It's a secret oncologists rarely share with their patients: around 25 percent of all cancers are untreatable, and the prognosis is worse for colon (colorectal) and lung cancers, with half of cases immune to chemotherapy.
But the untreatable may soon be very treatable with a new therapy that blends two approaches that have always been relegated to the fringes of medicine: fasting and high-dose vitamin C, given intravenously. Both have had hit-and-miss research results when used independently, but combining the two seems to have a super-charging effect that kills these hard-to-treat cancer cells without affecting the surrounding healthy cells.
The therapy is still in its early stages. It's been tested on lines of colorectal cancer cells in the laboratory with "remarkable effects," says lead researcher Valter Longo at the University of Southern California's Longevity Institute. Each therapy killed some of the cancer cells on its own, "but when used together, they had a dramatic effect, killing almost all cancerous cells."1
Longo and his team then tested the combined therapy on laboratory mice and saw the same positive results: their cancers started to reverse. Thanks to these exciting findings, five clinical trials on breast cancer and prostate cancer patients are now underway.
Although a variety of cancer cells were used in the experiment, the team discovered that the vitamin C/fasting combination was especially effective against cells that had a special mutation, one that makes cancer untreatable. This mutation protects the cancer cells from even the most powerful and toxic chemotherapy drugs—and when the mutation is detected, oncologists are told not to treat, as it will probably destroy the patient's quality of life for no good reason.
The mutation is on a gene called KRAS (Kirsten rat sarcoma viral oncogene homolog), but aside from smoking, researchers aren't sure why it happens. KRAS is responsible for signaling cells to grow and divide, but when it mutates, those signals can start the process of cancer.
If a diagnosis of cancer isn't bad enough, one that has a KRAS mutation is far worse. In one study, 63 percent of lung cancer patients who had a KRAS mutation died compared with 32 percent who didn't have it.2 In another looking at 116 lung cancer patients, the five-year survival rate for those with the mutation was just 11 percent, but 64 percent of those without the mutation reached the five-year mark.3
The mutation creates a protective shield around the cancer cell. Chemotherapy drugs—such as panitumumab, cetuximab and erlotinib—have had no effect whatsoever in patients with KRAS-mutated colorectal and lung cancers.
Until Longo's discovery, oncologists have been at a loss as to how to treat around a quarter of all cancers they see. Fasting and vitamin C have been tantalizing options for years, but the research hasn't been consistent, with a positive finding soon being overtaken by a negative one, and, as a result, both have been added to the growing list of unproven cancer therapies.
Not so fast
There's a good scientific basis for fasting as a cancer therapy. While the American Cancer Society advises cancer patients to eat plenty of calories and protein, especially during chemotherapy, it's also known the diet feeds the cancer. In 1931, German doctor Otto Warburg noticed that cancer cells were relying on sugar rather than oxygen for their energy, a process known as the "Warburg effect."
Starve the body of sugars, and the cancer cell will also die, or so the theory goes, and the process has been witnessed in laboratory tests. In one, 17 lines of cancer cells including samples of melanoma, glioma and breast cancer were "starved," and the researchers said the results were as successful as anything achieved by chemotherapy.
The cancer cells stopped growing, and, more significantly, the ones normally resistant to cancer drugs—possibly because of KRAS mutation—suddenly became sensitive to them. Fasting made the untreatable cancers treatable.4
A five-day fast can produce a 50 percent fall in glucose—the sugar in the blood—that is feeding the cancer and helping it grow, Longo estimates. The fast, followed by resumption of a normal diet, could also protect cancer patients against the worst ravages of chemotherapy without the same weight loss.5
But to really see a turnaround in the cancer, the patient would need to follow a strict diet, with a 40 percent reduction in protein, for months, and this is where the theory hits up against the hard wall of pragmatics. No oncologist would allow his patient to be on such a strict diet for so long during chemotherapy, indeed his ethical code would prevent him from even suggesting it, and so the fasting approach ran out of road.
A strict fast is just that: no food whatsoever other than regular sips of water, and this is extreme for even a healthy person, let alone someone with cancer. Seeing the dilemma, Longo has developed his own version of the fast, the fasting-mimicking diet (FMD), which he says delivers all the health benefits of a true fast without starving the patient (see box, right).
While fasting has been on the outer fringes of cancer treatment, vitamin C has at least flirted with the mainstream. Touted by American biochemist Linus Pauling more than 40 years ago, high-dose vitamin C (ascorbic acid) therapy was claimed to reverse end-stage cancers.
The way the vitamin was delivered didn't seem to matter, according to early researchers; patients given the vitamin orally or intravenously were improving.6 But the therapy was quickly abandoned when two clinical trials of oral vitamin C couldn't replicate the results.7
This could have been because it does matter how the vitamin is administered: it has to be done intravenously. One study reported that cancer patients on a vitamin C drip, given an average of 10 g a day, saw a benefit,8 but a later trial that followed the exact same protocols failed to see any improvement in a small group of patients with advanced cancer.9
Why were the researchers coming up with such different results? High doses of the vitamin can trigger a biological process in KRAS-mutated cancer cells that makes them produce ferritin, a protein that binds iron. Iron, in turn, is associated with cancer growth, especially colorectal cancer. There's a direct correlation between iron levels and survival in colon cancer; the higher the iron, the lower the survival rate.
And this could be why Longo's two-punch approach of fasting and vitamin C is working. Fasting reduces levels of ferritin in the body, and this allows the vitamin C into the cancer cell to kill it.
The approach could also make chemotherapy more effective, but that's a short-term gain. Longo sees the day when milder drugs without the neutron-bomb effects of chemo will be given to cancer patients. And, possibly, the day will come when cancer isn't treated with any drugs at all, but just with a short fast and vitamin C.
A fast of sorts
A true fast—no food and just sips of water—is extreme, and few can stay on it for very long, but it could be very good for us. Seeing the dilemma, Valter Longo at the University of Southern California's Longevity Institute has devised a five-day fast that delivers the benefits but avoids the agony.
He has developed his own commercially available fasting plan, L-Nutra, which he claims mimics a true fast, and consists of vegetable soups eaten twice a day, olives, vegetable chips, nuts and bars made of nuts. He's also developed supplements as well as drinks and teas to keep the body hydrated.
He recommends people fast for five days every six months or so, but there are some key dietary changes that he advocates everyone should follow most of the time.
- Reduce your protein. Eat just 0.31 grams of protein per pound of body weight a day, meaning a person weighing 140 lb (63.5 kg) would be allowed 43 grams a day.
- Cut down on fish. Eat just one to two servings a week. Replace with plant-based food such as vegetables.
- Reduce sugars. An essential part of any diet, reduce your sugar intake to almost zero, and cut back on pasta and bread.
- Take vitamins. The essential vitamins include omega-3 and -6 fatty acids and vitamin C.
- Eat good fats. Get your fats from olive oil, nuts and fish.
- Cut back on the booze. Try to eliminate alcohol as much as possible.
- While fasting is good for almost everyone, Longo cautions that people over the age of 70 should check with their doctor before starting.
How much C?
Longo recommends going on a vitamin C "feast" for a few weeks every six months, when up to 6 g should be taken every day, or up to the level of bowel tolerance. Beyond that, the vitamin can cause diarrhea. But therapeutic doses for treating cancer and other chronic problems can be higher still. Doses given in clinical trials have ranged from 0.15 g to 0.7 g per kg of body weight every day. At the upper level, a person weighing 140 lb (63.5 kg) would be taking nearly 10 g a day.
That's 50 times the highest recommended dose of 200 mg, and a far cry from the recommended daily allowance of just 95 mg.