Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation.
Omega-3 Fatty Acids. A diet rich in PUFAs should include plenty of omega-3 fatty acids. This type of PUFA is found in cold-water fish, such as salmon, tuna, mackerel and herring.
When there is more than one double bond, they are called polyunsaturated fatty acids (poly = many). Examples of polyunsaturated fatty acids, or PUFAs, are vegetable oils, nut oils, and fish oils. PUFAs are liquid at room temperature. Further, because fish oils have the greatest number of double bonds and are the most unsaturated, they are sometimes also called highly unsaturated fatty acids or HUFAs. For example, EPA has 5 double bonds and DHA has 6, more than any other essential fatty acid.