As winter approaches, it’s common to feel more vulnerable to colds, flu, and other seasonal illnesses. Colder weather not only affects your comfort but also challenges your body’s ability to fight infections. However, with the right approach, you can prepare yourself for winter by supporting your immune system, particularly through optimising your diet and gut health.
Here are some practical tips to help you stay well this winter.
1. Focus on Immune-Supporting Nutrients
A healthy, balanced diet is essential for supporting your immune system, particularly during winter. Specific nutrients play a critical role in immune function, and ensuring you get enough of these can help keep illnesses at bay:
Omega-3 Fatty Acids: Omega-3s help to reduce inflammation in the body and are important for maintaining a healthy immune response. Oily fish, such as salmon, mackerel, and sardines, are excellent sources. For vegetarians, flaxseeds, chia seeds, and walnuts are good plant-based alternatives (Calder, 2017).
Zinc: This mineral is essential for immune function and plays a key role in fighting off infections. Zinc can be found in foods like meat, shellfish, lentils, seeds, and nuts (Gammoh & Rink, 2017). If you would like to be sure you are eating enough zinc, try out these tips:
- Choose porridge at breakfast. A medium portion of porridge made with milk contains about 1.8mg of zinc. Top with almonds, cashews, or pumpkin seeds for extra zinc.
- Add beans to curries, casseroles, and salad. A half can of mixed beans or snack pot of baked beans contains 1.2mg of zinc.
- Choose wholegrain carbohydrates whenever possible. Wholegrain rice and bread can contain more than double the amount of zinc of white versions.
Vitamins A, C, and E: These vitamins are powerful antioxidants that support immune function. Include a variety of vegetables in your diet, such as carrots, spinach, and sweet potatoes (for vitamin A), citrus fruits and peppers (for vitamin C), and almonds or sunflower seeds (for vitamin E), to ensure you’re getting these important nutrients. You may have heard that vitamin C can treat a cold or flu. Unfortunately, there is no scientific evidence to support this claim. However, vitamin C plays an important role in supporting our natural immune system through its antioxidant effects. The average adult needs 40 mg of vitamin C per day, which can be easily reached through food alone. This means you do not need to take supplements to meet your vitamin C requirement.
Many fruits and vegetables are good sources of vitamin C, including:
- Citrus fruits like oranges, lemons, and grapefruits.
- Peppers of all colours but especially yellow.
- Berries like strawberries and blackcurrants.
- Leafy green vegetables like broccoli and Brussels sprouts.
- Potatoes, both regular white potatoes and sweet potatoes.
If you would like to include more vitamin C in your diet, try these tips:
- Drink a glass of freshly squeezed orange juice with your breakfast. One average glass of orange juice contains about 50 mg of vitamin C. Eat an orange for a healthier choice with more fibre and less sugar.
- Add berries to porridge, yoghurt, or desserts. Half a cup of raw strawberries contains about 45 mg of vitamin C.
- Try stuffed peppers or add mixed peppers to stir-fries. Half a red pepper contains about 100 mg of vitamin C, more than twice the amount your body needs.
Vitamin D: With limited sunlight in winter, vitamin D levels tend to drop, which can impact your immune system. Vitamin D is crucial for helping the body fight off respiratory infections. You can increase your intake through foods like eggs, oily fish (e.g. mackerel, salmon, or sardines), and fortified products. In the UK, a daily supplement of 10µg (400IU) is recommended for all adults during autumn and winter. If you would like to include more vitamin D in your diet, here are three tips:
- Aim to eat oily fish like salmon, sardines, and mackerel at least once a week. One average salmon fillet (100g) baked contains 10 µg of vitamin D. Serve with new potatoes and mixed steamed vegetables or salad for a balanced meal.
- Avoid removing the egg yolk when cooking omelettes and other egg dishes. Each egg yolk contains about 2.3µg of vitamin D.
- Choose milk, spreads, and breakfast cereals fortified with vitamin D. These foods have added vitamin D and should have their vitamin D content listed on their nutrition label.
2. Maintain a Healthy Weight
Maintaining a healthy weight through balanced eating and regular physical activity is also important for immune health. Carrying excess weight, particularly around the abdomen, can impair immune function and increase inflammation in the body. Focusing on nutrient-dense foods like fruits, vegetables, whole grains, and lean proteins can help you maintain a healthy weight and improve overall well-being.
3. Optimise Gut Health with a Balanced Diet
Your gut microbiome, the collection of bacteria and microorganisms in your digestive system, has a huge impact on your immune function. A diverse and healthy microbiome can strengthen your body’s response to infections, while a poor diet can weaken it.
Rich and Diverse Dietary Patterns: A Mediterranean diet, plant-based diets, and diets high in fruits, vegetables, nuts, seeds, and whole grains are positively associated with a healthy gut microbiome. These diets are rich in fibre, which feeds beneficial bacteria in the gut, promoting diversity and overall health (Valdes et al., 2018).
