Our bodies are incredibly finely tuned instruments. Hundreds of thousands of years of evolution have honed our internal systems to work symbiotically to keep us healthy and tackle any threats to our natural homeostasis. Myriad independent systems have developed an uncanny ability to recognize and remove any elements or toxins that might harm us or don’t support an essential bodily function. These combined systems form what is colloquially termed our ‘immune system.’
Our immune system starts with our skin, which acts as a natural defence against surface germs entering the body. If we happen to breathe in any airborne toxins, the mucus lining of our lungs quickly traps them in the large tubes comprising our bronchi and expels them via our cough and sneeze impulses. Other airborne toxins captured in the mucus lining of our noses and sinuses drain into, and are neutralized by, the harsh acidic environment of our stomachs or are ‘blown’ directly back out. If we eat or drink recognizably toxic substances, our body produces a violent stomach contraction and throws it quickly back up. Other solid material that can’t be absorbed and metabolized as useful nutrients is filtered by our liver and removed via our bowels.
Similarly, our kidneys filter and remove fluid-soluble waste that our bodies don’t need and expels them via the ureters and bladder. Urine and acidic vaginal secretions help to kill and remove pathogens that attempt to enter the body via other routes. The largest organ in our body, our skin, plays a further remediative role by removing excess metals and minerals whenever we sweat. But what if we break our skin, or toxins find a way to by-pass any of these natural defences? This is where the often misunderstood and underappreciated lymphatic system has a very special purpose in your body’s ongoing battle with detoxification.
The Lymphatic System
The primary purpose of the lymphatic system is to transport lymph fluid, which carries critical infection-fighting white blood cells, called leukocytes, to the body’s tissues where they can attack and neutralize any pathogens that get past the other detoxification centers. ‘Pathogens’ are any microorganisms including bacteria, viruses, and cancer that cause disease. Some bacteria, such as the ones lining our gut and aid in digestion, are beneficial—whereas certain other strains release toxins and create havoc inside our bodies. Diseases caused by bacteria include food poisoning, cholera, typhoid, whooping cough, and gonorrhoea. Viruses, create damage by finding their way directly into our cells where they rapidly multiply and destroy healthy cells from within. Diseases caused by viruses include influenza (flu), colds, measles, mumps, rubella, chicken pox, AIDS, and hepatitis C. Cancer, is the body’s own cells that reproduce out of control and spread to other healthy organs. White blood cells ingest and destroy these pathogens. White blood cells are produced in our red bone marrow stem cells and migrate to other parts of the lymphatic system such as the thymus, spleen, and lymph nodes for maturation and rapid deployment.
Lymphocytes are a special type of disease-fighting white blood cell produced and circulated in two forms: T-cells and B-cells. B-cells make special Y-shaped proteins called antibodies. Every pathogen contains unique chemicals called antigens that are recognized as foreign to the body. B-cells create a specific type of antibody that has a perfect chemical ‘fit’ for each antigen profile. When a B-cell with a similar antibody profile meets an antigen, the lymphocyte reproduces very quickly and makes many copies of the antibody in order to neutralize the pathogen. These ‘custom’ antibodies stick to antigens on the surface of germs, creating clumps that subsequently alert your body to the presence of unwanted intruders.
T cells, developed in the thymus, are the primary agents for killing pathogens that reach healthy tissues. T-cells produce special proteins which instruct phagocytes—pathogen-eating cells—to seek out and destroy antibody-bound antigens. (See the video below for a live demonstration of this process.) Auxiliary cells called basophils secrete inflammatory agents, or histamines, that cause vasodilation which also attracts the disease-fighting leukocytes to the point of infection. The body may also generate a fever in response to infection by raising its internal temperature out of its normal range. Fevers help to speed up the body’s response system to an infection while at the same time slowing the reproduction of the pathogen. After the infection has passed, memory T-cells persist in the body as sentinels to provide a faster reaction to subsequent infection by any pathogens expressing the same profile.
This is why adults and teenagers tend to get fewer colds than young children—their bodies have learned to recognize and immediately attack many of the viruses that cause colds. It’s also why an initial violent reaction to an unfamiliar pathogen can cause quick overreactions to less toxic subsequent exposures, such as bee stings, nut allergies, and asthma. This same immune mechanism also represents the principle behind vaccinations, which introduce pathogens in a weakened form into the body so it can ‘learn’ the specific antigen profile associated with a particular disease without a violent reaction, and generate the memory lymphocytes to prepare for a potentially stronger subsequent attack.
