Was Linus Pauling Right About Vitamin C for Cancer and Brain Health?

Modern medicine has not been kind to Dr. Linus Pauling. He is the only person to have received two unshared Nobel Prizes: one for Chemistry in 1954 and one for Peace in 1962. But it is his research into vitamin C for cancer and vitamin C for the common cold that has disturbed most health professionals. They have spent years trying to dispute his enthusiasm for vitamin C. A brand new study in the highly respected journal PLOS One (June 10, 2026) suggests that Dr. Pauling may have also been right that vitamin C is essential for improving brain health!

Vitamin C and Brain Health

Most people associate Dr. Linus Pauling with his work on Vitamin C for the common cold. But he was also exploring the role of vitamin C in brain health.

In an article in the New York Times (April 20, 1968), the author, John Noble Wilford, pointed out that Dr. Pauling:

“…cited recent research to support his theory that the brain and nervous system may be especially affected by deficiencies in vitamins and other chemical substances. Human beings, he said, may be subject to a sort of “cerebral scurvy or cerebral pernicious anemia.” This, he added, could be due to either heredity or poor diet or both.

“Other chemical deficiencies that he associated with mental disorders included vitamin C, thiamine, folic acid and glutamic acid. ‘This simple argument leads us to the possibility of a localized cerebral avitaminosis [vitamin deficiency] or other localized cerebral deficiency disease,’ Dr. Pauling concluded.”

Fast Forward Over 50 Years

Vitamin C still may not get the respect it deserves. Many nutrition experts think of this crucial nutrient as protection against scurvy, a rare vitamin deficiency that leads to fatigue, gum disease, joint pain and many other complications. But vitamin C plays a crucial role in immune function, gene expression and enzymatic reactions.

The new study from Japan in PLOS One (June 10, 2026) suggests that ascorbic acid also plays a critical role for brain function. The researchers analyzed imaging data from over 2,000 older people. They also monitored vitamin C levels in the blood. People with low levels of ascorbic acid in their blood had reduced gray matter in their brains. They also had fewer neuronal connections in the part of the brain involved in self-reflection and autobiographical memory.

The Japanese researchers introduce their research this way:

“Vitamin C is essential for improving brain health. It is a crucial antioxidant in the brain that plays a role in several biological functions, including acting as a cofactor in various enzymatic reactions, serving as a neuromodulator, and being involved in regulating certain peptide hormones… A study on genetically modified mice showed that long-term high vitamin C intake was important for maintaining brain cholesterol homeostasis and preventing age-related oxidative damage. Dietary antioxidants significantly contribute to the protective effect against oxidative damage and the maintenance of neuronal function.

“A previous study provided evidence of the association between vitamin C intake and the development of dementia. Engelhart et al. studied the association between vitamin C intake and the development of Alzheimer’s Disease (AD) using 5,395 male and female participants from the Rotterdam Scan Study. They reported that higher vitamin C intake was associated with an 18% lower relative risk (RR) for AD [Alzheimer disease]. As such, its potential therapeutic applications in neurodegenerative diseases such as AD, Parkinson’s disease (PD), Huntington’s disease, multiple sclerosis, and amyotrophic lateral sclerosis, as well as in psychiatric disorders including depression, anxiety, and schizophrenia, are being investigated.”

Dr. Pauling would be thrilled. After so many decades his hypothesis may eventually be vindicated.

The authors conclude that:

“Plasma vitamin C levels are also significantly associated with cognitive performance, suggesting that adequate plasma vitamin C levels may support cognitive functions and potentially counteract cognitive decline. Furthermore, the association between plasma vitamin C levels and mental health, especially depression, has indicated an inverse correlation where lower blood vitamin C levels were associated with an increased prevalence of depressive symptoms.”

These Japanese researchers have seemingly demonstrated that Dr. Linus Pauling was way ahead of his time. To this day, however, most healthcare professionals dismiss his research and his conclusions.

Dr. Linus Pauling Gets Trashed

The headlines have been ruthless:

A Vox Headline (Feb. 27, 2015) stated:

“How Linus Pauling duped America into believing vitamin C cures colds”

The author states unequivocally:

“…everything we know about research shows that mega-doses of vitamin C are absolutely, positively useless at fighting colds. All that extra orange juice will do nothing to shorten your sniffles.”

There are many more reports just like that.

Nutrition experts have insisted for decades that extra vitamin C is a waste of money. They maintain that all a woman needs is 75 mg daily. Men have a recommended daily allowance (RDA) of 90 mg.

What About Vitamin C for Cancer That is Hard to Treat?

If you think nutritionists have been hard on Linus Pauling, most oncologists have been far more critical.

For example, an article in the highly regarded journal Science (Feb. 6, 2014) stated this about Dr. Pauling’s work on vitamin C for cancer:

“His own forays into the clinic with this idea were embarrassing, and more competently run trials (several of them) have failed to turn up any benefit.

