To E or not to E?

November 12, 2004

Aileen Burford-Mason, PhD, Special to CTV.ca

Updated: Wed. Nov. 10 2004 2:56 PM ET

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/1100115617636_95524817/?hub=\

Health

The problem with the study on vitamin E is that it is simply not good

science.

The study was a meta-analysis -- a statistical technique where

researchers combine data from all the available clinical trials on a

single issue, to give us an overview of whether something is helpful or

harmful.

A good meta-analysis is a useful tool. It can help put apparently

contradictory studies into perspective, and allow doctors to provide

their patients with an overview of the effectiveness or ineffectiveness

of treatments. In an era of information overload, where thousands of new

medical papers are published every day, such summary papers reduce the

amount of reading necessary to keep abreast of new developments.

But a major problem with this approach is that a good meta-analysis of

badly designed studies still results in bad statistics. Statisticians

have a saying for this: " Garbage in equals garbage out. " In the case of

this study, the " garbage " involved failure to make sure that all the

clinical trials analyzed in the same meta-analysis used the same form of

vitamin E.

There are two forms of vitamin E: the natural form found in food, and

synthetic vitamin E, manufactured in the laboratory. Some synthetic

vitamins are identical to their natural counterparts; but this is not

true of vitamin E. In nature, vitamin E occurs as eight related chemical

compounds – the tocopherols (alpha, beta, delta and gamma) and the

tocotrienols (alpha, beta, delta and gamma). All of these are present in

food or natural supplements. However, synthetic vitamin E contains only

alpha-tocopherol.

Although there is not complete agreement between researchers, many

studies now suggest that gamma-tocopherol, not alpha-tocopherol,

provides superior protection against cancer and heart disease.

Moreover, experiments in humans and animals have shown that giving

alpha-tocopherol alone, as happens when synthetic vitamin E supplements

are given, can block absorption of gamma-tocopherol. There are therefore

good theoretical reasons to be wary of taking synthetic vitamin E.

It is interesting to note that natural vitamin E is the only form

available in health food stores. Drug stores do carry the synthetic

form, but even there, most bottles of vitamin E on the shelves are

natural. Natural vitamin E is therefore the form that the public

generally uses. Only in some of the large-scale clinical trials do we

see synthetic vitamin E regularly used.

Over half a century ago the Shute brothers – medical doctors in Ontario

– pioneered the use of vitamin E for the treatment of heart

disease-related conditions, such as intermittent claudication, angina,

thrombophlebitis and the prevention of and recovery from heart attacks.

Suspecting that synthetic vitamin E, first synthesized in 1938, might

not have the same benefits as natural or food form, they used vitamin E

prepared from wheat germ oil.

You might ask why synthetic vitamin E is still used in clinical trials,

when there have been questions raised about its efficacy and safety for

several decades? It's hard to say. Maybe it is because it's cheaper. Or

perhaps because most of the studies using it were piggy-backed onto drug

trials – one in a trial of statin drugs in heart patients, and the other

of Hormone Replacement Therapy (HRT) in post-menopausal women – and the

drug companies who make the synthetic form may have donated it.

You might also ask why the researchers who produced these latest

meta-analyses failed to separate out studies using the different forms

of vitamin E before doing their analysis. After all, the first rule of

science is to eliminate all possible sources of bias. If a detrimental

effect was seen only with synthetic vitamin E, then lumping together

studies using synthetic and natural vitamin E introduces a source of error.

The challenge to the researchers now is recognize that the form of

vitamin E used in different clinical trials is a confounding variable,

and to repeat their analyses, this time, clearly distinguishing between

the different forms.

The only way we will know for sure if there are risks attached to taking

vitamin E supplements is to evaluate the safety of natural and synthetic

supplements separately. After all, if synthetic vitamin E has a

detrimental effect, as has been suspected for some time, we need to know.

