All fats and oils are made up of three fatty acid molecules and a glycerol molecule. The fatty acid molecules are made up of carbon, oxygen and hydrogen. The number of hydrogen atoms attached to carbon atoms in the molecule determines its saturation. Each carbon atom could hold two hydrogen atoms. When two adjacent carbon atoms are each missing one hydrogen atom, they form a double bond between themselves. If the fatty acid has two or more of these double bonds it is called polyunsaturated. Scientists have suggested that saturated fats may be associated with an increase in the less desirable LDL (low-density lipoprotein) cholesterol in the blood. This has led to increased popularity of oils such as safflower, walnut, sunflower seed, corn, cotton seed, sesame seed, and peanut oils which are good sources (in that order) of polyunsaturated fatty acids.