Foods to boost your immune system
Staying strong and not succumbing to the Coronavirus is by far the best option, so it’s important to follow all the hygiene advice.
But what other action can you take to support your health and the health of your family?
Fortunately there’s a lot you can do to support your wellbeing.
A healthy immune system is your best defence against Coronavirus, or any other virus.
Although not much is known about this new strain of Coronavirus, we do know a lot about boosting the immune system to fight viral infections.
The following evidence-based recommendations (see references at the end) can support immune function, provide symptom relief and may help shorten the severity and duration of illness.
Good nutrition is the number one priority for a fully functioning immune system.
Diets that are high in fruits and vegetables are beneficial as they provide vitamins, minerals, polyphenols and anti-oxidants.
Include some of the following immune boosting foods in your diet on a daily basis, to build your resilience to fight any virus.
Vitamin C is first on the list because there is so much clinical data on its antiviral properties.
It is a potent antioxidant and contributes to immune defence by supporting many cellular functions of the immune system, including inhibiting viral replication.
Sub-optimal levels of Vitamin C can impair immunity and increase susceptibility to infections.
Vitamin C is water soluble and can’t be stored in the body.
To best support your immune function, consume Vitamin C rich foods at least three times a day.
Here are a few of the top Vitamin C superfoods:
- Red peppers
- Berries (fresh or frozen)
- Citrus fruits
- Kiwi fruit
Reduce your intake of refined sugar and processed foods which suppress your immune system.
Glucose and Vitamin C use the same GLUT1 receptor, so excessive glucose is thought to affect the ability of Vitamin C to get into the cell, which may compromise immune function.
Optimal levels of this vitamin are really important.
It modulates the immune system and promotes innate immunity.
The main source of Vitamin D is through sunlight, therefore we can be prone to low levels during the Winter.
It’s important to test your Vitamin D levels before supplementing.
Increase your intake of vitamin D rich foods such as:
- Fatty fish (salmon, mackerel, anchovies, sardines & herring)
Zinc can reduce the duration and the severity of the common cold.
It plays a key role in antioxidant and anti-inflammatory pathways, keeps the immune system strong, supports growth and promotes wound healing.
Zinc rich food sources include:
- Shellfish and meat
- Chickpeas, lentils
- Nuts and Seeds
Selenium is a key nutrient for the immune system, providing defence against bacteria, cancer and viruses.
It has antioxidant and anti-inflammatory properties.
Eating two Brazil nuts a day is enough to maintain adequate selenium levels in your body.
Garlic contains compounds that can enhance the functioning of the immune system.
Clinical trials demonstrate a significant reduction in the number, severity and duration of upper respiratory infections.
Research shows that elderberry substantially reduces the duration and severity of cold and upper respiratory symptoms.
It has been shown to have potent antiviral activity reducing symptoms of flu.
If you have an auto-immune condition, use Elderberry with caution, because of the way it stimulates the immune system.
70% of our immune system is in our gut (microbiome).
These beneficial bacteria play an important role in our health and immune function.
To support your immune system increase the diversity and quantity of plant based fibre that you eat.
The recommended daily amount of fibre for an adult is 30g – many people consume far less than this.
Aim for 3 portions of fruit and 7 fist sized portions of vegetables a day, also include nuts, seeds, oats, beans, lentils and wholegrains.
A tablespoon of fermented food daily (kimchi, sauerkraut, kefir) is beneficial for gut and immune health, as it is a rich source of probiotic bacteria.
Research shows polyphenols are antiviral, anti-inflammatory, antioxidant, regulate the immune system and support gut health.
Polyphenols are found in fruit and vegetables, eat a rainbow!
For example: green tea, turmeric, ginger, cocoa, raw cacao, red grapes, blackcurrants, berries (cranberries, blueberries, blackberries etc), apples, cherries, citrus fruits, flax seeds, red onion, legumes, cruciferous vegetables (broccoli, cauliflower, kale, watercress, cabbage etc), spices (cinnamon, cumin, coriander etc) herbs (rosemary, thyme, oregano etc) and olive oil.
Drink 2 litres of water and herbal tea daily.
Sleep is important for resilience and for supporting the immune system.
Natural killer cells are essential in the early immune response against viruses.
Their function is reduced by poor quality sleep.
Prioritise an 8 hour sleep opportunity every night and follow these tips to improve your sleep:
- Sleep in a cool, dark room
- Don’t use screens 2 hours before bed, because exposure to blue light suppresses Melatonin production
- Put your phone on airplane mode at night and charge it in another room
- Expose yourself to daylight within 30 minutes of waking
Long term stress lowers the activity of your immune system, making you more prone to illness.