Aileen Burford-Mason is an immunologist and nutritional consultant in

Toronto

******************************************************************************

Vitamin E may do more harm than good

CTV.ca News Staff

Updated: Wed. Nov. 10 2004 5:10 PM ET

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/1100100073716_95509273/?hub=\

CTVNewsAt11

People who take vitamin E supplements in the hope that it will help them

live longer may be doing themselves more harm than good, a new study has

found. But at least one Canadian nutritional expert has reservations

with the study.

Dr. Edgar Miller of Johns Hopkins University in Baltimore, conducted the

study and found that people taking high doses of vitamin E may be more

likely to die earlier.

" I think people take vitamin E because they think it is going to make

you live longer, but this (study) doesn't support that, " Miller told

reporters Wednesday, admitting he was surprised by his team's findings.

Miller and his colleagues didn't conduct a new study on the vitamin,

also called alpha-tocopherol. They simply re-analyzed 19 studies

conducted between 1993 and 2004.

The trials involved more than 136,000 mostly elderly patients in North

America, Europe and China. The dosages of vitamin E ranged from 16.5 to

2000 IU per day, with the median around 400 IU.

His team found that people who took 200 IU (international units) of

vitamin E a day or more for a year died at a higher rate during the

study than people who did not take supplements.

" It's about a five per cent increased risk at 45 years in the trials

pooled together, " Miller told a meeting of the American Heart Association.

" That doesn't sound like a lot, but if you apply it to 25 per cent of

the (U.S.) adult population taking vitamin E, that is significant. "

The trials involved older adults with chronic diseases and the authors

don't know if the findings would apply to younger, healthy adults.

People often take vitamin E for its antioxidant properties, hoping it

will help counter oxidation by unstable " free radical " molecules, which

damage cells and can accelerate aging and lead to heart disease and cancer.

According to the analysis, there is no increased risk of death with a

dose of 200 IU per day or less; there may even be some benefit. But in

higher doses, the vitamin may actually promote oxidative damage and may

overwhelm the body's natural antioxidants, Miller says.

Natural vs. synthetic source

The average U.S. diet supplies 6 to 10 IU of E, from such things as

nuts, oils, whole grains and green leafy vegetables. Multivitamins

usually contain about 30 IU.

About two-thirds of people who take vitamin E supplements take 400 IU or

more, Miller says.

" We don't think that people need to take vitamin E supplements, that

they get enough from the diet, " he said.

Health Canada guidelines suggest 1,000 mg, or approximately 660 IUs, of

Vitamin E as a daily upper limit for healthy adults between 19 and 70

years of age.

But Aileen Burford-Mason, an immunologist and nutritional consultant in

Toronto, sees problems with the study.

" I am not particularly concerned about the study because I think

basically, it is bad science, " she told CTV News.

She says the study's main fault is that it doesn't distinguish between

natural source vitamin E and synthetic source.

" Vitamin E is not a drug; there are different forms, and the different

forms really are of greater significance. There are difference between

synthetic vitamin E and natural vitamin E, which contains eight

different chemically related forms of vitamin e that we get naturally in

food, " she says.

" Some of those other forms that are not present in the synthetic form

may well be more important in preventing heart disease and cancer. "

She says most health food stores sell natural source vitamin E, though

synthetic forms are available. She said that the meta-analysis included

clinical trials which used synthetic form vitamin E, which may account

for their results.

November 12, 2004

Dear David,

I once was privileged to see a famous photographer's exhibit in NYC. He

started the Micro photography revelation, His name was Roman Vishniak (sp?).

I saw blown up very large, for the exhibit wall a side by side set of

photos, one natural vitamin B6, the other synthetic vitamin B6, the

difference was startling, the natural one had very symmetrical shapes and

very pleasing to the eye, the unnatural one had jagged shapes and lines and

was very unsettling to see!

I haven't see Vitamin E undre the electron microscope, but I can just

imagine the difference! Nora G

-