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  • Writer's pictureAmy Donovan (BNatMed)

Winter Health Resilience - Understanding Immunity

Tips to help you thrive through the chill

Winter snow

Winter's cold and often damp weather can make us more prone to getting sick, which can be hard on our immune system. Adding these seasonal changes to overall daily stress, poor food choices or food quality, and our busy lifestyles puts even more pressure on our body's ability to stay healthy.

Supporting your body with foods, habits, herbs, and nutrients can boost the immune system and enhance our resilience to stay healthy and prevent ills and chills.

What is the 'immune system'?

The immune system is like the body's defence team. It protects us from germs (pathogens) like bacteria and viruses that can make us sick. It's made up of different organs, cells, and proteins that work together to fight off any unwanted invaders that enter our body. When it recognizes these germs, it attacks them to keep us healthy.

The immune system has two branches

Our immune system is made up of 2 branches.

A healthy immune defence involves a cascade of innate (built-in) and adaptive (learned via exposure to certain bacteria, viruses, etc) immune responses that protect against infection. 

Innate (inherited/built-in) Immunity

The innate immune system is the body's first line of defence against an infection. It works to act quickly, usually within minutes to hours after a pathogen (like a virus or bacterium) enters the body.

It protects us through...

  1. Physical Barriers: Skin and mucous membranes like in our nostrils, mouth, gut, etc which act as barriers to block pathogens from entering the body.

  2. Chemical Barriers: Substances such as stomach acid and enzymes in saliva and sweat that can destroy invading organisms. Does anyone remember Pac-Man? I always think of enzymes like this.

3. Cellular Defences: Special immune cells, like macrophages and neutrophils, which can ingest and destroy pathogens - they are a lot like Pac-Man too! These cells are found throughout the body, including in the blood and tissues like lymph nodes and lymph tissue in the gut.

4. Inflammatory Response: When there is an injury or infection, the innate immune system triggers inflammation to help isolate the area and attract immune cells to it. This results in redness, heat, swelling, and pain - just think of when you get a prickle or a burn. Great in the short term, but imagine the result on the body if this is kept up long term. Something that I see in clinic often and really important to address.

5. Fever: Increased body temperature that can help kill pathogens and enhance the function of immune cells.

Adaptive (learned) Immunity

When we encounter a new pathogen (bacteria, virus, etc) for the first time, our adaptive immune system takes time to respond because it needs to activate and grow specific B and T cells.

B cells and T cells are two types of white blood cells that play crucial roles in our immune system, helping us fight off infections and diseases.

B cells develop from bone marrow stem cells and are passed on in utero from our mother. They are primarily responsible for producing antibodies - proteins that latch onto foreign invaders, like viruses and bacteria, marking them for destruction or neutralizing them directly. Each B cell receives the message to make a specific antibody for each invader. When there is a match it activates and starts to produce many copies of that antibody.

T cells come in different types, but two of the main kinds are helper T cells and killer T cells. Helper T cells live up to their name by coordinating an immune response. They signal to other cells (including B cells) the best time and approach to successfully fight the invaders. Killer (NK) T cells also live up to their name - special forces of the immune system sent out to seek and destroy cells in the body that have been infected by viruses or have become cancerous - targeting and eliminating threats, and they can also order other immune cells to do the same. Pretty gangster, right?!

This activation of B and T cells can take about a week to become effective.

Bacteria divide so rapidly, reaching almost 20 million bacteria in just one day. So when you think about how quickly a single bacterium can multiply, roughly a week for our immune system to take effect is far too long.

However, our adaptive immunity is smart and remembers certain pathogens we've already been exposed to so it then knows what action to take if it crosses paths with us again.

Thankfully though, the quick response we need is taken care of (hopefully) by our innate immune system - coming to our aid during the first few hours and days of exposure to a new pathogen. We depend on our innate immune system to protect us from an infection being able to take hold. 

With their powers combined, B cells and T cells form a powerful defence system that adapts and responds to protect the body from a broad scope of health threats.

Keeping both branches of our immune system strong and ready to act can require extra support in winter and also during times of chronic stress.

stress and immunity

Stress and the immune system are closely connected

The HPA (hypothalamic-pituitary-adrenal) axis (a system that controls stress responses) and the immune system work together and help regulate each other. Glucocorticoids or stress hormones such as cortisol, directly affect how the immune system functions. This regulation helps prevent the immune system from overreacting and also provide short-term, protective antiinflammatory effects. However, during long-term stress, the HPA axis becomes taxed and can't regulate the immune system well, leading to weakened immune function.

weather and immunity

Seasonal changes themselves are a stress

Environmental and seasonal changes like a drop in temperature, a decrease in sunlight hours, and damp conditions, known as seasonal stressors, can suppress the immune system just like any other stressor. They increase circulating glucocorticoid (stress hormone) levels and redirect energy away from the immune system in a bid to restore balance across the whole body or where it deems it most necessary.

