In the last eighteen months, we’ve been hearing more than usual about immunity. The risk of COVID-19 has increased how much we think about our own resistance to disease. Whilst a balanced immune system may not prevent us from catching viruses; it can minimise the effect that these viruses have on our bodies.
The immune system is the bodily system that protects us from foreign substances, cells, and diseases by producing an immune response to fight invading cells. Our diet can play a huge role in naturally supporting our immune system and the health of our gut. The key in all this is to have an immune system that is balanced, not weak and not too strong either. Too much immune response is just as problematic as too little. Here are a few ideas to help your immune system help you.
Our gut and our immune system
Gut health is proven to strengthen the immune response to infection. 70% of our immune system is present in our gut and this is formed from an early age*. If our gut bacteria is imbalanced, such as too much ?“bad” bacteria, this can confuse our immune system causing it to start attacking our own cells. While our immune system is busy reacting to healthy cells, not only is it easier for us to become ill but it’s also harder to heal and recover. So how can we keep our gut microbiota balanced?
We can reduce practises which damage our friendly gut bacteria. These include taking anti-biotics, eating high sugar foods, high red meat diet and excessive alcohol. Instead we should encourage our ‘friendly’ bacteria by eating the right foods. Gut-supporting foods are high in fibre, specific vegetables like garlic and onions (pre-biotics) and live, fermented foods, like kefir, kombucha and sauerkraut (pro-biotics). Our fibre intake should be approaching 30g a day – which can be quite a challenge but it is possible. It’s important to understand a little more about fibre. There are two types:
Foods high in soluble fibre (soluble in water) help to lower ‘bad’ cholesterol by reducing the amount of cholesterol that is absorbed into the bloodstream from our intestine.
Insoluble fibre does not dissolve in water and is undigested by the body. For this reason, it helps to keep the gut moving and promote regular bowel movements. This is one of the reasons it has been linked with reducing both constipation and the risk of bowel cancer.
Here are some food sources of both types of fibre. Try to eat both in your daily diet.
|Type||Major food sources||Examples||Physiological effects|
|Soluble fibre||Fruits, vegetables, some cereals and beans||Apples, bananas, citrus fruits, carrots, barley, oats and kidney beans||Delays gastric emptying, slows down glucose absorption and can lower blood cholesterol|
|Insoluble fibre||All plants, wheat, rye, fruit and vegetables||Wheat products and brown rice||Increase faecal bulk and decrease transit time|
And here’s a table of foods to give you an idea where you might get your fibre from:
|Food||Grams of fibre||Food||Grams of fibre|
|Chia seeds per 100g||34.5||1 half large avocado||5|
|Av. portion baked beans||14||1 medium apple with skin||4.5|
|Almonds per 100g||12.5||1 medium potato with skin||4|
|Oats per 100g||10.6||1 cup of strawberries||3|
|Lentils per 100g||7.9||1 medium banana||2.6|
|Chickpeas per 100g||7.6||1 portion of spinach||2|
|Raspberries per 100g||6.6||1 medium carrot||1.5|
|1 medium pear with skin||5.5||1 slice of brown bread||1|
Focus on plants and eat the rainbow
In principle, the more plant-based your diet, the more you will improve your immune system. Fruits and vegetables are full of micronutrients which play a vital part in keeping our immune system (and our whole bodies) healthy.
Together with antioxidants and zinc, Vitamin C is also key and because we do not make or store it, our diet is crucial to providing enough Vitamin C for our immune system to function properly. Try to eat high Vitamin C foods as raw as possible, since high heat can destroy this precious vitamin. Selenium (Brazil nuts are a high provider) has also recently been linked to improving our resistance to infection.
Immune supporting shopping list
Here are a dozen fantastic immune supporting foods:
A diverse diet is a healthy diet!
Should I supplement?
We should also remember the value of Vitamin D in our fight against becoming ill. Research** shows that it has a vital part to play in reducing inflammation and disease. In the winter it's difficult to get sufficient Vitamin D, with sunlight less strong and less frequent. I'd recommend looking into taking a supplement to maintain your vitamin D levels, especially when sunlight levels are low. Also consider how much light nutrition you are receiving. Here’s a link to a podcast I recorded with Neina Sheldon from Light Matters.
Lastly if you look after yourself in a wider sense, you will also help your immune system function better. Try to keep your stress levels managed, hydrate yourself and get plenty of sleep. All the usual self-care principles will help keep your immune system healthy.
Hope you can take these positive steps to keep yourself protected all year round.
The Mindful Eating Clinic
Eating therapy, weight management and nutrition advice
**Cynthia Aranow, MD. Vitamin D and the Immune System. March 2, 2011
* Geuking MB, Köller Y, Rupp S, McCoy KD. The interplay between the gut microbiota and the immune system. Gut Microbes. 2014 May-Jun;5(3):411-8. doi: 10.4161/gmic.29330. Epub 2014 Jun 12. PMID: 24922519; PMCID: PMC4153781.