Current evidence suggests that no one food or supplement will boost your immune system. Sorry! Instead, a healthy immune system is reliant on a number of factors. We must eat well, be more active, stress less, and sleep better. Lifestyle medicine at its best. Some of us are finding this a whole lot easier said than done – Covid-19. But let’s look at eating well and what foods will support a healthy immune system for you now, and in the future.
We know that eating well supports the gut microbiome i.e. the trillions of micro-organisms (bacteria, fungi and viruses) that live and work for us in our gut. Many bacteria are especially beneficial to our immune system as most of the immune system is also located in the gut. Good bacteria work for the immune system by:
- maintaining and contributing to a healthy gut lining
- producing nutrients
- protecting our tissues from toxic waste products.
So, if we eat well for the gut microbiome we eat well for the immune system.
What should I eat for a healthy immune system?
Include the following foods in your daily diet to ensure you are meeting the needs of your healthy gut.
Eat PRObiotics – these are the foods which contain healthy bacteria as part of their make up. Think live yogurts, sauerkraut, kimchi, and keffir. Olives and pickles are also fermented foods but haven’t been as widely studied. We are not sure of their impact on the immune system. I’m not really a fan of kimchi, and sauerkraut tends to give me lots of wind, but I eat natural yogurt every day. I regularly include olives and pickles in my diet – probably 3-4 times per week – with olives going into sauces and salads, and pickles in my salads and sandwiches.
Eat PREbiotics – these are the foods which contain a type of soluble fibre which feeds our good bacteria and stimulates their growth. Think oats, bananas, apples, artichoke, and asparagus. My daily porridge with seasonal Bramley apples ticks the box for me here. With summer just around the corner artichokes and asparagus will go on my shopping list for a delicious salad.
Eat wholegrains – these are the foods which still contain the outer husk of the cereal grain. Think brown rice and pasta, barley, buckwheat and quinoa, as well as rye and other wholegrain labelled breads. I find quinoa tricky to cook but love barley in soups and stews and have also used it for risotto. Peanut butter on rye bread with a banana and a smidge of honey is a quick-fix easy and delicious lunch. Team with a pot of natural yogurt and you are ticking a wealth of boxes for your immune system.
Eat pulses and legumes – Think lentils, peas, chickpeas, beans and peanuts. Lentils are super as thickeners to soups and stews or to make a lovely dahl. Peas go with everything in my house, chickpeas – though a bit windy too – are consumed as hummus, in curries, and occasionally cold in a salad. I throw a handful of peanuts into salads and stir fries when I am not eating the nut butter on toast! Totally plant based and totally yummy for you and your gut.
Eat plenty of fruits and vegetables – eating a rainbow of colourful fruits and vegetables offers up all sorts of goodies nutrient wise. Variety is considered key as different colour fruits and vegetables provide a slightly different nutrient profile. Think seasonally. Eat as many different colours as you can through the day for your best efforts to support your immune response.
Top tip: think fruit or vegetable at each meal and snack time.
What foods are not helpful to a healthy immune system?
Processed foods – I am afraid I won’t be advising you to eat lots of highly processed foods such as biscuits, cakes and pastries, or foods containing lots of artificial sweeteners. Not only are these foods nutrient poor but we tend to eat them instead of a healthy diet. Result? We deprive our bodies of good nutrition that keeps our bodies and minds in good health.
What nutrients will boost my immune system?
Optimising nutrition for a healthy gut is exactly the same as eating well for a healthy gut – boosting is not available unfortunately. Read about individual nutrients if you are interested in their unique properties. If you just want to know what to eat – just reread what’s written above!
Vitamins A, B, C, D, and E
These are the vitamins which have been mostly associated with a healthy immune system, and each for a variety of reasons:
- Vitamin A helps to maintain gut structure and lining, as well as mounting the immune response. Preformed sources are animal based such as eggs, milk, yogurt, cheese and oily fish. Plants give us betacarotene which is made into active vitamin A in the body. Red, yellow and green fruits and vegetables are good sources of betacarotene. Tomatoes, carrots, mango, papaya, and spinach are some examples of what to eat.
- B Vitamins influence the production and activity of natural ‘killer cells’ once they recognise a pathogen. Good sources are both plant and animal based. Plants: green leafy vegetables such as broccoli, cabbage and spinach, wholegrain cereals, and chickpeas. Meat, salmon, milk, cheese, eggs and fish provide us with all the B vitamins we need.
- Vitamins C and E help to protect cells from stress, and are also involved in making specialised cells which mount an immune response. Great sources of Vitamin C are citrus fruits, blackcurrants, broccoli, Brussels sprouts, potatoes and peppers. As vitamin E is soluble in fat rather than water we look to healthy oils such as plant oils, nuts and seeds as well as wheat germ for our intake.
- Vitamin D helps some immune cells mount the immune response and destroy pathogens. We get most of our Vitamin D from the sunlight and should all be taking a supplement October through to April when we begin to restock our Vitamin D levels. Looking to foods we find Vitamin D is found in oily fish, red meat, egg yolk and fortified foods such as breakfast cereals and milk.
Minerals – zinc, selenium and iron
These are considered especially important to a healthy immune response:
- Zinc tends to be better absorbed from animal sources such as beef and seafood. Good plant based sources are wheat germ, beans, nuts and tofu.
- Selenium – Brazil nuts (2 per day is enough), mushrooms, meats and wholegrains are all great sources of selenium.
- Iron – red meat is a really good source of iron. If you want to reduce your intake of red meat look to chicken and fish as alternative animal sources or whole-grains, legumes and fortified breakfast cereals for vegans/vegetarians. Including a source of fruit or vegetables with each of your meals and snacks will optimise your uptake of the iron from the animal or wholegrain source.
So we see whether we focus on foods or individual nutrients, supporting our immune system is all about consuming a variety of foods, and recognisable on the plate is always a good thing : )