The Lymph Transport System
The lymphatic circulatory system is separate from, but connected to, the cardiovascular (blood transport) system. As blood passes through the main arteries of the body it moves into thin-walled capillaries, which permits diffusion of nutrients, gases, and wastes into and out of the tissue cells. Blood plasma also diffuses through the thin capillary walls and penetrates into the spaces between the cells of the tissues. Some of this plasma diffuses back into the blood contained within the capillaries, but a significant portion becomes embedded in the tissues as interstitial fluid. To prevent the accumulation of excess fluids, small one-way vessels called lymphatic capillaries extend into the tissues to absorb excess fluids and return them to circulation.
This interstitial fluid picked up by lymphatic capillaries is known as lymph. Lymph very closely resembles the plasma found in the veins: it is a mixture of about 90% water and 10% solutes such as proteins, cellular waste products, dissolved gases, and hormones. Lymph also contains bacterial cells that are picked up from diseased tissues and the white blood cells that fight these and other pathogens. Lymphatic capillaries merge together into larger lymphatic vessels to carry lymph throughout the body. The structure of lymphatic vessels also closely resembles that of veins: they both have thin walls and many check valves due to their shared function of carrying fluids under low pressure. Unlike blood, lymph is transported through lymphatic vessels solely by the contractions of skeletal muscles, which constrict the vessels to push the fluid forward. Check valves prevent the fluid from flowing back toward the lymphatic capillaries when the muscles are relaxed.
Lymph fluid is deposited in small, kidney-shaped lymph nodes scattered throughout the body. The lymph nodes function as collectors and filters of lymph that enters from inflowing lymph vessels. Reticular fibers of the lymph nodes act as a net to catch any debris or cells that are present in the lymph. Outflowing lymph vessels then carry the filtered lymph out of the lymph node and towards the lymphatic ducts. Two main lymphatic ducts, the thoracic and the right lymphatic duct returns filtered lymph directly back into the circulating venous blood supply so that it can be recirculated as plasma. Any waste and toxins picked up by the lymph transport system and returned into the circulating blood supply is filtered by the liver and kidneys and ultimately removed via the colon or urethra.
Disorders of the Immune System
Normally, these disease-fighting and detoxification systems work seamlessly together to achieve the goal of keeping the body disease-free and in comfortable homeostasis. Occasionally, one or more of these systems break down and create chronic, and sometimes fatal, dysfunction. Disorders of the immune system fall into four main categories:
- Immunodeficiency disorders (primary or acquired);
- Autoimmune disorders (in which the body’s own immune system attacks its own tissue as foreign matter);
- Allergic disorders (in which the immune system overreacts in response to an antigen);
- Cancers of the immune system.
Immunodeficiency disorders happen when a part of the immune system is missing or not performing its intended function. Some people are born with an immunodeficiency (known as primary immunodeficiencies), although symptoms of the disorder might not appear until later in life. Immunodeficiencies can also be acquired through infection or produced by drugs (these are sometimes called secondary immunodeficiencies). Examples of primary immunodeficiencies that can affect kids and teens are:
• IgA deficiency is the most common immunodeficiency disorder. IgA is an immunoglobulin that is found primarily in the saliva and other body fluids that help guard the entrances to the body. IgA deficiency is a disorder in which the body doesn’t produce enough of the antibody IgA. People with IgA deficiency tend to have allergies or get more colds and other respiratory infections, but the condition is usually not life-threatening.
• Severe combined immunodeficiency (SCID) is also known as the “bubble boy disease” after the Texas child with SCID who lived in a germ-free plastic bubble. SCID is a serious immune system disorder that occurs because of a lack of both B and T lymphocytes, which makes it almost impossible to fight infections.
• DiGeorge syndrome (thymic dysplasia), a birth defect in which kids are born without a thymus gland, is an example of a primary T-lymphocyte disease. The thymus gland is where T lymphocytes normally mature.
• Chediak-Higashi syndrome and chronic granulomatous disease (CGD) both involve the inability of phagocytes to consume antibody-tagged pathogens.
Acquired (or secondary) immunodeficiencies usually develop after someone has a disease, although they can also be the result of malnutrition, burns, or other medical problems. Certain medicines also can cause problems with the functioning of the immune system. Acquired (secondary) immunodeficiencies include:
• HIV (human immunodeficiency virus) infection/AIDS (acquired immunodeficiency syndrome) is a disease that slowly and steadily destroys the immune system. It is caused by HIV, a virus that wipes out certain types of lymphocytes called T-helper cells. Without T-helper cells, the immune system is unable to defend the body against normally harmless organisms, which can cause life-threatening infections in people who have AIDS.
