The Lymphatic System and Beta Glucan:
by Susan Valentino, Ph.D.
Practitioners everywhere are talking about the immune system. Immune responses are described as if immune cells just float around in the blood directing each other to destroy invaders. This is true in part, but immune cells have a home, it is called the lymphatic system (lymph system). The lymph system is largely under-studied and greatly unappreciated. This system of internal fluids, separate from the circulatory system, contributes enormously to immune function and is responsible for keeping all body fluids clean.
The human body is 60-70% fluid and these fluids must be kept clean and germ-free. The complex lymphatic system handles a large portion of the internal waste generated by the metabolic functions of cells. Living cells generate wastes that are excreted into the spaces between cells. This waste is transported by lymph vessels to the lymph nodes, which filter out the impurities and dump the clean fluid into the bloodstream. Considering the great importance of just this function it is surprising that traditional medical practice pays little attention to the lymph system as a whole. The most that one can expect is a check for gross lymph node abnormalities and enlargements. The lymph system is highly underrated as an indicator of health, which is a profound oversight because poor lymphatic function can lead to fluid stagnation in the tissues. Some conditions that can arise from such fluid stagnation include tonsillitis, appendicitis and fibrocystic breasts.
The lymph system, like the circulatory system, is composed of and extensive network of vessels that connect with lymph nodes throughout the body. Lymph nodes (when healthy) are small, bean-shaped organs with a net-like interior (filter). Within in the netting are white blood cells mainly macrophages and lymphocytes. These cells travel through the blood stream by the billions to all the lymphoid organs: nodes, spleen, and the tissues of the lungs, digestive and urinary tracts, and the genital organs. The lymphocytes reach every organ of the body through the lymphatic channels and generally keep moving. Some macrophages on the other hand remain in specific locations and become what are known as "resident" macrophages.
The lymphatic vessels and cells of the digestive tract have many functions and capabilities unique to this location. The lymph vessels and organs "associated" with the digestive tract are called "gut-associated lymphoid tissue" or GALT. Considering the fact that more than a ton of food may pass through the digestive tract of an adult human annually with little or no adverse immune-mediated reactions as a result, it is apparent that GALT have some unique characteristics. The immunologic challenge represented by exposure to dietary proteins is generally controlled and is known as "oral tolerance". Oral tolerance also works to protect the "good" gut microbial flora from attack by immune cells. However, further discussion of oral tolerance is beyond the scope of this writing.
Swollen lymph nodes are an indication of a localized infection as lymph vessels "drain" various parts of the body and swelling indicates that the node is very active in fighting an infection. If the amount of cell waste exceeds the lymphatic system's ability to remove it lymphatic stagnation can occur. Things like allergens (dietary and airborne), and toxins (pollution) that result in inflammation, infection, and cell death result in increased waste that must be removed. Often there is more waste than the liver and kidney's can remove, and this waste accumulates in the blood and lymph channels.
Proper functioning of the lymphatic system is a cornerstone of good health, yet it is often over-looked by Western medicine. There is no doubt that the lymph system affects health and that lymphatic fluid must be kept clean and flowing. Without fluid balance immune function is impaired, and in extreme cases germs are not carried away and blood poisoning or septicemia can result.