Increased blood levels of all forms of vitamin E may reduce the risk of mild cognitive impairment in older adults, says a new study from Europe.
The study – said to be the first of its kind to evaluate the effects
of all eight forms of vitamin E in mild cognitive impairment (MDI) and
Alzheimer’s disease (AD) – found that the risk of MDI was 15% and 8%
lower in people with the highest levels of tocopherols and tocotrienols,
There are eight forms of vitamin E: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). Alpha- tocohperol is the main source found in supplements and in the European diet, while gamma-tocopherol is the most common form in the American diet.
«The increasing evidence about vitamin E family neuroprotective properties warrants further investigation of their role in age-related cognitive decline and AD, to better define the composition of vitamin E supplements (for people with MDI and AD),» wrote the researchers.
«Evaluating plasma levels of all vitamin E forms may help to identify elderly people who could benefit from vitamin E supplementation,» they added.
Results showed taht, compared with people with normal cognitive function, people with MCI and Alzheimer’s had lower average levels of tocopherols and tocotrienols, and total vitamin E.
In addition, participants with MCI and Alzheimer’s also displayed higher blood levels of markers of vitamin E damage. According to researchers, mild cognitive decline often precedes the onset of Alzheimer’s, and there is accumulating evidence to suggest that oxidative and nitrosative stress plays a role in the development of the disease.
«In our study, the depletion of all plasma vitamin E forms, together with the increased indexes of vitamin E oxidative/nitrosative damage were shown in both AD and MCI, supporting the hypothesis that (oxidative and nitrosative stress) are early phenomena in AD, and suggesting a potential role of vitamin E in neurodegeneratiton,» they said.