May 2024
Winter is sweeping across South Africa, and the colder temperatures often usher in a different set of lifestyle patterns and daily habits. Many enjoy having a good reason for later wake-up calls, more snuggling up, tucking into comfort foods and warming up with extra hot drinks. However, the colder environment boosts the survival and longevity of infectious cold and flu viruses, and our closer contact in indoor settings can facilitate an easier spread of respiratory viruses. If you are spending less time outdoors in the sunshine, you may also experience a drop in vitamin D levels which is essential to optimal immune system functioning.
As we adapt to the changing season, we need to bear in mind the impact on our lifestyles and accordingly adjust our nutritional needs. If there’s a drop in our levels of daily physical activity, then it is likely there is also a dip in our daily energy requirements. It is important to be mindful that in our efforts to keep warm, we are not taking in more energy than we use.
Here’s an evidence-based roadmap for navigating nutrition this winter from Registered Dietitians, Mpho Tshukudu and Maryke Gallagher, both spokespeople for ADSA, (The Association for Dietetics in South Africa).
Maintaining a healthy balanced diet
Both Mpho and Maryke point out that the warming ‘comfort foods’ we tend to prefer in winter can still be healthy, balanced meals. Maryke says, “Warm foods such as stews, soups, casseroles and curries can also be healthy, nutrient dense and help with weight maintenance. The non-starchy vegetables that are so crucial to healthy eating are delicious ingredients that enhance the aromas, flavours and textures of winter dishes.
If you’re aware that you are shopping for less salad ingredients in winter, then make sure you are instead stocking up regularly with more vegetables across the colour spectrum such as carrots, baby marrows, brinjals, mushrooms, sweet peppers, onions, garlic, ginger, broccoli, cauliflower, spinach and kale. Winter dishes also lend themselves well to adding legumes such as beans, lentils and chickpeas which are rich in fibre and plant-based protein. When you are making winter soups, curries and pasta sauces pack in as many different non starchy vegetables and legumes as you can. Use a tomato base and plant-based oils such as olive and avocado oils instead of butter or cream. It’s also a good time to focus on using herbs and warming spices in your recipes. Some of these can help curb food cravings and boost the nutrient density of your winter meals.” she continues.
It’s also important to stick to a regular eating pattern and avoid constant snacking or ‘grazing’. Before you reach for a snack, be mindful of your hydration level as we often reduce our water intake in winter, and it becomes easier to mistake thirst cues for hunger. The same basics of healthy eating should be maintained during the colder months. Eat plenty of vegetables and fruit every day, choose the whole-grain options whenever you can and limit highly processed foods that are high in sugar, salt and unhealthy fats.
Hot drinks are a particular pleasure and comfort in winter, but that’s not a good reason to increase your caffeine and sugar intake. Hot water simply infused with a slice of lemon or ginger is hydrating and delicious and a popular winter favourite. Be mindful of drinking enough plain water. Maryke advises, “Limit milky and creamy hot drinks and rather try out unsweetened caffeine-free teas such as rooibos, as well as fruit, spice and herbal infusions. Ingredients such as ginger, cloves and turmeric are immune-supporting and spices like cinnamon help to curb sweet cravings, so add them to herbal teas like rooibos.”
Staying active despite the weather
Mpho highlights the importance of staying active despite colder temperatures and shorter daylight hours. She says, “There are several simple strategies that we can use to ensure we’re getting enough daily exercise. Remember that moving our bodies raises body temperature, so being active is an easy way to warm up when the day is cold. During the working week, always take the stairs and start taking short walks after lunch to get some sunlight and boost your vitamin D levels. Daily walks also improve digestion and refresh the mind. On the weekends, when you have more free time, plan outdoor activities like longer walks, participate in park runs, cycle or take up any fun outdoor activity. It helps to set up a home workout space and use apps or online videos for guided exercise routines that require no or little equipment. Even just 15 minutes of exercise, yoga or dancing can make a difference to your mood and supports your immune system and overall body functions.”
Supporting your immune system through good nutrition
While there’s no one proven food or food supplement that can “boost” the immune system, there are a range of nutrients that support immune function and health. Both dietitians emphasise the importance of a balanced diet consisting mainly of minimally processed whole foods to ensure that you benefit from those nutrients.
