Dr. Natalie Walch

Natural Cold & Flu Season Support

Supporting the body through cold and flu season

Natural cold and flu prevention begins with the foundations of health.  Reducing exposure to infectious organisms is only part of the equation. Cultivating a healthy internal terrain is also important in decreasing susceptibility to infectious disease. 

A typical cold and flu season begins in October and lasts until March. There are several factors that contribute to the rise of viral respiratory illness during the Fall and Winter months. One potential reason is that many of us spend more time inside climate controlled buildings in the winter months. Dry indoor air can damage the nasal mucosa and make us more susceptible to respiratory infections.

These are also the months in which many of us are getting less fresh air and exercise, and consuming more sugar. Each of these factors can affect immunity and our resilience to infectious disease. You don’t have to wait for Fall and Winter to starting thinking about immune support. Strong immunity and resilience to disease can be cultivated all year long.

So, what does it mean to “support the immune system”? Supporting the immune system involves decreasing susceptibility to disease by improving vitality. The immune system is an incredibly intricate body system that helps detects foreign organisms.  Symptoms and illness arise in response to these pathogens; i.e. elevating body temperature to kill off a virus (fever). Having adequate nutrients and a healthy, active lifestyle can facilitate appropriate immune responses.

Germ Theory vs. Terrain Theory

There is a distinct difference in the approach many conventional doctors and naturopathic doctors take to infectious disease. The basis for this difference in philosophy partially comes from two opposing views on infectious disease: Germ Theory and Terrain Theory. There is a long history of various theories regarding human susceptibility to infectious disease.  The modern debacle around infectious disease largely comes from the work of 19th century scientists: Louis Pasteur, Claude Bernard and Pierre Antoine Béchamp.

Pasteur held that external organisms cause disease, and did not acknowledge how host susceptibility may play a role. This became known as Germ theory. Germ theory has since dominated the conventional medical model and drives public health policy. This philosophy tends to focus on reduction or elimination of pathogenic organisms.

Bernard and Béchamp, on the other hand, believed that external microorganisms only become pathogenic after environmental factors cause the internal “terrain” to become depleted. This has become the basis for the Terrain theory. Naturopathic philosophy is rooted in the belief that we can create the conditions for optimal health to prevent infectious disease. This means cultivating a healthy internal environment and robust immune responses that protect us from infection.

I am including this information to bring awareness to the fact that you do have control over your susceptibility to disease. In all likelihood, there is truth to each of these theories.

Conventional medicine focuses on germ theory:

  • Ubiquitous hand sanitizer and antibacterial cleaner use
  • Heavy reliance on antibiotics
  • Fever suppression (Tylenol, Ibuprofen, etc.)
  • Vaccines are the cornerstone of public health measures

Naturopathic medicine focuses on terrain theory (and uses the above when absolutely necessary!):

  • Reducing inflammation through a nutrient dense diet
  • Stress reduction and mindfulness
  • Reduce toxin exposure
  • Optimize gut health and function
  • Regular movement and fresh air
  • Herbs and nutritional supplements that support the immune system
  • Supporting fevers when appropriate
  • Immune training with homeopathic prophylaxis

For the context of this article, the preventative measures I describe below follow the principles of naturopathic medicine and terrain theory. The goal of each of these therapies is to improve overall wellbeing and vitality, thereby reducing susceptibility to infectious disease.

Focus on the Foundations of Health

The foundations of health are the basic needs of the human body that must be met for deep and lasting healing to occur.  These foundations also set the stage for strong immunity. Cultivating healthy habits in all aspects of your life will work harmoniously to create a state of wellbeing.

Fresh air and sunlight

Fresh air and sun exposure becomes particularly important if you live in a cold climate. It’s easy to spend our entire day indoors during the winter months. Don’t underestimate the power of spending sometime in nature, breathing fresh air and seeking out sunlight!  Spend at least 15-20 minutes outside daily, and in the sun when possible. If you must be indoors all day, open the windows in your home or office for fresh air as much as possible.


Focus on drinking purified water as your primary beverage. I recommend filtering your drinking water with an under-the-counter reverse osmosis filter, or counter top Berkey filter. Brita and Pur filters are designed to improve taste, and may not filter chlorine, pesticides, and other contaminants. Avoid soda, alcohol, juice, energy drinks and other sugary beverages as much as possible. Herbal teas and water infused with fresh fruit can be a good alternative to sugary drinks.


