Monday Sept 7, 2015 (foodconsumer.org) -- A new study suggests that lower intake of vitamin C, but not other antioxidants may be a risk factor for Alzheimer's disease.

The study found older men and women who had greater carotid intima–media thickness tended to have lower levels of vitamin C suggesting that vitamin C may have some protective effect against vascular damage.  The carotid intima–media thickness (C-IMT) may indirectly indicate the degree of vascular damage.  

Scientists found the vitamin C-IMT link after analyzing the associations between antioxidant vitamins including vitamins A, C, E and also plasma antioxidant enzymes superoxide dismutase and glutathione peroxidase, with C-IMT.  The subjects involved in the study had no or very mild cognitive impairment.

The scientists found that compared with study participants in the lowest vitamin C quartile, those in the higher quartiles were less likely to have IMT greater than 1.2 mm.  Levels of other vitamins and enzymes were not as significantly associated with the thickness as vitamin C.

The study concluded that an adequate vitamin C concentration may be important for protection against Alzheimer's disease, and vascular and cognitive ageing.

M. C. Polidori  , C. Ruggiero , M. F. Croce, T. Raichi, F. Mangialasche, R. Cecchetti, L. Pelini, L. Paolacci, S. Ercolani and P. Mecocci, Association of increased carotid intima–media thickness and lower plasma levels of vitamin C and vitamin E in old age subjects: implications for Alzheimer’s disease, Journal of Neural Transmission, April 2015, Volume 122, Issue 4, pp 523-530