Covid-19 has deeply impacted our physical and mental well-being and inspired people to reconsider their focus on healthy ways of eating and living. However, a barrage of disinformation available online has only negated the good influence that nutritious food habits can have on the consumers. Dr Suparna Ghosh-Jerath, Professor and Head, Community Nutrition at Public Health Foundation of India debunks the myths and fact checks some commonly believed health facts.
Can a special diet or a single prevent COVID-19 infection and what is your dietary advice for those who have mild COVID-19 or recovering from it?
Dr Ghosh: Several nutrients are known to boost our immunity and enhance our ability to fight infections including COVID-19. A healthy, balanced and diverse diet which has a mix of several beneficial nutrients can play a critical role in fighting COVID-19 infection rather than a single food or a substance.
It would perhaps be wrong to say that a single food or supplement can protect us from getting the COVID-19 infection. Nevertheless, having a healthy diet is important in supporting our immune function. Zinc and vitamins C, A, and D to maintain a well-functioning immune system. Supplementation with vitamins C and D, as well as zinc and selenium, have been highlighted as potentially beneficial for individuals with, or at risk of, respiratory viral infections or for those in whom nutrient deficiency is detected.
Thus, like recommendations for a normal healthy population, diets rich in fruits, vegetables, and whole grain foods are promoted. These diets contain high amounts of vitamins and minerals which are important modulators of the immune system. In addition, they are good sources of water, antioxidants, and fibre, all of which play a role in the controlling non communicable and lifestyle related diseases like hypertension, diabetes, and weight gain, some of the most important risk factors for COVID-19 complications.
Emerging research shows that gut health may be compromised by COVID-19 infection and that gut microbiome status can influence health outcome in patients with COVID-19. The probiotics (which are tiny living microorganisms, including bacteria and yeast) and prebiotics (types of fiber that the human body cannot digest serve as food for probiotics) are purported to have a potential role in supporting the gut microbiome to help reduce severity of COVID-19 infection. Therefore, high fibre foods including fruit and vegetables, wholegrain, beans and some fermented foods which have probiotics in them can help play a role in developing and maintaining a healthy gut microbiome that will in turn support the immune system apart from other health benefits.
Adequate intakes of beneficial macro and micronutrients may be attained through a diverse daily diet that includes lentils and beans, dairy foods, nuts, seeds, meat, fish, eggs, apart from fruits, vegetables and whole grains. While vitamin D can be obtained from some dietary sources, it is mainly synthesised endogenously through exposure of the skin to sunlight.
Here are some interesting guidelines provided by the Indian Dietetics Association:
Good nutrition helps the body fight infections, so provide adequate but not excessive nutrients (avoid overfeeding) and maintenance of healthy body weight is important.
Increase frequency of meals to compensate for the increased caloric requirements of fever.
The food should include a variety of foods including energy-rich foods, meat, milk, legumes and pulses, fruits and vegetables.
Consider supplementation with vitamin C, zinc, vitamin A, B6, D, E, iron, folate and fiber if not getting enough from the diet.
Increased consumption of fruits and vegetables is encouraged to improve antioxidant levels in the body.
Ensure enough sleep, reduced stress, exercise, avoid intake of alcohol & tobacco products
Does staying hydrated boost your body’s first line of defence against the virus?
Hydration is indeed a key element to maintaining a healthy immune system. As most of us are out of our normal routines during this COVID-19 Pandemic, it is important that we properly hydrate ourselves . Our immune system depends on the nutrients in our blood stream, and our blood stream is made mostly of water! We cannot properly transport the nutrients required for several bodily functions in each organ system if we are not properly hydrated. Hydration also facilitates the detoxification pathways using which we clear out any foreign invaders and other waste materials from our body. Hence keeping oneself hydrated is an important prerequisite to fight against infections.
How much fluid is usually recommended if someone has COVID-19 infection or recovering from it?
Dr Ghosh: We lose water when we breathe, urinate, pass motion and sweat. We need to replenish this lost water by consuming more fluids and water for our body to function optimally. Since the daily water requirement is influenced by our age, sex, physical activity level, our dietary intake, body composition, environmental conditions, presence of disease etc. the recommended intake of water varies widely. When someone has COVID -19 infection, there could be extra fluid losses due to increased sweating with fever, water losses due to increased breathing rate, vomiting and diarrhea. In order to account for these additional losses, we need to take extra fluids over above the normal requirements
An average healthy adult would need 2 to 3.5 litres of fluids depending on the criteria mentioned above. But this recommendation also includes fluids from other beverages and food. Around 20 percent of our daily fluid intake comes from food and other drinks. So drinking eight glasses of water a day sounds easy to remember and follow though it’s not suitable for everyone. Thus a person with COVID infection or recovering from it needs to take fluids over and above these daily requirements to keep oneself well hydrated
Do we need to take dietary supplements (with micronutrients) to prevent or treat COVID-19?
Dr Ghosh: Dietary supplementation with selected vitamins (e.g., A, B, C, and D), minerals (e.g., selenium, zinc, and iron), and omega-3 fatty acids are suggested as treatment option for COVID-19 patients andas preventive therapy against lung infection. However, the use of dietary supplements to prevent infections remains questionable.
Except for the role of vitamins D and C, zinc, and selenium in patients with deficiencies of those nutrients, there are no clear and convincing studies that support the role of dietary supplements’ use in COVID-19 prevention and treatment in healthy, well-nourished individuals. Moreover, as the risk of elevated intake of some nutrients due to the popularity of dietary supplements, effective consumer education on rationale use of dietary supplements and health-protecting behaviours against COVID-19 should be developed.