“He was the real deal, and accomplished about four or five times as much as anyone would consider a very good career.

“But that makes it all the more sad to see what became of him in his later years…I’d also heard of his relentless advocacy for Vitamin C, which gradually (or maybe not so gradually) caused people to think that he had slightly lost his mind. Perhaps he had; there’s no way of knowing. But the way he approached his Vitamin C work was a curious (and sad) mixture of the same boldness that had served him so well in the past, but now with a messianic strain that would probably have proven fatal to much of his own earlier work.”

Vitamin C for Cancer is a “Zombie Idea”

Other researchers have been even more disdainful.

An article in the journal Science-Based Medicine (August 18, 2008) by Dr. David Gorski describes Dr. Pauling’s research into vitamin C for cancer as “pseudoscience”:

“Treating cancer with high-doses of vitamin C is a zombie idea that began with Linus Pauling, and has failed to die ever since. But has new research vindicated this idea? No. No in any meaningful way.”

Vindicating Linus Pauling

Vitamin C for Colds

You can read my article about vitamin C for colds at this link. Our eGuide on Colds, Coughs & the Flu also provides additional information on vitamin C for upper respiratory tract infections at this link.

But please do not take my word for it. Here is an article in the journal Life (Jan. 3, 2022) by two scientists, one from Finland and the other from Australia.  They seem less willing to trash vitamin C than their American colleagues. In fact, they seem quite open-minded and willing to examine the data about vitamin C for cancer and colds. The title of their article is:

“Bias against Vitamin C in Mainstream Medicine: Examples from Trials of Vitamin C for Infections”

They introduce their overview this way:

“Evidence has shown unambiguously that, in certain contexts, vitamin C is effective against the common cold. However, in mainstream medicine, the views on vitamin C and infections have been determined by eminence-based medicine rather than evidence-based medicine…While most of our examples are from JAMA, it is not the only journal with apparent bias against vitamin C, but it illustrates the general views in mainstream medicine. We also consider potential explanations for the widespread bias against vitamin C.”

They go on to discuss similar biases against vitamin C for cancer:

“Our paper is primarily focused on vitamin C for infections, but we briefly comment on the controversy about vitamin C and cancer for two reasons. Firstly, after his work on vitamin C and the common cold, Pauling became interested in the effects of vitamin C on cancer. Secondly, there is a comprehensive sociological analysis of the severe biases in the assessment of vitamin C’s effects on cancer.

“Over the decades since the 1980s, the biological rationale for vitamin C for cancer has not diminished; rather, an increase in biochemical understanding has made clinical effects even more plausible.”

Conclusions:

“The belief that vitamin C is ‘ineffective’ against the common cold is widespread. For example, a survey of general practitioners in the Netherlands found that 47% of respondents considered that homeopathy is effective against the common cold, but just 20% of the respondents considered that vitamin C was effective. Given the wide range of demonstrated biochemical effects of vitamin C, many of which have been known for more than half a century, and the benefits observed in numerous placebo-controlled trials in the 1970s, it is concerning that so few general practitioners believed vitamin C to be effective; yet, that is what the survey found. This is one illustration of how deeply physicians have been influenced by the flawed presentations of the vitamin C field in textbooks and major journals.

“This bias is unfortunate because vitamin C is safe and inexpensive, and therefore even reasonably small treatment effects are well worth taking into consideration.”

Vitamin C for Cancer: New Evidence!

A study published in Redox Biology (November, 2024) is titled:

“A randomized trial of pharmacological ascorbate, gemcitabine, and nab-paclitaxel for metastatic pancreatic cancer”

Researchers at the University of Iowa performed a randomized clinical trial of high-dose intravenous vitamin C to treat stage IV metastatic pancreatic cancer. The ascorbic acid was given in combination with standard treatment and the control group got standard treatment only.

The results were so promising that the investigators stopped the trial early. Vitamin C doubled median overall survival time from 8 months to 16 months. The lead investigator added that patients seemed to feel better when vitamin C was added to the regimen.

By the way, at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, researchers reported on a “landmark” trial of the drug daraxonrasib. The headline in the BMJ (June 5, 2026) was:

“Pancreatic cancer: New drug results prompt standing ovation at oncology conference”

Here is how the article begins:

“A new drug for advanced pancreatic cancer is being hailed as a major breakthrough after trial results showed that it almost doubles survival time in patients previously treated with chemotherapy.

“Phase 3 trial results for daraxonrasib, a once daily oral treatment, have been described as a potential ‘revolution’ in treating pancreatic cancer, which has the lowest survival of all common cancers, with five year survival less than 7%.

