Vitamin Study ANH

[Guest guest]

By the ANH team

 

5 March 2007

 

On 28th February we saw headlines around the world once again

condemning vitamin supplements. The stimulus? A Serbian doctor, Goran

Bjelakovic, who was involved in an earlier canning job on vitamins –

in 2004 on vitamin supplements for reducing risk of gastrointestinal

cancers (Lancet 2004; 364: 1219–28) – somehow found himself doing it

all over again. This time he published in the US-based Journal of the

American Medical Association (JAMA). On both occasions, his papers

triggered headlines around the world which appeared to have just one

purpose: getting people to stop taking vitamin supplements.

 

Interestingly, in a bout of apparent schizophrenia for JAMA,

Bjelakovic and colleagues' views are fundamentally opposed to those

of Fairfield and Fletcher published in the same journal some two

years earlier (JAMA 2002; 287:3116-3126). Fairfield and Fletcher

broke the long-standing anti-supplement agenda of the JAMA by

supporting supplementation as a means of reducing risk of key chronic

diseases. But it seems it's now back to business as usual for JAMA.

 

On the top of the Serbian's hit list were the favourites: vitamin E

and beta-carotene. Dr Bjelakovic, given his previous work, appears to

have a bit of thing for antioxidant supplements which he considers to

be beta-carotene, vitamin A, vitamin C, vitamin E and selenium. From

the point of view of any informed scientist, this is a peculiarly

narrow perspective on what is meant by `antioxidant supplements'.

First of all the vitamins in question are not automatically

antioxidants. In certain forms (especially as synthetic, isolated

forms) and dosages, they can actually have the reverse effect – and

act as pro-oxidants. Secondly, the dose and form of the vitamin are

critical to determining how the vitamin will behave in the body, as

are the other nutrients which are consumed at the same time.

 

To give an example, high doses of vitamin E (the very forms that have

swayed Bjelakovic's analysis) actually reduce the body's absorption

of the more important antioxidant form of vitamin E, gamma-

tocopherol, the predominant form in foods and high quality vitamin E

supplements.

 

It was seriously remiss of Bjelakovic and his team to not emphasise

that; a) the studies they used to condemn these vitamins were nearly

all performed using synthetic forms of the vitamins that behave in

the body in remarkably different ways to the natural forms and b) to

not make clear the effects their study selection approach would have

on the final results.

 

Looking further at this second, crucially important point,

Bjelakovic's team found 815 trials that were potentially relevant.

But they culled out a massive 747 (yes – a jumbo jet load!) of these

trials, leaving just 8% of the total number for the number crunching!

The most important reason given by the authors themselves for the

exclusion of studies (responsible for 50% of the exclusions – a total

of 405 trials) was " mortality was 0 in both study groups. "

 

Consider what effect this might have on bias. If you remove 50 % of

the studies because they didn't cause any increased risk of death –

how can you say that vitamin supplements overall cause a 5% increase

in risk of death….it simply beggars belief that the JAMA can tolerate

this type of science.

 

This is just one of the stunning problems with Bjelakovic's study. Dr

Steve Hickey (of the ANH Expert Committee) and colleagues reveal more

reasons for the flawed nature of the Bjelakovic's meta-analysis –

click here to view their rebuttal submitted and approved for

publication in the Journal of Orthomolecular Medicine.

 

Bjelakovic's specialty appears to be meta-analyses (statistical study

of studies). The application of a lot of statistics to a given data

set does not change the quality of the data set. In fact it can often

magnify inherent problems in the data. Bjelakovic's data set is

poorly selected and severely compromised – and the results of his

analyses do not provide any reflection on the risk of supplementing

with vitamin A, beta-carotene, vitamin C, vitamin E or selenium, the

targets of the meta-analysis. In fact, the results tell you

absolutely nothing about taking, either the natural forms of these

supplements, or the effects of taking all these nutrients together,

the common way they are taken by most people – as

multivitamin/mineral supplements.

 

Newspaper headlines on 28 February were as dire

as " Supplements `raise death rate by 5%' " (The Times,

UK ), " Vitamins `could shorten lifespan' " (BBC News, UK ), " Des

vitamines dangereuses pour la santé? " (Le Soir , France )

and " Another knock on antioxidants " (Los Angeles Times, USA ). But

they may not have had the impact that was hoped for by certain

interest groups. Judging by the vehement and often irrational hatred

for vitamin supplements shown by elements of the orthodox medical

profession closely aligned with the pharmaceutical industry, it seems

likely that the main objective both of Bjelakovic's meta-analysis and

the resultant articles was to stimulate a turn-around in the

increasing numbers of people who are side-stepping pharmaceutical

medicine in their quest for health.

 

Just like all the other factors Bjelakovic and his colleagues failed

to consider, clarify or include in their meta-analysis, it seems that

another important factor has been ignored. And that's the millions of

people who have derived benefits from taking supplements, combined

with other aspects of a healthy lifestyle. These people will need a

little more than a computer-generated, reductionist, flawed analysis

of past studies of pharmaceutical forms of vitamins to put them off.

 

So will we.

 

Links:

 

Journal of the American Medical Association, Bjelakovic et al

 

Times online article, 28 Feb 2007, Supplements 'raise dealth rates by

5%' "

 

BBC News, Vitamins 'could shorten lifespan', 28 Feb 2007

 

Rebuttal by Dr Steve Hickey, ANH Scientific Expert Committee

[Guest guest]

So much for clinical studies and unbiased scientific research. It

seems these folks had an agenda and fullfilled it to the best of

their ability! That's really disgusting to mislead people that way.

You know this was all over the news, scaring people from using

vitamins. I wonder who funded that useless piece of junk science and

to what end?

 

Nagla

 

 

, " chrisgaren555 "

<chrisgaren555 wrote:

>

> By the ANH team

>

> 5 March 2007

>

> On 28th February we saw headlines around the world once again

> condemning vitamin supplements. The stimulus? A Serbian doctor,

Goran

> Bjelakovic, who was involved in an earlier canning job on vitamins –

 

> in 2004 on vitamin supplements for reducing risk of

gastrointestinal

> cancers (Lancet 2004; 364: 1219–28) – somehow found himself doing

it

> all over again. This time he published in the US-based Journal of