Oregon: Researchers at Oregon State University have discovered how vitamin E deficiency may cause neurological damage by interrupting a supply line of specific nutrients and robbing the brain of the “building blocks” it needs to maintain neuronal health. The findings – in work done with zebrafish – were just published in the Journal of Lipid Research. The work was supported by the National Institutes of Health.
The research showed that zebrafish fed a diet deficient in vitamin E
throughout their life had about 30 percent lower levels of DHA-PC, which
is a part of the cellular membrane in every brain cell, or neuron.
Other recent studies have also concluded that low levels of DHA-PC in
the blood plasma of humans is a biomarker than can predict a higher risk
of Alzheimer’s disease.
Just as important, the new research studied the level of compounds
called “lyso PLs,” which are nutrients needed for getting DHA into the
brain, and serve as building blocks that aid in membrane repair. It
showed the lyso PLs are an average of 60 percent lower in fish with a
vitamin E deficient diet.
The year-old zebrafish used in this study, and the deficient levels
of vitamin E they were given, are equivalent to humans eating a low
vitamin E diet for a lifetime. In the United States, 96 percent of adult
women and 90 percent of men do not receive adequate levels of vitamin E
in their diet.
DHA is a polyunsaturated fatty acid, or PUFA, increasingly recognized
as one of the most important nutrients found in omega-3 fatty acids,
such as those provided by fish oils and some other foods.
“This research showed that vitamin E is needed to prevent a dramatic
loss of a critically important molecule in the brain, and helps explain
why vitamin E is needed for brain health,” said Maret Traber, the Helen
P. Rumbel Professor for Micronutrient Research in the College of Public
Health and Human Sciences at OSU and lead author on this research.
“Human brains are very enriched in DHA but they can’t make it, they
get it from the liver,” said Traber, who also is a principal
investigator in the Linus Pauling Institute at OSU. “The particular
molecules that help carry it there are these lyso PLs, and the amount of
those compounds is being greatly reduced when vitamin E intake is
insufficient. This sets the stage for cellular membrane damage and
DHA is the needed nutrient, Traber said, but it’s lyso PLs which help get it into the brain. It’s the building block.
“You can’t build a house without the necessary materials,” Traber
said. “In a sense, if vitamin E is inadequate, we’re cutting by more
than half the amount of materials with which we can build and maintain
Some other research, Traber said, has shown that the progression of
Alzheimer’s disease can be slowed by increased intake of vitamin E,
including one study published last year in the Journal of the American
Medical Association. But that disease is probably a reflection of years
of neurological damage that has already been done, she said. The
zebrafish diet used in this study was deficient in vitamin E for the
whole life of the fish – as is vitamin E deficiency in some humans.
Vitamin E in human diets is most often provided by dietary oils, such
as olive oil. But many of the highest levels are in foods not routinely
considered dietary staples – almonds, sunflower seeds or avocados.
“There’s increasingly clear evidence that vitamin E is associated
with brain protection, and now we’re starting to better understand some
of the underlying mechanisms,” Traber said.