PROBLEM TO BE SOLVED: To provide low-density lipoprotein (LDL) oxidation inhibitors in the form of medicines or functional foods, where the inhibitors are safe even if taken for a long period of time, can prevent the oxidation of LDL effectively, and exert anti-atherosclerosis preventive and improving effect.SOLUTION: LDL oxidation inhibitors in the form of medicines or functional foods (supplement) that contain as an active ingredient a low molecular weight water-soluble nuclear protein containing 50 to 100% of a fraction having a molecular weight of 3000 or less derived from the milt of a fish, such as salmon, trout, herring, and cod are prepared. Such an LDL oxidation inhibitor is generally used as an atherosclerosis preventive and improving agent in a dosage form, such as capsules, tablets, granules, and drinks.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】長期間服用しても安全であり、低密度リポタンパク質(Low-density Lipoprotein:LDL)の酸化を効果的に防止することのでき、抗アテローム性動脈硬化の予防・改善効果を奏する、医薬品や機能性食品の形態のLDL酸化抑制剤を提供すること。【解決手段】サケ、マス、ニシン、タラ等の魚類の白子由来の、分子量3000以下の画分を50~100%含む低分子化された水溶性核タンパク質を有効成分として含有する医薬品又は機能性食品(サプリメント)形態のLDL酸化抑制剤を調製する。かかるLDL酸化抑制剤は、通常カプセル剤、錠剤、顆粒剤、ドリンク等の剤形でアテローム性動脈硬化症の予防・改善剤として用いられる。【選択図】なし