No cancer risk reductions seen with antioxidants

Anonymous

"NEW YORK (Reuters Health) - In the large Women's Antioxidant Cardiovascular Study, participants who took beta carotene, vitamin C, vitamin E, or a combination of supplements had no significant reductions in their risk of cancer.

The clinical trial, which involved 7,627 women who were followed for an average of 9.4 years, was conducted by Dr. Jennifer Lin and colleagues at Harvard Medical School in Boston, and is published in the Journal of the National Cancer Institute.

The patients were randomly assigned to a placebo group, or to 500 mg ascorbic acid daily, 600 IU alpha-tocopherol every other day or 50 mg beta-carotene every other day. Overall, 624 women developed invasive cancers and 176 died from their disease.

Compared with women who took placebo, the relative risk of developing cancer was almost identical in the vitamin C group, the vitamin E group and the beta carotene group...."

http://www.reuters.com/article/healthNews/idUSTRE4BT50T20081231

lisasayers

Would be curious to know the quality of the vitmins tested.  Most of the reported negative outcomes related to specific vitamin therapies (such as beta carotene and vitamin E and lung cancer) are due to the use of these synthetic, toxic vitamins.  Vitamins need to be from a natural source and have the same bioidentical structure as naturally-occurring vitamins found in the human body.  Synthetic vitamins need to be avoided. 

Sassa

Sorry, Lisa, but a chemical is a chemical is a chemical no matter if it is "natural" or synthesized in a lab.  As long as the chemical formula and structure is the same, there is no difference.

It is wrong information like this that enables consumers to be ripped off price wise for "organic" or "natural" products.

lisasayers

Great...I'll let my doctor know that...since those words came directly from him.  I'll let him know that the expert on the internet corrected me! LOL

Yazmin

................And treatment choices are hard, indeed. If there is no benefit to antioxidants, what are we going to use to reduce our recurrence risk? Apparently, there are scores of drugs with two problems: not only don't they provide no benefit whatsoever: they also work in reverse!!! Here we gooooo:

Ralph W. Moss, Ph.D. Weekly CancerDecisions.com Newsletter #383 03/15/09 SHADOW FALLS ON ANTI-ANGIOGENIC DRUGS For the past dozen years, drugs that inhibit the growth of new blood vessels - a strategy called anti-angiogenesis - have been the main hope of conventional oncology. These drugs were inspired by the work of the late Judah Folkman, MD of Harvard Medical School, who thought that tumors could be controlled by cutting off their blood supply. Drugs based on Folkman's concept include Avastin (bevacizumab), Erbitux (cetuximab) and Sutent (sunitinib). The clinical benefit of these agents, especially when used alone, is small. They are mainly used in conjunction with standard chemotherapy. Some doctors (such as Stanislaw Burzynski MD, PhD) believe that when used appropriately and in combination they have greater potential than is revealed in phase III clinical trials. But now, a new study has raised the disturbing prospect that this class of drugs might have the contradictory effect of helping tumors invade normal tissues and organs, i.e., to metastasize. It is the process of metastasis that ultimately kills most patients with advanced cancer. "People have thought that angiogenesis-inhibiting therapy should hinder metastasis, but these studies show this is not necessarily the case," says Gabriele Bergers, PhD, an associate professor at the University of California, San Francisco (UCSF), who wrote a paper on this with coworkers at UCSF and the Catalan Institute of Oncology-IDIBELL, in Spain. Initially, anti-angiogenic drugs did shrink tumors. But then these tumors showed an unexpected surge in growth, spreading both locally and to distant organs. The authors believe that this increased invasiveness might be a tumor's response to the "starvation" induced by the drugs in question. "A well vascularized tumor is well fed and happy," said UCSF scientist Douglas Hanahan, Ph.D. "It has no driving force to become more invasive. We hypothesize from the mouse models that if you cut off the tumor's blood supply this drives the cancer to become more invasive-more metastatic-as it seeks more oxygen and nutrients." Thus, the overall effect of giving anti-angiogenic drugs might be the opposite of what was intended. This team tested the anti-angiogenic drug Sutent in mice that had been implanted with either pancreatic or brain cancer (glioblastoma). In both cases, tumors shrank or stabilized during the first few weeks of treatment. But after this initial period of apparent benefit, there was an adaptive response on the part of the tumor. For instance, the glioblastomas invaded the adjacent normal brain tissue, while pancreatic tumors metastasized to the animals' livers. "Our animal studies are consistent with some clinical results that human glioblastomas adapt to the angiogenesis-inhibiting drugs," Bergers said. "Scientists have reported results from a clinical trial in which a subset of patients developed tumor recurrence at many sites during the course of treatment with bevacizumab [Avastin], an angiogenesis inhibitor. The recurrence was measured by MRI imaging." What is the practical import of these findings? The authors believe that there is no reason to stop using these agents. "While anti-angiogenesis drugs are in general not proving to be an enduring success, this does not mean they aren't valuable therapies," Bergers said. "There is growing evidence that the drugs improve the quality of life, or even provide increased survival - typically of a few months for glioblastoma patients. The drugs also can reduce edema in brain tumors and in some instances restore memory and speech." But I am left wondering how drugs that seemingly increase the invasiveness of tumors also increase patients' survival. It is time for a reappraisal of the actual effects of these drugs. This is imperative because of the extreme cost of many of these agents. Avastin can cost more than $100,000 per patient per year (and that's for the agent itself, not its administration - "parts, not labor," to quote Leonard Saltz, MD). The government needs to look critically at drugs that do not appreciably extend life and may even "alter the natural history of tumors by increasing invasion and metastasis," to quote the current paper. Anti-angiogenesis has been a favorite concept of the cancer research establishment for many years. But it is turning out to be less effective and possibly more dangerous than expected. That is why I continue to believe that the greatest hope still resides in combining conventional with complementary and alternative medicine (CAM), such as is done at the German clinics that I wrote about in my recent special report. --Ralph W. Moss, Ph.D.

Anonymous

It's risky to extrapolate the results of the large study I cited.

A study showing that antioxidant supplements has no effect, does not mean that antioxidants have no effect on cancer rates.

Many dietary experts believe that removing compounds like antioxidants from their source foods and putting them in pill form is what compromises their efficacy. That there is a synergistic effect to the substance and all the others within the food source.

I do take a few antioxidants now that my treatments are complete. But not the ones mentioned (Vit. C, E, and beta-carotene). Those I get completely in my food. I take a Turmeric capsule every other day with a meal, as it seems that would be just like using it on food. And I take a green tea capsule on alternating days ... I love tea but just can't seem to like green tea.

Point being, and I can't see how anyone could argue this: get your nutrients, antioxidants, and vitamins in your food. Supplements may be in hundreds of trials, but until those trials reach their results, don't pin hopes on them doing anything good. In fact, if you read the full article, there is data showing that putting things into capsules may be doing more harm than good.

I have read similar things about soy. Dietary amounts are believed to be beneficial as their antioxidant properties seem to be stronger than their very weak estrogenic effect. The danger is in taking highly concentrated soy supplements as are commonly sold in "health" food stores.

crazy4carrots

And compounding the problem is that the anti-oxidant "value" of any food is first measured in the laboratory, and may well not have the same effect when ingested by humans (or animals, for that matter).

sarahgsc

There is a big difference between antioxidants in pill form and those found in food. There is plenty of evidence that those in food can help prevent cancer. See www.foodforbreastcancer.com for a list of recommended foods.