Every day we are exposed to bugs, but as we head into the colder months, we see an increase in cases of the flu, colds and other seasonal illnesses. But why is winter such a hotspot for getting sick?
When temperatures drop, we tend to spend more time indoors in close contact with others, making it easier for viruses to spread. At the same time, our bodies may be under more stress from cold weather, lack of sunlight (Vitamin D) and reduced physical activity, all of which can dampen our natural immune defences.
Understanding what happens inside the body when you're exposed to a bug and how you can naturally support your immune system is the first step toward a healthier, more resilient immune system this winter. Support your immune system to reduce the chance that the bug takes hold and support your immune system to respond when a bug does get through.
When a pathogen enters the body
The moment a pathogen (like a cold or flu virus) enters the body, your immune system kicks into gear. The immune system is an incredibly sophisticated network designed to detect and eliminate harmful invaders and reduce the severity of an illness. Once a virus is detected, your body releases chemical signals to call immune cells into action. These cells identify, attack and remove the virus, while also triggering inflammation, which is part of the healing process.
Your immune system has two key divisions, the 'innate' immune system and the 'adaptive' immune system
Innate immune system: Your body’s first and fastest line of defence against invading pathogens such as viruses, bacteria, and other harmful microbes. It’s called “innate” because you’re born with it, it’s always ready to act. This system can respond within minutes of exposure to a foreign invader and acts non-specifically, meaning it doesn’t distinguish between different types of pathogens. Its main goal is to stop or slow the spread of the invader before it can cause material harm.
Key components of the innate immune system include:
- Physical barriers like the skin and mucous membranes in your nose and throat, which block pathogens from entering your body.
- Chemical barriers such as stomach acid, antimicrobial proteins in saliva, and enzymes in tears that help destroy microbes.
- Cellular defenders including neutrophils and macrophages, natural killer cells and dendritic cells.
- Inflammatory response, which helps recruit immune cells to the site of infection and creates an environment that’s hostile to pathogens (fever, swelling, redness).
Think of the innate immune system as a rapid-response security team. It doesn’t need to know the identity of the intruder, it reacts instantly, sounding the alarm and sending out the first wave of defence to neutralise the threat.
Adaptive immune system: The adaptive (or acquired) immune system is slower to respond, but far more precise. It’s activated after the innate immune system has detected a serious or persistent threat and typically takes a few days to activate. However, once it’s active, it targets pathogens specific to the threat and creates long-lasting immunity.
There are two main types of adaptive immune responses:
- Humoral immunity, which involves B cells that produce antibodies. These antibodies lock onto specific antigens (unique markers on pathogens), neutralising them or marking them for destruction.
- Cell-mediated immunity, involving T cells. Helper T cells coordinate the immune response, while cytotoxic T cells seek out and destroy infected cells.
A key feature of the adaptive immune system is memory. After an infection or vaccination, memory B cells remain in the body. If the same pathogen is encountered again, these memory cells trigger a much faster and stronger immune response, often stopping the illness before symptoms even appear.
Together, the innate and adaptive immune systems form a dynamic and powerful defence network. The innate system acts fast and broadly, while the adaptive system learns, adapts, and protects you long-term. Different types of pathogens activate different responses. For instance, viruses often trigger strong adaptive immunity, while bacterial infections might engage more of the innate response at first.
Herbs for immune system support
Echinacea (Echinacea purpurea)
Echinacea is the darling of the immune boosting herbs. It is both immune-activating and immune-modulating. It helps to stimulate and strengthen the immune response and supports balance by regulating immune activity, preventing the cytotoxic T cells from becoming overactive. This makes it particularly useful during times of immune challenge. Echinacea is especially beneficial in the early stages of infection, where it can help the body mount a more effective defence and potentially reduce the severity or duration of illness. The evidence is that the active ingredients of extracts from the root of Echinacea are significantly more powerful than leaf extracts.
Kiwiherb products that contain Echinacea: Children’s Organic Echinature, Children’s Organic Throat Syrup, Organic De-Stuff for Kids, Echinature, ImmuneBerry, Organic ImmuneGuard, Herbal Throat Spray, Organic De-Stuff.
Olive Leaf (Olea europaea)
Olive leaf extract is immune supporting due to its high concentration of polyphenols. They offer strong antioxidant, antiviral, and antimicrobial effects. Olive leaf helps protect immune cells from oxidative stress by neutralising free radicals, which can impair immune function over time. It also supports the immune system’s innate response by enhancing the activity of white blood cells that identify and eliminate pathogens.
Kiwiherb products that contain Olive leaf: ImmuneBerry
Elderberry (Sambucus nigra)
Elderberry is rich in anthocyanins, a type of flavonoid with potent antioxidant and anti-inflammatory properties. Elderberry is known to help stimulate immune activity, enhancing the production of messenger molecules that help immune cells communicate and coordinate a defence. It may also prevent viruses from entering and infecting cells by blocking their ability to attach to host cell receptors. This unique antiviral action makes Elderberry particularly effective during the initial stages of viral infections, such as influenza. Regular use during cold and flu season may support quicker recovery and reduce symptom intensity.
