CRN castigates Lancet for incendiary reporting

[Guest guest]

http://foodqualitynews.com/news/ng.asp?id=55120 & n=wh41 & c=wokvpgxagwnympq

 

 

 

CRN castigates Lancet for incendiary reporting

 

 

 

04/10/2004 - The Council for Responsible Nutrition (CRN) has reacted

angrily to the article published in last week's Lancet - which

suggested that dietary supplements may be doing more harm than good,

and accused the journal of " creating publicity over practicing

journalistic integrity " .

 

Scientists from the University of Niss, Serbia and Montenegro, and the

Cochrane Hepato-Biliary Group carried out a review of previously

published trials, where antioxidant supplements had been used for the

prevention of gastrointestinal cancers.

 

The researchers looked at 14 randomised trials - totalling over

170,000 participants – before concluding that supplementation with

b-carotene, vitamins A, C, E, and selenium (alone or in combination)

compared with placebo on oesophageal, gastric, colorectal, pancreatic

and liver cancer incidences provided " no protective effect " .

 

They then went a step further and concluded there was " a small but

statistically significant increase of 6 per cent relative risk in

mortality among people taking antioxidants compared with placebo " . And

added that two combinations of supplements, namely b-carotene and

vitamin A and E, were associated with an even higher relative

mortality risk of 30 per cent for b-carotene and vitamin A and 10 per

cent for b-carotene and vitamin E.

 

" We could not find evidence that antioxidant supplements can prevent

gastrointestinal cancers; on the contrary, they seem to increase

overall mortality, " said lead researcher Dr Goran Bjelakovic.

 

The CRN expressed its unhappiness with many aspects of the research,

but saved its real annoyance for the way in which the Lancet had

reported the findings.

 

" It's not news to say that we don't know for sure what might prevent

cancer, " said Annette Dickinson, president of the CRN, questioning the

rationale of using " only three studies that focused on healthy people " .

 

" While studies can successfully draw upon unhealthy populations to

find solutions for healthy populations, antioxidant supplements alone

should not be expected to reverse the negative effects created by a

lifetime of smoking or poor dietary habits, " she said.

 

Her colleague – the CRN's vice president, scientific and international

affairs, John Hathcock – added that he saw little value in comparing

different supplements in the same meta-analysis.

 

" Comparing different supplements in the same meta-analysis results in

violating a primary rule of meta-analysis — combining only similar

studies — and discounts the valuable information one would otherwise

learn about the individual supplements, " said Hathcock.

 

" Averaging out the effect of beta-carotene and selenium in the same

meta-analysis is like saying if you have a husband who is morbidly fat

with a wife who is morbidly thin, you've got a couple with an ideal

weight, " he said.

 

However, the trade body was most aggravated by the way in which the

Lancet had decided to present the research by highlighting the

following quote by David Forman from the University of Leeds, UK and

Douglas Altman from Cancer Research UK: " If their findings are

correct, 9000 in every million users of such supplements will die

prematurely as a result. The prospect that vitamin pills may not only

do no good but also kill their consumers is a scary speculation given

the vast quantities that are used in certain communities " . The CRN

believed instead the journal should have focused on the fact this

research is still in its preliminary phase.

 

" Lancet's handling of this article makes it frighteningly clear that

we have moved into an age where getting headlines takes precedence

over a scientific journal's responsibility to report without bias, "

said Dickinson.

 

Indeed, Forman had told NutraIngredients.com last week that although

he felt comfortable with the conclusion there was no proof that

vitamin supplements had protective effects against gastrointestinal

cancer, he felt the authors of the study had more confidence in the

findings that supplementation could be responsible for premature

deaths than he did.

 

" This is somewhat preliminary and there are a number of statistical

problems with the way the researchers looked at the data, " he said. He

noted that a particular problem was the inclusion of one study, which

had used an " abnormal " group of patients, including people that were

unhealthy and smoked.

 

" Part of the problem is also that the researchers looked at all

available studies dealing with gastro-intestinal cancer and

supplementation, but they now need to do another study taking into

consideration all papers on mortality and supplementation, " he added.

 

The group is now carrying out such research, but – depending on the

results – it could have been beneficial to the supplement industry if

this study had been concluded before such potentially damaging

research was published.