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.
For those of you who have watched this film and want an evidence based analysis of the facts do have a look at this.
Artificial sweeteners – friend or foe?
There has been a lot of press and confusion about the role and safety of artificial sweeteners. Artificial sweeteners are used to provide sweetness while containing little to no calories. The European Food Safety Authority (EFSA), highly regulates all artificial sweeteners giving them an acceptable daily intake (ADI) value. For example, the ADI for aspartame, a 70kg adult would have to consume over 5 litres of Diet Coke everyday over a lifetime.Artificial sweeteners are not recommended for children under three years old.
With the pressure on the food industry to reformulate and reduce the amount of sugar in our foods, they are appearing more often and we are consuming more of them. They are used in a huge variety of products such as: diet soft drinks, jellies, yoghurts, desserts, chewing gum, sweets, I’ve even found then in digestive biscuits!
So, what are the concerns? Although swapping sugars for sweeteners reduces calorie intake, and has benefits for our dental health, there are concerns that sweeteners may interfere with our metabolism and even increase our appetite. There have been other concerns that sweeteners can alter gut bacteria which may be harmful. This has mainly been found in animal studies and the results of human studies have been mixed. Other studies have found that changes in our gut bacteria can be been linked to our weight and overall health, so it is possible that sweeteners may promote weight gain via changes to our gut bacteria. What is clear is that more human trials are needed to test this, and the EFSA have decided to review all sweeteners.
I would argue that we need to exercise the ‘precautionary principle’ here, before we see the evidence from better, bigger and longer-term studies on artificial sweeteners use, to find out for sure their benefits and risks. The best way to avoid problems associated with sugar, and artificial sweeteners is to slowly reduce them in your diet and your taste buds will adapt. Do not underestimate the ability of your body to adjust.
Iodine – why its important not to overlook this mineral in our diet
Although iodine tends not to be the first nutrient that springs to mind as a concern, this mineral is an essential part of all our diets as it is not produced by the body. Iodine deficiency has been described by the World Health Organization as the ‘the world’s greatest single cause of preventable brain damage’. Its needed to make our thyroid hormones, and these hormones are essential for many body processes including growth, regulating our metabolism and for the development of a baby’s brain during pregnancy and early life healthy growth and development.
Most people in the U.K. reach their iodine requirements, but at-risk groups for iodine deficiency are: those who avoid dairy (this is our main source of iodine in the U.K.), pregnant & breastfeeding women (due to the increased requirements).
Fish and shellfish, milk and other dairy foods (e.g. yogurt) provide the most amount of iodine per average portion. White fish provides more iodine than oily fish. Non-animal products such as cereals, potatoes, nuts and fruit and vegetables also contain some iodine but at much lower concentrations than animal sources of iodine, and even if eaten in large quantities are alone unlikely to provide enough iodine to meet requirements. For most adults in the UK, on average, over a third of their iodine comes from milk and other dairy foods. About 300 ml of milk is enough to meet the UK recommendation of 140 µg of iodine per day for an adult. Plant-based milk alternatives contain negligible amounts of iodine, although a few iodine-fortified products are now available (check the label). Seaweed is another good source but isn’t recommended more than once per week, especially brown seaweed like kelp, as excessive iodine can also cause thyroid problems.
So be aware if your diet is low or contains no dairy, shellfish or white fish particularly if you are planning a pregnancy or breast-feeding. If you have just switched to plant milks, then find one that does fortify with iodine and if you are vegan consult your GP to find the right iodine supplement for you.
Food, nutrition and our environment
I challenge you to walk into your local supermarket and guess what time of year it is, just from the food on display. We have year-round access to a huge variety of fruit and vegetables but isn’t that a good thing? From both our environments perspective and our health I would argue its not. We are all aware of the food miles strawberries have to travel in December and let’s be honest how tasteless they are and they like many fruit and veg lose nutrients during their long journey. In the winter months, many fruit and veg are best eaten frozen or even tinned, the freezing process retaining the nutrients, so they are actually better for us as well as the environment.
The UK has the highest consumption of ready meals in Europe – not a fact to be proud of, but its also a fact that the more processed a food is, the worse it is for the environment and the worse it is for us from a nutrition perspective too. All that processing involves energy, water, waste and the use a lot of plastic. We know the more processed a food is, the more the cell walls of the original ingredients have been broken down and so the energy is that much more accessible to our digestive systems, not to mention the nutrients that have been stripped out like fibre and vitamins during processing.
This is a huge and complex topic, but I hope you will stop and think about how you could make some small sustainable changes in the way you eat, find simple recipes to cook from scratch, try and cook with seasonal produce, reduce your waste and reduce the amount of processed foods you eat. Good food Oxford -https://goodfoodoxford.org/about-us/ have a charter we can all sign up to, with ideas on how to change our eating habits for our health, where to source food, help reduce food poverty and the future of our planet.