High-dose vitamin C makes cancer treatment more effective, trial shows
Written by Ana Sandoiu
Common treatment options for cancer, such as chemotherapy and radiation therapy, can be expensive and sometimes ineffective. However, a new clinical trial tests the effect of high-dose vitamin C in combination with standard treatment on health outcomes for patients with cancer.
A new clinical trial shows that a high dose of vitamin C can improve health outcomes for patients who are undergoing conventional cancer treatment.
Since then, further studies in animals and cancer cell cultures suggested that a high concentration of ascorbic acid might prevent and treat cancer.
More recent studies have examined the combined effect of high-dose vitamin C and conventional cancer treatment. Some of this research showed that patients who received the combined treatment had a slower progression of the disease, while others have suggested that the side effects of chemotherapy were less pronounced among those who also took high doses of vitamin C.
To obtain a high dose in these studies, vitamin C is usually administered using intravenous infusion. Vitamin C has a short half-life of only 2 hours in the human body, which is why it must be administered in high doses as a treatment.
A new clinical trial studies the effect of giving between 800 and 1,000 times the daily recommended dose of vitamin C to patients with brain and lung cancer.
The new research was led by scientists at the University of Iowa in Iowa City, and the results were published in the journal Cell Press.
Vitamin C passes human safety trial
As part of the human safety trial, 11 patients with brain cancer who were undergoing standard chemotherapy and radiation therapy were also administered three weekly intravenous infusions of vitamin C for 2 months, and then two weekly infusions for 7 months.
Each infusion raised the patients’ blood levels of vitamin C to 20,000 micromoles (μM). The average level of vitamin C in adults is approximately 70 μM.
This safety test was the first phase of a series of clinical trials that will investigate whether high-dose vitamin C can effectively increase the lifespan and quality of life for patients that are being treated with chemotherapy and radiation therapy.
Specifically, patients who also received high doses of ascorbic acid [IV Vitamin C] survived for 18 to 22 months compared with 14 to 16 months, which is the typical survival rate for glioblastoma.
For the upcoming phase II of the clinical trials, the scientists will examine the effects of vitamin C in participants with stage 4 lung cancer as well as in those with highly aggressive brain tumors, such as glioblastoma.
How vitamin C weakens cancer cells
The mechanism that might explain the potential efficacy of vitamin C in treating lung and brain cancer relates to the cancer cells’ metabolism.
As a consequence of the faulty metabolism that occurs inside the cancer cells’ mitochondria, these cells produce abnormally high levels of so-called redox active iron molecules. These molecules react with vitamin C and form hydrogen peroxide and hydrogen peroxide-derived free radicals.
Scientists think that these free radicals drive cancer cell death by damaging the cells’ DNA. The free radicals are also thought to weaken the cancer cells and make them more vulnerable to radiation therapy and chemotherapy.
“This paper reveals a metabolic frailty in cancer cells that is based on their own production of oxidizing agents that allows us to utilize existing redox active compounds, like vitamin C, to sensitize cancer cells to radiation [therapy] and chemotherapy.”
Garry Buettner, study co-author
Co-senior author Douglas Spitz also comments on the significance of the findings:
“This is a significant example of how knowing details of potential mechanisms and the basic science of redox active compounds in cancer versus normal cells can be leveraged clinically in cancer therapy,” he explains. “Here, we verified convincingly that increased redox active metal ions in cancer cells were responsible for this differential sensitivity of cancer versus normal cells to very high doses of vitamin C.”
If the approach proves effective in future clinical trials as well, the new treatment could also be significantly less costly than the standard treatment. To put this into perspective, 9 months of intravenous vitamin C treatment as part of the phase II trial currently costs less than one dose of chemotherapy.
“The majority of cancer patients we work with are excited to participate in clinical trials that could benefit future patient outcomes down the line. Results look promising but we are not going to know if this approach really improves therapy response until we complete these phase II trials.”
Bryan Allen, co-senior author
Vitamin C can target and kill cancer stem cells- CSC, study shows
Written by Ana Sandoiu
Published: Monday 13 March 2017
Cancer is currently one of the top killers worldwide, and the number of cancer cases is only expected to rise. Although there are a number of therapies available, most of them are toxic and cause serious side effects. New research examines the impact of the natural vitamin C on cancer cell growth.
In a recent study, vitamin C proves effective in killing cancer stem-like cells.
The global number of new cases of cancer are expected to grow by around 70 percent in the next 20 years.
In the United States, the National Cancer Institute (NCI) estimate that almost 40 percent of U.S. men and women will have developed cancer at one point during their lives.
There are various treatment options available for cancer, but they are not always effective; most of them are toxic, and they tend to have a variety of side effects.
In some more aggressive cases, the cancer does not respond to treatment, and it is believed that cancer stem-like cells are the reason why the cancer comes back and metastasizes.
New research, published in the journal Oncotarget, examines the effectiveness of three natural substances, three experimental drugs, and one clinical drug in stopping the growth of these cancer stem cells (CSCs.)
The study was conducted by researchers from the University of Salford in Manchester in the United Kingdom, and was led by Dr. Gloria Bonuccelli.
Vitamin C is up to 10 times more effective than experimental drugs
In total, the researchers measured the impact of seven substances: the clinical drug stiripentol, three experimental drugs (actinonin, FK866, and 2-DG), and three natural substances (caffeic acid phenyl ester (CAPE), silibinin, and ascorbic acid (vitamin C).)
The research focused on the bioenergetic processes of CSCs, which enable the cells to live and multiply. The study aimed to disrupt the CSCs’ metabolism and ultimately prevent their growth.
Of all the substances tested, the team found that actinonin and FK866 were the most effective. However, the natural products were also found to prevent the formation of CSCs, and Vitamin C was 10 times more effective than the experimental drug 2-DG.
Additionally, the study revealed that ascorbic acid [Vitamin C] works by inhibiting glycolysis – the process by which glucose is broken down within the cell’s mitochondria and turned into energy for the cell’s proliferation.
Dr. Michael P. Lisanti, professor of translational medicine at the University of Salford, comments on the findings:
“We have been looking at how to target cancer stem cells with a range of natural substances including silibinin (milk thistle) and CAPE, a honey-bee derivative, but by far the most exciting are the results with vitamin C. Vitamin C is cheap, natural, nontoxic and readily available so to have it as a potential weapon in the fight against cancer would be a significant step.”
“This is further evidence that vitamin C and other nontoxic compounds may have a role to play in the fight against cancer,” says the study’s lead author.
“Our results indicate it is a promising agent for clinical trials, and as an add-on to more conventional therapies, to prevent tumor recurrence, further disease progression, and metastasis,” Bonuccelli adds.
Vitamin C has been shown to be a potent, nontoxic, anticancer agent by Nobel Prize winner Linus Pauling. However, to the authors’ knowledge, this is the first study providing evidence that ascorbic acid can specifically target and neutralize Cancer Stem Cells – CSCs.
Written by Ana Sandoiu