Guest guest Posted June 13, 2005 Report Share Posted June 13, 2005 The following is the summary only of a study which was published in the Lancet last fall. I tried to post it, but my mail was always " endeliverable " . This is only the summary as all of it would be too lengthy. If you are interested enough, you can get it from the Lancet's web page. Note that the sample size is significant - 170,525 people studied. I can't send a link because a friend copied it from the Lancet's web site. You can access it too, but if you are not an MD, it will cost, I think, $30.00. Morton Summary Background Oxidative stress can cause cancer. Our aim was to establish whether antioxidant supplements reduce the incidence of gastrointestinal cancer and mortality. Methods With the Cochrane Collaboration methodology, we reviewed all randomised trials comparing antioxidant supplements with placebo for prevention of gastrointestinal cancers. We searched electronic databases and reference lists (February, 2003). Outcome measures were incidence of gastrointestinal cancers, overall mortality, and adverse effects. Outcomes were analysed with fixed-effect and random-effects model meta-analyses and were reported as relative risk with 95% CIs. Findings We identified 14 randomised trials (n=170 525). Trial quality was generally high. Heterogeneity of results was low to moderate. Neither the fixed-effect (relative risk 0·96, 95% CI 0·88-1·04) nor random-effects meta-analyses (0·90, 0·77-1·05) showed significant effects of supplementation with ß-carotene, vitamins A, C, E, and selenium (alone or in combination) versus placebo on oesophageal, gastric, colorectal, pancreatic, and liver cancer incidences. In seven high-quality trials (n=131727), the fixed-effect model showed that antioxidant significantly increased mortality (1·06, 1·02-1·10), unlike the random- effects meta-analysis (1·06, 0·98-1·15). Low-quality trials showed no significant effect of antioxidant supplementation on mortality. The difference between the mortality estimates in high-quality and low-quality trials was significant (Z=2·10, p=0·04 by test of interaction).ß-carotene and vitamin A (1·29, 1·14-1·45) and ß-carotene and vitamin E (1·10, 1·01-1·20) significantly increased mortality, whereas ß-carotene alone only tended to increase mortality (1·05, 0·99-1·11). In four trials (three with unclear or inadequate methodology), selenium showed significant beneficial effect on the incidence of gastrointestinal cancer. Interpretation We could not find evidence that antioxidant supplements can prevent gastrointestinal cancers; on the contrary, they seem to increase overall mortality. The potential preventive effect of selenium should be studied in adequate randomised trials. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 14, 2005 Report Share Posted June 14, 2005 I tried in vain to fully understand the medical mumbo-jumbo in the Lancet material. I gathered that ingesting isolated antioxidant supplements were associated with an increase in cancer incidence. By " viamin A, " for example, can we take it to mean that the full range of carotenoids (and not just carotene) were used in the studies? Was it natural or sythetic vit. E; E or E complex? I don't know for sure what it means, but I suspect that we're seeing the proliferation of " studies " showing detrimental effects, carcinogenic effects, etc., of nutritional supplement use, at a time when the government is on the verge of implementing efforts to take free access to supplements away from us. Is this a coincidence? It also concerns me, that we're not informed whether these studies exist, side by side, with possibly numerous other studies that show neutral or conflicting study outcomes. If recent studies show harm from antioxidant use, and these studies are the sole source of scientific info on the subject, we are led to one conclusion; a result which can sharply change, so that we're led to quite different conclusions, if we find out that there are studies that contradict these current study findings. You can show us these current studies, but you cannot " establish " whether antioxidant supplements reduce gastro-intestinal carcinogenicity, unless you scour the records in search of studies that are in conflict with these current ones; and, if you find such studies, reveal them to us, as well. JP - Morton Bodanis Monday, June 13, 2005 11:57 AM Anti-oxydents and mortality The following is the summary only of a study which was published in the Lancet last fall. (snip) Summary Background Oxidative stress can cause cancer. Our aim was to establish whether antioxidant supplements reduce the incidence of gastrointestinal cancer and mortality. (snip) ---------- Version: 7.0.323 / Virus Database: 267.6.9 - Release 6/11/2005 Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 14, 2005 Report