Dietary and Serum Level of Antioxidants in the Elderly with Mild Impaired and Normal Cognitive Function: A Case-Control Study

Antioxidants are considered essential components in neurodegenerative disease management since they can protect cells from oxidative damage. The current study aimed at evaluating the intake and serum level of selected antioxidants in subjects possessing mild cognitive impairment (MCI) compared with a cognitively intact control. The current prospective, case-control study was conducted in Tabriz from December 2016 to August 2017 on a total of 45 patients with MCI as a case group and another 45 healthy subjects matched by age and gender were recruited for the control group. After completing the mini-mental state examination (MMSE-12) questionnaire, the cases with MCI were identified using the modified Peterson standard. By a semi-quantitative food frequency questionnaire (FFQ), the common dietary intakes during the previous year were recorded and blood samples were collected. Of the 90 subjects in the current study, 61% were male and 39% female, with the mean age of 68.8 ± 5.5 years. There were no significant differences between the two groups with respect to dietary intakes of vitamin C, beta-carotene, and lycopene (P = 0.079, P = 0.413, and P = 0.455, respectively). The results of the studied parameters showed that serum beta-carotene and lycopene (P = 0.004 and P = 0.044, respectively) in healthy subjects were significantly higher than those of the elderly people with MCI. There was a significant correlation between Vitamin C dietary intake and serum level and cognitive scores in MMSE-12 (r = 0.231, P = 0.028 and r = 0.224, P = 0.033, respectively) and also between serum level of lycopene and cognitive scores(r = 0.388, P = 0.000). The subjects with mild cognitive impairment had a significantly lower serum levels of lycopene beta-carotene antioxidants compared with healthy subjects, and there was a positive correlation between serum level of vitamin C and lycopene and also vitamin C dietary intake and scores in the MMSE-12 test.