The human immune system is a complex set of processes and substances that must work synergistically 24 hours a day to keep us safe from attack by bacteria, viruses and parasites. It also has an important role to play in removing dead or faulty cells from the body. Just as important, however, is the immune system’s ability to turn off its response so that usual function can resume and chronic inflammation can be avoided.
Our bodies do a good job of keeping the multiple cells and processes of the immune system working in harmony, but good immune function depends on a steady supply of nutrients and the smooth running of associated systems such as the nervous system and the endocrine (hormonal) system. Supporting our immune system through the challenges of seasonal infections therefore requires an approach that combines both nutritional and lifestyle considerations.
Here is our multi-faceted plan for optimal immune support:
Celebrate colour in your food
Seek out a diet rich in colourful fruits and vegetables. Berries in particular contain plant compounds that act as powerful antioxidants, protecting the body from damage and potentially reducing inflammation. Add in beta-carotene-rich vegetables such as pumpkin and carrots, as well as green leafy vegetables to ensure a range of immune-supporting nutrients such as vitamins A, C and D.
Pick your proteins
Proteins provide the building blocks (amino acids) for immune cells and for the enzymes that support the processes of the immune system. Dietary protein needs to be sufficient in both quantity and quality to guarantee optimal immune function, as immune cells have specific amino acid requirements. Meats, fish and eggs can provide a complete set of the amino acids the body cannot make by itself, known as essential amino acids. In plant-based diets, take care to choose a range of protein-rich foods that complement each other, such as legumes and rice or wholegrains and nuts.
Don’t forget your fatty acids
The Omega-3 fatty acids, EPA and DHA, support the health of the immune system by influencing the structure and metabolism of all of our cells. Importantly, these oils appear to have a modulating effect that can keep the immune system’s inflammatory response in check. The fatty fish S.M.A.S.H. hits of Salmon, Mackerel, Anchovies, Sardines and Herring offer a choice for different taste preferences. Algae or an algal oil supplement offers a good alternative in plant-based diets.
Nurture your digestion
Good gut health is vital for good immune health because a large proportion of the body’s immune tissue is located in the gastro-intestinal tract. Look after your digestion by slowing down your eating, chewing properly and allowing some minutes of rest after your meals. Get extra gut protection by keeping hydrated between meals, avoiding ultra-processed foods and including vegetables in every meal.
Take action on sleep and stress
Getting enough sleep and managing your stress levels are crucial for optimal immune function. The two are tied up together, each affecting the other for better or for worse. Tackle them in tandem with a relaxing bedtime routine that includes dim lights, meditation, light reading or calming music.
Everyday movement and some exercise activities you enjoy can help to keep your immune system functioning well. Over-exercising can be counter-productive, causing inflammation and hindering healing. Exercising intuitively and balancing your activities with rest is key.
Our ancestors might have had seasonal access to some natural sugars in the form of honey and fruit. Today we are confronted with sugary treats at every turn. Metabolic conditions such as type 2 diabetes, unwanted weight gain and cardiovascular disease are all seen to improve when sugary foods are reduced in the diet. Sugar and the triggers biochemical processes it triggers in the body which have an inflammatory effect. It is not surprising therefore that there is increasing concern that sugar depresses the immune system, not only by creating inflammatory conditions in the body but also by suppressing the responsiveness of the immune system’s white blood cells.
Swap out refined sugar products for naturally-sweet fruit, eating whole fruits rather than fruit juices and choosing lower-sugar fruits such as apples and berries. Look for alternative snack foods such as yoghurt, nuts, olives or dark chocolate (made with 70% cocoa or above).
Take care with iron supplements
Excess iron in the body can dampen the immune system, so it is important to achieve the correct balance between low iron levels and excess supplemental iron intake. Unless your doctor has prescribed iron for you, consult your nutrition practitioner about the correct levels of supplementation for you.
Caution with the cold
We know that getting cold doesn’t give you a cold. However, prolonged exposure to cold with insufficient warming afterwards can be stressful for the body and take vital resources away from the immune system. Be intuitive about your cold exposure – a short cold shower after a sauna can bring immune-boosting benefits, but prolonged shivering in a damp and cold environment is another matter. Look out too for signs of damp in your home and have them cleared – mould spores can become airborne and provoke inflammation in our airways, exacerbating asthma and other respiratory conditions.
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Childs, C.E., Calder, P.C. and Miles, E.A., 2019. Diet and Immune Function. Nutrients, 11(8).
Kelly, B. and Pearce, E.L., 2020. Amino Assets: How Amino Acids Support Immunity. Cell Metabolism, 32(2), pp.154–175.
Menshawey, R., et al., 2020. Low iron mitigates viral survival: insights from evolution, genetics, and pandemics—a review of current hypothesis. Egyptian Journal of Medical Human Genetics 2020 21:1, 21(1), pp.1–14.
Radzikowska, U., et al., 2019. The Influence of Dietary Fatty Acids on Immune Responses. Nutrients, 11(12).