“In the RASolute 302 trial of 500 patients with metastatic pancreatic ductal adenocarcinoma (PDAC), those taking daraxonrasib as a second line treatment lived for a median of 13.2 months while chemotherapy recipients lived 6.7 months. Patients in the daraxonrasib group had fewer side effects.”

Now please scroll back up to the University of Iowa study with high-dose vitamin C. You will see that intravenous vitamin C actually outperformed the “breakthrough” drug daraxonrasib. The oncologists gave the drug a standing ovation and virtually ignored the vitamin C study. I will let you draw your own conclusions.

Not the First Study of Vitamin C for Cancer

The University of Iowa scientists are solid researchers. Dr. Joseph Cullen is a professor of Surgery and Radiation Oncology at the University of Iowa. One of his colleagues, Bryan Allen, MD, PhD, is professor and chief of Radiation Oncology at the University of Iowa. They and a number of colleagues have been studying the effects of high-dose vitamin C for hard-to-treat cancers over the last two decades.

Dr. Cullen told StudyFinds (December 1, 2024):

“Through every step of the process, it continued to improve. We did it in cells, it worked great. We did it in mice, it worked great. Then our phase one trials looked very promising. So, the progression has just been phenomenal, really. For example, in one of our phase 1 trials for pancreatic cancer, where we combine high-dose IV vitamin C with radiation, we still have three long-term survivors. They’re out nine years at this point, which is far beyond the typical survival range.”

This team of investigators reported on a study of high-dose vitamin C (ascorbate) in glioblastoma patients. This kind of brain cancer is especially deadly. When IV vitamin C is added to radiation and chemotherapy, survival is also improved.

Here is how they and their colleagues describe their vitamin C (ascorbate) research (International Journal of Molecular Sciences, Oct. 8, 2021):

First, they acknowledge the key role of Dr. Linus Pauling and his colleague, Dr. Ewan Cameron, in developing intravenous vitamin C therapy for challenging cancers.

They wrote:

“This research has produced promising results for some of the most aggressive cancer types including glioblastoma (GBM), non-small cell lung cancer (NSCLC), and pancreatic cancer. Historically, these aggressive cancers respond poorly to radiation and chemoradiation treatment approaches, accentuating the need to explore alternative and adjuvant therapies like P-AscH⁻[high-dose Vitamin C].”

“Interest in the use of pharmacological ascorbate as a treatment for cancer has increased considerably since it was introduced by Cameron and Pauling in the 1970s. Recently, pharmacological ascorbate has been used in preclinical and early-phase clinical trials as a selective radiation sensitizer in cancer. The results of these studies are promising. This review summarizes data on pharmacological ascorbate (1) as a safe and efficacious adjuvant to cancer therapy; (2) as a selective radiosensitizer of cancer via a mechanism involving hydrogen peroxide; and (3) as a radioprotector in normal tissues. Additionally, we present new data demonstrating the ability of pharmacological ascorbate to enhance radiation-induced DNA damage in glioblastoma cells, facilitating cancer cell death. We propose that pharmacological ascorbate may be a general radiosensitizer in cancer therapy and simultaneously a radioprotector of normal tissue.”

The bottom line is that some hard-to-treat cancers may respond surprisingly well to high-dose intravenous vitamin C. The Iowa investigators mention glioblastoma, sarcoma, pancreatic cancer and non-small cell lung cancer (NSCLC). Why is this research mostly ignored?

Vitamin C for Cancers in Women

A study published in the journal Antioxidants (May 19, 2024) reports that intravenous vitamin C can be a powerful addition to cancer treatments:

“Until the end of the 20th century and with a deepening understanding of the distribution of pharmacokinetics, ascorbate was found to inhibit cancer cell proliferation and tumor growth in almost all preclinical models without obvious side effects when the concentrations of ascorbate reached the levels of millimoles, called high-dose ascorbate. Over the past three decades, studies on the antineoplastic effects of ascorbate as a single agent or in combination with other chemotherapeutic agents have grown substantially in various cancers, including gynecological cancers. These results indicate that high-dose ascorbate exhibits potent antitumor activity, as well as synergy with chemotherapeutic drugs in various cell and animal models of cancer.”

Conclusions:

“High-dose ascorbate has been shown to be a potential therapeutic agent that inhibits cell proliferation, reduces invasive capacity, and acts synergistically with chemotherapeutic agents in preclinical models of ovarian, endometrial, and cervical cancers.”

Final Words on Vitamin C for Cancer, Colds and Brain Health:

Dr. Linus Pauling was a genius. He cannot rise from the grave so I will say it for him:

“I Told You So!”

Despite the naysayers, vitamin C research has persisted. Although mainstream medicine seems to want to bury this “zombie” nutrient, it keeps returning.

If researchers continue to follow up on Dr. Linus Pauling’s research, they might be surprised to discover that vitamin C has indeed lived up to his expectations.

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