Low blood levels of all eight forms of vitamin E (four tocopherols and four tocotrienols) are linked to an increased risk of developing cognitive impairment, says a new study from Finland.
Data collected from 140 elderly Finnish people over eight years indicated that higher levels of gamma-tocopherol, beta-tocotrienol, and total tocotrienols were associated with lower risk of cognitive impairment, according to data published in Experimental Gerontology .
“Our results suggest that serum levels of tocopherols and tocotrienols are associated with the risk of cognitive impairment in older adults, which reinforces the hypothesis that each of the natural forms of vitamin E plays a unique role in human health,” wrote the authors, led by Francesca Mangialasche from the Karolinska Institutet in Stockholm.
“Evaluating only alpha-tocopherol might therefore not provide the most accurate measure of vitamin E status in humans.”
To read our recent feature exploring the role of vitamin E in brain health, please click here: Vitamin E: The ‘overlooked’ nutrient and its brain health benefits
Data from participants of the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study were used to evaluate the incidence of cognitive impairment in elderly people. Cognitive impairment was defined by the researchers as mild cognitive impairment (MCI) or Alzheimer's dementia.
MCI is reported to be linked to an increase in brain cell damage and death from oxidative and nitrosative stresses. This is related to a loss of cognitive function and an increased risk of Alzheimer's, the most common form of dementia and currently affects over 13 million people worldwide.
Results of the study indicated that associations exist between the risk of cognitive impairment and serum vitamin E levels, as well as vitamin E oxidative/nitrosative damages. The isk of cognitive impairment was lower in subjects with higher levels of gamma-tocopherol, beta-tocotrienol, and total tocotrienols, reported the researchers.
On the other hand, subjects who developed cognitive impairment were found to have lower serum levels of alpha and gamma tocopherol, total tocopherols, total tocotrienols, and total vitamin E, with statistically significant association with gamma-tocotrienol.
Specifically, they had significantly lower levels of gamma-tocopherol and gamma-tocotrienol than controls. Significantly higher levels of 5-NO2-gamma-tocopherol/gamma-tocopherol ratio (one of the vitamin E oxidative/nitrosative indices) were also detected in this group of subjects.
‘A need for all forms of vitamin E’
The results were welcomed by WH Leong, Vice President of Carotech Inc, which supplies the palm-derived tocotrienol/tocopherol complex, Tocomin SupraBio. “For a long time, the nutritional and scientific community assumed that vitamin E is synonymous with alpha-tocopherol, which is somewhat of a misnomer. In nature, Vitamin E consists of eight chemically distinct compounds, 4 tocopherols and 4 tocotrienols represented by alpha, beta, gamma, and delta prefixes.
“This new study coming out from Europe once again validates the protective role of each individual vitamin E form, especially the tocotrienols, in improving cognitive functions of older adults.
“Contrary to what has been spread over the internet, tocopherols do not interfere with tocotrienols’ function. As a matter of fact, this study yet again proves that we need both tocopherols and tocotrienols. They are important in its natural forms as found in our diet and as nature intended.”
Source: Experimental Gerontology
Volume 48, Number 12, Pages 1428-1435, doi: 10.1016/j.exger.2013.09.006
“Serum levels of vitamin E forms and risk of cognitive impairment in a Finnish cohort of older adults”
Authors: F. Mangialasche, et al.