Updated: Jul 23, 2020
Tips for how to support your immune system through healthy eating.
During these challenging times our health and wellbeing is a primary concern to us all. We know that for many of you
understanding how factors in your lifestyle, fitness and nutrition could be improved to support better health is important. We asked dietitian and nutritionist Paula Mee what we can do to promote and bolster our immune system by adapting to a good and sustained eating pattern.
Q: How can we improve our immune system through food? A: Think of building a resilient immune system by supporting it with a good eating pattern over time.There is no one single nutrient or food that supports and sustains your immune system. It relies on a full complement of essential amino acids (proteins), vitamins, minerals, fibre and phytonutrients that we rely on for full body health – both mental and physical health. A well-functioning immune system is critical for survival. The immune system must be constantly alert, monitoring for invading microbes and pathogens. A well-functioning immune system:
The cells of the immune system must be able to distinguish self (human cells) from non-self.
Our immune system provides good defence against harmful microbes, by identifying and eliminating them and by maintaining a memory of immunological encounters.
The immune system must also tolerates innocuous food components from digestion and allows them enter body to nourish us
And the immune system must tolerate non-threatening microbes which live in the colon.
This collection of microbes is called the microbiome. We live in a symbiotic relationship with our microbes. We need them and they need us.
The immune system is complex involving many different cell types distributed throughout the body ( but most are around the gut or digestive tract) and they have many different chemical mediators some of which are involved directly in defence while others have a regulatory role. A pattern of eating that helps the immune system contains all of the following components
Includes foods containing healthy probiotic bacteria.
Found in live foods like natural yoghurt – these can modify the gut microbiome and enhance immune function. Seventy percent of your immune cells are found around your intestine, helping to form resistant barriers against bad bacteria. To express their benefits, probiotics or beneficial bacteria must be active or ‘alive’ and reach the gut in sufficient quantities and so resist the effects of stomach acids. There they can make life harder for the bad bacteria. You can boost these friendly bacteria by including low fat probiotic kefir and live natural yoghurts as daily foods. For an indulgent week-end breakfast, top your date and apple pancakes or your spicy compote and granola with a generous dollop of probiotic natural yoghurt.
Research has found that immune cells can only be activated to fight infection if Vitamin D is available in the body. It is vital for the normal function of the immune system. Hopefully you will have some stores of Vitamin D tucked away after the sunshine this Summer. We can make this vitamin by exposing our face, arms and legs to UV rays. We can also ensure we have enough of this vitamin by regularly enjoying vitamin D rich foods, like oily fish (salmon and smoked mackerel), eggs and fortified foods/ supplements. Take more time for a leisurely breakfast in the lockdown. Top your wholemeal toast with some mashed sardines, a little black pepper or chilli flakes and warm under the grill.
Selenium in seafood
The trace element Selenium is crucial for the immune system to function normally. A deficiency appears to result in immune suppression of our protective ability to fight viral infections. Brazil nuts are the richest natural sources of selenium (although this is soil dependent), followed by fish, shellfish, offal, meat, chicken and game. Make a super fast shellfish sandwich for lunch. Combine some tinned white crab flesh with avocado, lemon mayo, watercress and cucumber on sourdough bread
The Zinc Link
The mineral zinc helps develop white blood cells, the immune cells that fight off foreign bacteria and viruses. A zinc deficiency can greatly increase our risk of infection. Zinc is found in abundance in oysters and shell fish. Lean red meat is another good source but vegetarians have to rely on other foods to ensure adequate zinc, such as pumpkin and other seeds, fortified cereals and low fat yoghurt and milk. Add a tablespoon of natural yoghurt and a dessertspoon of pumpkin seeds to your favourite lamb tagine or vegetable curry for some colour, texture and zinc levels.
Other Vitamins and Minerals
Protective vitamins, minerals and other components found in fruit, vegetables, herbs and spices are called phytonutrients. A steady and consistent intake of these phytonutrients helps to keep our immune systems working properly. Probiotics help feed good bacteria in gut – SCFAs and reduce/manage inflammation. In particular mushrooms help in the production of white blood cells, a type of immune cell in the body. Research suggests that they phytonutrients found in mushrooms can help white blood cells to act more aggressively against foreign bacteria. The very best kinds of mushrooms are shiitake and maitake, which are available now in most supermarkets. Vitamin C contributes to the normal function of the immune system during and after intense exercise. Broccoli and other cruciferous vegetables, such as cabbage, kale, Brussels sprouts and cauliflower are good sources of vitamins in general. Broccoli also contains glucosinolates which help to stimulate the body's immune system. Make a home made fresh mushroom soup. Use a little celery, onion, carrot, ginger and garlic as a base, then add half shiitake and half portabello mushrooms.