Coronavirus and nutrition – fact and fiction
I hope you are as well as possible during these difficult and unsettling times. Understandably, everyone is worried and wants to do everything possible to protect themselves and others from catching Covid-19. Unfortunately, this fear around the coronavirus pandemic has given rise to all kinds of nutritional quackery, supplements and snake oil products claiming to ‘boost’ your immune system. Keto diets, vitamin C shots and herbal remedies are just some of the misconceptions I’ve seen touted. Please avoid any product using the terms ‘immunity boosting’ or ‘COVID-19 protective’ in its advertising. These are red flags for scientific quackery.
Just to be clear, no single food, nutrient, diet or supplement that will ‘boost’ immunity or prevent you from catching Covid-19. Enticing as it may sound, you don’t want to be ‘boosting’ your immune system. The term, ‘boosting’ is very misleading but it seems to be being used everywhere. An immune system which is ‘boosted’ or over-active can lead to problems such as allergies or autoimmune disease, and some of the more serious complications associated with Covid-19. Anyone peddling such advice does not understand how the immune system works. The only way we can safely ‘boost’ our immune system is through immunization.
A healthy and active immune system is critical to fighting off the Coronavirus. Instead of talking about ‘boosting’ immunity, we should be talking about ‘maintaining’ or ‘supporting’ immunity to avoid infection. We know a varied and balanced diet can ‘support’ our immune system. It can also give us the feeling we are proactively doing some-thing to help ourselves and others, in a time when we are all feeling powerless and vulnerable.
Other lifestyle factors to support immunity
Nutrition is not the only way you can support your immune system, making sure you take regular, but NOT excessive exercise. Studies have shown that regular moderate exercise lowers your risk of infection, more is not necessarily better. Many studies show that long, hard, continuous sessions (over 90 minutes) can temporarily lower your resistance to infection, so this is not the time to be aiming for your PB! Make sure you fuel your exercise too particularly with good quality carbohydrates like porridge. Sufficient carbohydrate can reduce stress hormone levels and the associated drop in immunity following exercise. Exercising with low glycogen stores is associated with bigger increases in stress hormone levels and greater suppression of your immune cells. So now is not a good time to experiment with intermittent fasting diets!
Sleep is also really important as we know lack of sleep depresses the immune system, making you more susceptible to illnesses and infection. During sleep your body produces anti-bodies and cytokines, proteins that co-ordinate your body’s response to infection and inflammation. One study found that getting fewer than 6 hours sleep a night can quadruple your risk of getting a cold. Also try where you can, stick to your usual bed and waking times, the body and mind thrives on routine. Avoid blue light for an hour before you go to bed, read, take a bath, listen to music. Do you really need to see the news again, when it’s probably only going to unsettle you? Finding activities that you find relaxing and enjoyable are key from meditation to art, you now have the time to give it a go. I sketched for the first time for probably 20 years this week and found it remarkably relaxing, my kids were even able to recognize what it was!
So, what is this balanced diet?
A balanced varied diet is key, but what does this mean in practice in term of nutrients? Ensure you’re consuming plenty of foods rich in vitamins A, C and E, vitamin B6, zinc, iron and magnesium – nutrients that are vital to the functioning of the immune system. To get these into your diet focus on fresh, frozen and tinned fruit and vegetables, whole grains – the brown rice, pasta, quinoa, oats, lean proteins, beans, eggs, lentils, nuts and seeds, and low-fat dairy while limiting highly-processed foods. I’m sure it’s a message your familiar with and it doesn’t mean deprevation, food is one of life’s pleasures we still can access, however eating too many processed food which are basically ‘empty calories’ mean we won’t be getting all these important nutrients.
Another key message for a balanced diet is variety in all the food groups – so eat the rainbow of colours in fruits and veg – get your kids to make a chart. The blue, purple, red and orange fruits and veg are rich in flavonoids which have antioxidant properties that help support immunity. A 2016 study showed that flavonoids play an essential role in the respiratory tract’s immune defence system, an excellent reason to include a wide range your diet.
There is one other way that nutrition has its greatest impact on our immunity is through our gut. Our gut is host to trillions of microbes that produce chemicals (such as short chain fatty acids) that play a key role in the body’s immune response to infection and maintaining health. In fact, 80% of immune cells reside in the gut. These microbes feed off the fibre from the grains, fruits and veg that we cannot digest and they thrive on a variety of plant fibre, hence one of the reasons variety in the diet, is so important. These plant fibres are called pre-biotics. Particularly beneficial pre-biotics are onions, garlic, pulses, artichokes, leeks, asparagus and whole grains.
So, the best way to increase the beneficial microbes in your gut is by eating a wide range of plant-based foods, which are rich in fibre, and limiting ultra-processed foods. Eating a Mediterranean-style diet with plenty of fruit, vegetables, pulses, nuts, seeds and whole grains has been shown to improve the diversity of gut microbes and reduce inflammation. If you can’t get fresh fruit and vegetables while self-isolating, then buy frozen, which are just as nutritious as fresh. You can also increase the number of foods that are probiotics like kefir, natural live yogurt, saukraut, kombucha and sourdough bread. These foods are fermented and contain the live microbes that exist in our gut. You can also take probiotic supplements but there is such a huge range to choose from make sure you select one with robust evidence that the bacteria actually survive our stomach acids and make it to your gut. If you want to read more about Gut health Dr Megan Rossi is a research leader in this area and here is her website.https://www.theguthealthdoctor.com/
I hope you find this helpful and use this unprecedented phase of enforced home living as a chance too cook more from scratch, experiment with new recipes and nourish yourselves with a varied balanced diet.