Not all antioxidants prevent cancer

The Cochrane institution is respected for its objective handling of medical topics. In the most recent report from The Lancet today, the news is not big, but there is a very useful summary of the results of previous studies involving the preventive effects of antioxidants. The results have been divided into groups according to the respective antioxidants involved and according to the respective types of cancer in the gastrointestinal tract.
The good news is that selenium seems to be able to prevent cancer in the gastrointestinal tract. It both reduces the incidence of cancer and mortality by 50% in the group of people taking selenium compared to the other group taking placebo.
The disappointing news is that certain other antioxidants do not have any cancer-preventive effect in the studies mentioned and in some cases they even have harmful effects - mainly attributed to betacarotene. This is a well-known fact. The authors are inclined to think that the ones who might be harmed by antioxidants are people who are not very strained by the harmful free radicals in the first place. However, the authors will not warn against taking moderate doses of antioxidants or eating fruits and vegetables, and they thereby recognize the importance of getting moderate amounts of these antioxidants.
The study should be a memento for the authorities who prevent the public from being informed with fair and useful information on effects as well as side effects of dietary supplements. This censorship conceals positive as well as negative research results to the consumer who is left only to pure speculation about the use and dosage of the antioxidants which could be very beneficial if used correctly.
Antioxidants prevent atherosclerosis with great probability, but, naturally, this must happen before the atherosclerosis is far advanced. Based on his own research, the Californian Nobel Prize Winner Louis Ignarro, one of the world's leading experts in vascular surgery, has recently in very clear terms encouraged anyone who want to avoid having blood clots to take supplements of vitamin C and -E.
In the last three months alone, the Vitality Council have posted at least six press releases about new scientific research regarding antioxidants; all involving important - in some cases essential - new knowledge from the leading research centres around the world.
Reference:
Goran Bjelakovic, Dimitrinka Nikolova, Rosa G Simonetti, Christian Gluud Antioxidant supplements for prevention of gastrointestinal cancers: a systematic review and meta-analysis Lancet 2004; 364: 1219-28.