Positive Health Online

Abstract

MANGIALASCHE and COLLEAGUES,  (1)Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Institute of Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy. francesca.mangialasche@ki.se investigated the association between serum levels of tocopherols and tocotrienols, markers of vitamin E oxidative/nitrosative damage (α-tocopherylquinone, 5-nitro-γ-tocopherol) and incidence of cognitive impairment in a population-based study.

Background

Vitamin E includes eight natural antioxidant compounds (four tocopherols and four tocotrienols), but α-tocopherol has been the main focus of investigation in studies of cognitive impairment and Alzheimer's disease.

Methodology

A sample of 140 non-cognitively impaired elderly subjects derived from the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study was followed-up for 8years to detect cognitive impairment, defined as development of mild cognitive impairment (MCI) or Alzheimer's dementia. The association between baseline serum vitamin E and cognitive impairment was analyzed with multiple logistic regression after adjusting for several confounders.

Results

The risk of cognitive impairment was lower in subjects in the middle tertile of the γ-tocopherol/cholesterol ratio than in those in the lowest tertile: the multiadjusted odds ratio (OR) with 95% confidence interval (CI) was 0.27 (0.10-0.78). Higher incidence of cognitive impairment was found in the middle [OR (95% CI): 3.41 (1.29-9.06)] and highest [OR (95% CI): 2.89 (1.05-7.97)] tertiles of the 5-NO2-γ-tocopherol/γ-tocopherol ratio. Analyses of absolute serum levels of vitamin E showed lower risk of cognitive impairment in subjects with higher levels of γ-tocopherol, β-tocotrienol, and total tocotrienols.

Conclusion

Elevated levels of tocopherol and tocotrienol forms are associated with reduced risk of cognitive impairment in older adults. The association is modulated by concurrent cholesterol concentration. Various vitamin E forms might play a role in cognitive impairment, and their evaluation can provide a more accurate measure of vitamin E status in humans.

References

Mangialasche F(1), Solomon A, Kåreholt I, Hooshmand B, Cecchetti R, Fratiglioni L, Soininen H, Laatikainen T, Mecocci P, Kivipelto M. Serum levels of vitamin E forms and risk of cognitive impairment in a Finnish cohort of older adults. Exp Gerontol. 48(12):1428-35. Dec 2013. doi: 10.1016/j.exger.2013.09.006. Epub Oct 72013.  

Comment

The above research demonstrated that higher levels of tocopherol and tocotrienol - vitamin E forms - are associated with lower risk of cognitive impairment, which is modulated by cholesterol concentration. The authors state that vitamin E forms might play a role in cognitive impairment, and their evaluation can provide a more accurate measure of vitamin E status in humans.