Tools for Immune Defense

When it comes to contracting respiratory viruses, it’s certain that avoidance and good hygiene are the most essential tools for prevention, and nothing can replace that. It’s also almost universally accepted that both the pathogen virulence and the health of the individual influence susceptibility to illness and disease severity.
Immune health and resilience depend on many factors, and while each infectious disease is different, in many cases a person’s total burden of inflammation probably plays a role in susceptibility. Inflammation is involved in most chronic diseases, and accumulated stress, whether it’s physical or emotional stress, likely exacerbates it.

In addition to preventative hygiene and social distancing, our best defenses to prevent infections or minimize severity are to balance inflammation and promote healthy immune responses. The cornerstones of a holistic prevention strategy include a balanced diet rich in phytonutrients and key nutrients, and healthy lifestyle, including ensuring restorative sleep and managing stress.  Moderate exercise is also important, as it supports cardiovascular, respiratory and lymphatic health. In addition to exercise, there are a handful of home methods to invigorate your lymphatics, including dry skin brushing, salt scrubs, and contrast hydrotherapy.

Lymph is essentially the waterway of your immune system, with the gut as a major headwater, as 70% of the immune system is contained in the gut. That’s at least one of the main reasons that diet is so important to immune health.

Pursuing a gentle dietary cleanse or following an anti-inflammatory diet can reduce the overall load on the immune system and bring down inflammation.  At a minimum, this means pulling out inflammation promoters like sugar, processed foods, refined carbohydrates, alcohol, fried foods, and other foods that don’t feel right in your gut or create a sense of inflammation.   The other important piece of a cleanse, besides avoidance, it to then emphasize nutrient dense foods, clean proteins, typically a broad array of vegetables and healthy fats like olive oil and avocados. For a deeper dive, check out Farmacopia’s cleanse guides, or consider a Whole30 or 21-Day Sugar Detox diet.

Immune building soups can provide deep nutrition. This typically consists of simple broths with aromatic and antiviral herbs like garlic, oregano, rosemary, thyme, and ginger. One can use bone broth or vegetable broth as a base, adding immune protective herbs such as reishi and astragalus into the broth base. Into the finished soup, nutrient density will be enhanced by including a plethora of veggies like leafy greens, radishes, and sea veggies as well as mushrooms like shiitake, maitake or oysters, all of which have general antiviral activity.

There are a number of medicinal plants that have a long and deep history of antiviral activity and have been used for hundreds, if not thousands of years. These might include Elderberry, Astragalus, Reishi, Licorice, Baical skullcap, Thyme, Rosemary, Cinnamon, Clove, Garlic, and many, many others.

Each of these herbs have been studied to varying degrees in humans, in laboratory animals or in vitro to try to understand their complex and varied impacts on the immune system.  Some herbs may inhibit viruses at cell receptor sites, while others may inhibit viral replication. Others stimulate or suppress various immune messengers like cytokines. Others may act as antioxidants, playing a potential role in reducing collateral damage caused by immune activation. Many herbs impact several of these mechanisms. Keep in mind that herbs that work against some viruses may not be similarly effective for others. My take-home is that it will always be more complex than it seems, and that the actions of botanicals cannot be reduced to mechanisms.  Choosing which herbs to incorporate into your immune regimen is a personal decision and one that a good holistic or integrative provider can assist you with. While many of these herbs have good safety data, there may be some contraindications, and so it’s really best to find a knowledgeable health care provider who can consult with you regarding your unique situation and constitution.

Elderberry is well known for its use in influenza, with at least 3 randomized controlled trials demonstrating improvement in flu symptoms.  Elderberries may inhibit the ACE2 receptor, which certain viruses use for cell entry in the lungs. Elderberry has been shown to increase cytokines in one small human study and there have been some concerns expressed about the potential that it could potentiate a cytokine storm in susceptible individuals. I have not seen or heard any case reports on elderberry contributing to a cytokine storm, despite its very broad use as an antiviral. Furthermore, the impacts of elderberry on the immune system cannot be reduced to cytokine activity alone. Elderberry also acts as antioxidant and probably has a net anti-inflammatory effect.  Of course, if you have a sense that elderberry is not right for you, don’t take it!

Reishi mushroom, astragalus, licorice and baical skullcap are all considered general immune tonics with antiviral and immune modulating actions, and are largely anti-inflammatory. Astragalus is typically used for general prevention only and is discontinued in acute viral illnesses. Licorice in higher dosages has some safety concerns for anyone with high blood pressure or who has at risk for low potassium levels. Some herbs may have drug interactions, so you should speak with your provider about that. By and large, I stick to food based amounts for thyme, rosemary, garlic, cinnamon and clove, or I might recommend diffusing them as essential oils into the air (except the garlic!).

There are some key nutrients that support immune health, chiefly Zinc, Vitamin C, Vitamin D, and Vitamin A. Certainly a deficiency in any of these nutrients will impair immune function, and the question is whether supplementation beyond meeting our basic needs will enhance immunity.

  • Vitamin C enhances immune cell function, especially in respiratory tract and protects from excessive inflammation.  While the data on Vitamin C only shows modest impacts on reducing duration of colds, there is some data that suggests it may reduce the severity of lower respiratory infections. High doses can cause diarrhea.
  • Zinc improves antiviral immune responses and may inhibit viral replication. There is some thought that zinc in the form of lozenges or a liquid, where it can more readily contact the throat, may be more effective. High doses can deplete copper and cause nausea.
  • Vitamin A may enhance immune barrier function, along all mucosal surfaces, which includes the respiratory tract and the gut.  High doses can be toxic to the liver, to fetuses and to young children, so you want to pay attention to dosage and keep it to short term use. Cod liver oil is a popular food based source of Vitamin A, although there can be a considerable variation of Vitamin A content between brands.
  • Vitamin D is an immune modulator, meaning that it promotes balanced immune responses. While it may enhance overall immunity, it likely also regulates inflammation. A simple blood test can tell you whether you have sufficient Vitamin D levels.

When specifically considering respiratory health, I also think about supporting healthy glutathione levels, which you can read about here in depth.

Stress management may be the most important thing we can do to enhance our resilience. Stress has clear detrimental impacts on the immune system and our propensity for inflammation. We manage stress by moving away from habits that create overwhelm or feel draining.  And move toward what feels authentically good- play, laughter, movement, breath, rest, nourishing self-care, connection, and gratitude. Find your center and hold it with love and tenderness.  

Get specific to you!

If you are looking for customized support for lung and immune health or most other health conditions, check out my telemedicine clinic for California residents. Now through the month of April 2020, I’ll be offering expanded sliding scale services for immune wellness. Go to my website at for more details about my practice, or contact my office at 707-332-9696 for details and scheduling.

Important Disclaimers: This blog is educational and it does not constitute or replace medical advice. The information contained here has not been evaluated by the FDA. Consult your healthcare provider for any interventions that might be appropriate for your personal needs and circumstances, especially if you have any medical conditions, are taking medications, or are pregnant or nursing, or if you are acutely ill. The use of the terms you, I, our does not imply that this represents any form of advice. Dr. Bridget Somine is an independent naturopathic health care provider at Farmacopia and does not receive any financial compensation for purchases there and has no direct affiliation with any herb or supplement company.


Food sources of nutrients:


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Herbs and Nutrceuticals for RNA viruses:

D’Adamo, antiviral activity of many herbs, nutraceuticals and pharmaceuticals:

Yarnell, Botanicals for Emerging viruses:

Time restricted eating: