The present invention provides a composition for improving vascular endothelial function, comprising: an ingredient selected from a monounsaturated fatty acid having 20 carbon atoms or more, a salt thereof, and an ester thereof as an active ingredient, in which the ratio of the monounsaturated fatty acid having 20 carbon atoms or more to the total fatty acids in the composition is 10 wt% or greater. The present invention also provides a composition for improving sleep, comprising an ingredient selected from a monounsaturated fatty acid having 20 carbon atoms or more, a salt thereof, and an ester thereof as an active ingredient.
