vitamin A

Antioxidants May Cause More Harm Than Good in Cancer Patients

Source: medscape.comAuthor: Zosia Chustecka While alternative health gurus often encourage increasing antioxidants in the diet and the taking of antioxidant nutritional supplements such as beta-carotene, vitamins A, C, and E, and selenium, new research findings suggest that antioxidants could do more harm than good, especially in cancer patients. The idea is discussed in a perspective article on the promise and perils of antioxidants for cancer patients in the July 10 issue of the New England Journal of Medicine. Coauthor David Tuveson, MD, PhD, professor and deputy director of the Cold Spring Harbor Laboratory Cancer Center in New York, explained in an interview with Medscape Medical News that the idea that antioxidants could be useful in cancer goes back to Linus Pauling, and is based on observations that oxidation within cells is needed for cell growth. "As cancer cells growth rapidly, a cancer cell would have more oxidation within it than a normal cell," he added, and the hope was that antioxidants would interfere with these cellular oxidative processes and would suppress the growth. "Although some early preclinical studies supported this concept," the authors write, there have now been several clinical trials that have shown no effect of antioxidants on reducing the incidence of cancer, and there have even been suggestions of harm in persons who are at risk for cancer. Dr. Tuveson noted a clinical trial from Scandinavia in the early 1990s, which found that high doses of antioxidants, particularly beta-carotene, were associated with more lung cancer rather than less as had been hoped for. There was [...]

Charlotte Parker2014-07-14T15:04:19-07:00July, 2014|Oral Cancer News|

Vitamin E may have adverse effect in head and neck cancer

Source: www.tele-management.ca According to a clinical trial, vitamin E supplements may increase the risk of a secondary tumor in those with head and neck cancer. Previous studies have suggested that a low dietary intake of antioxidants such as vitamins E and C might be linked to an increased risk of cancer. But there is no clear evidence that taking supplements decreases the risk. Researchers in Quebec, Canada, report on a trial of vitamin E and beta-carotene, which is related to vitamin A, in patients with head and neck cancer. The patients took either supplements or placebo during radiation therapy and afterwards. The beta-carotene was stopped after a year, because a trial showed that those taking it who also smoked had an increased risk of getting lung cancer. The current trial showed that those on vitamin E were at increased risk of developing a second cancer while they were on the supplement, compared to those on placebo. But their risk was lower once the supplements had stopped. Overall, there was no difference between the two groups after eight years. These patients were at high risk anyway, so it is not really clear whether the results can be generalized to the whole population. There is clearly more research to be done before we can be clear whether vitamins can help in the fight against cancer.

Oral Cancer Foundation News Team - A2013-11-05T07:40:00-07:00November, 2013|Oral Cancer News|

Vitamin E may have adverse effect in head and neck cancer

Source: www.newsfix.ca Author: Robert Cervin According to a clinical trial, vitamin E supplements may increase the risk of a secondary tumor in those with head and neck cancer. Previous studies have suggested that a low dietary intake of antioxidants such as vitamins E and C might be linked to an increased risk of cancer. But there is no clear evidence that taking supplements decreases the risk. Researchers in Quebec, Canada, report on a trial of vitamin E and beta-carotene, which is related to vitamin A, in patients with head and neck cancer. The patients took either supplements or placebo during radiation therapy and afterwards. The beta-carotene was stopped after a year, because a trial showed that those taking it who also smoked had an increased risk of getting lung cancer. The current trial showed that those on vitamin E were at increased risk of developing a second cancer while they were on the supplement, compared to those on placebo. But their risk was lower once the supplements had stopped. Overall, there was no difference between the two groups after eight years. These patients were at high risk anyway, so it is not really clear whether the results can be generalized to the whole population. There is clearly more research to be done before we can be clear whether vitamins can help in the fight against cancer.

Oral Cancer Foundation News Team - A2013-07-29T08:43:11-07:00July, 2013|Oral Cancer News|

Adapting the science of supplements and cancer prevention

Source: www.cancer.gov Author: Carmen Phillips Numerous studies suggest that avoiding excess weight, exercising regularly, and eating a diet heavy on fruits and vegetables decreases the risk of many diseases, including cancer. But as the expanding obesity epidemic has shown, there are major obstacles to getting broad swaths of people to adopt such a healthful lifestyle. So, for many years, cancer researchers have investigated whether specific nutrients—those that epidemiologic and animal model studies have suggested could sway cancer’s course—could decrease cancer risk. Much has been learned from this work, researchers in the field say, but, as is the case with treatment, each new discovery points to new areas of focus and other potential avenues of progress. With promising bioactive compounds in the pipeline, many prevention researchers are focused on figuring out not just whether something like sulforaphane, a natural compound found in broccoli and broccoli sprouts, can kill cancer cells in a test tube or animal model—which it does, quite well—but how, at the molecular level, it accomplishes this task, whether there are some cancer cells that are more likely to respond to it, and whether there are ways of discerning early on that the intervention is having its intended effect. Prevention: A Complex Matter A number of supplements have been tested in large prevention trials, including vitamins A, C, and E; selenium; beta-carotene; and folic acid. At least one trial has demonstrated a reduction in cancer deaths with a combination of supplements, while several others found no reduction or even [...]

Oral Cancer Foundation News Team - A2009-12-17T19:42:35-07:00December, 2009|Oral Cancer News|