The liver brain axis is critical in neurodegenerative diseases, with lipid metabolism influencing neuroinflammation and microglial function. A systematic investigation of the genetic relationship between lipid metabolism abnormalities and ND, namely, Alzheimer's disease, Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis, is lacking. To assess potential causal links between ND and six lipid parameters, two-sample Mendelian randomization was used.