Official News Magazine of the Canadian Snowbird Association
Can you reduce your COVID-19 risk by changing your health?
by Dr. Susan Reicheld
Why do some people get sicker than others from COVID-19? Who is more likely to get this disease? How can I avoid getting this disease? How can we treat this virus?
These are questions that we are all asking ourselves. We are learning more every day about COVID-19 and how it is transmitted, how it enters our body and how our immune system responds to this virus.
It is useful to divide COVID-19 into four stages: Prevention, Infection, Inflammation and Recovery. The best approach for affected individuals appears to be different for each phase.
Prevention entails limiting your exposure to the virus through social distancing, hand hygiene, and the use of masks, where appropriate.
The infective stage of COVID-19 involves the entry and replication of the virus. The body’s response to the infection triggers an inflammatory state, which results in tissue damage.
Recovery from COVID-19 will vary depending on how sick you become from the disease. The typical time to recover is two to six weeks. It is longer for those who require ventilatory assistance.
While all groups are affected by the COVID-19 pandemic, the elderly and those with underlying medical conditions are at the greatest risk. These are the individuals who typically have issues with their immune systems. While we can’t prevent aging, we can adhere to healthy living strategies that mitigate the effect of age and thereby enhance our immunity.
Hypertension, diabetes and coronary disease are common conditions associated with an increased risk of COVID-19 infection and severe lung injury with worse outcomes. In one report, there was a 30% incidence of hypertension in COVID-affected patients. Diabetes is known to affect innate immunity. Innate immunity is the body’s first line of defence against infections, including COVID-19. Even short-term elevations of blood sugar have been shown to compromise innate immunity. Diabetes is also associated with an increased inflammatory response, which is part of the body’s later response to the infection.
Regular physical activity throughout the day and moderate physical activity of 150 minutes per week have been shown to improve blood pressure control. Diabetes, sugar and lipid metabolism are also better controlled with regular, low-intensity activity. Sedentary lifestyles approximately double the risk for coronary heart disease. The medical conditions most commonly associated with COVID-19 can all be improved through physical activity.
Obesity also appears to increase the severity of COVID-19 disease in affected individuals. Fat cells in obesity secrete pro-inflammatory substances, generating tissue damage as COVID-19 progresses from infection into the inflammatory stage. Any underlying medical condition associated with chronic inflammation can worsen the outcome of a COVID-19 infection.
COVID-19 gains access to the body through the ACE 2 (angiotension converting enzyme 2) receptor, which appears to be a “docking station” for this virus. The ACE 2 receptor is present in both the heart and lungs and also plays an important role in the immune system. The role of ACE 2 is complicated, however, since the presence of ACE 2 is felt to be protective against lung injury despite it being an entry point for COVID-19. There is still much research being conducted to understand the role of ACE 2 in this disease.
Supplements and COVID-19
Vitamin D is involved in the body’s immune function. Vitamin D deficiency results in a higher rate of upper respiratory tract infections, especially in people with asthma and COPD. A deficiency of this vitamin is also associated with several autoimmune diseases.
Our bodies obtain vitamin D through UVB (ultraviolet B) light exposure to our skin and orally through our diet. Vitamin D is then converted to an active form by the liver, kidney and our immune cells. Recommended daily exposure to UVB light varies by skin colour and geographic location. White skin types are recommended to have about 10 minutes of exposure to the sun midday, while darker skin types should increase exposure to about 30 minutes. There are no age parameters attached to these UVB recommendations. As we age, our skin has a decreased ability to manufacture vitamin D. Seniors are, therefore, more likely to require oral supplementation.
Recommendations for oral supplementation vary as well. Some health authorities recommend people at risk of influenza and/or COVID-19 take 10,000 IU per day for a few weeks, followed by 5,000 IU per day. Other health authorities recommend regular supplementation of 800 IU per day with a limit of 4000 IU per day. There are no clear, specific guidelines and the varying recommendations will also depend on your underlying vitamin D levels. Short-term (a few weeks), high-level vitamin D supplementation is not toxic to most individuals.
Remember that it is possible to get too much of a good thing. It is not necessary to get a sunburn to obtain your recommended dose of vitamin D from the sun, and long-term, high-dose oral supplements can cause problems.
Vitamin D, via its active metabolites, influences more than 200 genes. Receptors for vitamin D are extensively distributed throughout the cells lining the respiratory tract and in immune cells. Cells in both the upper and lower airways secrete antimicrobial peptides that also inhibit viruses from entering the body. Vitamin D can increase the production of these peptides. Vitamin D also regulates the expression of ACE 2 in lung tissue.
Vitamin D doesn’t just appear to play a role in the infective stage of COVID-19. It also influences the subsequent inflammatory stage, which is responsible for disease severity. Vitamin D inhibits inflammatory molecules and is believed to be involved in balancing the immune system.
Other dietary components which have been studied in influenza and other human coronaviruses are plant-based polyphenols and flavonoids found in a wide variety of foods. Edible plants with high polyphenol levels include berries, plums, cherries and apples. Black beans and white beans also have high levels of polyphenols, as do such nuts as hazelnuts and pecans. Foods high in flavonoids include citrus fruit, blueberries, spinach, dark chocolate and nuts, to name but a few. This list of beneficial foods is not exhaustive and you can check the polyphenol content of your favourite fruits, vegetables, nuts and legumes online to ensure that your diet is rich in these important substances.
Extracts from a species of elderberry have been shown to have anti-viral properties against a different type of coronavirus by blocking attachment of the virus and inhibiting replication. A pomegranate polyphenol extract was found to have other beneficial effects against the influenza virus. Although plant extracts have been shown to be beneficial in the study of viruses other than COVID-19, the best way to obtain the benefits of polyphenols and flavonoids is to maintain a diet rich in plant-based food.
This is not our first pandemic, nor is it going to be our last. We know that the interaction of COVID-19 with our immune system is complex and can involve immune suppression as well as hyper-activation. With no effective, universal treatment for COVID-19 and no current vaccine, the best defence against this disease is minimizing your risk of exposure and maintaining a balanced, healthy immune system.