How to boost your immune system


Would you like to know how to boost your immune system to better resist disease and sickness? Naturopath Megan Taslaman shares some key tips to help you through the winter season.

An overview of our immune system

The main purpose of the immune system is to protect our body from harmful external substances – casually known as germs. These germs may range from any number of bacteria, viruses, fungi/yeasts or parasites. Technically ‘germs’ are organisms that have DNA and since viruses do not have DNA the better overarching term is pathogen.

Our immune system comprises of tissue, organs and cells. The tissues create what I call ‘the first line of defence’. The cells are what elicits the response to the invading intruder – otherwise known as the pathogen. Some pathogens are welcomed by our bodies. We need them for our survival and evolution. Other pathogens are not welcome since they may trigger a disease process. If pathogens (bacteria, viruses, parasites, fungi) have a role to play within our bodies or if they are to be kept in check then we need to have our ‘nuts and bolts’ in order. Our ‘nuts and bolts’ are our organised systems and healthy tissue components.

Essentially there are four general functions of the immune system:

  1. Creating a barrier between our body and the external environment, what I call ‘the first line of defence’.
  2. Understanding and identifying if the pathogen is an invading intruder. This is an innate intelligence that we are born with. Our innate immune system.
  3. Our immune system response to an unwanted pathogen. That is the organisation of the T-cell army so that each cell knows what to do to get the job done and overcome the intrusion.
  4. Immune cell intelligence and generation of a memory system. This is called the acquired or adaptive immune system. It’s our cells ability to remember the pathogen so that upon another invasion a quicker response can be assembled. This is the principle behind immunisation.

Our first line of defence

Our ‘first line of defence’ is the first point of contact to the outside world. This includes: the sebum in our skin; our sweat and tears; the integrity of our mucous membranes; the pH of our saliva so that pathogens don’t slip through (e.g. our stomach acid), and of course the pH in different compartments of our body – e.g. our urinary tract! And not to mention the diversity of our microbiome or gut flora.

In order to keep our ‘first line of defence’ at an optimal level of health and function, it’s important to correct any issue.

For example, if you are suffering from indigestion or heartburn, it may be that the pH of your stomach acid is too high which means your stomach acid is too alkaline. This can potentially allow bacteria and viruses to slip through the digestive system. Another example is if you have a skin condition such as eczema or dermatitis. Treating this condition will help to rebuild the integrity of your skin and rectify any local inflammation.

If you suffer from sinusitis or hay fever, you may require mucous membrane support of the upper airways.

If you have any digestive issue such as intestinal permeability or SIBO, Crohn’s disease or Coeliac disease, this may hinder the absorption and assimilation of key vitamins and minerals which effectively support immunity and boost your immune system as well as other systems.

Innate Immune system functioning

T cells are white blood cells that originate within the bone marrow along with every other cell in the body. After differentiation they become a specific T-cell with a specific function. Amongst the specialised functions of this detailed and complex system are surveillance of the immune system, organisation and communication, killing an invader (Natural Killer Cells), engulfing the intruder and helping out the B cells for acquired immunity.

The different types of T cells that have different roles work together to keep us free from infection. It’s when our system is overwhelmed that this system breaks down. Overwhelm may come from any number of factors such as having too many toxins or pollutants in the body, inadequate body systems or poor screening, a highly virulent intruder (an infectious disease), poor quality sleep or oxidative stress (from being overweight for example), or any other stress on the body.

Acquired or Adaptive immune system

B cells are the highlight of the acquired immune system. T cells give a helping hand to the B cells so they work together to ensure a memory and checking system is in place. The main function of B cells is to clean up the mess and create molecules called antibodies. These antibodies are important for specific recognition of future infection so that disease doesn’t ensue.

For the health and maintenance of our immune system it’s important to consider a whole system optimal health approach that encompasses dietary and lifestyle factors, past illness, comorbidity conditions and stress management techniques.

The invaders (aka pathogens)

Here is an overview of viruses, bacteria, fungi/ yeasts and parasites.


Viruses are a major part of our life on Earth. They may be seen as an alien or unwelcome intruder because they require a ‘host’ cell for survival and replication. Viruses are not actually living cells since they rely on a ‘host’ cell that being an animal or bacteria, in order to replicate. We have more viruses in the air, water systems, our bodies than we could comprehend. Thus far our knowledge of viruses is that they do not actually serve us or have a purpose except for causing disease. But what if they did have a purpose? What if they played a crucial role in our existence, and our ability to adapt and evolve?

