More than 2,500 years ago, Hippocrates said: “Let food be thy medicine and medicine be thy food. Medicine has advanced significantly since that time and we have a far better appreciation for the benefits of modern science in curing a number of diseases. This article focuses on the effects of diet on COVID-19 symptoms. Most healthcare scientists will agree that proper nutrition must be maintained in order to mitigate the symptoms of this severe acute respiratory disease. It is critical that the immune system be supported through diet and exercise. Notwithstanding external intervention, maintenance of a healthy immune system is critical to a patient’s survival against COVID-19 and many other diseases. In addition, a healthy diet is no replacement for vaccination.
A critical co-morbidity related to COVID-19 is chronic obesity. Ketogenic Diet (KD) is able to induce a fast weight loss while maintaining lean body mass. Moreover, KD has anti-inflammatory and immune-modulating properties, which may help in preventing the cytokine storm in infected patients. Hence it may help reduce ventilation requirements and respiratory failure. In essence, the Ketogenic diet encourages your body to burn fats into ketones once the sugars are fully converted to glucose. Type 1 diabetics must be monitored when going on a ketogenic diet due to ketosis. However, generally, ketosis is safe for most people.
There are at least two clinical trials ongoing in Italy addressing the value of incorporating KD into the medical regimen for treating COVID-19 patients. Some authors suggest that a low-carbohydrate diet may be an effective tool to ameliorate respiratory failure.
Greene et al. determined that adherence to the Mediterranean diet was negatively associated with both COVID-19 cases and related deaths across 17 regions in Spain. They also found a negative association between following the Mediterranean diet and COVID-19 related deaths across 23 countries (Turkey, Greece, Italy, Japan, Chile, Spain, Portugal, Israel, Finland, Norway, Iceland, United Kingdom, Ireland, France, Denmark, Sweden, Canada, Hungary, Germany, Austria, Australia, Switzerland, and United States). In all cases, the results were adjusted for factors of well-being and physical inactivity. From a cardiovascular study, it has been suggested that the anti-inflammatory properties of the Mediterranean diet are due to the high polyphenol content (70–72) from fruits, vegetables and extra virgin olive oil. Furthermore, they conclude, primarily because of the complexity of the data, that even though their study suggests a negative relationship between following the Mediterranean diet and COVID-19 cases and related deaths, further studies are required to determine whether Mediterranean diet consumption reduces the risk of COVID-19 and/or chronic disease risk reduction. However, it was noted that the Mediterranean diet and other dietary approaches that reduce inflammation and risk for chronic disease might reduce the risk for severe COVID-19 pathology and mortality.
However, according to Angeliki M. Angelidi et al., the Mediterranean diet may have potential to address adverse conditions associated with COVID-19 infection and severity, improve mortality and the overall well-being of affected populations. This arises from the corroborated studies that clearly show, in particular for obese people that the Mediterranean diet is one of the healthiest dietary patterns worldwide, reputed for its demonstrated preventive effect of cardiovascular diseases and type-2 diabetes in several trials Notwithstanding the foregoing comments suggested a negative impact from the diet, it is regarded as a standard treatment for patients with cardiovascular disease and obesity. Again, this diet is characterized by the inclusion of mainly plant-derived nutritional components, including legumes, nuts fruits, vegetables, and olive oil, all of which are significant sources of bioactive polyphenols.
The DASH diet is a recognized treatment for hypertension, heart disease, and kidney disease. This diet can slow the progression of both heart disease and kidney disease. DASH—short for "Dietary Approaches to Stop Hypertension" underscores the need to eat fresh nuts, fruits, vegetable, whole grains low-fat dairy, while reducing consumption of sugary foods and drinks, sodium, and red and processed meats. Numerous studies show wide-ranging health benefits of the DASH diet. A consistent body of research has found that DASH lowers blood pressure in people with high blood pressure but also normal blood pressure even without lowering sodium intake.
Several human trials are currently in progress to assess the therapeutic indices of drugs already approved for other diseases (i.e., drug repurposing), and in combination with dietary supplements like vitamin C, vitamin D, vitamin B12, probiotics, and zinc (Zn). As an example, Zn is commonly utilized both prophylactically and as a treatment for COVID-19. Primarily impacting the elderly, Anada S. Prasad noted that Zn supplementation studies in the elderly have shown decreased incidence of infections, decreased oxidative stress, and decreased generation of inflammatory cytokines (a disastrous side effect of COVID-19). A worldwide assessment of the value of supplements in ameliorating the symptoms of the SARS virus are difficult to obtain due to the biases inherent in how the data is obtained, parsed and analyzed. That said, individual trials such as the ones described above can shed light on the importance of good nutrition and the healthy use of supplements.
In as much as obesity, cardiovascular disease, kidney disease, etc. are co-morbidities of COVID-19, a nutritionally appropriate diet with supplements has been shown across a variety of diseases to have a positive outcome on patients with these diseases. It is not surprising that during this pandemic, COVID-19 symptoms could be mitigated through proper nutrition and intake of supplements. Christian Roberts and James Barnard recognized in 2005 the deleterious effects of lack of exercise and poor nutrition. Indeed, they pointed out that this “epidemic” of metabolic diseases cardiovascular, Type 2 diabetes, and cancer appear to be derived from inactivity and poor nutrition. Now, more than ever, with the pandemic, and there is little doubt that there will be future deadly outbreaks of virus born diseases, it is important to exercise, eat properly and supplement your diet with zinc, vitamin C, vitamin D, and omega-3 fatty acids, among other vital nutrients. However, there are studies that have shown that a well rounded diet and a person generally free of disease, does not need all these supplements. Final word, speak with your physician and consider your personal situation first.
Written By: Lawrence D. Jones, Ph.D.