Dietary antioxidants and dementia in a population-based case-control study among older people in South Germany

Oxidative stress is believed to play a central role in the pathogenesis of Alzheimer's disease (AD), a neurodegenerative disease. Antioxidants may prevent the onset AD as high dietary intake of vitamin C and E were reported to be associated with lower risk of the disease. The objective of this study was to evaluate the serum levels of antioxidants in persons with mild dementia to test whether it is associated with lower levels of antioxidants in a cross-sectional study in the population of the "Activity and Function in the Ederly in Ulm" (ActiFE) study. Main exposure measures were vitamin C, vitamin E, β-carotene, lycopene, and coenzyme Q10 as analyzed by HPLC. Main outcome measures were mild cognitive impairment among 74 mildly demented compared to 158 age- and gender-matched controls. We found that blood vitamin C and β-carotene concentrations were significantly lower in demented than in control persons even after adjusting for school education, intake of dietary supplements, smoking habits, body mass index, and alcohol consumption (3rd versus 1st tertile: OR: 0.29, 95% CI, 0.09-0.96 and 0.13, 95% CI, 0.03-0.55, respectively). No associations were found for vitamin E, lycopene, and coenzyme Q10. Our findings suggest an association of vitamin C and β-carotene with dementia. However this is limited to the cross-sectional character of our study and longitudinal data will give further insight into this association.