Ingestible compositions and the invention provides a method at low doses for improving brain function. According to the present invention, (wherein X is absent or X-Pro-Pro-Leu-Thr-Gln-Thr-Pro-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro-Glu-Y, or represents any of the Asn-Ile or Ile, or), representing Val-Met wherein Y is absent or, X-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro- (wherein X is absent, it represents one of the Pro Thr-Gln-Thr-Pro, Pro-Leu-Thr-Gln-Thr-Pro, or Leu-Thr-Gln-Thr-Pro, expression Glu-Y method for improving brain function by an active ingredient a salt thereof or) representing Val-Met or absent, for improving brain function, the composition, and the administration of the peptides or salts thereof is provided for medium Y that.本発明は脳機能を改善するための低用量で経口摂取可能な組成物および方法を提供する。本発明により、X-Pro-Pro-Leu-Thr-Gln-Thr-Pro-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro-Glu-Y(式中Xは存在しないか、またはIleまたはAsn-Ileのいずれかを表し、式中Yは存在しないか、またはVal-Metを表す)、または、X-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro-Glu-Y(式中Xは存在しないか、Thr-Gln-Thr-Pro、Pro-Leu-Thr-Gln-Thr-Pro、Leu-Thr-Gln-Thr-ProまたはProのいずれかを表し、式中Yは存在しないかVal-Metを表す)またはそれらの塩を有効成分とする、脳機能改善用組成物、およびこれらのペプチドまたはその塩を投与することにより脳機能を改善する方法が提供される。
