Dewaxed brown rice (DBR), which is prepared by removing only the outermost wax layer of brown rice using a new rice milling technique, has improved water absorbency, digestibility, and taste compared to regular brown rice. DBR has a nutritional value close to that of brown rice, including a rich amount of lipopolysaccharides that are known to improve cognitive function in mice. This study thus aimed to verify the influence of continuous DBR ingestion on cognitive function among elderly individuals. The present study employed a crossover comparison design using the Revised Hasegawa Dementia Scale to assess cognitive function. Our findings confirmed that long-term DBR ingestion contributed to the prevention and reduction of overall cognitive decline, especially among elderly individuals with low cognitive function. Thus, DBR has the potential to be a useful staple food that maintains brain homeostasis among elderly individuals.