In major NDDs such as AD, PD, and ALS, n-3/n-6 PUFAs, SCFAs, and MCFAs participate in key pathological processes through unique pathways—including Aβ deposition and tau phosphorylation in AD, α-Syn aggregation and mitochondrial dysfunction in PD, and neuromuscular junction (NMJ) degeneration and glutamate excitotoxicity in ALS. Here, MAPT is linked to Alzheimer disease.