Share Posted June 14, 2005 John Polifronio wrote: >I tried in vain to fully understand the medical mumbo-jumbo in the Lancet material. I gathered that ingesting isolated antioxidant supplements were associated with an increase in cancer incidence. By " viamin A, " for example, can we take it to mean that the full range of carotenoids (and not just carotene) were used in the studies? Was it natural or sythetic vit. E; E or E complex? > I suggest that you go to www.lancet.com and look it up. Mumbo-jumbo? Hardly. >I don't know for sure what it means, but I suspect that we're seeing the proliferation of " studies " showing detrimental effects, carcinogenic effects, etc., of nutritional supplement use, at a time when the government is on the verge of implementing efforts to take free access to supplements away from us. Is this a coincidence? > The difference between this study and the proliferation of studies is the sample size, the time over which the study was made, and the methodology used. I think that you want me to do all of your research for you. >It also concerns me, that we're not informed whether these studies exist, side by side, with possibly numerous other studies that show neutral or conflicting study outcomes. If recent studies show harm from antioxidant use, and these studies are the sole source of scientific info on the subject, we are led to one conclusion; a result which can sharply change, so that we're led to quite different conclusions, if we find out that there are studies that contradict these current study findings. You can show us these current studies, but you cannot " establish " whether antioxidant supplements reduce gastro-intestinal carcinogenicity, unless you scour the records in search of studies that are in conflict with these current ones; and, if you find such studies, reveal them to us, as well. > I have a friend who, when faced with something which conflicts with his preconceived notions, looks for conspiracy theories. If you won't go to the published site for the whole story and examine it, at least do some research to support your position. Morton >JP > > >- > Morton Bodanis > > Monday, June 13, 2005 11:57 AM > Anti-oxydents and mortality > > > > The following is the summary only of a study which was published in the > Lancet last fall. > (snip) > > Summary > > Background Oxidative stress can cause cancer. Our aim was to establish > whether antioxidant supplements reduce the incidence of gastrointestinal > cancer and mortality. > (snip) > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 16, 2005 Report Share Posted June 16, 2005 How you came to the conclusion that I want you to do " all (my) research for (me) " escapes me. You never told me if you thought it a coincidence that we're seeing a sharp increase in studies that work to undermine trust in vitamin supplementation, at a time when the government will soon deprive us of free access to supplements. I have no doubt that you can find unwanted side-effects with supplement use, but it's entirely too easy to oversimplify and distort the findings with details and complexities of which the general public is completely in the dark. By the way, shouldn't we first see studies " establishing " that there are dangers associated with cigarette smoking or booze? I think it's clear that we already have a mountain of studies showing devastating mortality and morbiity outcomes from nicotine and alcohol use. Are you aware of any efforts by the government to place severe restrictions on our access to cigarettes and booze? I'm not aware of any. Children have it a little harder, getting cigarettes at their local market; but anyone knows that millions of children smoke, and drink booze easily and freely. Perhaps you should address these two problems before you warn us against vitamins. I don't have to go to Lancet. I already know that many of the studies done on vitamins are badly flawed, and are conducted with appalling ignorance about, or prejudice against, nutrition and nutritional-supplement use. Many of these studies have the goal of diminishing public confidence in vitamin use, long before any actual study is conducted. This is the same government that promotes dairy for " calcium. " This is the same government that has had to revise, and revise again, their preposterous dietary " pyramid, " because of the laughable nutritional ignorance and pro-food-industry prejudices that are evident from tip to base. Whatever dangers you can show us connected with vitamin use, pale to utter insignificance when placed in contrast to the grave side effects and outright lethality (not to mention the embarrassing uselessness) of countless pharmaceuticals. How is it that the government is working to keep vitamin supplements away from us, but we can't get through dinner if the tube happens to be switched on, without