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From: JOHN on 5 Aug 2008 06:35

40 something years after Irwin Stone first said this..
http://www.eurekalert.org/pub_releases/2008-08/niod-vci080108.php

Public release date: 4-Aug-2008
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Contact: Joan Chamberlain
niddkmedia(a)mail.nih.gov
301-496-3583
NIH/National Institute of Diabetes and Digestive and Kidney Diseases

Vitamin C injections slow tumor growth in mice

High-dose injections of vitamin C, also known as ascorbate or ascorbic acid,
reduced tumor weight and growth rate by about 50 percent in mouse models of
brain, ovarian, and pancreatic cancers, researchers from the National
Institutes of Health (NIH) report in the August 5, 2008, issue of the
Proceedings of the National Academy of Sciences. The researchers traced
ascorbate's anti-cancer effect to the formation of hydrogen peroxide in the
extracellular fluid surrounding the tumors. Normal cells were unaffected.

Natural physiologic controls precisely regulate the amount of ascorbate
absorbed by the body when it is taken orally. "When you eat foods containing
more than 200 milligrams of vitamin C a day--for example, 2 oranges and a
serving of broccoli--your body prevents blood levels of ascorbate from
exceeding a narrow range," says Mark Levine, M.D., the study's lead author
and chief of the Molecular and Clinical Nutrition Section of the National
Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the
NIH. To bypass these normal controls, NIH scientists injected ascorbate into
the veins or abdominal cavities of rodents with aggressive brain, ovarian,
and pancreatic tumors. By doing so, they were able to deliver high doses of
ascorbate, up to 4 grams per kilogram of body weight daily. "At these high
injected doses, we hoped to see drug-like activity that might be useful in
cancer treatment," said Levine.

Vitamin C plays a critical role in health, and a prolonged deficiency leads
to scurvy and eventually to death. Some proteins known as enzymes, which
have vital biochemical functions, require the vitamin to work properly.
Vitamin C may also act as an antioxidant, protecting cells from the damaging
effects of free radicals. The NIH researchers, however, tested the idea that
ascorbate, when injected at high doses, may have prooxidant instead of
antioxidant activity. Prooxidants would generate free radicals and the
formation of hydrogen peroxide, which, the scientists hypothesized, might
kill tumor cells. In their laboratory experiments on 43 cancer and 5 normal
cell lines, the researchers discovered that high concentrations of ascorbate
had anticancer effects in 75 percent of cancer cell lines tested, while
sparing normal cells. In their paper, the researchers also showed that these
high ascorbate concentrations could be achieved in people.

The team then tested ascorbate injections in immune-deficient mice with
rapidly spreading ovarian, pancreatic, and glioblastoma (brain) tumors. The
ascorbate injections reduced tumor growth and weight by 41 to 53 percent. In
30 percent of glioblastoma controls, the cancer had spread to other organs,
but the ascorbate-treated animals had no signs of disseminated cancer.
"These pre-clinical data provide the first firm basis for advancing
pharmacologic ascorbate in cancer treatment in humans," the researchers
conclude.

Interest in vitamin C as a potential cancer therapy peaked about 30 years
ago when case series data showed a possible benefit. In 1979 and 1985,
however, other researchers reported no benefit for cancer patients taking
high oral doses of vitamin C in two double-blind, placebo-controlled
clinical trials.

Several observations led the NIH researchers to revisit ascorbate as a
cancer therapy. "Clinical and pharmacokinetic studies conducted in the past
12 years showed that oral ascorbate levels in plasma and tissue are tightly
controlled. In the case series, ascorbate was given orally and
intravenously, but in the trials ascorbate was just given orally. It was not
realized at the time that only injected ascorbate might deliver the
concentrations needed to see an anti-tumor effect," said Levine, who noted
that new clinical trials of ascorbate as a cancer treatment are in the
planning stages.

Data from Levine's earlier studies of the regulation and absorption of
dietary vitamin C were used in the revision of the Institute of Medicine's
Recommended Dietary Allowance for the vitamin in 2000. In the current study,
Levine led a team of scientists from the NIDDK and the National Cancer
Institute (NCI), both components of the NIH, as well as the University of
Kansas. "NIH's unique translational environment, where researchers can
pursue intellectual high-risk, out-of-the-box thinking with high potential
payoff, enabled us to pursue this work," he said.

###

For more information about cancer, please visit the NCI website at
www.cancer.gov, or call NCI's Cancer Information Service at 1-800-4-CANCER
(1-800-422-6237).

The NIDDK conducts and supports research in diabetes and other endocrine and
metabolic diseases; digestive diseases, nutrition, and obesity; and kidney,
urologic, and hematologic diseases. Spanning the full spectrum of medicine
and afflicting people of all ages and ethnic groups, these diseases
encompass some of the most common, severe, and disabling conditions
affecting Americans. For more information about NIDDK and its programs, see
www.niddk.nih.gov.

The National Institutes of Health (NIH) - The Nation's Medical Research
Agency - includes 27 Institutes and Centers and is a component of the U.S.
Department of Health and Human Services. It is the primary federal agency
for conducting and supporting basic, clinical and translational medical
research, and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and its programs,
see www.nih.gov.


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