What should you be eating to boost your immune system? The answer may be slightly different for everyone due to bio-individuality, individual food intolerance, cultural considerations, personal preferences, food access, etc. Here are the basics of eating to support whole-body wellness:

  • Eat your food slowly and consciously
  • Enjoy your company, if you have it!
  • Remove electronics and other distractions from your eating environment
  • Avoid your food intolerance(s)
  • Focus on eating an organic, whole foods diet:
    • A wide variety of fruits and vegetables, with at least one serving of vegetables per meal
    • Pastured raised, organic, and grass fed meat and eggs
    • Whole grains such as brown rice, quinoa, millet, buckwheat, oats, and rye
    • Whole beans and legumes: lentils, chickpeas, pinto beans, black beans, etc.
    • Nuts and seeds
    • Probiotic rich foods: sauerkraut, kimchi, unsweetened yogurt, miso, kefir, kombucha, etc. 
    • Fresh rosemary, thyme, and garlic are anti-viral and add excellent flavor to your cooking
  • Avoid:
    • Sugar
    • Processed and fast food
    • Alcohol
    • Foods containing processed white flour (breads, muffins, pasta, cakes, pastries, crackers, etc.)

Sleep & blue light exposure

High quality sleep is essential for optimal immune function and chronic disease prevention. Ideally, you should be sleeping for 7-9 hours each night. If you have difficulty falling or staying asleep, consult with your naturopathic doctor for support.

Melatonin is a hormone secreted by the pineal gland in response to light changes. Blue light waves emitted from electronic devices can alter your natural circadian rhythm and sleep cycle by suppressing melatonin release.  I recommend turning off all electronics at least one hour before bed. Blue light blocking glasses may be helpful in mitigating the negative effects of blue light.


Movement is essential for supporting overall health and vitality. If you do not exercise regularly, start with 10 minutes of movement (preferably walking) daily and work your way up. If you do exercise, aim for 30 minutes of moderate daily exercise.  This may include brisk walking, bike riding, jogging, dancing, skating, swimming, yoga, etc. Moving your body should feel good and nourishing! Over-exercising can deplete the body and create more inflammation.

Stress reduction and healthy relationships

Stress is a normal, and sometimes healthy part of life. Without physiologic and psychological stress, we are not pushed out of our comfort zones and able to adapt to different situations. However, chronic stress can take a toll on the body and affects immune function, disease susceptibility and overall vitality. Common stress reduction techniques include: breathing exercises, meditation, yoga, exercise, tai chi, progressive muscle relaxation, and cold water therapy.

Cold Exposure and Immunity

Cold exposure stimulates the sympathetic nervous system and increases endorphin release.  This endorphin release can elevate mood and have a positive effect on brain function. Cold exposure has also been shown to have a potent immune stimulating effect and elevates levels of circulating immune cells. Hydrotherapy (or water therapy)  involves the use of cold water applications on the body, and is one way to receive the benefits of cold exposure. This can range from cold towel applications to complete immersion in a cold tub or ice bath.

Ending showers on cold: The easiest way to increase cold exposure is by ending your showers with cold water. While this can seem difficult if you live in a cold weather climate, you may find it improves your cold tolerance and increases your energy. Start with 10 seconds, and work your way up to 30-60 seconds at the end of your shower.

Cold water walking: A similar effect can be achieved by walking in dewy grass, a cold stream or cold tub of water up to the ankles or knees. This variation can also have a very calming effect on the nervous system.

Cold plunge: Complete immersion in a cold tub or ice bath is often the most challenging way to implement cold water therapy. I recommend starting with a cool bath for 30 seconds, and working your way up to more intensive cold exposure. The Wim Hof method involves a series of breathing exercises and cold water therapy that has innumerable benefits to immune activity and overall vitality. Check out this website for more resources. 

Nutritional Supplements

When used appropriately, nutritional supplements can support overall vitality and immune function.  Nutritional supplements should be used in addition to the foundations of health listed above. They are not a replacement for proper diet, hydration, movement, sleep and stress management! It is clear that several micronutrients work synergistically at every level of the immune response. These include: vitamins A, C, D, E, zinc, vitamins B6 and B12, folate, iron, copper and selenium. Sufficient amounts of these nutrients ensure integrity of physical barriers to pathogens, as well as proper immune cell function. Supplementing with the nutrients below may support immunity and a healthy respiratory tract:

  • Vitamin A
  • Vitamin C
  • Vitamin D
  • Vitamin E
  • Zinc
  • NAC
  • Probiotics
  • Quercetin

Taking a high quality multi-vitamin and/or trace mineral supplement may be the most promising way to obtain all of these nutrients. Specific populations, including those with nutritional deficiencies, may need more than the recommended dietary allowance. Your naturopathic doctor can help you identify potential deficiencies, and decide which nutrients are most supportive for you.

Herbs that support immune function

Elderberry syrup: Made from dried elderberries, this syrup can be taken daily throughout cold and flu season for prevention and immune support. Elderberries are rich in powerful anti-inflammatory flavonoids and anthocyanins. They also contain high levels of vitamins A and C. Elderberry syrup is an excellent immune support option for kids because it tastes great!  Elderberry syrup is readily available at most health food stores and Whole Foods. Alternatively, you can make your own at home; here is my favorite recipe.