Kiwiherb products that contain Elderberry: Children’s Immune Drops, ImmuneBerry
Thyme (Thymus vulgaris)
Supports the immune system through its potent antimicrobial, antioxidant, and anti-inflammatory properties. The herb is rich in active compounds such as thymol, which help neutralise harmful bacteria, viruses, and fungi, reducing the burden on the immune system. Additionally, Thyme’s antioxidant action helps combat oxidative stress, a key factor that can weaken immune defences over time. By reducing inflammation in the respiratory tract and promoting mucosal health, Thyme helps manage symptoms of infections and enhances the body’s natural ability to fend off future pathogens.
Kiwiherb products that contain Thyme: Children’s Goodnight Chest Syrup, Children’s Organic Chest Syrup, Children's Organic Throat Syrup, Organic De-Stuff Rub, Herbal Throat Spray, Dual-Action Chest & Lung Support
Andrographis (Andrographis paniculata)
Andrographis powerful immune-modulating herb widely used in traditional medicine systems to combat infections and boost overall immune resilience. Andrographis also helps regulate inflammatory responses, preventing excessive immune reactions that can cause tissue damage during illness.
Kiwiherb products that contain Andrographis: Speedy Recovery
Nutrients and vitamins that nourish the immune system
Vitamin C
Vitamin C plays a crucial role in strengthening the immune system by acting as a powerful antioxidant that protects immune cells from damage caused by harmful free radicals. It also enhances the production and function of white blood cells, which are the body’s primary defenders against infections. Consuming vitamin C-rich foods like kiwifruit, oranges, mandarins, strawberries, broccoli, and capsicums helps ensure your immune system remains robust and ready to respond to pathogens.
Zinc
Zinc is essential for the proper development and communication of immune cells, which are necessary for mounting an effective immune response. It supports both innate immunity and adaptive immunity. A zinc deficiency can weaken the immune system, leading to increased vulnerability to infections. Incorporating zinc-rich foods such as pumpkin seeds, chickpeas, lentils, cashews, and seafood helps maintain optimal immune function.
Fermented foods
The gut is home to a large portion of the immune system, where gut-associated lymphoid tissue (GALT) helps recognise and respond to harmful microbes. Fermented foods provide beneficial probiotics that help balance the gut microbiome, which in turn strengthens the gut barrier and modulates immune responses. Regularly eating fermented foods like sauerkraut, kimchi, yoghurt, kefir, miso, and tempeh supports the immune system by promoting a healthy and resilient gut environment.
Garlic and Ginger
Garlic and Ginger contain natural compounds with antimicrobial and anti-inflammatory properties that directly support the immune system’s ability to fight infections. Garlic’s allicin helps combat bacteria, viruses, and fungi, while ginger improves circulation, facilitating the delivery of immune cells throughout the body. These ingredients help enhance immune surveillance and reduce inflammation, which is vital for maintaining immune balance.
But good immunity is not all about herbs, nutrients and vitamins. Lifestyle plays an important supporting role.
Lifestyle tips for winter wellness
Sleep: It is critical for immune regulation because it allows the body to produce signalling proteins that help coordinate immune responses and inflammation control. Without adequate sleep, the immune system is weakened and has an increased susceptibility to illness. Getting 7 to 9 hours of quality sleep each night ensures your immune system remains effective in protecting against pathogens.
Exercise: Physical activity supports the immune system by boosting circulation and the movement of lymph, which helps immune cells travel efficiently throughout the body to detect and respond to threats. Moderate exercise also helps regulate inflammation and reduces stress hormones that can suppress immunity. Regular movement enhances immune surveillance and resilience, making it easier for the body to prevent and fight infections. Try and move your body throughout the day and exercise 2-5 times a week.
Stress: Chronic stress negatively impacts the immune system by increasing cortisol levels, which suppress immune cell function and reduce the body’s ability to mount an effective defense. Managing stress through techniques such as yoga, meditation, or breathwork helps lower cortisol levels, restoring immune balance and improving the body’s ability to respond to pathogens.
Sunlight: Exposure to natural daylight regulates the circadian rhythm, which influences immune function by optimising the timing of immune cell activity. Daylight also supports vitamin D synthesis in the skin, a critical nutrient that modulates both innate and adaptive immunity.
Winter bugs are unavoidable, but with the right knowledge and habits, you can help your immune system stay strong and resilient. Incorporating immune-supportive foods, herbs, and lifestyle practices can reduce your risk of illness and support faster recovery. Start building your defences now to enjoy a healthier, more vibrant winter season.
Be your natural best this winter.