Why eating to support the immune system is so important

It’s an utterly helpless feeling (and I speak from personal experience), seeing your child struggle to breathe due to an asthma attack. I wouldn’t wish it on any parent, yet childhood asthma is on the increase, with more and more children being prescribed inhalers.

There are many different triggers for asthma including colds and viruses, emotional stress, cold weather, exercise and allergies. But can diet affect asthma?

My answer is that being well-nourished, using diet and/or supplements, can play a role in modifying our response to some of these triggers by supporting our immune system.

The research: studies linking diet and asthma are inconclusive – and there’s a distinct lack of the important, ‘gold standard’ Randomised Controlled Trials. Studies have looked at associations between the ratio of Omega 3 to Omega 6 fats, Vitamin D deficiency, supplemental and dietary antioxidants, fruits and vegetables. The available epidemiologic evidence (based on population studies) is weak but is supportive with respect to vitamins A, D, and E, zinc, fruits and vegetables – and a Mediterranean diet for the prevention of asthma. Inflammatory markers (such as IL 17) are raised in Asthma – and we know that we can modulate these markers with diet and supplements – so while the research isn’t specific, there are definitely opportunities to explore. But it’s a very personalised approach – what contributes towards inflammation in one person is not the same as the next. It’s a balance between our genetics, our environment and increasingly, our gut: which is why in our nutrition clinic we look at personalised nutrition programmes, not one-size fits all.

Reasons why childhood asthma has increased includes:

  • C-sections instead of vaginal births increase the chance of allergies, including asthma, by altering the initial bacteria in the gut. Gut flora is a major, overlooked part of our immune system regulation.
  • Bottle feeding instead of breast feeding results in different, less protective gut flora – again impacting the immune system
  • Childhood antibiotics wipe out the protective good bacteria in the gut
  • A diet lacking in nutrients and fibre but high in sugary, refined and processed foods and exposure to environmental chemicals can push the body towards inflammatory pathways
  • Genetic predisposition towards an imbalanced immune response

So what can we do?

The obvious way is to simply support a balanced immune system using food and/or supplements:

1. Eat your nutrients: Vitamin C and B Vitamins to support the adrenal glands which produce hormones including anti-inflammatory cortisol (steroid asthma inhalers mimic cortisol production and reduce inflammation). Vitamin C also helps to support the immune system, as well as reduce  histamine. In asthma (as well as hayfever and eczema) too much histamine is produced, increasing inflammation. Vitamin D is now known to be a powerful modulator of the immune system – and Vitamin A, zinc and selenium offer additional immune support; Vitamin A, found in brightly coloured fruits and vegetables (as well as butter in the form of retinol) helps to keep mucus membranes healthy. Magnesium can help to keep airways relaxed so magnesium-rich foods (or supplements) such as nuts, seeds and dark green leafy vegetables are a great addition to the diet.

2. Probiotic foods: live natural yogurt, or fermented foods such as miso, sauerkraut and kefir help to repopulate the gut with ‘good’ bacteria. A good quality probiotic supplement has the same effect, and is especially important after a course of antibiotics. Eating prebiotic foods, including vegetables such as artichokes, leeks, onions and asparagus help to feed the ‘good’ bugs; a vegetable-rich diet is an important factor in gut health. Over 70% of our immune system is located in the gut – so it’s imperative that digestive health is considered.

3. Reduce food sensitivities or allergens: common foods include wheat, dairy, shellfish, eggs, soy, corn and peanuts. It’s better not to just guess – a short-term elimination diet or food intolerance testing for children is a better idea, under the guidance of a qualified Registered Nutritional Therapist. It’s important that children don’t miss out on nutrients!

4. Raise Omega 3s: Whilst inconclusive in asthma research, it is known that Omega 3 oils – found in oily fish (mackerel, herring, salmon, sardine), flaxseeds, chia seeds, pumpkin seeds and walnuts promote the anti-inflammatory pathways in the body. A high intake of sugar, processed vegetable oils and trans fats, or a lack of B vitamins and minerals including zinc can prevent the beneficial Omega 3 fats from progressing down their anti-inflammatory route.


5. Boost phytonutrients from plants: 
Red onions and apples are easy apples
to get into children’s diets and contain quercetin which reduces histamine production (another option is quercitin supplements). Hot chocolate (made with cocoa) is a great dietary addition: cacao, cocoa and dark chocolate (70%+ cocoa solids) are potent antioxidant sources and can reduce leukotrine production (excessive leukotrines are a major factor in asthma attacks). We’ve got plenty of chocolate-orientated snacks on our website including: chocolate tasty bites, chocolate flapjacks and energy balls as well as chocolate breakfast porridge! Ginger, turmeric and bromelain (from pineapple) also have potent anti-inflammatory properties.

6. Reduce food additives and colourings: – certain E numbers including MSG, tartrazine, benzoates, sulphur dioxide and sulphites can be linked with asthma. Check food packet ingredients – they’re surprisingly common, and in anything from dried apricots and raisins to children’s medications.

The indisputable scientific evidence around diet and asthma isn’t yet there – but there are so many ways to modulate our response to asthma triggers via diet and supplements, my personal view is that it’s ridiculous not to try.  

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