The graphics below from Statista show the number of confirmed cases in the U. Health Coronavirus New york Hospitals. World Health Organization advice for avoiding spread of coronavirus disease COVID Hygiene advice Clean hands frequently with soap and water, or alcohol-based hand rub. Wash hands after coughing or sneezing; when caring for the sick; before, during and after food preparation; before eating; after using the toilet; when hands are visibly dirty; and after handling animals or waste.
Maintain at least 1 meter 3 feet distance from anyone who is coughing or sneezing. Avoid touching your hands, nose and mouth. Do not spit in public. Cover your mouth and nose with a tissue or bent elbow when coughing or sneezing. Discard the tissue immediately and clean your hands. Medical advice Avoid close contact with others if you have any symptoms. However, double-blind randomized clinical trials directed by Charles Moertel of the Mayo Clinic failed to show any positive effects of high dose vitamin C in cancer patients, as reported in two papers in the journal of New England Journal of Medicine.
So why did the Pauling and Mayo Clinic trials have different results? There are at least two crucial differences. First, the Mayo Clinic trials abruptly stopped the ascorbate administration, switching to traditional chemotherapy, when the patient developed signs of tumor progression.
Thus, the overall median time of vitamin C treatment under the Mayo Clinic trials was only 2. Secondly, the Mayo Clinic trials administered 10 g of daily ascorbate to patients only orally, while the Cameron and Pauling trials administered their vitamin C both orally and intravenously. This difference in the two dosage routes proved highly consequential. In contrast, the same dose given intravenously, as used in the Pauling studies, would produce peak plasma concentrations of nearly 6 mM, more than 25 times higher.
When given orally, vitamin C concentration in human plasma is tightly controlled by multiple mechanisms acting together: intestinal absorption, tissue accumulation, renal reabsorption and excretion, and potentially even the rate of utilization.
However, when ascorbate is administered intravenously or intraperitoneally the tight controls are bypassed, and pharmacologic millimolar plasma concentrations of vitamin C can easily be achieved. For example, a phase I clinical study revealed that ascorbate concentrations could safely reach mM with intravenous infusion of g of vitamin C. In this study, plasma concentrations around 10 mM were sustained for at least 4 hours which, based on preclinical studies, is sufficient to kill cancer cells.
This new knowledge has rekindled interest and spurred new research into the clinical potential of vitamin C. We will not discuss these clinical studies as there are already several reviews on the topic. Virtually all studies show improved quality of life for cancer patients by minimizing pain and protecting normal tissues from toxicity caused by chemotherapy. Additionally, vitamin C showed synergistic effects when combined with radiation and standard chemotherapies. Unfortunately, these studies were not designed as large-scale, randomized controlled trials and thus the efficacy of high dose vitamin C therapy remains to be determined.
There are at least three challenges that have thus far prevented large-scale, randomized controlled trials of vitamin C for cancer therapy. First, vitamin C is not patentable.
Therefore, there is no financial incentive for pharmaceutical companies to support vitamin C clinical trials, and those that have been done have largely relied on government grants and small private donations. Second, as discussed above, vitamin C cancer therapy has a long history of controversy. Due to the Mayo clinical studies in the s, many orthodox, mainstream clinicians have a prejudice against vitamin C therapy.
Fortunately, a growing number of recent and rigorous preclinical studies have begun resolving the third challenge, which may also lead to overcoming the first and second barriers. Mechanistic insights into the action of pharmacological vitamin C will generate more explicit scientific hypotheses and allow clinicians to design better trials to investigate those hypotheses, ultimately leading to a definitive answer to the question: can the pharmacological administration of ascorbate benefit cancer patients?
Recently, we discussed the potential mechanisms by which vitamin C may act in cancer patients in Nature Reviews Cancer. Here we will highlight one of the mechanisms discovered by our group that relates to Ras protein. More than 80 years ago, the biochemist Otto Warburg observed that cancer cells consume more glucose and produce more lactate even in the presence of ample oxygen as compared with normal cells.
This phenomenon, called aerobic glycolysis or the Warburg effect, has been exploited for visualizing tumors in the clinical setting by imaging their uptake of the radiolabeled glucose analog, [18F] fluorodeoxyglucose FDG , via Positron Emission Tomography PET. Although the exact mechanism by which glucose reprograming contributes to tumorigenesis remains unclear, numerous genetic and pharmacological studies showed that this metabolic switch can be essential for cancer survival and proliferation.
Thus, targeting glycolysis may offer cancer patients a more selective strategy to treat cancer. Our group and others showed that oncogenic mutations in KRAS or BRAF contribute to the Warburg effect and the addiction to glucose in part by upregulating a glucose transporter, GLUT1, that allows cancer cells to take up glucose efficiently. The increased DHA uptake in mutant cells produced oxidative stress, increasing the level of reactive oxygen species ROS in cells because intracellular DHA was rapidly reduced back to vitamin C at the expense of glutathione GSH , a master antioxidant in cells.
Based on these results, Weill Cornell Medicine is currently conducting a Phase II clinical trial to examine the effects of intravenous high dose vitamin C in the treatment of KRAS-mutant cancers, and Sun Yat-sen University Cancer Center in China are conducting placebo-controlled, randomized Phase III clinical trials in colorectal cancer patients in combination of chemotherapy.
While KRAS and BRAF mutations are certainly two of the most frequently mutated oncogenes in human cancer, they are not the only mutations known to affect glucose metabolism and sensitivity towards ascorbate therapy.
Vitamin C as a cancer therapy has had a controversial past. What has been intriguing are small clinical trials that suggest some responses, but with no clear rationale for why cancers should respond to vitamin C or a path forward for explaining which patients are most likely to respond. Now a growing number of preclinical studies are showing how high-dose vitamin C might benefit cancer patients. Importantly, these preclinical studies provide a clear rationale and potential biomarkers that may help personalize the therapeutic approach and identify patient populations that are likely to respond to high-dose vitamin C therapy.
Since the mechanisms of action of vitamin C are becoming better defined, we can propose vitamin C combinations in a more rational, hypothesis-driven manner. In addition, given the current high financial cost of new cancer drugs, it seems rational to improve the effectiveness of current therapies by studying their clinical interactions with vitamin C.
In our view, the implementation of this treatment paradigm could provide benefit to many cancer patients. Lewis Cantley is a founder and member of the senior advisory boards of Agios Pharmaceuticals and Petra Pharmaceuticals, which are developing novel therapies for cancer. The Cantley laboratory also receives financial support from Petra Pharmaceuticals. We welcome your comments on this post.
All comments must follow our comment policy. Menu Contact Dictionary Search. Weber said: The patients who received vitamin C did significantly better than those who did not get vitamin C. President Donald Trump wrote in a tweet that the not-yet-proven combination therapy: Has a real chance to be one of the biggest game-changers in the history of medicine. Patriots Help Bring 1. Andrea D. Steffen I use the alphabet to paint words that become a beautiful and inspiring image in the reader's mind.
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