Erythrocyte α-linolenic acid is associated with the risk for mild dementia in Korean elderly.

n-3 polyunsaturated fatty acids (PUFA) play an important role in brain development and function, but there is conflicting evidence between the relationship of n-3 PUFA and dementia in the elderly. The purpose of the present study was to test the hypothesis that n-3 PUFA content of erythrocytes is associated with mild dementia in elderly Koreans. Fifty-seven elderly (age ≥65 years) patients (19 male, 38 female) were recruited, and indicators of dementia (intake, erythrocyte fatty acid composition, and Mini-Mental Status Examination-Korean Version [MMSE-K]) were evaluated. Patients were divided into groups based on their MMSE-K score: normal control group (score >21 [n = 24]) and deficit group (score ≤21 [n = 33]). Multivariate-adjusted regression analysis showed that a higher level of α-linolenic acid (ALA; 18:3n-3) significantly decreased the risk of mild dementia after adjusting for age, sex, and height. MMSE-K score was also significantly and positively associated with erythrocyte ALA and total n-3 PUFA. However, erythrocyte levels of docosahexaenoic acid (22:6n-3) and eicosapentaenoic acid (20:5n-3) were not significantly related with the risk of mild dementia and MMSE-K score. Dietary intake was also not significantly associated with the risk of mild dementia and MMSE-K score after adjusting for age, sex, height, and energy intake. In conclusion, ALA derived from plant sources of n-3 PUFA, but not eicosapentaenoic acid and docosahexaenoic acid from fish, decreased the risk for mild dementia among the Korean elderly.