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Friday, 05 December 2008
Vitamin C or E pills do not help prevent cancer in men, concludes the same big study that last week found these supplements ineffective for warding off heart disease.
The public has been whipsawed by good and bad news about vitamins, much of it from test-tube or animal studies and hyped manufacturer claims. Even when researchers compare people's diets and find that a vitamin seems to help, the benefit may not translate when that nutrient is obtained a different way, such as a pill.
"Antioxidants, which include vitamin C and vitamin E, have been shown as a group to have potential benefit," but have not been tested individually for a long enough time to know, said Howard Sesso of Harvard-affiliated Brigham and Women's Hospital in Boston.
The Physicians Health Study, which he helped lead, was designed to do that. It involved 14,641 male doctors, 50 or older, including 1,274 who had cancer when or before the study started in 1997. They were included so scientists could see whether the vitamins could prevent a second cancer.
Participants were put into four groups and given vitamin E, vitamin C, both, or dummy pills. The dose of E was 400 international units every other day; C was 500 milligrams daily.
After an average of eight years, there were 1,929 cases of cancer, including 1,013 cases of prostate cancer, which many had hoped vitamin E would prevent.
However, rates of prostate cancer and of total cancer were similar among all four groups.
The study was funded by the National Institutes of Health and several vitamin makers. Results were being reported Sunday at an American Association for Cancer Research conference in Washington.
"Well-conducted clinical trials such as this are rapidly closing the door on the hope that common vitamin supplements may protect against cancer," said Marji McCullough, nutrition chief at the American Cancer Society. "It's still possible that some benefit exists for subgroups that couldn't be measured, but the overall results are certainly discouraging.
"The American Cancer Society recommends getting these and other nutrients by eating a mostly plant-based diet with a variety of vegetables, fruits and whole grains. A bonus is that this type of diet helps to prevent obesity, which increases the risk of several cancers."
About 12 percent of Americans take supplements of C and E. The new study does not mean these vitamins have no value, just that they didn't prevent cancer in this group of doctors, who may be healthier than the general population, said Dr. Peter Shields, deputy director of Georgetown University's Lombardi Comprehensive Cancer Center.
The best bet, he said, is to do things that are known to prevent the disease — eat right, maintain a healthy weight, and exercise.
Source:
Associated Press/Yahoo News
Author: Marilynn Marchione
http://news.yahoo.com/
Comments:
This study has received a lot of attention, not only because it is published in JAMA (Journal of American Medical Association), but also because it is perceived as a myth buster, which provides the proof that vitamins C and E are not as essential and important as once thought. Unfortunately, this is one more in a series of confusing studies almost intended to scare people away from supplements. Indeed, healthy diet and lifestyle are of vital importance, however this should not undermine the importance of supplementation. The researchers mention that vitamin supplementation did not appear to be useful or harmful in the study group and both of these are incorrect conclusions. There are several flaws to the study design as many critics have already pointed out: the study participants were physicians who are more likely to follow a healthier lifestyle and diet than other people and the doses of vitamin E and C were surprisingly lower than the ones which are proven to be effective in several other studies. In addition, the study tested a synthetic form of vitamin E (containing a mixture of isoforms, some of which are harmful) and vitamin C.
These factors are important to consider before arriving at the results. It should also be noted that within days after these results were disclosed, there were other clinical studies published elsewhere which proved that vitamin C is in fact good for the heart and was even more effective than statins to reduce the C-reactive proteins (CRP) without any side effects. (C-reactive protein indicates inflammation in the body and sometimes is used to diagnose a few of the diseases and is considered a cardiovascular risk factor). Furthermore, another study established the importance of vitamin E in preventing breast cancer. It is disappointing to see that these studies as well as findings from Dr. Rath's Research Institute research did not get as much interest from the media, which proves their biased reporting. Pharmaceutical companies provide major funding to all the news sources including journals such as JAMA, The New England Journal of Medicine and others.
This study also indicates that single agent approach, which imitates pharmaceutical's "one drug-one disease" method, is not effective in the case of nutrients. Dr. Rath's research has pioneered the nutrient synergy approach that uses the benefits of individual nutrients to its full potential. The nutrient synergy approach has been confirmed in numerous publications as the most effective way to control key mechanisms of cancer in a comprehensive way. In our studies vitamin C and E in combination with other synergistic nutrients can act on cancer cells in multiple ways such as blocking the enzymes causing metastasis of cancer, reducing angiogenesis, selectively toxic to cancer cells, etc. In addition our clinical trials have also proven that the human body requires more than just vitamin C and E to be healthy and to prevent many chronic diseases including cancer and heart disease. Please read these and other results on www.drrathresearch.org
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