Keep stress levels in check and make time for daily relaxation.
Laughter on the other hand has been shown to increase natural killer cell and immune function.
If you would like personalised advice about supplements or nutrition, or to arrange testing then you can email me at email@example.com.
Nicola Allenby is a Nutritional Therapist with a specialised interest in the Functional Medicine approach to health. Functional Medicine is a science based approach to health, that looks at the underlying cause of a health problem. It treats the whole body system holistically, rather than just focusing on symptoms.
She is regulated by the Association of Naturopathic Practitioners (ANP) and The Association for Nutrition and Lifestyle Medicine (BANT) and holds professional liability insurance with Balens Ltd.
I do not claim to diagnose, treat, mitigate or cure coronavirus or any other disease.
Nutritional Therapy is not a substitute for professional medical advice and treatment.
A Review of Micronutrients and the Immune System–Working in Harmony to Reduce the Risk of Infection (2020). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/
Comparison of Immunomodulatory Effects of Fresh Garlic and Black Garlic Polysaccharides on RAW 264.7 Macrophages (2017). Available at https://www.ncbi.nlm.nih.gov/pubmed/28196294
Dietary Selenium in bacterial and viral infections (2015). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4288282/
Effect of Flavonoids on Upper Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-Analysis (2016). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863266/
Effects of beta-glucans on the immune system (2007) Available at https://www.ncbi.nlm.nih.gov/pubmed/17895634
Efficacy and safety of elderberry extract in treatment of influenza A and B virus infections (2004). Available at https://www.ncbi.nlm.nih.gov/pubmed/15080016
Elderberry treats upper respiratory symptoms (2019). Available at https://www.ncbi.nlm.nih.gov/pubmed/30670267
Expert consensus on comprehensive treatment of coronavirus disease in Shanghai (2020). Available at https://mp.weixin.qq.com/s/bF2YhJKiOfe1yimBc4XwOA
High-dose vitamin C treatment of new coronary pneumonia (2020). Available at http://2yuan.xjtu.edu.cn/Html/News/Articles/21774.html
Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance (2018). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6340979/
Nutritional Treatment of Coronavirus (2020). Available at http://orthomolecular.org/resources/omns/v16n06.shtml
One Health, Fermented Foods, and Gut Microbiota (2018). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6306734/
Prevention and Treatment of Influenza, Influenza-Like Illness, and Common Cold by Herbal, Complementary, and Natural Therapies (2017). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5871211/
Probiotics and paraprobiotics in Viral Infection: Clinical Application and Effects on the Innate and Acquired Immune Systems (2018). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006794/
Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure (2014). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284776/
Regulation of Immune Function by Polyphenols (2018). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5925142/
Sleep, immunity, and circadian clocks: a mechanistic model (2010). Available at https://www.ncbi.nlm.nih.gov/pubmed/20130392
Short natural sleep is associated with higher T cell and lower NK cell activities (2011). Available at https://www.ncbi.nlm.nih.gov/pubmed/21496482/
The effect of mirthful laughter on stress and natural killer cell activity (2003). Available at https://www.ncbi.nlm.nih.gov/pubmed/12652882
The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines (2001). Available at https://www.ncbi.nlm.nih.gov/pubmed/11399518
Therapeutic Perspective of Vitamin C and Its Derivatives (2019). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6721080/
Treatment of the Common Cold in Children and Adults (2012). Available at https://www.aafp.org/afp/2012/0715/p153.html
Three Intravenous Vitamin C Research Studies Approved for Treating COVID-19 (2020). Available at: http://orthomolecular.org/resources/omns/v16n12.shtml?utm_source=BioMedica+Nutraceuticals+2015&utm_campaign=666b79f0cc-Coronavirus+Update_UK&utm_medium=email&utm_term=0_968862c004-666b79f0cc-57567405&mc_cid=666b79f0cc&mc_eid=ac5890c534
Vitamin C enters mitochondria via glucose transporter GLUT1 (2005). Available at https://www.ncbi.nlm.nih.gov/pubmed/16195374
Vitamin D and airway infections: a European perspective (2016). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4806418/
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data (2017). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5310969/
Vitamin effects on the immune system: Vitamin D & A take centre stage (2008). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2906676/
Zinc in Infection and Inflammation (2017). Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5490603/
Copyright © 2020 Nicola Allenby & protected under UK & international law. All rights reserved.