Expert / 9 November, 2017 / Christine Bailey
With the weather becoming bitterly cold, we decided to dig deep into our 2013 archive to find some winter words of wisdom from nutritionist Christine Bailey on how to survive against winter viruses.
By Christine Bailey MSc PGCE MBANT CNHC
The change of seasons often signals the onset of coughs and colds. This year take action and support your children’s immune system naturally. Nutritionist Christine Bailey explains the best foods to pile on your plate.
With the cool weather and winter season looming you may be looking to give you or your children’s immune system some additional support. The change of seasons can put additional stress on the body. This combined with less exercise especially outdoors and a shift to more comfort carb rich foods can weaken our immune response making us more vulnerable to winter ills. A healthy immune system is dependent on an optimal intake of the right nutrients and the best way to boost these is through your diet. Here are some top immune supporting foods to include.
Research published in the journal Nature Immunology this year demonstrated that eating leafy greens may help stimulate the production of a special type of immune cell known as an innate lymphoid cell, which helps protect the body from invading pathogens and also provides a balance between ‘good’ and ‘bad’ bacteria in the intestine. Leafy greens such as kale, spinach and broccoli are also rich in glucosinolates known for their anti-cancer properties. Why not try making up a green smoothie: simply blend together spinach with a little lemon, pear and banana with water or coconut water until smooth. Another great option is kale chips – you can buy these from health shops or make your own. See my cookery blog for ideas.
Oats are rich in immune supporting nutrients such as selenium and beta-glucans, which have been shown to enhance neutrophil action, a type of immune cell. Oats also act as a prebiotic stimulating the growth of healthy bacteria in the gut, which helps supports immune function. Porridge with a little cinnamon is a great warming breakfast option. Alternatively snack on oat cakes with some nut butter for a healthy snack.
Mushrooms particularly Shiitake, Maitake and Reishi contain immune boosting polysaccharides including beta glucans, which can enhance our body’s defences, protect against cancer and possess anti viral properties. They also contain a little vitamin D – this is crucial for our immune system so make sure your level is optimal (see below).
Research published in journal Immunology Letters have shown that the active polyphenol found in green tea (EGCG) has the ability to increase the number of regulatory immune support T-cells improving immune function and reducing inflammation in the body. While green tea is not really appropriate for children you can add the matcha green tea powder to cakes, muffins and ice cream.
Yogurt and Kefir
Your digestive tract contains the largest number of immune cells of your whole body, constituting approximately 60% of your entire immune system. Including fermented foods like yogurt and kefir can help maintain healthy bacteria to crowd out harmful microbes and stimulate immune-cell production. Kefir is also a useful source of vitamin K and vitamin D both important vitamins for immune health. If you want to know how to make your own kefir check out my nutrition blog on my website.
Butternut Squash and Sweet potato
Orange flesh fruit and vegetables are packed with carotenoids, Vitamin A and vitamin C – essential nutrients for immune function. Vitamin A has anti-viral properties and is vital for supporting the cells of the skin, gastrointestinal tract and lungs – the main barriers that separate you from the outside world. One of the easiest ways to cram these into your diet is to make up a lightly spiced Butternut squash or sweet potato soup.
Salmon and other oily fish
Essential fatty acids found in oily fish are important for maintaining the cells in the gut and research from Michigan State University and East Carolina University suggests that an omega 3 fat known as docosahexaenoic acid (DHA) appears to increase activity of immune system cells, specially “B” white blood cells. Salmon is also a source of vitamin D. Vitamin D is essential for a healthy immune system and maintaining optimal levels through the winter may help prevent the flu (see below). There are lots of ways to get more oily fish in your diet – whether it’s a homemade salmon dip, using smoked mackerel fillets in salad, homemade salmon nuggets or fish cakes. Aim for at least 3 portions each week.
Quality whey protein powder provides all the key amino acids to support the production of glutathione, an immune boosting antioxidant and preserves levels of glutamine an important fuel for immune cells. It also contains immune enhancing constituents such as immunoglobulins, lactoferrin needed for tissue repair and maintaining a healthy gut barrier. If you exercise a lot whey protein may be a good option for you post training.
Citrus fruits are packed with vitamin C, which makes immune cells stronger and helps the immune system identify and attack invaders. It also helps make interferon – which is part of the body’s own natural defence system enabling you to fight off infection. During the winter it is worth increasing your intake as high levels can help prevent the flu. Other good sources including berries, Kiwi Fruit and Red Pepper
Nuts and Seeds
Nuts and seeds especially sunflower seeds and almonds are good sources of vitamin E. Vitamin E is an important antioxidant protecting our fatty tissues and cell membranes from damage and fighting infections. Just 35g or ¼ cup of sunflower seeds contains 12mg which meets your daily recommended needs. Why not try adding seeds to homemade crackers, bars or breads.
