There are many drawbacks to a sedentary lifestyle including weight gain, poor circulation, and an increased risk for chronic diseases.
The growing rates of obesity, diabetes, and cardiovascular disease directly link to a sedentary lifestyle. One of the many physiological systems negatively affected by the lack of movement is the lymphatic system. This system plays a key role in both immune response and circulatory health.
The Lymphatic System:
Many have seen a diagram of the lymphatic system, yet knowledge of its role in the body is generally poor. The lymphatic system consists of lymphoid tissues (or organs) connected by a drainage system of vessels known as lymphatics. There are two kinds of lymphoid tissues: primary and secondary. Primary lymphoid tissues include the bone marrow and the thymus (located near the heart). Secondary lymphoid tissues include every other lymphoid organ in the lymphatic system. Examples include lymph nodes, tonsils, adenoids, the appendix, Peyer’s patches and spleen (2).
Primary lymphoid organs make and mature immune cells that will activate it when there is an infection. Secondary lymphoid organs represent the headquarters where immune cells can kill infected cells and analyze them for a tailored immune response. When one has a respiratory infection, for example, the tonsils get larger and tender. This is because there is a concentration of immune components and fluid in the lymphoid organs that are closest to the infection.
Lymphatic system roles also include the recycling of blood plasma and immune components that leak out of blood vessels and in connective tissues. This fluid is eventually brought back into circulation.
Lymphatic Flow & Drainage:
All lymphoid organs and tissues, with the exception of the spleen, connect to a drainage network known as the lymphatics. In a diagram, the lymphatics are depicted by the many lines that connect the lymph nodes (and other lymphoid organs) together.
The lymphatic vessels that make up the lymphatics originate in connective tissues, which are common sites of infection and the collection of fluids. The lymphatics collect leaked blood plasma and immune components (known as lymph) taken to secondary lymphoid organs and eventually returns it to circulation.
Lymphatic flow is unidirectional and not pumped by the heart. A series of one-way valves throughout the lymphatics prevent backflow. Body movement directs this flow. Movement, therefore, is a driving force behind lymphatic drainage and proper immune response. Lymphatic drainage helps prevent the collection of fluids (edema) and activate resident cells in secondary lymphoid organs.
Osteopathic manipulative treatment (OMT) promotes lymphatic flow and drainage (especially in cases where the patient can’t move) which contributes to faster healing. Massage therapy too can help stimulate the movement of collected fluids and lymph from inflammation, injury, or infection.
Adverse Effects of Poor Lymphatic Flow:
Poor lymphatic flow can lead to the collection of fluids or swelling throughout the body but more so in the limbs. Additionally, poor lymphatic flow translates into impaired immunity due to its connection to the immune response. In the case of lymphedema, a condition characterized by lymphatic blockages, the fluid from tissues cannot leave the area. Thus, it collects and leads to swelling (usually of the legs and arms). This condition has no cure and can restrict the range of motion and result in discomfort. Lymphoedema is sometimes caused by cancer treatments or lymph node removal (1).
“Lymphedema.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 21 Dec. 2017, www.mayoclinic.org/diseases-conditions/lymphedema/symptoms-causes/syc-2037468
Parham, Peter, and Charles Janeway. The Immune System. Third ed., Garland Science, 2009.