Echinacea and goldenseal tinctures:  Echinacea and goldenseal are two strong antimicrobial herbs that can be taken at the first onset of cold and flu-like symptoms. Echinacea also has immune modulating and anti-inflammatory actions and can be used preventatively. Check with your naturopathic doctor for specific dosing.

Garlic/onions: Fresh garlic and onions can be added to your cooking daily. Garlic is an excellent antimicrobial herb that can be taken at higher doses during acute illness. Onions contain high levels of quercetin, which is a flavonoid with anti-inflammatory and antioxidant properties. Quercetin also helps lower histamine and can modulate exaggerated immune responses related to seasonal allergies.

Mushrooms: there are many medicinal mushrooms with immune modulating constituents.  Reishi mushroom (Ganoderma lucidum) is specifically well-known for enhancing immune function. It can be taken in capsules, as a tincture, or a tea. Four Sigmatic has unique and tasty mushroom blends that are easy to incorporate into your daily coffee or tea.

Homeopathic Prevention and Treatment

Homeopathy is phenomenal medicine for preventing and treating infectious disease. Taking a specific remedy that matches your unique constitution regularly will help strengthen your immune system and overall vitality. A trained homeopath or naturopath who practices homeopathy can help you identify your constitutional remedy.

Specific homeopathic remedies can be used to prevent infectious disease. The remedy influenzinum, for example, contains the most likely flu strains for the respective year. Homeopathic influenzinum is highly efficacious and has virtually no side effects. Please schedule with Dr. Walch to discuss her specific protocol.

A trained homeopath or naturopathic doctor can treat acute infectious disease with homeopathy. The right remedy will typically shorten cold and flu severity and duration.

It’s OK to Get Sick Sometimes

Don’t forget, it’s normal to get sick once and awhile! In fact, it can be a sign that your immune system is active and well. The key is balance. An over-active or under-active immune system can set the stage for more severe symptoms. Your body knows how to heal. Take good care of your body, and it will take care if you!

If you develop any symptoms of acute infectious illness such as fever, sore throat, cough, shortness of breath, skin rash, runny nose, congestion, ear pain, abdominal pain, etc. please consult your physician.


About Dr. Walch: Dr. Natalie Walch is a licensed naturopathic physician with a focus on chronic gastrointestinal diseases, skin concerns, autoimmunity and inflammation. She is currently accepting new patients at her office in Kent, WA. For personalized recommendations, and strategies to keep you and your family healthy, call 253-854-8880 to schedule.

Disclaimer: The information in this article is not medical treatment or advice. You should always consult  your physician before beginning any new treatment protocol.


Teller, M. Germ Theory Versus Terrain Theory: The Wrong Side Won the Day. July 30, 2019. Retrieved from: https://www.westonaprice.org/health-topics/notes-from-yesteryear/germ-theory-versus-terrain-the-wrong-side-won-the-day/

The differences between germ theory, terrain theory, and the germ terrain duality theory. JOOJ Nursing and Healthcare.

Brenner IK, Castellani JW, Gabaree C, Young AJ, Zamecnik J, Shephard RJ, Shek PN. Immune changes in humans during cold exposure: effects of prior heating and exercise. J Appl Physiol (1985). 1999 Aug;87(2):699-710. doi: 10.1152/jappl.1999.87.2.699. PMID: 10444630.

Wahl S, Engelhardt M, Schaupp P, Lappe C, Ivanov IV. The inner clock-Blue light sets the human rhythm. J Biophotonics. 2019 Dec;12(12):e201900102. doi: 10.1002/jbio.201900102. Epub 2019 Sep 2. PMID: 31433569; PMCID: PMC7065627.

Mooventhan A, Nivethitha L. Scientific evidence-based effects of hydrotherapy on various systems of the body. N Am J Med Sci. 2014;6(5):199-209. doi:10.4103/1947-2714.132935

Calder PC. Nutrition, immunity and COVID-19. BMJ Nutrition, Prevention & Health. 2020;bmjnph-
2020-000085. doi:10.1136/bmjnph-2020-000085

Gombart AF, Pierre A, Maggini S. A Review of Micronutrients and the Immune System-Working in
Harmony to Reduce the Risk of Infection. Nutrients. 2020;12(1):236. Published 2020 Jan 16.

Chen C, Zuckerman DM, Brantley S, Sharpe M, Childress K, Hoiczyk E, Pendleton AR. Sambucus nigra extracts inhibit infectious bronchitis virus at an early point during replication. BMC Vet Res. 2014 Jan 16;10:24. doi: 10.1186/1746-6148-10-24. PMID: 24433341; PMCID: PMC3899428.

Link to list of studies on homeoprophylaxis

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