I’ve recently listened to an excellent podcast by Dr Zach Bush.  Dr. Zach explains this hypothesis that is incredibly interesting and defies science and what we know about viruses to date. I highly recommend listening this this if you’ve got a spare 90 minutes! We have billions of viruses within our environment including within our bodies, Viruses are ubiquitous and pre-date human life. They are not actually ‘alive’ since they only house genetic material but are unable to reproduce, produce energy, metabolise, or eat. Simply put, they are not multi-cellular, but rather packages of a couple of genes. So therefore, a virus does not have the intelligence to overcome the human organism. The hypothesis is that our bodies actually can make viruses to help us adapt and evolve? It’s role is to update the tissue within us to help us with biodiversity. And the ‘real’ trigger for the disease process is not actually the virus but instead environmental pollution within the environment that is carried by the virus and into our tissue. If viruses inject the host cell (our cells) with the intention to update/ or correct a few genes and it happens to be tagged with environmental pollution such as particulate matter, then this may well cause the viral clumps that overwhelm our immune system. An interesting viewpoint and plausible cause of the current pandemic – (Podcast on Ben Greenfield Fitness with Dr. Zach Bush)


Bacteria are a major part of our life. They are also known as ‘germs’! We need bacteria for our survival. For ease and understanding, there is ‘good’ and ‘bad’ bacteria. Probably the bad is called the germs. The good is commensal, meaning that it is a part of our wellbeing. For example, bacteria in our large colon are important to produce short chain fatty acids (SCFAs) which are crucial for a healthy mucosal lining of our colon. Commensal bacteria are largely non-harmful, except when they become opportunistic. This is where the environment (within our body) allows for specific bacteria to thrive. An example is Klebsiella, which if high may be an indicator of small intestinal bacterial overgrowth (also known as SIBO) causing issues such as flatulence, indigestion, bloating or diarrhoea. These are just a couple of examples.

Fungi and yeasts

Fungi and yeasts are also opportunistic. Most bodies have some fungi and yeasts, but if a favourable environment allows for them to become prolific then issues can eventuate. For example, too much wine, processed foods, yeasts may cause a candida overgrowth with signs and symptoms being bloating, brain fog, pain, lethargy, nausea, headaches.


And then we have the parasites. Those living organisms (multi-cell) that have the ability to create quite a bit of havoc within us. Think Bali belly, Delhi belly, and many other gastro type bugs. They set up home, and may cause diarrhoea, vomiting, nausea, constipation and many other non-digestive related issues.

 Cold and flu viruses

Cold and flu viruses are common viruses we see year in year out. Viruses associated with the common cold include more than 100 different serotypes of rhinoviruses which account for 30% – 50% of respiratory illnesses. Corona viruses cause 10% – 15% of respiratory infections and each of the para-influenza and adenoviruses cause 5% of these infections.

Cold and flu viruses are plentiful with more mutations (slight changes) causing them to be ubiquitous within our environment. In autumn/ winter they can cause up to 80% of upper respiratory tract infections. As Dr. Zach Bush hypothesises (see pod cast) every year cold and flu is worse in Autumn when there isn’t enough greenery to reabsorb environmental toxins. This would make sense then that in every country there is more evidence of cold and flu during the autumn months.

How you can boost your immune system

As mentioned, boosting your immune system warrants a whole systems approach to health and wellness incorporating many different factors. However, there are some key players that this season are worth a look at to supplement.


Zinc is involved in numerous physiological reactions with at least 300 enzyme reactions in the body. It is an active helper of the immune system via the T cells communication network. The mineral effectively help with symptoms of the common cold. The mechanism of action is within the cell membrane where zinc functions to reduce local inflammation, swelling and mucous production. Zinc is important to make proteins, and DNA and is part of the matrix for tissue building. So hence zinc is also helpful for wound healing, skin issues and hair loss to name a few areas. Zinc also helps to create our lovely hydrochloric acid (stomach acid) which is important for digestion of proteins. The body does not have a storage system for zinc, so ensuring daily adequate consumption is vital.

Scientific research – zinc

Oysters contain zinc

A meta-analysis in 2016 (which is a group of clinical trials that are analysed for evidence) has shown that zinc lozenges with a dose of 80mg of zinc per day effectively shortens the duration of signs and symptoms associated with a cold virus.

Other randomised controlled trials concluded that zinc supplementation given as an adjunct treatment for pneumonia reduced mortality.

Foods rich in zinc

Foods with the highest amount of zinc are red meat and oysters. Zinc is also widely available in nuts, seeds, legumes and grains, however the naturally occurring phytates and lignans inhibit the absorption of zinc from the foods. Therefore, it’s important for vegans and vegetarians to consider supplementation of zinc or be proactive in soaking legumes, nuts and seeds to remove the phytates. Zinc also competes for absorption with iron, so if supplementing best to keep these minerals apart.


Sunshine at Dee Why Beach helps absorb Vit D

D is for differentiation. Vitamin D helps in the organisation and development of cells and body tissue. Hence it is crucial for the development and maintenance of our immune systems. In addition to the immune system, Vitamin D is important for bone health, mood, blood sugar metabolism and therefore chronic disease prevention. Vitamin D is a fat-soluble vitamin, so is stored in the body but generally diminishes over the winter months. Factors that inhibit our absorption of vitamin D include: lack of sun exposure, too much use of sunscreen, pollution.

