Diabetes, Brain and Heart Health: Is it time for an Authoritative Review on Vitamin E?
As summer fades and fall approaches in the northern hemisphere, the cycle of life comes to mind. What will senescence bring? Cognitive decline is evident in 45-49 year olds and it continues with aging (Singh-Manoux et al, 2012). Can better nutrition change the outcome?
Haptoglobin is an antioxidant protein which helps prevent hemoglobin-induced oxidative damage. Genetic polymorphisms in the haptoglobin protein are known to interact with vitamin E status, partially explaining a 3-5 fold effect on cardiovascular disease risk in some individuals with diabetes (Vardi et al, 2012). In a new study, Ravona-Springer and colleagues report a similar interaction between haptoglobin genotype and cognitive functioning in elderly individuals with diabetes. Unfortunately, they do not report vitamin E status.
Because few foods are naturally-rich or fortified with vitamin E, most people are not consuming recommended amounts of vitamin E. Vitamin E is required, in fact the body preserves vitamin E concentrations in the brain during periods of low intake, to protect membranes from lipid peroxidation (Lebold & Traber, 2013). Beydoun and colleagues examined the relationship of antioxidant status with depressive symptoms in US adults (20-85y). Women with elevated depressive symptoms had lower serum levels of vitamin E (26 vs 30 μmol/L) and vitamin C (43 vs 60 μmol/L) as well as all carotenoids compared with their non-depressed counterparts. Maes and associates also reported lower vitamin E concentrations (≈23 μmol/L) in American individuals with major depression vs normal volunteers (≈32 μmol/L), as did Owen and colleagues in Australians.
Dietary vitamin E recommendations are based on limited studies in vitamin E deficient individuals and the last authoritative review was published in 2000. Maybe it is time to revisit the science to define optimal vitamin E status based on indicators of adequacy to maintain health rather than deficiency, i.e. red blood cell hemolysis.
Ravona-Springer R, Heymann A, Schmeidler J, Guerro-Berroa E, Sano M, Preiss R, Koifman K, Hoffman H, Levy A, Silverman JM, Schnaider-Beeri M. Haptoglobin 1-1 genotype is associated with poorer cognitive functioning in type 2 diabetic elderly. 2013 Diab Care doi:10.2337/dc12-2250
Lebold KM, Traber MG. Interactions between α-tocopherol, polyunsaturated fatty acids, and lipoxygenases during embryogenesis. 2013 Free Rad Biol Med doi:10.1016/j.freeradbiomed.2013.07.03
Singh-Manoux A, Kivimaki M, Glymour MM, Elbaz A, Berr C, Ebmeier KP, Ferrie JE, Dugravot A. Timing of onset of cognitive decline: results from Whitehall II prospective cohort study. 2012 Br Med J doi:10.1136/bmj.d7622
Beydouin MA, Beydouin HA, Boueiz A, Shroff MR, Zonderman AB. Antioxidant status and its association with elevated depressive symptoms among US adults: National Health and Nutrition Examination Surveys 2005-6. 2012 Br J Nutr doi:10.1017/S000711451467
Maes M, De Vos N, Pioli R, Demedts P, Wauters A, Neels H, Christophe A. Lower serum vitamin E concentrations in major depression another marker of lowered antioxidant defenses in that illness. 2000 J Affect Disord doi:10.1016/S0165-0327(99)00121-4
Owen AJ, Batterham MJ, Probst YC, Grenyer BFS, Tapsell LC. Low plasma vitamin E levels in major depression: Diet or disease? 2005 Eur J Clin Nutr doi:10.1036/sj.ejcn.1602072
Melamed-Frank M O, Lache O, Enav BI, Szafranek T, Levy NS, Ricklis RM, Levy AP. Structure-function analysis of the antioxidant properties of haptoglobin. 2001 Blood doi:10.1182/blood.v98.13.3693
Vardi M, Blum S, Levy AP. Haptoglobin genotype and cardiovascular outcomes in diabetes mellitus – natural history of the disease and the effect of vitamin E treatment. Meta-analysis of the medical literature. 2012 Eur J Intern Med doi:10.1016/j.ejim.2012.04.009