Fatty acid symbols. Computer artwork of omega 3 and omega 6 symbols over an oil background. The signs represent two of the fatty acids important in the human diet. Omega 3 fatty acids are contained in oils present in some saltwater fish. They have been found to be beneficial to the heart and help the body to use energy more efficiently. The omega 6 sign represents gamma linolenic acid, one of the essential fatty acids. It is a polyunsaturated fat found in certain plant oils including linseed and soya-bean oil. Deficiency of essential fatty acids can cause skin problems, weight loss and irregular oestrus.