Fit2Thrive Journal October 2025
Fortify Your Immune System for Winter
As the days grow shorter and the air turns crisp, winter brings with it a heightened risk of seasonal illnesses. Colds, flu, and other respiratory infections become more common as we spend more time indoors, in closer proximity to others. While we can't eliminate the risk of getting sick, we can take proactive steps to support and strengthen our immune systems. This guide will walk you through key lifestyle and dietary strategies to help you stay healthy and resilient throughout the winter months.
The Power of Movement: Exercise for a Stronger Immune System
Regular physical activity is a cornerstone of a healthy immune system. Research shows that moderate-intensity exercise, such as brisk walks, an upbeat exercise class or a gym circuit, can lead to a host of benefits for your body's defences. A 2018 study published in the Journal of Sport and Health Science found that acute exercise acts as an immune system adjuvant, improving defence activity and metabolic health [1].
There is a clear inverse relationship between moderate exercise and the risk of illness. However, it's essential to strike the right balance. While consistent, moderate activity strengthens your immune system, prolonged and intense exercise without adequate rest can have the opposite effect, temporarily suppressing immune function and increasing the risk of upper respiratory tract infections [1]. Aim for at least 150 minutes of moderate-intensity exercise each week to reap the immune-boosting benefits.
Nourish Your Defences: The Role of Diet and Gut Health
What you eat plays a pivotal role in the health of your immune system. A balanced diet rich in a variety of nutrients is essential for optimal immune function. A significant portion of your immune system resides in your gut, making gut health a critical factor in your body's ability to fight off pathogens.
Gut Health: The Foundation of a Strong Immune System
The gut microbiome, the vast community of microorganisms living in your digestive tract, is intricately linked to your immune system. Research from Harvard Medical School has shown that diet directly affects immunity through the gut microbiome [2]. Certain foods, like those rich in branched-chain amino acids, are metabolised by gut bacteria into compounds that help regulate the immune response and reduce inflammation. To support a healthy gut microbiome, incorporate a variety of fibre-rich foods into your diet, such as fruits, vegetables, whole grains, and legumes. Fermented foods like yoghurt, kefir, sauerkraut, and kimchi are also excellent sources of beneficial bacteria that can enhance microbiome diversity and improve immune responses.
Fruits, Vegetables, and Herbs: Nature's Immune Boosters
Fruits and vegetables are packed with vitamins, minerals, and antioxidants that are essential for a healthy immune system. Aim to eat a colourful variety of produce to ensure you're getting a wide range of nutrients. Citrus fruits, for example, are an excellent source of vitamin C, a powerful antioxidant that supports the function of immune cells.
Herbs and spices have also been used for centuries to support immune health. Many possess potent antiviral, antibacterial, and anti-inflammatory properties. Some of the most effective immune-boosting herbs include:
Elderberry: Known for its antiviral properties, elderberry can help reduce the severity and duration of colds.
Ginger: A powerful anti-inflammatory, ginger can help soothe a sore throat and reduce inflammation.
Turmeric: This vibrant yellow spice contains curcumin, a compound with strong antioxidant and anti-inflammatory effects.
Echinacea: Often used to stimulate the immune system, echinacea may help reduce the severity of colds.
The Sunshine Vitamin: Vitamin D in the UK Winter
Vitamin D, often referred to as the “sunshine vitamin,” is essential for maintaining a healthy immune system. Our bodies produce vitamin D when our skin is exposed to sunlight. However, in the UK, the sun is not intense enough between October and early March for us to produce adequate amounts of this vital nutrient. As a result, a significant portion of the UK population has low vitamin D levels during the winter months [3].
The UK government recommends that everyone consider taking a daily vitamin D supplement during the autumn and winter months. The recommended dose for adults and children over the age of one is 10 micrograms (400 IU) per day [4]. This is especially important for individuals with dark skin, as they may not produce enough vitamin D from sunlight even during the summer months.
Let There Be Light: The Importance of Early Light Exposure
Light exposure, particularly in the morning, plays a critical role in regulating our circadian rhythms, the body's internal 24-hour clock. These rhythms influence a wide range of bodily functions, including sleep, hormone production, and immune responses. Disruptions to our circadian rhythms can negatively impact our immune system.
Getting natural sunlight exposure shortly after waking can help to anchor your circadian rhythm, promoting better sleep at night and supporting a healthy immune system. Aim for 10-30 minutes of direct sunlight exposure each morning. If natural sunlight is limited, especially during the dark winter months, using a light therapy lamp can be a helpful alternative.
The Restorative Power of Sleep
Quality sleep is non-negotiable for a healthy immune system. While you sleep, your body undergoes a process of repair and regeneration. During this time, your immune system releases proteins called cytokines, some of which help promote sleep. Specific cytokines need to increase when you have an infection or inflammation, or when you're under stress. Sleep deprivation can decrease the production of these protective cytokines, as well as infection-fighting antibodies and cells.
Studies have consistently shown that people who don't get enough quality sleep are more likely to get sick after being exposed to a virus. Aim for 7-9 hours of quality sleep per night to give your body the rest it needs to maintain a strong and effective immune system [5].
Immune-Boosting Tea Suggestions
A warm cup of herbal tea can be a comforting and effective way to support your immune system during the winter. Many herbs have immune-boosting properties and can help to soothe a sore throat, reduce congestion, and fight off infection.Add a teaspoon of honey to these recipes to add even more benefits. Here are a few suggestions for immune-boosting teas:
Ginger and Turmeric Tea: Combine fresh ginger and turmeric root in hot water for a potent anti-inflammatory and antioxidant-rich brew.
Elderberry Tea: You can find pre-made elderberry tea bags or make your own by steeping dried elderberries in hot water.
Echinacea Tea: Echinacea tea is widely available and can be a great way to support your immune system at the first sign of a cold.
Peppermint Tea: Peppermint is a natural decongestant and can help to clear your sinuses and soothe a sore throat.
Conclusion
Supporting your immune system this winter doesn't have to be complicated. By incorporating these simple yet powerful strategies into your daily routine, you can give your body the tools it needs to stay healthy and resilient. From regular exercise and a nutrient-rich diet to adequate sleep and vitamin D supplementation, these proactive steps can make a significant difference in your ability to fend off winter illnesses and enjoy a healthy and vibrant season.
References
[1] 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. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6523821/
[2] Harvard Medical School. (2021, November 16). Diet, Gut Microbes, and Immunity. https://hms.harvard.edu/news/diet-gut-microbes-immunity
[3] Forth with Life. (2025, July 30). 2025 Vitamin D Deficiency Statistics of UK Adults. https://www.forthwithlife.co.uk/blog/uk-vitamin-d-statistics/
[4] NHS. (2020, August 3). Vitamin D. https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
[5] Besedovsky, L., Lange, T., & Born, J. (2012). Sleep and immune function. Pflügers Archiv - European Journal of Physiology, 463(1), 121–137. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3256323/