Fibre-Rich Foods: Foods high in fibre, such as oats, legumes, vegetables, and whole grains, can help promote a more diverse microbiome. Studies show that even short-term dietary changes can significantly impact the microbiome. For example, switching from a low-fibre, meat-heavy diet to a plant-based, high-fibre diet (30 grams/day or more) can improve gut health within just 24 to 48 hours (Valdes et al., 2018).
Probiotics and Fermented Foods: Fermented foods like yogurt, kefir, sauerkraut, and kimchi provide live probiotics—healthy bacteria that support your gut and immune system. If you don’t consume fermented foods regularly, you may want to consider a probiotic supplement with strains such as Lactobacillus or Bifidobacterium, which can enhance immune responses and strengthen gut barrier function (Kechagia et al., 2013).
4. Stay Hydrated
Even though we might not feel as thirsty in the colder months, it’s important to stay hydrated. Water is essential for maintaining healthy mucous membranes in your respiratory tract, which help protect against infections. Aim to drink plenty of water each day and consider warm drinks like herbal teas to keep your fluid intake up during winter.
5. Prioritise Sleep
Sleep plays a vital role in supporting immune health. Lack of sleep can weaken your immune system, making you more prone to illnesses. Aim for 7-9 hours of restful sleep each night to give your body the opportunity to rest and repair. Creating a calming bedtime routine and keeping a regular sleep schedule can help improve sleep quality (Irwin, 2015).
6. Stay Active
Physical activity is important for maintaining immune function. Regular exercise helps improve circulation and enhances the activity of immune cells that fight infections. You don’t need to do intense workouts—moderate activities like walking, cycling, or yoga can be highly beneficial. Aim for at least 30 minutes of activity on most days, even if it’s cold outside (Nieman & Wentz, 2019).
7. Dress Warmly and Stay Comfortable
Cold weather can suppress immune function, making you more vulnerable to illnesses like colds and flu. Dressing in warm layers and keeping your home at a comfortable temperature can help protect your health. Make sure to cover your head, hands, and feet when going outside to retain body heat.
8. Limit Sugar and Alcohol
Excess sugar and alcohol can weaken your immune response. High sugar intake can reduce the ability of white blood cells to fight off infections, while alcohol can dehydrate the body and impair immune function. It’s important to enjoy these in moderation, focusing instead on nutrient-dense foods that support your body during winter (Calder, 2020).
9. Stay Connected and Manage Stress
Winter can sometimes feel isolating, but staying connected with loved ones is crucial for mental and physical well-being. Chronic stress and loneliness can weaken your immune system, so maintaining social interactions—whether through phone calls, video chats, or safe meetups—can help. Managing stress through activities like meditation, yoga, or hobbies can also improve your immune function (Cohen et al., 2015).
Conclusion
Winter can be a challenging time for staying healthy, but by supporting your immune system and optimising your gut health, you can reduce your risk of seasonal illnesses. A nutrient-rich diet with plenty of immune-supporting nutrients, regular exercise, good hydration, and sufficient sleep all contribute to keeping your body strong during the colder months. Additionally, adopting a Mediterranean or plant-based diet rich in fibre can help establish a healthy microbiome, which is key to robust immune function. Stay warm, stay connected, and prioritise your health this winter.
References
Calder, P. C. (2017). Omega-3 fatty acids and inflammatory processes: From molecules to man. Biochemical Society Transactions, 45(5), 1105-1115.
Calder, P. C. (2020). Nutrition, immunity, and COVID-19. BMJ Nutrition, Prevention & Health, 3(1), 74-92.
Cohen, S., Janicki-Deverts, D., Doyle, W. J., Miller, G. E., Frank, E., Rabin, B. S., & Turner, R. B. (2015). Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. Proceedings of the National Academy of Sciences, 109(16), 5995-5999.
Gammoh, N. Z., & Rink, L. (2017). Zinc in infection and inflammation. Nutrients, 9(6), 624.
Irwin, M. R. (2015). Why sleep is important for health: A psychoneuroimmunology perspective. Annual Review of Psychology, 66, 143-172.
Kechagia, M., Basoulis, D., Konstantopoulou, S., Dimitriadi, D., Gyftopoulou, K., Skarmoutsou, N., & Fakiri, E. M. (2013). Health benefits of probiotics: A review. ISRN Nutrition, 2013, 481651.
Martineau, A. R., Jolliffe, D. A., Hooper, R. L., Greenberg, L., Aloia, J. F., Bergman, P., & Griffiths, C. J. (2017). Vitamin D supplementation to prevent acute respiratory infections: Individual participant data meta-analysis. BMJ, 356, i6583.
Nieman, D. C., & Wentz, L. M. (2019). The compelling link between physical activity and the body’s defense system. Journal of Sport and Health Science, 8(3), 201-217).
Valdes, A. M., Walter, J., Segal, E., & Spector, T. D. (2018). Role of the gut microbiota in nutrition and health. BMJ.