Foods For A Healthy Immune Function

There’s no doubt that diet and lifestyle can play a big part in keeping us fit and well and supporting a robust immune function. Optimum health is very much at the top of the agenda for us all right now with the spread of the Corona virus (Covid 19) but, it’s important to note that you can’t take a one-size-fits-all approach to nutrition because what’s right for one person may be absolutely wrong for another. The personalised nutrition advice that I offer in my clinic, or  via an online appointment, is based on a thorough understanding of you, your medical and family history, your symptoms and your diet and lifestyle.

However, there is some general nutrition advice I can give you to support your immune function and help you and your loved ones keep fit and well, build up your resilience or enhance your recovery from illness. Here are some key areas to think about:

Vitamin C

Most of us know that vitamin C is important for immune function. It’s a powerful antioxidant and some studies have shown that it may help to protect against respiratory conditions, which is particularly relevant at the moment. Think vegetables, not fruit, when it comes to increasing vitamin C in your diet. For example a raw red pepper contains almost 3 times as much vitamin C per 100g as an orange, and leafy green veg, like spinach, kale or cabbage about twice as much. However many vegetables you’re eating at the moment, double it, as it will pay dividends in vitamin C terms.

If you’re thinking about supplementing vitamin C, it’s best to spread the dosage across the course of the day rather than taking it all in one go, because vitamin C is water soluble, so this will help keep a steady supply in the bloodstream. There are lots of good quality options out there. I’m a big fan of the Biocare vitamin C powder, as it’s easy to add to drinks throughout the day. However, you should consult your GP if you’re undergoing any form of treatment, because high doses of vitamin C supplements may interact with your medication.

Vitamin D

It’s always best to know your vitamin D status before taking supplements, because that way you’ll know if you need a maintenance or a therapeutic dose. However, if the spread of Covid 19 means that you’re not keen on going to your local surgery right now, it’s probably fairly safe to assume that you’re low in vitamin D, because most of the UK population is deficient by March.

Vitamin D is found in very small amounts in food, chiefly oily fish and liver, but the best source is sunlight. It’s so essential to our health and well-being that our body produces it through exposure to the UVB rays in sunshine. Vitamin D is fat soluble, which means that it can be stored in the body cells until we need it, but even if you spent a lot of time in the sun last summer, by this time of year your supplies are likely to have run out.

You might think of it as the bone nutrient, and it’s true that vitamin D plays a very important role in bone health because we need it for the absorption of calcium. But it also has a much broader role, underpinning a robust immune function and supporting mental health and well-being. Public Health England recommends that all of us take vitamin D through the winter, so if you’re not already doing this, a dose of 1,000IU for adults or 400IU for children is a sensible maintenance dose. There are lots of good brands around, but one of my favourites is Better You, who do a very nice series of vitamin D sprays.

Beta Glucans

Eating foods that are naturally high in beta glucans can help to modulate the immune function and make it more efficient. These are complex sugars found in the cell walls of certain plants or fungi, such as shitake and reishi mushrooms or oats. Beta glucans support the body’s innate ability to recognise and take action against a potential pathogen like a virus by activating the complement system, which enhances the ability of antibodies and immune cells to take defensive action. Adding dried reishi mushrooms to casseroles, soups and smoothies is a great way to boost beta glucans in your diet.

If you’re considering a supplement, opt for a 1/3 or 1/6 formula (which will be specified in the label), as this is the form which is the most beneficial. I like a product called Elderberry Complex by Bionutri, which is an effective combination of antioxidants and beta glucans for optimal immune support.  Be sure to check with your doctor if you’re taking any medication, to avoid potentially harmful interactions, and always respect the dosage on the label, because excessive doses of beta glucans may actually reduce the benefits.

Gut Health

Over 70% of our immune cells are in the digestive tract and rely on beneficial bacteria in the gut to work well. Eating foods which have prebiotic properties can help to tune up the bacteria and keep the protective mucus membrane of the gut in great shape. Onions, garlic, Jerusalem artichoke, leeks and asparagus all have prebiotic properties, so try to include them in your diet on a daily basis. Fermented foods such as kefir, kimchi or sauerkraut are naturally probiotic and can be very therapeutic for the gut. Simple starter kits can be found online, if you’d like to try your hand at fermentation.

Variety really is the spice of life when it comes to supporting a healthy gut microbiome, and eating a broad range of different foods will help with this, so challenge yourself to eat 50 different foods across the week, rather than sticking with the same few recipes. It’s not as hard as you might think: mix it up a bit with your choice of vegetables; add different herbs and spices to your meals; experiment with unusual grains like quinoa, amaranth, polenta, millet or buckwheat, instead of the same old rice or pasta; and try different meats, fish, or pulses.

If you’re considering taking probiotic supplements, it’s important to know that it’s not all about the numbers. There has been a recent trend towards products with extremely high doses, but there’s no evidence that this is more effective and high-dose probiotics may cause bloating and digestive discomfort for sensitive individuals, so a lower dose is certainly more appropriate if you struggle with IBS and can still be effective. Look for a broad spectrum product that contains a combination of strains such as lactobacillus acidophilus, Bifidobacterium lactis and lactobacillus bulgaricus which can help to provide optimal immune support. There are several good suppliers to choose from and Bionutri, Biocare and Biokult are three good options worth considering. Anyone with a compromised immune function should consult their GP before taking probiotics, due to a possible risk of triggering bacterial infection.

Cooking Methods

B vitamins and vitamin C are water soluble, so if you’re in the habit of boiling your vegetables, you risk losing up to 40% of these nutrients when you strain the water down the sink. Consider steaming or steam-frying, a method that involves a small amount of oil, a splash of liquid and a frying pan with a lid, which can be very effective in retaining the nutrient content.

In most cases, cooking reduces the nutrient content of fruit and vegetables to some degree, but tomatoes are an exception to this. They’re packed with a powerful antioxidant called lycopene, which actually increases in concentration when cooked. This includes freshly cooked tomatoes, tinned tomatoes or tomato ketchup.

There are multiple other ways that diet and lifestyle can help to underpin the immune function and improve your health and well-being but I hope you find these general suggestions a helpful start. If you feel that you’d benefit from some personalised nutrition advice during this tricky time, book in for my 1-hour Nutrition & Health MOT, which we can run remotely via video link, to help you ensure that you’re looking after yourself as well as possible.

Wishing you all the best of health. Keep well and keep safe!

Jackie