With the intensification of population aging， the number of patients with cognitive impairment continues to increase. However， existing drugs have a limited therapeutic effect on these diseases， and therefore， it is important to prevent or delay the onset of related diseases. Recent studies have shown that diet is closely associated with cognitive impairment in the elderly， and improving dietary structure or increasing essential nutrients can reduce the incidence rate of cognitive impairment and slow down its progression； however， some results remain controversial. This article reviews the current status of research on the impact of nutrition and diet on cognitive impairment in the elderly， in order to provide new ideas for the prevention and treatment of cognitive impairment.