Supporting your immune function

During the colder months, our risk of illness naturally increases. Coughs, colds, flu and COVID—can take a toll on our bodies, energy, and mood. Fortunately, we’re not powerless. Supporting your immune system with targeted nutrition, lifestyle habits, and stress management can make all the difference.

Understanding your Immune System

Your immune system is a complex, highly intelligent network of cells, tissues, and organs designed to defend against harmful invaders like viruses, bacteria, and toxins.

1.      Innate Immune System

This is your first line of defence. It includes physical barriers like your skin, mucous membranes in your lungs, gut, and genitals, as well as secretions like saliva and stomach acid. It also includes immune cells that quickly attack invaders within hours of entry—white blood cells like neutrophils and monocytes. However, it’s a general response and doesn’t ‘remember’ previous attacks.

2.      Adaptive Immune System

When the innate system can’t hold the line, the adaptive immune system steps in. It uses T cells to destroy infected cells and B cells to produce antibodies that target specific invaders. This system ‘remembers’ pathogens, which is how vaccines work.

The Gut-Immune Connection

It’s becoming increasingly clear that gut health and immune function are deeply intertwined. A thriving gut microbiome supports immune regulation, reduces unnecessary inflammation, and even helps regulate T cells, key players in the adaptive immune system. Disruptions in gut health—often due to poor diet, antibiotics, or chronic stress—can lead to immune overactivity, more frequent infections, and even post-viral issues like brain fog, which is common in long COVID.

Foods to heal

• An anti-inflammatory, plant-based diet high in fruit and vegetables, which are rich in fibre, antioxidants, and phytochemicals.

• Healthy fats from avocado, nuts, seeds, and olive oil.

• High-quality protein, fish, plant-based protein from legumes, tofu, and nuts and seeds, lean meat.

Key Immune-Supporting Nutrients

Vitamin C - This water-soluble vitamin helps maintain physical barriers, reduces inflammation, and neutralizes free radicals. Top sources: Citrus fruits, berries, kiwifruit, papaya, red capsicum, broccoli, kale, cauliflower.

Vitamin A - Essential for mucosal integrity and immune cell development. It’s both an antioxidant and infection-fighter. Top sources: Liver, eggs, sardines, cod liver oil, spinach, carrots, kumara, and cantaloupe.

Vitamin D - Known as the “sunshine vitamin,” it boosts immune cell activity and helps the body produce antimicrobial proteins. Top sources: Oily fish (salmon, sardines), egg yolks, cheese, butter, and safe sun exposure.

Zinc - A critical mineral for immune cell development and communication. It’s also a powerful antioxidant and antiviral. Top sources: Oysters, red meat, poultry, seeds (especially pumpkin and sunflower), nuts, beans, and whole grains.

Selenium- Supports immune cell function, reduces oxidative stress, and promotes a healthy gut microbiome. Top sources: Brazil nuts (just 1–2 a day!), seafood, organ meats.

Quercetin and Rutin - These plant compounds (polyphenols) have antiviral and anti-inflammatory effects and can break down mucus and reduce histamine production. Top sources: Apples, onions, berries, citrus, buckwheat, chia seeds, coriander, and tomatoes.

Natural Remedies when Illness Strikes

Lemon + ginger + turmeric + manuka honey: This combination is soothing, anti-inflammatory, and antibacterial.

Garlic: Has antibacterial, antifungal, and antiviral properties. Great in soups or teas with fenugreek to help loosen congestion.

Onions and chillies: High in vitamin C, quercetin, and warming compounds that clear sinuses and fight inflammation.

Mushrooms: Especially shiitake, reishi, and turkey tail—boost white blood cell production and contain ergothioneine, a potent antioxidant.

And don’t forget the basics: hydration, saltwater gargles, chamomile or peppermint tea, and rest.