Scientific research – vitamin D

Several clinical trials including randomised controlled trials and meta-analysis concluded that vitamin D sufficiency is inversely associated with acute respiratory tract infections.

Foods rich in vitamin D

Salmon, Mackerel, Sardines, Cod Liver Oil, Shiitake mushrooms. The best source of vitamin D is sun exposure – 10 – 30 minutes per day



Quercetin is a polyphenolic flavonoid compound that is anti-inflammatory and helps to stabilise the mast cells. It’s the mast cells that release a histamine response causing inflammation. Hence quercetin is a very important compound for those who have chronic allergies or sinusitis because it helps to repair and support the mucous membranes of the upper airways. Quercetin has a powerful antioxidant affect through its effect on the glutathione pathways and enzyme activities. Quercetin helps to regulate the body’s glutathione levels. Glutathione is our body’s main detoxifier generated in the liver. We want our glutathione levels to be regenerated due to the overwhelming amount of toxins and environmental pollutants that burden our systems. These external environmental toxins include chemicals, glyphosate, particulate matter (car exhaust fumes), plastics, solvents and preservatives to mention a few.

Foods high in Quercetin

Quercetin is found in Red Onions

Red onions, onions, apples, red grapes, broccoli, cherries, kale, tea and red wine (go easy on the red wine)!


Vitamin C

Vitamin C is important to quench free radicals with its antioxidant properties so therefore is an important vitamin for immune system health. Foods high in vitamin C include onions, broccoli, Brussels sprouts, cauliflower, capsicums, leafy greens, tomatoes, squash, parsley, citrus fruits, apples.


Selenium is important to protect the body from infection by quenching free radicals. It’s also a support key mineral for thyroid gland function and DNA production. Foods with good amounts of selenium include brazil nuts, shell fish, eggs, beef, chicken, eggs and pork


Iron is an important part of your red blood cells since its carry’s oxygen from your lungs around your body and is important for energy and immune system health. Foods include meat and oysters. The best plant sources of iron include beans, lentils, tofu, cashews, spinach, whole-grains, potatoes.

Vitamin A

Vitamin A is a primary anti-infective vitamin and aids the health of the gut mucosa or lining. It’s a fat soluble vitamin and cannot be synthesised in the body so must be consumed through the diet. Major functions include vision, the immune system and for reproduction. Foods high in vitamin A include eggs, liver and foods high in beta-carotene such as sweet potatoes, silver beet, spinach, broccoli, carrots, squash.

Building Resilience with a robust immune system

Lifestyle factors for a healthy resilient immune system

  • Adequate sleep – aim for a minimum of 8 – 9 hours per night for adults; 10+ for children and infants. Chronic sleep insufficiency places a stress on your system which impacts your immune system.
  • Regular exercise – this helps to stimulate your lymphatic system which supports your immune system. Exercise also helps with weight management and fat loss as well as stress management all of which help to keep the immune system in check.
  • Stress management techniques such as mindfulness activities, meditation, or hobbies.
  • Don’t smoke and limit your exposure to secondary smoke.
  • Mindfulness activities such as meditation
  • Adopt herbal teas as a part of your daily ritual for fluid intake

Dietary factors for a healthy immune system

  • A balanced and whole food diet – non-processed organic, or biodynamic food with a broad range of fruits, vegetables, nuts, seeds, whole unrefined grains, some dairy, eggs, pot-set non-sweetened yoghurt, some lean organic / grass fed meat OR organic soy/ tofu; legumes & grain combinations as an alternative protein source for vegans.
  • 5-7 servings of vegetables and fruit daily which include either ½ cup cooked or 1 cup raw for most serving sizes.
  • Limit alcohol consumption and ensure you have 3-4 days of consecutive alcohol-free days. This helps to repair the liver and unburden your detoxification pathways. A good quality red wine contains appreciable amounts of resveratrol and quercetin which is good for the immune system. A small glass is enough for this!
  • Limit or exclude processed, packaged and refined foods.

Herbal medicine

Let’s not forget herbal medicine which can assist in different areas of the immune system depending on which area of the body we are focusing on. Herbs that I regularly use to assist in immune system function including support of the nervous system include: Andrographis, Echinacea, Astragalus, Siberian Ginseng, Withania, Mushroom complex, Thyme, Poke root, Rosemary, St. Johns Wort, Chamomile, Lemon Balm, Rhodiola, Passionflower.

You can read more about building immunity resilience here and here.

Summary – bringing your immunity all together

Building a strong and robust immune system warrants a ‘wholistic’ approach to health and wellness. Each and every one of us has a unique set of strengths and weaknesses within our body depending on our genetic makeup, our life history and our day to day management of work and stress. Naturopathy is a system of healing that provides a personalised treatment plan encompassing dietary and lifestyle recommendations, nutritional and herbal medicine prescription. This article provides an overview on ways to boost your immune system. However this will not replace a personalised treatment plan that focuses solely on the individual – you! There are many areas to consider in building a robust immune system and thus would be explored within a naturopathic appointment.



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