The differential effects of fatty acids on enterocytic abundance of amyloid-beta

Consumption of a Western-styled diet enriched in saturated fatty acids (SFA) relative to polyunsaturated fatty acids is positively associated with risk for Alzheimer's disease. Whilst potential causal mechanism are unclear, there is increasing evidence that chronic ingestion of SFA enriched diets promote increase the plasma levels of lipoprotein-associated amyloid-β (Aβ). However, the effects of dietary mono- and poly-unsaturated fats (MUFA/PUFA) on nascent lipoprotein Aβ abundance have not been previously reported.

Wild-type C57BL/6 J mice were maintained on low-fat control chow (LF) or diets enriched in either SFA, MUFA, or PUFA for 9 months. Enterocytic abundance of Aβ was determined with quantitative immunofluorescent microscopy and plasma Aβ was measured by ELISA.

The chronic ingestion of SFA-enriched diet increased the enterocytic abundance and plasma concentration of Aβ compared to LF control mice. The mice maintained on MUFA or PUFA diet showed comparable enterocytic and plasma Aβ levels to the LF control mice.

The data indicates that a diet enriched in SFA significantly increases the enterocytic Aβ production and secretion into the circulation, whilst MUFA and PUFA enriched diet do not exert such effects.