Vitamin C: A Controversial Cancer Fighter

The idea that Vitamin C could be used to fight cancer was originated by Linus Pauling in the early 1970s. In a collaboration with British cancer surgeon Ewan Cameron, he used intravenous and oral Vitamin C as cancer therapy for terminal patients, claiming the patients were living up to four times longer with the Vitamin C treatment. Linus Pauling spent years promoting megadoses of Vitamin C for cancer, and promoted its use for the common cold as well. Now, it is generally accepted as an important vitamin for a healthy immune system, but controversy surrounds its use in fighting cancer.

Critics have disputed Linus Pauling's clinical findings as inaccurate, claiming that the patients who received Vitamin C began the study less sick than the control group. Some have questioned when the patient was defined 'terminal'. The Mayo Clinic conducted their own clinical trials with Vitamin C and did not find the high-dose (10,000 mg) any more affective than a placebo.

So, what do we know about Vitamin C? Does it fight cancer or not?

In science, anyone should be able to duplicate a study and get similar results. The fact that the Mayo Clinic got different results seems to dispute the findings of Linus Pauling. It leaves the rest of us confused, which study is right? Does Vitamin C fight cancer or not?

If we leave it at that, it seems to favor the Mayo Clinic results. An earlier study was proved wrong. But it is equally important to compare the trials. The Mayo Clinic claimed to have duplicated the the Linus Pauling trial, but they didn't. You can't compare the results, because they conducted two very different trials. In science, if you are going to duplicate an experiment, you need to follow ALL of the criteria - this was not the case in the second Vitamin C trial. There were three distinct differences:

1. In the Mayo Clinic trial, the majority of patients had already been treated with chemotherapy. 87% of the Mayo Clinic patients versus 4% of the Pauling patients were pre-treated with chemo. Since cytotoxic chemotherapy damages the immune system, this in itself will have a dramatic effect on survival results.
   
   
2. The Mayo Clinic used only oral Vitamin C, while the Pauling trial administered intravenous Vitamin C, an important difference pointed out by doctors from the National Institute of Health (NIH) stating that the intravenous administration is more bioavailable than oral, and may be a key factor in the different results.
   
   
3. The Pauling trial continued for the life of the patient, while the Mayo Clinic trial discontinued as soon as the patient could no longer take their oral medications, or if they showed some progression of the disease. Interestingly, NONE of the Mayo patients died while receiving Vitamin C, all of their deaths occurred after the vitamin had been taken away from them.
   
   

The Mayo Clinic results seem to neither confirm nor deny the Pauling results.

Perhaps it would help to understand what research has shown us in terms of how Vitamin C fights cancer.

Conventional wisdom says that antioxidants like Vitamin C help prevent cancer by scavenging free-radical molecules that can cause damage to our DNA.

This is not a complete picture, though, and in some research, some cancer-implanted mice that were not fed antioxidants, had no significant DNA damage. This led researchers to suspect there was another mechanism involved. A protein called HIF-1, known to be dependent on free radicals may have the answer. This protein was abundant in untreated cancer cells, and absent in Vitamin C treated cells. The HIF-1 helps cancer cells convert sugar to energy without the use of oxygen, and helps build new blood vessels that will bring in fresh oxygen supply. A rapidly growing tumor quickly drains oxygen in its vicinity, so making HIF-1 is critical to its continued survival, but HIF-1 needs a supply of free-radicals. By removing free-radicals, antioxidants essentially stop HIF-1, and the tumor.

More research is being done all the time. There are plenty of examples of cancer fighting activity, it may be some time before we understand the full complexity of how it all works. It takes a greater understanding of the behavior of cancer cells, as well as the interactions with our own immune system.

There is significant global research that shows that Vitamin C enhances the affect of chemotherapy. There have been a small handful of reports trying to dispute this, claiming it may 'possibly' interfere with chemotherapy (possibly is not the same as probably), but this is small when compared with number of studies showing a positive result with a number of chemotherapy treatments including: Arsenic Trioxide, Cisplatinum, Cyclophosphamide (Cytoxan), Doxorubicin (Andriamycin), Dacarbazine (DTIC), Gemcitabine (Gemzar), Interferon-alpha 2b, Imatinib (Gleevec), Mitomycin C, Paclitaxel (Taxol), Etoposide, 5-FU (fluorouracil), Tamoxifen, and Vincristine (Oncovin).

How does it enhance chemotherapy?

It reverses chemotherapy-resistant cancer cells, increases the delivery of chemotherapy into the cancer cell, makes the cell membrane more permeable, and decreases the drug resistance through several mechanisms.

In Japan and many other countries, Vitamin C is administered alongside chemotherapy. In many elite clinics, Vitamin C is given to improve success rate, and general overall health. So, while some try to stir up controversy and throw its efficacy into question, Vitamin C is already in use all over the globe and showing positive results.

While there is excitement that surrounds the use of Vitamin C to help in the fight against cancer, it is not a treatment in itself. Perhaps this is why there are a few critics who worry that patients will forego treatments recommended by their doctors hoping Vitamin C will cure them.

Your body doesn't produce Vitamin C, it must be obtained from food, and it isn't stored in the body, so we must constantly consume foods that contain Vitamin C to make sure we are getting enough. This is even more critical when your body is fighting disease. Your immune system needs to stay strong, so a constant and ample supply of Vitamin C is needed.

While Vitamin C is not a cure for cancer, it is a powerful member of your cancer-fighting and prevention team. Like everything else, it all needs to work together. If we are fighting something as tricky as cancer, we need to use everything we've got.