• Immunodeficiencies caused by medications. Some medicines suppress the immune system. One of the drawbacks of chemotherapy treatment for cancer, for example, is that it not only attacks cancer cells, but other fast-growing, healthy cells, including those found in the bone marrow and other parts of the immune system. In addition, people with autoimmune disorders or who have had organ transplants may need to take immunosuppressant medications, which also can reduce the immune system’s ability to fight infections and can cause secondary immunodeficiency.
In autoimmune disorders, the immune system mistakenly attacks the body’s healthy organs and tissues as though they were foreign invaders. The causes for this response are not fully understood, but my own clinical experience investigating and treating a broad range of autoimmune diseases indicates that the chronic presence of specific externally introduced pathogens and/or nutritional deficiencies is often to blame. (See specific case studies analyzed elsewhere on this blog.) There are over eighty different types of diseases thought to be autoimmune-related, as listed below:
Allergic disorders occur when the immune system overreacts to low-magnitude exposure to antigens (allergens) in the environment. The immune response can take the form of severe swelling, watery eyes, and sneezing, sometimes manifesting in full airway closure leading to suffocation if not treated immediately with antihistamines or epinephrine. Allergic disorders include:
• Asthma, a respiratory disorder that can cause breathing problems, often involves an allergic response by the lungs. If the lungs are oversensitive to certain allergens (like pollen, molds, animal dander, or dust mites), breathing tubes can become narrowed and swollen, making it hard for a person to breathe.
• Eczema is an itchy rash also known as atopic dermatitis. Although not necessarily caused by an allergic reaction, eczema most often happens in kids and teens who have allergies, hay fever, or asthma or who have a family history of these conditions.
• Allergies of several types can affect people of all ages. Environmental allergies (to dust mites, for example), seasonal allergies (such as hay fever), drug allergies (reactions to specific medications or drugs), food allergies (such as to nuts), and allergies to toxins (bee stings, for example) are the common conditions people usually refer to as allergies.
The immune system is also susceptible to cancer. Leukemia, which involves abnormal overgrowth of leukocytes, is the most common childhood cancer. Lymphoma involves the lymphoid tissues, and is also one of the more common childhood cancers.
Prevention and Maintenance of the Immune System
Under normal circumstances, natural immunity against most diseases is developed throughout our lifetime by the accumulation of memory T and B cells after an infection. To some degree, natural exposure to non-lethal pathogens is actually healthy and proactive in exercising our immune systems and keeping it prepared to fight a broad range of potential diseases. Empirical studies support this, showing that children who hand-wash dirty dishes, for instance, are less prone to various sickness than those raised in homes with dishwashers.
Excessive use of antibiotics has also been linked to immune disorders. Not all bacteria are killed by antibiotics, and those that survive reproduce quickly, producing new super-virulent strains that are resistant to both the latest generation of antibiotics as well as our natural immune memory cells.
Newborn infants can acquire some temporary immunity from infection thanks to antibodies that are passed on from their mother, either across the placenta from the mother’s blood or through breast milk while nursing. Another reason among many to nurse newborns the natural way rather than using commercial baby formula.
There is of course another way that immunity can be acquired or bolstered beyond natural exposure to external pathogens. For all its current controversy, immunization, administered responsibly in single and appropriate doses at the right stages of juvenile and adult development, has been shown to prevent, and in some cases entirely eradicate (as with smallpox), many debilitating and life-threatening diseases.
If you acquire an immune disorder, the best medicine is to analyze and discover the cause triggering the response, which almost always involves the (chronic) presence of one or more toxic agents which can normally be easily removed to return your body to normal health. (My book Be Your Own Health Detective shows you how you can analyze and diagnose the cause of any illness.) In the case of allergies, where the body is overreacting to known healthy allergens, growing research suggests the body can be retrained to recognize these allergens as non-toxic, thus avoiding the uncomfortable and often life-threatening histamine response.
The bottom line when managing your body’s powerful immune system is to let it do its job with minimum encumbrance from antibiotics used to fight off non life-threatening infections or from unnatural exposure to overly antiseptic living environments where short term protection only creates long-term dependence and susceptibility to ‘real’ pathogens. As with all things in life and health, the familiar adage is sage and true: use it (gently and responsibly), or lose it.
By Reid Jenner