The invention provides a safe and stable plasmalogen, a formulation thereof, and a method for assessing presymptomatic dementia. More specifically, the invention comprises: a supplement or a foodstuff as a processed product for the mitigation, improvement, or prevention of dementia having as an active ingredient a plasmalogen with [omega]-3 highly unsaturated fatty acid ([omega]-3HUFA) bonds, etc.； a formulation for the treatment of neurodegenerative disease and/or mental illness； and a method for assessing presymptomatic dementia in a subject, where the subject is an adult who has not yet developed dementia (normal subject). The supplement or foodstuff comprises a plasmalogen-containing complex lipid, etc., that has been extracted and separated from the organs and specific sites in the living tissue of a chicken, and has a composition ratio unique to the living tissue in which a DHA-containing [omega]-3HUFA derivative is transferred to the living tissue of a chicken raised on feed containing the [omega]-3HUFA derivative.本發明課題在於提供一種安全、穩定之縮醛磷脂與其製劑及失智症未病狀態的判定方法。一種源於活體組織，萃取分離自其特定部位與內臟器官，且由去除副產物之蛋白質區分及水溶性低分子量區分後的全部脂質之純化物所構成之具有活體組織特異性之構成比的含有縮醛磷脂之複合脂質；一種藉由對該複合脂質以磷脂酶A1(PLA1)進行酵素處理，去除包含溶血體之甘油磷脂質類並萃取分離去除鞘磷脂，來製造具有活體組織特異性之構成比的純化縮醛磷脂等的方法；一種以藉由該方法所製造之ω-3HUFA結合型之純化縮醛磷脂等為有效成分之作為失智症之預防用營養補充品或食品的加工品；以及一種神經退化疾病及/或精神疾病之治療用製劑、及判定失智症未病狀態的方法。