endless ads about prostate, hemmorhoidal, " male, " diarrheic, constipation, statin, etc.drugs foisted on us interminably? When these ads bluster at us, they're invariably accompanied by warnings that some of these drugs may give rise to a plethora of dangerous side-effects (even including death), usually vastly worse than anything claimed against vitamins. Anyone that knows what's going on in conventional medicine will tell you, that hardly anyone takes seriously the admonition to " see your doctor " before taking this or that supplement; not because the advice is fundamentally bad, but because you have to search day and night for a doctor that knows squat about nutrition, in spite of which they're constantly " advising " their patients that nutrition has little or nothing to do with health and illness. JP - Morton Bodanis Our aim was to establish > whether antioxidant supplements reduce the incidence of gastrointestinal > cancer and mortality. > (snip) Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 16, 2005 Report Share Posted June 16, 2005 Hooray for you John! I agree with you completely. Linus Pauling, for instance, did research into Vitamin C. He also is one of the few people to have won TWO Nobel prizes. Now, the Linus Pauling Institute denigrates and contradicts the research Pauling did on Vitamin C. Why? Do they have more information from better research? Nope. They have been bought out. This but one of many examples. Alobar - " John Polifronio " <counterpnt Wednesday, June 15, 2005 10:01 PM Re: Anti-oxydents and mortality > How you came to the conclusion that I want you to do " all (my) research > for (me) " escapes me. > > You never told me if you thought it a coincidence that we're seeing a > sharp increase in studies that work to undermine trust in vitamin > supplementation, at a time when the government will soon deprive us of > free access to supplements. I have no doubt that you can find unwanted > side-effects with supplement use, but it's entirely too easy to > oversimplify and distort the findings with details and complexities of > which the general public is completely in the dark. > > By the way, shouldn't we first see studies " establishing " that there are > dangers associated with cigarette smoking or booze? I think it's clear > that we already have a mountain of studies showing devastating mortality > and morbiity outcomes from nicotine and alcohol use. Are you aware of any > efforts by the government to place severe restrictions on our access to > cigarettes and booze? I'm not aware of any. Children have it a little > harder, getting cigarettes at their local market; but anyone knows that > millions of children smoke, and drink booze easily and freely. Perhaps > you should address these two problems before you warn us against vitamins. > > I don't have to go to Lancet. I already know that many of the studies > done on vitamins are badly flawed, and are conducted with appalling > ignorance about, or prejudice against, nutrition and > nutritional-supplement use. Many of these studies have the goal of > diminishing public confidence in vitamin use, long before any actual study > is conducted. This is the same government that promotes dairy for > " calcium. " This is the same government that has had to revise, and > revise again, their preposterous dietary " pyramid, " because of the > laughable nutritional ignorance and pro-food-industry prejudices that are > evident from tip to base. > > Whatever dangers you can show us connected with vitamin use, pale to utter > insignificance when placed in contrast to the grave side effects and > outright lethality (not to mention the embarrassing uselessness) of > countless pharmaceuticals. How is it that the government is working to > keep vitamin supplements away from us, but we can't get through dinner if > the tube happens to be switched on, without endless ads about prostate, > hemmorhoidal, " male, " diarrheic, constipation, statin, etc.drugs foisted > on us interminably? When these ads bluster at us, they're invariably > accompanied by warnings that some of these drugs may give rise to a > plethora of dangerous side-effects (even including death), usually vastly > worse than anything claimed against vitamins. > > Anyone that knows what's going on in conventional medicine will tell you, > that hardly anyone takes seriously the admonition to " see your doctor " > before taking this or that supplement; not because the advice is > fundamentally bad, but because you have to search day and night for a > doctor that knows squat about nutrition, in spite of which they're > constantly " advising " their patients that nutrition has little or nothing > to do with health and illness. > > JP Quote Link to comment Share on other sites More sharing options...
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