Impact of chub mackerel and quinoa supplementation on hepatic lipid composition and DHA accumulation in 5xFAD mice

The correlation between Alzheimer's disease (AD) and reduced neuronal docosahexaenoic acid (DHA, 22:6n-3) levels suggests that dietary strategies aimed at enhancing brain DHA could slow disease progression and ameliorate symptoms. Given the liver's central role in lipid metabolism, this study evaluated the impact of diets enriched in DHA (via chub mackerel, Scomber colias) and quinoa (Chenopodium quinoa) on the hepatic lipid profile and DHA accumulation in an AD mouse model. Thirty-two 5xFAD transgenic mice were assigned to four dietary groups: Control (standard AIN-93 M diet), Chub mackerel (CM; AIN-93 M + 10% chub mackerel), Quinoa (Q; AIN-93 M + 5% quinoa), and Chub mackerel + Quinoa (CM + Q; AIN-93 M + 10% chub mackerel + 5% quinoa). Although total lipid content remained similar across groups, the mice fed with Q diet had the highest hepatic triacylglycerols (TAG; 37.5 ± 6.9% of total lipids) when compared to CM and CM + Q groups (25.7 ± 2.0% and 29.0 ± 2.7%, respectively). The CM + Q group showed the most elevated hepatic n-3 polyunsaturated fatty acids (n-3 PUFA; 16.3 ± 2.8%) and DHA (12.2 ± 2.8%). DHA enrichment was observed only in TAG and free fatty acids from CM (7.5 ± 3.6% and 2.9 ± 1.2%, respectively) and CM + Q (8.2 ± 2.1% and 3.0 ± 1.0%, respectively). These findings indicate that combining quinoa with chub mackerel significantly enhances hepatic DHA accumulation and modulates lipid metabolism, presenting a promising dietary approach for managing AD-associated lipid dysregulation.