What are health effects of monounsaturated fats?

Complex: When substituted for (not added to) saturated fats, monounsaturated fats, as found in olive and canola oils, can raise the HDL (good) cholesterol and have been associated epidemiologically with reduced incidence of heart disease and death. The mediterranean diet (found by googling this term) can provide a specific example of a good diet rich in monounsaturated fats.