Suffering from back-to-back colds and illnesses doesn’t have to be an inevitable part of winter. While you may think that being particularly prone to colds and flu is just bad luck, there are a lot of proactive steps you can take to support a strong immune system – starting with your diet.
As around 70 to 80 per cent of your immune system is located in your gut, eating foods that support gut health is a good place to start, along with eliminating foods that may be damaging to your gut and weaken your immune system response. I’m a health and nutrition coach, and these are the five foods I recommend reducing or cutting out of your diet if you want to avoid catching every cold or virus that is spreading around this season.
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Consuming sugar can impact your immune system
Sugar
If you get sick regularly, limiting added sugars in your diet can be one of the best ways to support your immune system. Within 30 minutes of eating simple sugars (like glucose, refined sugar and fructose), the ability of macrophages – a type of white blood cell – to eat up invading viruses and bacteria decreases by 50 per cent, and this effect lasts for at least five hours. So if you’re exposed to a virus or bacteria, not only are you more likely to become ill, but you may also potentially suffer for longer if your diet is high in sugar.
Meanwhile, research shows that poor blood sugar control is one of the biggest risk factors for poor outcomes to almost any infection. So cutting down on the sweet stuff could be one of the most effective ways to support a strong immune system.
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Deli meats and processed meats can promote inflammation
Deli meats
Processed and deli meats such as ham, sausages and bacon have been classified as group 1 carcinogens, as they can damage the gut and are linked to an increased risk of developing colorectal cancer, so you should already be trying to limit your consumption of them. But particularly so when you’re focusing on supporting your immune system. These meats are high in saturated fats, which may contribute to immune system inflammation, as well as promote inflammation in the body, which can lead to a number of diseases. Our verdict? Swap for lean meats like chicken and turkey, or upgrade for nitrite-free options wherever possible.
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Crowding out ultra-processed foods can support your immune system
Ultra-processed foods
We all know eating a diet high in ultra-processed foods isn’t ideal for our health, for a number of reasons. But chances are, when our diet is centred around ultra-processed foods including ready meals, snacks and crisps, we are likely not meeting our daily fruit and vegetable requirements, nor our suggested daily fibre intake, both of which can support a healthy microbiome and immune system for fighting off those endless cold and flu bugs. Meanwhile, some of the ingredients in these foods, such as emulsifiers, artificial sweeteners and preservatives, can alter your gut bacteria and damage the gut lining, promoting inflammation and immune dysfunction. All the things we don’t want for a strong immune system!
You don’t necessarily have to go cold turkey on these foods, as it can be very hard to do, but crowding out ultra-processed foods with whole food alternatives and plenty of fruit and vegetables can be beneficial for your overall health and well-being. Simply checking the ingredients list on products and avoiding ones with unrecognisable ingredients or things you couldn’t use for cooking at home is a good place to start when knowing what to cut out first.
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Alcohol may contribute to a weakened immune system
Alcohol
Drinking alcohol is another thing that may contribute to a weakened immune system and leave you more susceptible to coming down with regular colds and other illnesses. Not only can alcohol contribute to blood sugar imbalances (another issue linked to poor outcomes from infection), but it also requires the mineral zinc to metabolise it out of the body.
Zinc plays many important roles in the body, including helping in the development and function of immune cells, and enhancing the body’s ability to fight infections. Therefore, if our zinc intake is frequently used to metabolise alcohol, we may become deficient and not have an adequate supply for its other crucial functions. Meat, seafood, nuts and seeds, and dairy products are all good dietary sources of zinc, so ensure you eat plenty of these if you do still like to enjoy the occasional tipple.
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Fast food may drive inflammation and cause imbalances in the gut
Fast food and fried food
As the author of How to Understand and Balance Your Hormones, I know that much like ultra-processed foods, fast food and fried foods are also worth cutting out of your diet when you’re looking to support a healthy immune system. These foods may drive inflammation and cause imbalances in the gut, which can contribute to immune dysfunction.
Meanwhile, the packaging used for fast foods often contains plastics like phthalates, which can leach into your meal. These are known endocrine-disruptors, which means they can disrupt the hormone messengers within your body, while also reducing the diversity of gut bacteria, which is required for a strong and healthy immune system.
