Dietary methionine regulation of cognitive function: Evidence, mechanisms, and implementation strategies.

Cognitive disorders, a rapidly growing public health concern, can be prevented by a healthy diet. Several studies have shown that protein intake is a key modulator of cognitive function. The development of precision nutrition has allowed the study of specific amino acids within proteins, with many studies reporting that the level of methionine (Met) intake plays a central role in modulating cognitive function. Methionine has both beneficial and detrimental effects on cognitive function, depending on various factors, and a comprehensive summary of its effects on brain health is urgently required. Here, the effects of different Met intakes on cognitive function were systematically reviewed. The effects of Met on learning and memory are strongly correlated with different intervention doses and periods, and the sex, age, and physiological status of the recipients. Furthermore, the mechanisms underlying the effects of Met were discussed, which acts through reduction-oxidation homeostasis, gut microbiota alterations, and epigenetic modifications. Moreover, methods of altering Met levels in the body are comprehensively summarized, and strategy for achieving precise Met nutrition was summarized and proposed. In summary, precise Met nutrition for cognitive function is important. Improvements in brain function may be achieved by adjusting dietary Met levels, which is convenient, efficient, and worthy of further investigation.