How to Support Your Immune System This Winter
The cold weather shouldn't bother you anyway
As the colder months settle in across Australia, many of us notice a rise in sniffles, sore throats, and low energy. Winter brings several changes that put extra strain on our immune systems.
But with some mindful adjustments, we can give our bodies the support they need to stay well through the season.
Why We Get Sick More Often in Winter
First of all, let’s go through the reasons why we tend to get sick more often in winter. There are several factors combine to challenge our immunity and can potentially throw us off balance:
Lower sunlight exposure leads to reduced vitamin D levels—a nutrient essential for immune balance. Research suggests that up to 58% of Australians have insufficient vitamin D in winter.
Cold, dry air compromises the protective mucous membranes in your nose and throat, making it easier for viruses to take hold.
We tend to spend up to 90% of our time indoors during winter, often in poorly ventilated spaces where airborne viruses can spread more easily.
Lifestyle changes—like eating heavier meals, sleeping less, or exercising irregularly—can negatively affect immune function.
If you are a regular reader or listener of Ask Dr Vincent, you probably would have already heard me saying these, but we all need a bit of a reminder, myself included:
70% of your immune system lives in your gut. This is why what you eat plays a crucial role in how well you fight off infections.
One night of poor sleep can reduce your immune response by up to 70%, according to research from the University of California.
A large-scale study published in JAMA Internal Medicine found that walking more than 8,000 steps per day was associated with a significantly lower risk of dying from all causes, and other research shows it also reduces the frequency of upper respiratory tract infections, like the common cold, by enhancing immune surveillance and circulation.
Antioxidants, particularly apple phenolics, have been shown to reduce inflammation and oxidative stress—two key factors in immune dysregulation. Their ability to support gut health also adds another layer of immune protection. Unlike synthetic supplements, phenolics from whole food sources are better recognised and utilised by the body.
6 Ways to Strengthen Your Immunity Naturally
1. Feed Your Gut
Support your microbiome with fibre-rich foods—like sunflower fibres, oats, legumes, apples, and leafy greens—and fermented products like yoghurt or kimchi. A well-fed gut supports a well-regulated immune system.
2. Walk More, Move Consistently
Even 20 minutes of walking daily can reduce inflammation and improve immune cell function. Aiming for 7,000–8,000 steps per day is linked to fewer colds and better overall immunity, especially when movement is consistent over time.
3. Soak Up the Sun (When You Can and Safely)
Try to get natural sunlight on your skin for 10–30 minutes a few times a week. If you're at risk of deficiency, especially during winter, consult your GP or nutritionist about whether vitamin D supplementation is appropriate.
4. Prioritise Sleep
Sleep is not a luxury—it’s a critical repair phase for your immune system. Your body produces infection-fighting cytokines while you sleep, and these drop when you’re sleep-deprived.
5. Hydrate for Immune Health
Water helps maintain the mucous membranes in your nose and throat—your body’s natural barrier against airborne pathogens. Aim for 1.5 to 2 litres a day, even if you’re not sweating as much as in summer.
6. Support Your Skin—Your First Line of Defence
Your skin is a physical barrier against pathogens. Cold weather can dry it out, leading to cracks and irritation that compromise this protection. Wash your hands regularly but also moisturise them and for your whole body, use a gentle cleanser, moisturise regularly, and nourish your skin from within by consuming healthy fats and antioxidants. Keeping your skin hydrated and healthy isn’t just about vanity and appearance—it’s an important part of your immune strategy.
Immunity isn’t built overnight, but it is shaped daily—through how we eat, move, rest, and manage stress. Think of this winter as an opportunity to reconnect with your body’s needs, and to support it with simple, evidence-based habits.
By choosing antioxidant-rich foods, staying active, prioritising rest, and caring for your gut, you’re not just avoiding illness—you’re building long-term resilience.