When polyunsaturated oils are hydrogenated they?

When polyunsaturated oils are hydrogenated, they undergo a chemical process that adds hydrogen atoms to the oil, converting liquid oils into more solid forms, such as margarine or shortening. This process increases the oil's shelf life and stability, but it can also create trans fats, which are associated with negative health effects. As a result, hydrogenated oils may contribute to Heart disease and other health issues when consumed in excess. Therefore, many health organizations recommend limiting the intake of hydrogenated oils.