The present invention discloses a method comprising administering a monosaccharide and/or polysaccharide as an active ingredient, for decreasing the accumulation of di-carbonyl compounds in the human body. Said monosaccharide is a monomer of said polysaccharide, and the molecular weight of the polysaccharide ranges from 29 kDa to 36 kDa. The monosaccharide and/or polysaccharide can be used to prevent or treat nephritis or diseases associated with di-carbonyl compounds, or other diseases caused by carbonyl-stress, and can also be used to make the relevant drug.