Key nutrients that support immune health include:
Vitamin C – is found in foods like broccoli, citrus, guavas and bell peppers. It enhances iron absorption, so pair vitamin C-rich foods with iron-rich ones.
Vitamin D – exposure to sunlight is important for the body to synthesise vitamin D. Food sources include oily fish, eggs, and enriched foods.
Vitamin A – is important for respiratory health. It is found in carrots, sweet potatoes, and leafy greens.
Omega-3 Fatty Acids – have anti-inflammatory properties and are found in fish, like salmon and plant sources like flaxseeds and chia seeds.
Probiotics and Prebiotics – support gut health and overall immunity. Probiotic-rich foods include yoghurt and fermented vegetables, while prebiotics are found in foods like garlic, onions, and asparagus.
Zinc – is found in shellfish, legumes, seeds, and nuts. It supports immune cell function and respiratory health.
When it comes to zinc supplementation and upper respiratory infection, Maryke points out, “Research has shown that Zinc supplementation might help to stave off respiratory infection symptoms and cut illness duration, but quality of evidence is variable, and there is currently no clarity on optimal formulation or dosage. A pooled analysis of 28 clinical trials involving 5446 adults with respiratory tract infections showed that zinc supplementation in the form of zinc acetate or zinc gluconate salts helped to reduce symptoms severity by day 3 of infection and reduced the overall duration of illness. Other studies included in this research paper showed no difference in risk of developing infection and cold symptoms or duration of illness. These findings are promising, but more research is needed in this area. Prioritising food sources of immune supporting nutrients is important, and it is best to discuss supplementation with a registered dietitian who can assess your individual needs and make recommendations on the use of supplements.”
Supporting mental well-being during the winter months
Some people experience seasonal affective disorders (SAD) or other mood related issues during winter and nutrition can play a role in supporting mental health. Mpho says, “There is bi-directional communication between the brain and gastrointestinal tract, called the gut-brain axis. Therefore, what happens in the gut has an effect on the brain function and vice-versa. So, mood-related disorders also affect the functioning of the gut.”
These are Mpho’s tips for mental well-being:
- Maintain good gut health by eating whole grains, legumes, fruits, vegetables, nuts, seeds, spices and herbs that feed the gut microbiome with nutrients that support important body functions including immune system regulation and mental health. Ninety-five percent of serotonin and 50% of dopamine are produced in the gut. These neurotransmitters are important for mental health.
- People with SAD tend to crave and eat more carbohydrate rich foods in winter, especially in the evenings. These high carbohydrate meals make them energetic and more awake. However, the body needs less energy in the evening to allow the body to be tired so that you can sleep. The high carbohydrate intake therefore affects sleep quality and duration. The next morning you will wake up tired, craving more carbohydrates, and having little energy for exercise. The combination of high carbohydrate meals and lack of sleep can result in unwanted weight gain.
- Eat balanced meals including low glycemic index (GI) and high fibre carbohydrates such as wholegrains, beans and lentils, vegetables and fruits. Include lean protein and healthy fats in all meals. Nuts and seeds are good sources of healthy fats. These give sustained energy and avoid energy dips that can worsen depressive states.
- Low levels of vitamin B, vitamin D and omega-3 fatty acids are linked to depressive symptoms. Vitamin B sources are leafy vegetables such as morogo or imfino, spinach, kale, beet leaves, sweet potato leaves; whole grains such as sorghum, millet, rice, corn, oats; bean and lentils; nuts and seeds, and animal proteins such as eggs, red meat, fish and poultry. Include omega-3 fatty acid rich foods such as ‘oily’ fish including sardines, salmon, mackerel, herring and tilapia; and plant foods such as walnuts, chia seeds, hemp seeds and flaxseed. Vitamin D rich foods are oily fish such as sardines and salmon, as well as liver and eggs.
- Exercise three or more days a week as physical activity increases the production of the feel-good neurotransmitters in the brain known as endorphins.
- Make sure you get some sunlight in the morning or during the day, as even 10 minutes can boost your mood and help you get some vitamin D. If it is safe, exercise outdoors or go for a hike.
- Turn off devices and screens two hours before sleep time to allow your body to fall asleep easier.
Staying healthy during winter involves more than just avoiding colds and flu. By adjusting your diet to include immune-supporting nutrients, maintaining physical activity, and supporting mental health through balanced meals and sufficient sleep, you set yourself up for a healthier and more enjoyable winter season.