Vitamins 'do more harm than good'!

Gazz

ITN report on Yahoo news:

Taking supplements such as vitamins A and E could actually do more harm than good, experts say.
A review of 67 studies found "no convincing evidence" that antioxidant supplements beta-carotene, vitamin A, vitamin C, vitamin E and selenium increase longevity and could even shorten life expectancy.
Experts said: "Beta-carotene, vitamin A and vitamin E given singly or combined with other antioxidant supplements significantly increase mortality."
However, Vitamin C did not appear to have any effect one way or the other, and the team said more work was needed into this supplement and into selenium.
The beta-carotene dose ranged from 1.2mg to 50mg daily, with an average of 18mg, while vitamin C ranged from 60mg to 2000mg daily, with an average of 497mg.
When the different antioxidants were assessed separately and low risk of bias trials were included and selenium excluded, vitamin A was linked to a 16 per cent increased risk of dying, beta-carotene to a 7 per cent increased risk and vitamin E to a 4 per cent increased risk.
In the low risk of bias trials, the "antioxidant supplements significantly increased mortality", the authors wrote.
Goran Bjelakovic, a visiting researcher who carried out the review at Copenhagen University Hospital in Denmark, added: "We could find no evidence to support taking antioxidant supplements to reduce the risk of dying earlier in healthy people or patients with various diseases.
"The findings of our review show that if anything, people in trial groups given the antioxidants beta-carotene, vitamin A, and vitamin E showed increased rates of mortality.
"There was no indication that vitamin C and selenium may have positive or negative effects. So regarding these antioxidants we need more data from randomised trials. The bottom line is that current evidence does not support the use of antioxidant supplements in the general healthy population or in patients with certain diseases."
Patrick Holford, a nutritionist who has formulated some supplements for the firm Biocare, said the Cochrane review was a "stitch up". He added: "Antioxidants are not meant to be magic bullets and should not be expected to undo a lifetime of unhealthy habits.
"But when used properly, in combination with eating a healthy diet full of fruit and vegetables, getting plenty of exercise and not smoking, antioxidant supplements can play an important role in maintaining and promoting overall health."


So basically,because vitamin supplements don't increase the live expectancy of a patient with a terminal disease it actually reduces it.The same will happen to a healthy individual!!!

Gazz

By Sky News:

A row is brewing after a report claimed that taking antioxidant vitamin supplements was not only useless but could actually damage your health.
The Cochrane Collaboration - a review of 67 studies involving more than 230,000 men and women - found "no convincing evidence" that the supplements cut the risk of dying, the study said.
"Even more, beta-carotene, vitamin A, and vitamin E seem to increase mortality," the experts wrote.
A furious Health Food Manufacturers' Association told Sky News online that the study was "in essence, systematically flawed".
"The analysis focused on one broad category of study, then evaluated just 67 of the 748 studies that could be included in the review.
"Therefore, the paper's conclusions are drawn on less than 9% of available evidence. In no way can this review be considered comprehensive."
Independent nutritionist Dr Marilyn Glenville was equally scathing. "This report needs to be taken with quite a large pinch of salt," she told us.
"First, it's a re-analysis of an old trial that came out last February - and there was widespread criticism of it then - and secondly it's selective in what it reveals.
"For example, it ignored the 405 studies where no deaths were reported and when it did look at the others it included, it did not eliminate those that were completely unconnected - accidents, car crashes, etc - so they could not be seen as relevant."
Dr Glenville, a specialist in women's health, says she sees a place for vitamin supplements in modern life.
"Ideally, you would get all the nutrients from natural sources but it's unrealistic nowadays what with the depletion of the soil itself and the distance over which the food is carried.
She points out tests done on some green beans transported over a long distance that were found to contain only 11% of the vitamin C expected.
"The Food Standards Agency, set up to look after the general public's health, gave this response: "The FSA hasn't yet seen the Cochrane Collaboration publication and so cannot comment in detail on this study.
"Most people should be able to get all the nutrients they need by eating a varied and balanced diet.
"If consumers do choose to take supplements, it is important they are informed and they may also wish to consult with their GP."

splinter

TinyTom

This is to do with storage of vitamins in fat leading to toxicity I believe.

I dont supplement with Vitamin A because of this risk but Vit E is essential for bbers IMO.

Plus these studies arent concerning hard training people who need a lot of antioxidants.

Gazz

And the study focused more on synthetic Vitamin E rather than its natural counterpart.

The current study's authors acknowledged that because most of the people involved in the trial were aged 60 and older and had conditions such as heart disease,the findings might not apply to young healthy adults.


Vitamin E,like vitamins A,D and K,is fat soluble. These are thought to be more risky in higher doses because,unlike very large doses of water soluble vitamins which can simply be washed out in the urine,these stay in the body and can be toxic.So in peoples quest to rid their bodies of free radicals they're actually poisoning themselves with exessive doses.

razg

Bear in mind these conclusions will be based upon statistical analysis which may be fairly questionable.

Gazz

Agreed.Like the subjects all being terminaly ill.The media obviously missed this crucial fact and splattered the headline 'vitamins reduce you life expectancy' all over the place.

razg

Selection bias is a major problem with this kind of study. The fact is that those with existing problems are more likely to try and medicate them through supplementation, so the sample of those who supplement versus those who do not is very distinct. This is why double-blind procedure with random assignment is the only way to produce data that you can really draw conclusion from. It's a shame that more sensationalist journalists aren't acquainted with statistics.

splinter

Yup agreed there, and for a study on vitamins you need a vast sample size of 5000 or so to be relevant.

Due to all the different conditions people have its a very difficult study to tackle however!