Nutritional Support for Your Immunity and Corona Virus (SARS-CoV-2)
We have all now become familiar with the novel coronavirus, SAR CoV-2, which was first identified in Wuhan, China in late 2019 as the cause of coronavirus disease 2019 (COVID-19). Coronaviruses were identified as human pathogens in the 1960s and infect both humans and a variety of animals, including birds and mammals.
Typically the illness presents in humans as a respiratory or gastrointestinal infections and symptoms can range from a common cold to more severe lower respiratory infections. More recent observations show that in addition, changes in blood platelets triggered by COVID-19 could contribute to the onset of heart attacks, strokes, and other serious complications in some patients (1).
Take control of our Health
There is currently so much information circulating about risk factors, proposed treatments and patient outcome it can seem overwhelming to say the least! So if there is a second wave what are the main actions we can make to take control of our health and potentially minimise some of the risk outside necessary government guidelines for social distancing, wearing a mask and shielding? A second wave during the flu-season means we should really act now if we want to optimise health, lower inflammation in the body and boost the immune system. This Is the ideal time to focus on nutritional strategies, natural supplementation and lifestyle changes as we are still in the Summer and positive behavioural changes are typically easier in the long, sunny days when we are feeling more optimistic. Right now, positive changes can also help focus our minds and if we start taking control of our health we can feel more empowered in these turbulent times.
One of the key areas we consider with covid-19 is the immune response. Many of us will have been made aware or have heard of the overactive inflammatory response or ‘cytokine storm’, associated with the virus. Cytokines are small proteins which are released by different cells in the body, including the immune system and they coordinate the body’s response to infection. This action also triggers inflammation which is a natural and healthy response as long as it is not excessive.
In some covid-19 patients excessive levels of cytokines are released which activate more immune cells and this results in hyperinflammation (2). Ultimately, this can lead to severe outcomes and even death. Unfortunately as we get older, or because of certain underlying health conditions, our immune system may not be as strong as a younger person. Older people in general have less effective immune reactions to the virus and worse outcome but we must be aware that patients under 65 with certain underlying health conditions are also at moderate – high risk (3).
There is a plethora of research now on how the immune system responds to the corona virus but we need to recognise that it is complex field and there are many areas we do not fully understand. While developing new drugs or repurposing old drugs is the centre stage for medical treatments we do need to also integrate the role of nutrition and lifestyle in optimising immunity. Within Nutritional Therapy when we think about targeting the immune system we need to create a nutrient dense and metabolically appropriate diet, reduce inflammatory pathways and focus on the gut!
The Immune System and The Gut. What is the connection?
Often we hear, ‘we are what we eat’ and never more so than when it comes to our immune system and diet. A large percentage of our immune system is in the gastrointestinal tract. To have a healthy immune system we require a first line response from our ‘innate’ immune system which consists of phagocytes, neutrophils, mast cells etc. This attacks the invading pathogens. Secondly, we need our ‘adaptive’ immune system to follow with both T and B cells required to recognise the pathogen and remember it for future exposure. (4).
When the immune system is activated by an infection, energy is needed for both innate and adaptive response. Both undernutrition and overnutrition can have an adverse effect by not supplying enough of the right nutrients or creating inflammation through over consuming foods like refined carbs, added sugar, trans fats and too much saturated fats (5). Therefore, we need optimum nutrition from the right quantity and quality of foods.
One positive way we can boost our immune response through the gut is feeding our gut bacteria. The gut microbiome interacts continuously with the immune system and by eating a rich plant-based diet and plenty of healthy fibre we are creating a food source for gut bacteria and generating a healthy community of gut bacteria (6). The immune system in the gut can be further supported by using probiotics or probiotic foods especially if we have been suffering gut problems, have been on antibiotics, have malabsorption issues or suffer from a small-intestinal-bacterial overgrowth (SIBO).
Diet, Inflammation and Immunity
There are a number of factors which make someone high or moderate risk for covid-19. These are highlighted by the NHS and those in this category will have been made aware of strategies which must be taken to reduce the risk of catching the virus and should be adhered to.
There are also actions we can also take regarding diet and nutrition to reduce inflammatory responses in the body which impair immunity. This in particular applies to those who are suffering from any type of metabolic disorder as studies are demonstrating the link between Metabolic Syndrome and the progression and overall prognosis from covid-19. (7,8).
‘’Metabolic syndrome is the medical term for a combination of diabetes, high blood pressure (hypertension) and obesity. It puts you at greater risk of getting coronary heart disease, stroke and other conditions that affect the blood vessels (NHS, 2020)
The drivers behind Metabolic Syndrome are central obesity (abdominal fat), high blood pressure, insulin resistance and low HDL which is the healthy form of cholesterol to protect from heart disease(8). Diet and lifestyle interventions are key to managing and controlling Metabolic Syndrome and can reduce inflammatory markers. Constant chronic inflammation are integral to obesity, diabetes, hypertension and cardiovascular disease and pose a problem through delayed, and inferior immune response (9).
Clear evidence has been provided that Diabetes Mellitus is one of the leading risk factors for COVID-19. It should be noted that even outside covid-19 we are experiencing a worldwide epidemic of Diabetes with an estimated 463 million adults (20–79 years) in 2019 with the condition and by 2045 this will rise to approx. 700 million (10). This is a shocking figure but given the current pandemic more attention should be paid to diet and lifestyle driven disorders such as diabetes. It is time to be more aware of these metabolic disorders and look for signs and markers of a prediabetic state which can both lead to diabetes but can also impair immune response.
Dietary Strategies for Immunity
First and foremost, the evidence shows that eating a standard Western diet increases the risk of Metabolic Syndrome (11). A standard Western diet is characterised by a high intake of processed meat, refined carbohydrates, fried food, added sugars, red meat, diet soda and possibly too much dairy (12).
The quality and quantity of food matters! The right balance of foods and the right quantity can positively impact insulin secretion, insulin sensitivity, oxidative stress and inflammation which can all impact immune response (13). A diet to balance blood sugars, lower cholesterol, increase insulin sensitivity and improve metabolic health can generally be summed up as rich in fruits, vegetables, legumes and whole grains, fish, nuts, and low-fat dairy products.
Basic guidelines for better metabolic health and immune function
- If you are overweight or obese then weight loss is essential and making sure that you can do this using a sustainable, long term plan.
- Regulate blood sugars! This obviously applies to all metabolic conditions but constantly fluctuating blood sugar levels will contribute to inflammation.
- Eating a low glycemic diet can help reduce fluctuations in blood sugars.
- Make sure your cholesterol is in a healthy range.
- Have plenty of healthy fibre to maintain good gut healthy to promote better immunity.
- Eat the ‘rainbow’, literally! This ensures plenty of antioxidants and phytonutrients which are anti-inflammatory.
Eating Low Glycemic
To improve your metabolic state even if you are not obese, diabetic or suffering from hypertension it is best to focus on foods which have a low glycemic load.
‘’The glycemic load (GL) of food is a number that estimates how much the food will raise a person’s blood glucose level after eating it’’
Overall they can help by;
- Keeping sugar levels from going too high
- Reducing hunger between meals
- Reducing the body’s need for insulin – reducing insulin resistance
- Achieving weight loss
Carbohydrates which are high glycemic such as white bread, white pasta, white rice, sugar, sugary drinks, cakes, sweets, crisps etc can negatively impact health by directing the body to store more calories as fat, increase hunger and lower energy expenditure. Carbohydrates which are low glycemic load also have higher fibre content and this is really important when looking at lowering cholesterol levels as well.