Using castor oil regularly is a good remedy for supporting the body's lymphatic system, which in turn contributes to strong immune-enhancing effects. The lymphocytes, found in the lymphatic system, are types of white blood cells that help safeguard the body from threats such as foreign bacteria or toxins. Topical application of castor oil to the abdominal region, as was discovered by a small 2012 study, can help the body maintain proper levels of lymphocyte production as well as improve lymphatic drainage, increase blood flow, and protect the thymus gland.