Scientists from Oregon State University in Corvallis report that zebrafish fed a diet without vitamin E for nine months had about 30% less of a form of DHA known as DHA-PC, a component of the brain cell membrane.
In addition, the vitamin E-deficient fish had higher levels of hydroxy-DHA-PC, which can form after exposure to free radicals.
“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 lead researcher Dr Maret Traber, in an article on the university’s website.
The data, published in the Journal of Lipid Research, also indicated that the vitamin E-deficient fish had lower levels of lysophospholipids, compounds that join with Vitamin E to carry DHA into the brain.
“You can’t build a house without the necessary materials,” added Dr Traber. “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 the brain.”
The study was welcomed by Michael McBurney, PhD, VP Science, Communication & Advocacy – DSM Nutritional Products. “Docosahexaenoic acid (DHA) is an integral part of neural membrane phospholipids in the brain,” he told us. “This study, in a zebrafish model, demonstrates the essentiality of vitamin E in protecting the integrity of lipids in the brain. In summary, vitamin E helps preserve and protect our fat heads!”
Vitamin E and brain health
Vitamin E is a family of eight separate but related molecules: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). The majority of the science in the past has looked at vitamin E in the alpha-tocopherol form in the context of cardiovascular disease, cancer, and eye disease.
The new study adds to a growing body of science supporting the potential brain health benefits of the vitamin. Despite compelling evidence, the vitamin has been ‘overlooked’ by the medical and research community, said Dr McBurney.
“The medical and research communities have ignored vitamin E,” he said. “Fortunately, vitamin E was identified by the 2015 Dietary Guidelines Advisory Committee as a ‘shortfall nutrient’ because of the high prevalence of inadequate intake. This is encouraging and none too soon.
“Given aging populations and the antioxidant role of vitamin E, there should be greater interest in assessing vitamin E status.”
Human data
The new study with zebrafish helps us understand the mechanism of vitamin E in brain health, he said, and there is at least one study reporting benefits of vitamin E supplementation to help maintain cognitive function.
“Vitamin C helps recycle vitamin E and will be depleted first during oxidative stress. Plasma levels of antioxidant vitamins, especially vitamin C, are associated with indicators of cognitive function. This is important because there isn’t an ‘accepted’ medical treatment to prevent functional decline in patients with mild to moderate Alzheimer’s disease.”
Dr McBurney added that there is growing evidence that vitamin E may be important in maintaining liver function by reducing the accumulation of fat in the liver. Non-alcoholic fatty liver is becoming much more prevalent because of the incidence of obesity and overweight, he explained.
“Couple this observation with aging and a desire to maintain brain function, then it becomes obvious why the medical and health community should refocus on vitamin E.
“More effort should be expended assessing vitamin E status (circulating and tissue alpha-tocopherol concentrations) and relating status with functional health outcomes, just as has been done with vitamin D.
“This is much more important than trying to estimate dietary intake or assessing randomized, controlled trials (vitamin E vs placebo) without consideration of vitamin E status.”
Zebrafish
The Oregon-based researchers worked with zebrafish because they have many genes in common with human beings, thereby allowing researchers to study them to gain insights into human disorders and conditions.
For more information about how zebrafish can help understanding human development, the NIH has produced the following video:
The study was supported by the NIH’s National Center for Advancing Translational Sciences, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Institute of Environmental Health Sciences, all at the NIH.
Source: Journal of Lipid Research
Published online ahead of print, doi: 10.1194/jlr.M058941
“Novel function of vitamin E in regulation of zebrafish (Danio rerio) brain lysophospholipids discovered using lipidomics”
Authors: J. Choi, S.W. Leonard, K. Kasper, M. McDougall, J.F. Stevens, R.L. Tanguay, M.G. Traber