Aim: This review examines the biological basis of precision nutrition and evaluates evidence from conditions sharing pathophysiological mechanisms with dementia, exploring how this approach may more effectively mitigate dementia progression compared to conventional dietary recommendations. Method: A literature search was conducted in January-February 2025 across three electronic databases. Peer-reviewed articles and guidelines written in English focusing on nutrigenomics and dementia, or comorbidities with shared pathological mechanisms, were included. Results: Preliminary evidence indicates precision nutrition can modulate genetic and metabolic pathways relevant to dementia pathophysiology. Food-derived nutrient and non-nutrient molecules act as intracellular modulators underpinning nutrigenomics, influencing pathways associated with neuroinflammation and neurodegeneration. Key nutrient-gene interactions include omega-3 polyunsaturated fatty acids, Vitamin D, and B Vitamins. Single nucleotide polymorphisms within nutrient metabolic pathways carry implications for dementia due to associations with amyloid beta clearance, tau aggregation, and neurodegeneration. Precision nutrition is increasingly explored in Apolipoprotein E4 carriers, given this genotype's role in altering cerebral glucose metabolism and dysregulating cholesterol gene expression. Additionally, gut microbiome dysbiosis can trigger pro-inflammatory cascades driving neuroinflammation via the microbiota-gut-brain axis, underscoring its relevance to precision nutrition in dementia. Advances in multi-omics technologies, including proteomics, lipidomics, and metabolomics, paired with integrated biological data analysis, will deepen understanding of nutrient-gene interactions and strengthen the systems biology framework underpinning precision nutrition. Conclusion: Further mechanistic and clinical research is needed to determine the feasibility, acceptability, and effectiveness of precision nutrition for people living with dementia and their care partners.