Dyslipidemia, altered erythrocyte fatty acids and selenium are associated with dementia in elderly Nigerians

Dyslipidemia, reduced omega-3 and -6 fatty acids and antioxidative nutrients are modulatory risk factors associated with dementia. Diet, genetics and environment interact with nutritional metabolism and susceptibility to neurodegeneration. This study investigated the relationship between erythrocyte fatty acids and selected antioxidant nutrients in elderly Nigerians with vascular dementia (VD) and Alzheimer’s disease (AD). Forty VD (69.03±8.19 years) twenty AD (71.06±5.0 years) and forty control (67.5±6.8 years) subjects were studied. Anthropometric indices, blood pressure (BP) and body mass index (BMI) were measured in all subjects. Venous blood sample was drawn from all subjects and erythrocytes separated for the determination of fatty acids. Plasma lipids, selenium and vitamin E levels were also measured. There were no differences in BMI, weight and height among the three groups except for systolic BP that was lower in VD (148.3±41.8mmHg) than AD (156±36mmHg). Docosahexanoic acid and eicosapentanoic acid were lower in VD (6.3±2.2 and 2.0±1.6% total fatty acids [TFA]) and AD (5.4±3.1 and 3.0±1.7 %TFA) respectively than in controls (8.9±3.8 and 6.0±4.7%TFA). No variation was recorded in linolenic and arachidonic acids. Significant increases in triglycerides, LDL-cholesterol and decreased HDL-cholesterol were observed in both VD and AD when compared to controls (p<0.05 in all cases). Plasma selenium levels were significantly decreased in VD and AD than in controls. Eicosapentanoic and linolenic acids concentrations were negatively correlated with plasma total cholesterol. Low levels of erythrocyte omega-3 fatty acids and plasma selenium concentrations are associated with occurrence of vascular dementia and Alzheimer’s disease in elderly Nigerians.