mouth.2
By comparison, the recommended daily allowance for sustaining health is just 90 mg.
How it works
Researchers pushing the therapy through the approvals procedure say that the earlier studies were guaranteeing failure, whereas a research team from the University of Iowa, which has followed the Pauling/Cameron blueprint, are seeing promising results. Not only that, but they've also worked out the mechanism that makes vitamin C so effective against cancer.
In very early test-tube experiments, the researchers—led by biologist Garry Buettner—discovered that very high levels of vitamin C target only cancer cells and leave healthy cells alone. These preliminary tests were followed by safety (phase-I) trials, which determined that the therapy was well tolerated and safe. The team are currently running a phase-II clinical (human) trial to test whether the therapy will improve survival in patients with pancreatic and lung cancers when given on top of standard chemo-/radiotherapy, the two standard treatments for cancer.
In the meantime, Buettner has taken a closer look at the vitamin to determine why it's so effective against cancer. The vitamin breaks down easily in the bloodstream and, as it does so, it generates hydrogen peroxide (H202), a 'reactive oxygen species' (a type of free radical) that damages tissues and DNA. So, while healthy cells can easily remove H202 through an enzyme called 'catalase', cancer cells, which have very low levels of the enzyme, are less able to do so.3
Not for all cancers
This suggests that the types of cancer that reduce catalase in cells will respond best to vitamin C therapy, which is perhaps another reason for the mixed results from other studies. The next challenge, says Buettner, is to identify those cancers that reduce the cell's natural defences.
This may also explain why both Pauling and Cameron died of prostate cancer—Cameron in 1991 and Pauling in 1994, albeit at the age of 93—as that could be one of the cancers that doesn't decrease catalase and so isn't damaged by H202.
Other researchers who have adopted the Pauling/Cameron protocols are also seeing good results. When doctors at Gene Oasis Research and Innovation in Singapore gave daily IVC doses of 25-100 g to nine cancer patients, including some with terminal (stage-4) cancer, the patients survived well beyond their prognoses. In each case, they experienced marked improvement in quality of life, whereas their clinical condition immediately deteriorated on stopping the treatment.4
In the US, doctors at the Riordan Clinic in Wichita, Kansas, started giving a three-year-old boy high-dose IVC after chemotherapy had failed to reverse a neural tumour (glioma) of the optic pathway that was affecting his sight. After receiving around 7-15 g/week of IVC for 30 months, the doctors found that the tumour had shrunk or even disappeared from certain sites, whereas it had continued to grow despite the chemo.5
At the time of their deaths, both Pauling and Cameron could only hope that their vitamin C theory would some day be accepted. As Cameron wrote: "The matter is capable of arousing almost any emotion . . . with all grades of scorn, laughter, ridicule and pity in between. I hope to convince you that the whole research project has a perfectly sound scientific basis, and that Dr Pauling and I are neither gullible fools, nor are we charlatans."6
Fifty years on, the world is finally beginning to agree.
Daily doses of vitamin C
10 mg Getting less than this causes fatigue, inflammation, bleeding gums and eventually scurvy, which can be fatal
40 mg Generally recommended for infants
83.5 mg Consumed by the average woman
90 mg Generally recommended for adults
105.2 mg Consumed by the average man
250 mg-1 g Thought to prevent colds
1 g Can cause gastric problems if taken orally
(as ascorbic acid)
2 g Highest oral dose without diarrhoea or incontinence
5 g Typical 'starter' dose for intravenous
vitamin C (IVC) treatment
10-100 g Standard dose for IVC treatment
By mouth only
There are a few options still open to people who can't get intravenous vitamin C (IVC) infusions. Although standard supplements can't deliver the potency that IVC can, several preparations have been formulated as the next best thing. The late Dr Patrick Kingsley, who routinely treated cancer with high-dose IVC, recommended a daily dose of 16 g. But if IVC isn't possible, he recommended one of the following oral supplements:
Altrient C Lypo Spheric Vitamin C, made by LivOn Laboratories, is claimed to be the most bioavailable C supplement around—in other words, more of it gets into your bloodstream, and only around 9 per cent is excreted. It achieves this by coating the vitamin with liposomes (bubbles of fat) to protect the vitamin as it moves through the bloodstream, letting none of it get into the gut to cause side-effects. This is available from abundanceandhealth.com (UK) and livonlabs.com (US).
Bio En'R-G'y C, a powder made up of tiny crystals of l-ascorbic acid that can be diluted in juice or water, delivers 400 g of vitamin C per teaspoon (tsp); 4 tsp/day are recommended to maintain good health. The powder is available from many stockists and online.
Slow-release vitamin C drip-feeds the vitamin throughout the day. Dr Kingsley recommended taking such a formula last thing at night at a 4-g potency to reduce daytime intakes to 12 g. Slow-/timed-/sustained-release tablets are widely available in shops and online.
Who shouldn't take it
Although vitamin C has few side-effects other than diarrhoea and incontinence with high doses orally, it's still not for everyone.
It can cause anaemia in people with favism, a rare genetic blood disorder medically known as 'glucose-6-phosphate dehydrogenase (G6PD) deficiency'
High doses can cause kidney failure in people with poor kidney function
As vitamin C can increase body stores of iron, people with haemochromatosis, a rare genetic disorder where the body produces too much iron, should avoid it
Vitamin C can reduce uptake of other vitamins like B12 and of copper
In rare cases, vitamin C can cause kidney stones
The late WDDTY panellist Dr Patrick Kingsley advised against giving vitamin C for brain tumours, as large doses can lead to swelling of the brain.
Did you know
Humans are among the few mammals unable to make their own ascorbic acid (vitamin C) and so must obtain it from food or supplements
As it's a water-soluble vitamin, the body can't store it
Levels of vitamin C vary from person to person, although the average is around 2 g. Someone with just 300 mg has scurvy and is probably close to death
In 1753, natural scientists of the time found that citrus fruit could prevent scurvy
The term 'vitamin C' was coined in 1920 by British biochemist Jack Drummond; before that, it was known as the 'antiscorbutic' (anti-scurvy) 'vitamin'—from 'vital amines', a term created by Polish scientist Casimir Funk to describe the compounds he discovered in fruit and vegetables
High intakes of the vitamin can reduce the risk of heart disease and stroke
Foods with the highest levels of vitamin C are kiwi fruit and sweet red peppers
The standard birth control pill lowers vitamin C levels in
Two aspirin tablets taken daily for a week cut blood levels of vitamin C by half
High-dose vitamin C has never been officially approved to treat any condition.