STUDY FINDS HUGE VARIABILITY IN VITAMIN E ABSORPTION

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STUDY FINDS HUGE VARIABILITY IN VITAMIN E ABSORPTION

01-15-04

By Stauth, 541-737-0787

SOURCES: Maret Traber, 541-737-7977

Leonard, 541-737-9476

CORVALLIS - A new study has found that cereal fortified with vitamin E has a

very high rate of absorption into the bloodstream, whereas pills taken

separately with the same food have inconsistent effects, and taking the

supplements alone is largely useless.

The research was just published in the American Journal of Clinical

Nutrition by scientists from the Linus ing Institute at Oregon State

University.

The study points the way to more effective methods of taking this essential

vitamin if people wish to supplement their diet, said Maret Traber, a

professor with OSU's Linus ing Institute and national expert on vitamin

E who recently served on federal panels to update the RDA for this vitamin.

As an antioxidant, vitamin E is one of the most commonly taken vitamin

supplements in the world and included in virtually every multivitamin pill.

The research may explain, Traber said, why many past research studies done

with vitamin E have varied findings. It's quite possible, she said, that the

manner in which people took vitamin E supplements and the variation in its

bioavailability from person to person have yielded widely inconsistent

results about the value of this nutrient in heart disease and other

degenerative diseases.

It may also be time to consider routine fortification of more foods with

this vitamin, Traber said.

" For good reasons, Americans are increasingly moving towards low-fat diets, "

Traber said. " But average low-fat diets provide only about 5-8 international

units a day of vitamin E. The recommended dietary allowance of vitamin E is

30 I.U. and it's possible that higher amounts than that are useful for

optimal health. So we have to find ways to make sure everyone is getting

enough of this nutrient. "

A glitch, the researchers say, is that vitamin E is an oil, and people are

now being told to use oils very sparingly. It can be found in nuts, oily

fish, some vegetables and oils such as safflower, olive and canola oil. The

most common way that people get vitamin E is through rich desserts and

cooking oils.

" If people are getting all the vitamin E they need through a healthy,

balanced diet, that's great, " Traber said. " But we really don't want to be

telling people to eat more fat, and that's generally where vitamin E is

found. That's why it's appealing to find an effective way of obtaining this

nutrient, such as vitamin E fortification of what is essentially a low-fat

food. "

This controlled study was done by LPI scientists, funded by and in

collaboration with the Bell Nutrition Institute of General Mills.

In it, scientists tested the results of four different types of breakfasts:

a pill of 400 I.U. of vitamin E with skim milk; a serving of a wheat

breakfast cereal fortified with 30 I.U. of vitamin E; a serving of wheat

breakfast cereal fortified with 400 I.U. of vitamin E; and a serving of

wheat breakfast cereal with a pill of 400 I.U. vitamin E taken separately.

The pill of 400 I.U. vitamin E taken with just a glass of milk, in theory,

should have provided more than 13 times the RDA of this nutrient. But, in

fact, it raised the level of new vitamin E in the blood by only 3 percent.

By comparison, the cereal fortified with 30 I.U. vitamin E raised the blood

plasma level of new vitamin E five times higher than that, and the cereal

fortified with 400 I.U. raised the new blood plasma level 30 times higher.

The effect of a pill of 400 I.U. taken with a serving of plain wheat cereal

was inconsistent; some participants had a significant increase in blood

plasma levels of vitamin E, others almost none. " This study clearly showed

that applying vitamin E onto a grain cereal provided a huge and consistent

increase in its bioavailability, " said Leonard, an LPI research

assistant who conducted the study. " Even 30 I.U., the RDA for this vitamin,

produced a large increase in new blood plasma levels. "

According to Traber and Leonard, this indicates that people who are taking

vitamin E supplements only with liquids on an empty stomach are

accomplishing nothing and getting few if any benefits from the supplements.

The vitamin clearly is absorbed better if it is part of, or closely

associated with the digestion of a food that has some fat in it.

Vitamin E has been explored in recent years for its potential value in

prevention of heart disease, cancer, Alzheimer's disease and other health

concerns. The results of this study may explain in part why the other

research has often yielded inconsistent results, Traber said.

" It's now clear that vitamin E must be taken in a certain way to be

effective, either in a food containing vitamin E or in a supplement properly

associated with a food, " Traber said. " So anyone studying vitamin E for a

clinical response must now be sure they are using it in a regimen that

works. "

It may also be time to consider the expansion of vitamin E as a routine food

additive, she said.

" In our pursuit of low-fat diets, we increasingly are taking the fat out of

foods but not putting the vitamin E back, " Traber said.

There were a number of deficiency diseases in the early 1900s that have been

largely eliminated with routine vitamin supplementation of food staples like

flour and milk, Traber said. Chronic deficiencies of vitamin D led to

rickets, vitamin A to blindness and the B-vitamin niacin to pellagra. In the

developed world those diseases are now largely a thing of the past.

Vitamin E is an important antioxidant that prevents oxidation of

polyunsaturated fats in membranes and lipoproteins, including the LDL and

HDL forms of cholesterol. Although the scientific community is still divided

in its conclusions, some studies suggest vitamin E has an important role to

play in a healthy cardiovascular, neurologic and immune system.

http://oregonstate.edu/dept/ncs/newsarch/2004/Jan04/cereal.htm