We tend to think about immunity only when we’re run down – but true resilience is built in the background. From nourishing your gut to smarter sleep, here’s what really makes a difference…
Start with the gut
A balanced gut doesn’t just help digestion – it underpins almost every aspect of immune health. Around 70% of immune cells are based in the gut, where trillions of microbes filter pathogens, train immune cells, and regulate inflammation. When the microbiome is diverse, the whole system functions better. Support it by eating prebiotic fibres – think onions, garlic, leeks and artichokes – and fermented foods like kefir, sauerkraut and kimchi. You don’t need to overhaul your diet – just a few small swaps can help nourish a healthier microbial environment, which in turn boosts your defences.
Top up vitamin D
Vitamin D plays a central role in immune regulation, helping your body distinguish between friend and foe. Levels tend to dip after October as daylight fades, which can leave you more prone to fatigue, infection, and low mood and energy. The best first step is a blood test to check your status. If you’re low, a daily supplement can help to keep your immune system balanced throughout the darker months.
Treat sleep as essential
When it comes to immune strength, few things are as powerful as sleep. Overnight, the body produces proteins called cytokines, which help coordinate immune response and repair. Miss a night or two and the effect is noticeable. Studies show just one disrupted night can lower natural killer cell activity – the body’s front line of defence. Try to keep a consistent bedtime, limit late-night screens, and build a relaxing wind-down ritual. Warm light, quiet moments and gentle routine signal to the body it’s time to restore.
Protect your airways
Your airways are your first defence against viruses, and when they’re dry or irritated, that barrier weakens. The nasal passages and bronchial membranes act like filters, trapping pathogens before they can travel deeper. In winter, central heating and low humidity make this system more vulnerable. A humidifier can help maintain moisture in the air, while regular saline rinses clear allergens and pollutants. Try adding a drop of ravintsara essential oil to a tissue and breathing it in – it’s known for its antimicrobial and antiviral properties, and keeps airways feeling clear and supported throughout the day.
Keep it clean
It’s simple but powerful – clean hands remain one of the most effective defences against germs. Wash with lukewarm water and soap and keep a gentle sanitiser in your bag for when you’re out. Avoid touching your face, too. The mouth, nose and eyes are direct routes for pathogens.
Eat with purpose
What you eat sets the tone for immunity. Focus on whole, seasonal foods rich in the nutrients your body relies on most – vitamins A, C and D, zinc, selenium and omega-3 fatty acids. Deeply coloured fruit and vegetables provide antioxidant support, while oily fish and olive oil deliver the healthy fats your immune cells depend on.
Support the thyroid
As the light shifts and temperatures drop, the body naturally starts to adjust – metabolism, mood and energy levels all follow the rhythm of the season. The thyroid plays a central role in this process, helping regulate warmth, energy and balance. Support it by eating foods naturally rich in iodine, selenium and omega-3s, such as seaweed, fish, eggs, nuts and seeds. Daily exposure to natural light and a little mild cold, like a brisk morning walk, also help the body recalibrate. Small, steady habits like these keep your energy – and your immunity – in sync through the colder months.
Find your calm
Stress may start in the mind, but its effects reach every system in the body. When cortisol – the stress hormone – stays high for too long, it can interfere with immune function and leave you more susceptible to inflammation. The good news? Small, consistent resets make a tangible difference. Step outside for a few minutes of natural light, take a short walk after work, or pause for ten slow breaths when your shoulders start to tense. Even five minutes of stillness or journalling can help your nervous system reset. Calm isn’t a luxury – it’s part of staying well.