To provide a gnetin C high content melinjo extract rich in the content of gnetin C which is useful for prevention and/or treatment of diseases such as metabolic syndrome, diabetes mellitus, hypertension, gout, cancer, collagen disease, periodontal disease and the like and further for beauty care and/or protection of skin and of which intake/dosage or use amount can be reduced. An extract is extracted from melinjo fruit, by using an extraction solvent which is a mixed solvent obtained by blending at least one of an emulsifier, a cycrodextrin and an acid into water and/or an organic solvent.