Ways to support your immune system this winter -

it often comes down to the basics of life...

Sunlight - whenever possible in Winter, prioritize natural sunlight to assist your immune system and promote the production of vitamin D throughout the colder months to avoid seasonal affective disorder (SAD) symptoms.

Rest and quality sleep - Circadian rhythms are the innate biological patterns that regulate various physiological and behavioral processes in our bodies, such as sleep-wake cycles, hormone production, and body temperature fluctuations. Circadian rhythms influence immune system activity, including the release of immune-related molecules. Sleep disturbances or disruptions to the circadian rhythm can impair immune responses. Work to create a regular sleep-wake cycle and take plenty of rest when you can. If you get sick, make sure you are at least back to 80% before returning to work if possible!

Dress for the weather - Pretty obvious, but sometimes I see people wildly under-dressed for cold and wet weather! Stay warm and dry when possible. This isn't to say you need to keep yourself wrapped in cotton wool, or that oodie (at least not in public, please) but keeping a fairly constant temperature will help you stay well, particularly for those of you who run on stress, are burned out and not sleeping properly, or have an underlying health condition.

food and immunity

Supplements or food?

Winter doesn't have to mean '100 ways with broccoli' 🥦🥦🥦

There are plenty of quick, easy, and cheap options to ensure that you are eating a rainbow of colour each day 🌈

You can check out the Calyx website shop for our recipe e-books that combine nonsense free, with cheap and easy seasonal eating. Or go to the 5aday website to find out what's in season where you are and what you can make.

Eating seasonally also means you are cutting costs while getting the best nutritional bang for your buck.

It may take a bit more planning and preparation but is so worth it for the flavour, freshness, and your health.

However, if you find you are getting sick often, get down with the sickness (like really down), or struggle to shake it when you have been sick (taking 2 weeks to recover) then it is likely you will benefit from supplementing with both nutrients and using herbal medicine.

Vitamin C

Our bodies can't make our own vitamin C so daily intake is super important!

Vitamin C helps our immunity (obvs) but it also helps support wound healing and tissue regeneration (hello acne peeps), provides potent antioxidant protection against cellular damage (hello smokers, vapers, drinkers, and those working with chemicals), and supports a healthy adaptation to stress by supporting the adrenals (hello everybody!).

A rainbow of fresh fruit and veg daily will ensure you get a good amount of vitamin C, especially high in kiwifruit, frozen berries and cherries, and fresh citrus, but you may also benefit from a supplement aiming for a minimum of 250mg daily.


Zinc is essential for the proper functioning of over 300 enzymes in the body, but many people today don't get enough of this crucial mineral due to diet but also soil quality. Without enough zinc, your overall health and well-being can decline. You might face issues with your hair, skin, and nails, and your immune system may not work as well. Food sources are seeds, seafood, meat, and particularly organ meats. If supplementing aim for 15mg daily.

Echinacea for immunity


Echinacea modulates our immune function - meaning it helps to regulate function. If the immune system is underperforming, it will help to crank it up and support it, whereas if it over-functioning it can help to chill it out a bit to preserve precious energy.

Plant parts (leaves versus flowers versus roots) are really important with Echinacea as well as quality so this takes a bit of research (or a Medical Herbalist 🙋🏻‍♀️) to ensure you are getting the right dose, etc for you and not just sweepings off some factory floor in a capsule or tablet.


Fresh garlic is considered to be the most effective for strong antibacterial and antifungal action as the enzyme allinase required for converting alliin to allicin is destroyed through cooking. The end product, allicin has beneficial anti-inflammatory and anticancer actions.

You can check my Digest and Detox Dressing recipe here for a good garlic kick!

Household herbalism - Ginger, cayenne, turmeric, kawakawa, thyme

You can use these herbs daily to help keep your immune system in tip-top shape throughout winter by adding generously to food or making your own herbal teas. You might even like to create your own 'fire-cider' - here's a recipe (not mine).

Plus there are loads of options to increase your immune support when we work together one-on-one

If you are keen to make a start on making your immunity your priority this winter then there are loads more options to draw on when we work together. Having longer consultation times allows us to explore your health in depth and for me to be able to make possible connections between seemingly different aspects of your health to create a tailored approach to help get you feeling better and staying well for longer. Having access to practitioner-only quality products also helps get better results more quickly versus staring blankly at the shelf at the supermarket or Bargain Chemist trying to decide what's best.

If strengthening your immunity, checking in on your mood, or anything mentioned in this article is something you would like to explore, you can book a FREE 15-minute discovery call here.


I have appointments and packages for both new and existing clients.

You can book online here or if you are unsure what to book, please don't hesitate to reach out via email

Amy Donovan - Naturopath

Hey, I'm Amy - a qualified and registered Naturopath, Medical Herbalist and

Massage Therapist working from my private clinic in Te Awamutu, New Zealand.

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