Dietary pattern and antioxidants in plasma and erythrocyte in patients with mild cognitive impairment from China

Objectives: Oxidative stress and unhealthy dietary patterns are might correlate with the risk of mild cognitive impairment (MCI) patients to develop Alzheimer's disease. We explored the association between dietary pattern, plasma and erythrocyte antioxidants levels, and cognitive function in the older Chinese adults. Methods: The present study is a case-control study. A total of 138 MCI patients and 138 age- and sex-matched healthy subjects (aged from 55 to 75) were recruited. A food frequency questionnaire method was used for the dietary survey. Peripheral blood and morning spot urine were sampled for parameters detection. Cognitive function of the old subjects was measured by using the Montreal Cognitive Assessment test. Antioxidant parameters in plasma, erythrocyte, and urine samples were measured by using the assay kits. Plasma retinol, alpha-tocopherol, and flavonoids contents were detected by using high performance liquid chromatography and liquid chromatography mass spectrometer methods respectively. Results: The MCI patients had lower plasma total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol than control subjects (P < 0.01). MCI patients consumed less fish and more red meat daily than the controls (P < 0.05). Comparing with controls, lower plasma total antioxidant capacity, alpha-tocopherol, and higher level of malondialdehyde were detected in the MCI patients (P < 0.05). No significant difference of plasma flavonoids concentration, erythrocyte antioxidant enzyme activities, and urinary 8-hydroxy-2'-deoxyguanosine content was detected among the MCI and control subjects (P > 0.05). Conclusions: Lower plasma concentration of high-density lipoprotein cholesterol, total antioxidant capacity, and alpha-tocopherol levels, and a dietary pattern that is low in fish and high in red meat might contribute to the cognition impairment in older Chinese adults. (C) 2016 Elsevier Inc. All rights reserved.