We love this detailed explanation of how the immune system works and how herbs are used to support and assist our immune system. Thank you to Christine Thomas, Herbalist and Technical Writer who wrote this 🙂

The Immune System 

Our immune system is incredibly complex and well designed to keep our inner and outer worlds living in relative harmony. This is achieved by an elegant and intricate set of cells, proteins and organs whose purpose is to protect our bodies from infections and disease, and to assist in recovery from injury. This makes it essential to our survival but unfortunately there are many aspects of modern living that disrupt this delicate balance. Abnormalities of the immune system can lead to allergic diseases, immunodeficiencies and autoimmune disorders.

The immune system is the body’s version of the military. A vast army of cells and tissues is constantly on the lookout for invaders and once an enemy is spotted a targeted attack is mounted by immune system warriors. The soldiers are white blood cells (leukocytes), antibodies, the complement system (complementary to the antibody response of the adaptive immune system), the lymphatic system, the spleen, thymus and bone marrow. This system keeps a record of every germ (microbe) it has ever defeated in white blood cells known as memory cells (B or T lymphocytes). This means it can recognise and destroy the microbe quickly if it enters the body again before it can multiply causing sickness.

A fever is an immune system response which can happen in some infections and cause a rise in body temperature. This can kill some microbes and trigger the body’s repair process. Inflammation is the body’s way of signalling the immune system to heal and repair damaged tissue. Having a fever and inflammation can be unpleasant but they are signs that the body is doing its job. As well as the immune system the body has several other ways to defend itself against microbes including physical barriers, which are the first line of defence, such as skin, lungs, digestive tract and other defences such as body fluids like skin oil, saliva and tears. More than 70% of the body’s immune cells are located in the gastrointestinal tract which explains why good gut health is key to healthy bodily functions. The constant flushing of the urinary tract and the bowel also helps.

Overactivity of the immune system includes allergic and autoimmune diseases. Allergic diseases are common and can include allergy to foods, medications or stinging insects, anaphylaxis (life-threatening allergy), hay fever, sinus disease, asthma, hives, dermatitis and eczema. Autoimmune diseases include multiple sclerosis, autoimmune thyroid disease, type 1 diabetes, rheumatoid arthritis and psoriasis.

Underactivity of the immune system is also called immunodeficiency and it can be inherited, arise as a result of medical treatment (such as corticosteroids or chemotherapy) or be caused by another disease such as HIV/AIDS or certain types of cancer.

We are born with innate (non-specific) immunity. Our body’s natural barriers and rapid response team provide significant protection for our relatively naive immune system. As we are exposed to more pathogens we develop our acquired/adaptive (specific) immune system, comprised of antibodies and other memory cells that allow us to mount a quick response if we encounter the pathogen again. Both the innate and acquired immune systems are dependent upon healthy nutrition, a healthy gut microbiome, strong barrier integrity, adequate exercise and rest and management of stress.

On the whole, the immune system does a remarkable job of defending against disease-causing microorganisms but sometimes it fails and a germ will invade successfully causing sickness. Whether a person succumbs to pathogens often comes down to the state of their body with stress, tiredness and nutrition all playing a part. There are many ways to keep the immune system healthy including eating well, exercising and getting enough sleep but there is no quick fix.

Herbs that support the immune system 

Below are some herbs, divided by their actions, which may help support a healthy immune system in combination with general healthy living strategies.

Anti-allergics: These herbs modify an overactive immune response. Herbs such as albizia, baical scullcap, chamomile, feverfew, hemidesmus, nettle leaf, perilla, reishi

Anti-inflammatories: Reduce inflammation and assist pain. Herbs such as albizia, arjuna, baical scullcap, boneset, calendula, cat’s claw, chamomile, chickweed, coleus, dong quai, echinacea, elderberry, eyebright, garlic, graviola, grindelia, ivy leaf, liquorice, maritime pine, nettle leaf, parsley root, paw paw, perilla, poke root, pomegranate, rehmannia, reishi, rue, slippery elm, teasel root, turmeric, uva ursi, white willow, withania, yarrow

Antimicrobials: These include antibacterials, herbs which elicit a specific immune response to bacterial agents or have a direct antibacterial activity upon certain species of bacteria, antifungals which do the same but on fungi of various genus and species and antivirals which help eradicate viral organisms. Herbs such as baical scullcap, barberry, buchu, calendula, cat’s claw, cinnamon, echinacea, elderberry, elecampane, fennel, garlic, golden seal, graviola, green tea, horseradish, hyssop, juniper, lemon balm, maritime pine, parsley root, paw paw, pau d’arco, pomegranate, rue, sage, St. John’s wort, Siberian ginseng, thuja, thyme, uva ursi, wild indigo, yarrow

Antioxidants: Protect against oxidation and free radical damage. Herbs such as andrographis, astragalus, bilberry, cat’s claw, chickweed, cinnamon, elderberry, garlic, ginkgo, graviola, green tea, hawthorn, Korean ginseng, maritime pine, olive leaves, parsley root, perilla, pomegranate, rosemary, saffron, sage, St. Mary’s thistle, schisandra, slippery elm, thyme, turmeric, withania

Antipyretics (febrifuges): Herbs that reduce or prevent a fever. Herbs such as andrographis, baical scullcap, feverfew, lemon balm, ladies mantle, rehmannia, white willow, wild indigo, yarrow

Diaphoretics (sudorifics): Herbs which promote sweating during a fever. Herbs such as angelica, boneset, bupleurum, capsicum, chamomile, elder flowers, elecampane, garlic, golden rod, ginger, hemidesmus, hyssop, lemon balm, lime flowers, peppermint, prickly ash, vervain, yarrow

Immune enhancers (immune stimulants): Herbs which stimulate one or more aspects of the immune system. Herbs such as andrographis, cat’s claw, codonopsis, echinacea, golden seal, Korean ginseng, liquorice, poke root, reishi, Siberian ginseng, thuja, wild indigo

Immune modulators: Herbs that modulate and balance the activity of the immune system. Herbs such as astragalus, cat’s claw, cinnamon, dong quai, echinacea, elderberry, garlic, glossy privet, pomegranate, reishi, Siberian ginseng, teasel root, withania

Lymphatics: Herbs to improve the flow of lymphatic fluid or increase lymphatic drainage (detoxification). Herbs such as blue flag, calendula, clivers, echinacea, poke root, wild indigo