Honey & Bee Propolis:
Honey-lemon tea is commonly used for sore throats. Not only does the honey help coat irritated membranes and soothe coughs but also it has anti-microbial properties especially Manuka or Raw honey. Bee propolis is also known for its antimicrobial and immune-enhancing properties. If you have a sore throat just dissolve a teaspoon of Manuka honey in a glass of hot water with the juice of ½ lemon.
Great news for chocolate lovers!! But not just any type of chocolate. Raw Cacao powder is rich in flavonoids, antioxidants that help combat free radicals produced by the body, which can prevent the immune system from working optimally. It is also packed with zinc. Zinc is an antiviral nutrient and research has shown it can lessen cold duration and decrease its severity, if taken within 24 hours of the onset of symptoms. Add raw cacao to smoothies or raw homemade truffles or raw bars for a sweet treat. Other good sources of zinc include nuts, seeds, oysters and meat.
Garlic is a fabulous immune supportive spice – it’s antibacterial, antiviral and anti-fungal. For optimal benefits the garlic should be fresh and crushed which helps convert the chemical allicin to its active form.
Research has shown elderberry extracts have anti-viral properties and help tackle the flu virus reducing recovery time. Elderberry extracts are available as a liquid supplement known as Sambucol – these are great for children as it tastes naturally sweet
Coconut oil contains monolaurin made from lauric acid a type of medium chain triglyceride, which has been widely researched for its anti-microbial and anti-fungal properties. It is also effective against viruses including herpes virus. Use it in cooking or add to protein shakes for an extra immune boost.
Vitamin D – check your levels
Studies have shown that adults and children with higher vitamin D levels contract substantially fewer colds, flu and other viral infections. Vitamin D also seems to lower levels of inflammation too. So while it is important for bone health it plays a much more significant role in balancing and supporting the immune system. Vitamin D is mainly obtained via exposure to sunlight and there are in fact few food sources of vitamin D. These include oily fish, mushrooms and full fat dairy. But you are unlikely to get enough through foods. During the winter months levels can fall so it is worth checking your levels through a simple home spot blood test which you can obtain via my web site www.adancenutrition.co.uk. If your levels at low you can take a liquid emulsified supplement or a spray which is rapidly absorbed into the blood stream.
What to Avoid
Watch out for the following dietary and lifestyle factors, which can reduce your immune health
Excess Sugar. High intakes of sugar can suppress the ability of white blood cells to protect and fight against infection. Even 100g of sugar can have a damaging effect, which lasts for several hours.
Obesity. Increased cholesterol levels associated with obesity can inhibit immune functions including the ability of white blood cells to proliferate and produce antibodies
Alcohol and Caffeine. Alcohol, essentially another form of sugar depresses immune activity. Caffeine in coffee, tea and fizzy drinks is known to inhibit absorption of vital nutrients and directly suppress the immune system
Stress and Sleep. There are many studies to show how stress and reaction to stress by the individual can suppress the immune function. Learning how to deal with stress, rest and relaxation all form an important part in boosting our immune response. During our deepest level of sleep immune enhancing compounds are released so ensuring a good nights sleep really is vital for our health.
Pollution. Chemical stress from smoking, air pollution and other environmental chemicals can all weaken our immune system. Where possible buy organic produce.
Exercise. Gentle exercise can stimulate our lymphatic system and circulation thus enhancing our immune response. Over exercise however can actually result in a suppressed immunity.
Antibiotics. Over-reliance on antibiotics can actually lead to a depressed immune system and upset the balance of bacteria in the gut.
Immune Supporting recipe
Chicken Ginger Miso Soup
You can’t beat homemade chicken soup for comfort and healing – this one includes plenty of anti-inflammatory chilli, garlic and ginger and a immune supporting shitake mushrooms.
Preparation time: 15 minutes
Cooking time 2 hours 3 minutes
Storage: Freeze for up 1 month.
Chill for 2-3 days
Nutritional Information: per serving 396kcal, Protein 34.7g, Carbohydrates 10.2g of which sugars 7.7g, Total Fat 24g of which saturates 6.4g
Gurzell et. al. DHA-enriched fish oil targets B cell lipid microdomains and enhances ex vivo and in vivo B cell function April 2013 Journal of Leukocyte Biology vol. 93 no. 4 463-470
Zakay-Rones, Z. et al., ‘Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections’, J. Int. Med. Res., vol. 32(2), pp. 132-40 (Mar-Apr 2004).
Hulisz, D., ‘Efficacy of zinc against common cold viruses: an overview’, J. Am Pharm. Assoc., vol. 44(5), pp. 594-603 (Sep-Oct 2004).
Zakay-Rones, Z. et al., ‘Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B Panama’, J.Altern. Complement Med., vol. 1(4), pp. 361-9 (Winter 1995).
Ginde, A. et al., ‘Association between serum 25-hydroxy vitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey’, Arch. Intern. Med., vol. 169(4), pp. 384-90 (23 Feb. 2009).