A diverse, adequate, and balanced diet comprising both macronutrients and micronutrients plays a critical role in immune system function, potentially reducing the risk of infection as well as shortening treatment duration. However, even among healthy individuals who have not contracted the disease, inadequate dietary intake in both quantity and quality remains widespread, weakening the immune system and increasing susceptibility to illness.
Below are several nutritional principles to help maintain a healthy immune system and thereby prevent COVID-19.
Ensure adequate energy intake through daily meals
Many Vietnamese people have the habit of maintaining three main meals a day (breakfast, lunch, and dinner). However, some individuals skip meals, particularly breakfast. These habits result in daily energy intake failing to meet bodily requirements, leading to fatigue, a compromised immune system, and increased vulnerability to disease. To ensure sufficient energy intake from daily meals, individuals must avoid skipping meals, consume all three main meals, and incorporate mid-meal snacks (such as milk, yoghurt, fruit, or roasted/dried beans, peas, and seeds).
Supplement protein-rich foods in daily meals
Ensure a protein-rich diet to enhance resistance and limit COVID-19 transmission.
A diet adequate in protein is essential for the body to maintain a robust immune system and facilitate rapid recovery from illness. Protein provides the building blocks for synthesizing white blood cells and antibodies, which act as soldiers in the fight against invading bacteria and viruses. Protein is abundant in foods such as meat, fish, eggs, milk, and legumes. Each person should consume 5–6 portions of protein per day. Each portion of protein is equivalent to 40g of meat, fish, or shrimp, 1 chicken or duck egg, 1 block of tofu, or 1 cup of milk. A variety of foods should be combined in meals, utilizing both animal and plant protein sources to achieve the total daily protein requirement.
Incorporate foods rich in immune-boosting vitamins and minerals into daily meals
Increase the consumption of animal and plant-based foods high in vitamin A and carotenoids (such as liver, eggs, sweet potatoes, pumpkin, carrots, papaya, mango, and broccoli/cauliflower). Consume more green vegetables and fruits rich in vitamin C (such as oranges, pomelos, and guava), and foods containing high levels of zinc (such as legumes, almonds, pork, beef, oysters, and clams). Increase the intake of selenium-rich foods (such as eggs, mushrooms, shrimp, legumes, cereals, pork, and beef). Research indicates that zinc supplementation helps prevent infections, particularly pneumonia in the elderly.
Supplement foods rich in vitamin A and omega-3
These include fish and seafood. Fish should be included in meals at least twice a week. Vitamin A and omega-3 play a vital role in the respiratory immune system. Fish oil capsules can also be used as a daily dietary supplement. Additionally, seafood is an excellent source of zinc for the body's immune system.
Incorporate vegetables, tubers, and herbs rich in phytochemicals and essential oils into daily meals
Increase the use of onions, garlic, ginger, lemongrass, lemons, and aromatic herbs rich in phytochemicals and essential oils (such as mint, marjoram, and perilla) in daily meals, as these foods possess high antibacterial properties. Garlic oil capsules, 1–2 cloves of fresh garlic, warm ginger tea, or warm lemon-lemongrass water can also be consumed.
Supplement specialized, energy- and protein-dense nutritional formulations
The elderly, young children, patients with chronic diseases, and underweight or malnourished individuals often have inadequate dietary intake. These groups should supplement their diets with energy- and protein-dense nutritional formulations, such as liquid or powdered milk, tailored to their age and underlying medical conditions. Supplement no more than 500 calories per day, equivalent to 2 cups of milk. Consultation with a clinical nutritionist or healthcare professional is recommended to obtain guidance on selecting suitable products.
Supplement multivitamins, minerals, and fish oil
A balanced diet remains the most effective method for providing these vitamins and minerals. In cases of inadequate dietary intake, the use of multivitamin supplements containing vitamin A, vitamin C, vitamin D, zinc (Zn), and selenium (Se) may be considered under medical supervision. These nutrients help strengthen the body's immune system during the COVID-19 pandemic.
Drink plenty of water, especially warm water
Water should be consumed immediately at the slightest sensation of a dry throat. Ensure a daily intake of no less than 1,500 ml of warm water, consumed in small sips frequently throughout the day. Vulnerable populations, such as children and the elderly, should be encouraged to drink fluids regularly rather than waiting until they feel thirsty.
Avoid restrictive dieting; consume a diverse variety of foods
During this period, it is essential to consume a diverse range of foods that are colorful and nutritionally rich. Aim to eat no fewer than 15 different food items per day, including condiments and spices.
Limit greasy, fried, and sweet foods
These foods provide high energy but can cause bloating and indigestion while failing to supply adequate protein and vitamins essential for the body's immune system.
Ensure food safety and hygiene
Consume thoroughly cooked food and boiled water. Meats, fish, and eggs must be cooked completely. Keep raw and cooked foods separate. Unused fresh food must be stored in the freezer, and cooked food that is not eaten immediately should be stored in the refrigerator. Wash hands before eating, before and after food preparation, after using the restroom, or after touching high-risk surfaces. Limit eating out at public eateries.
Limit alcohol consumption, parties, and large gatherings
Limit gathering in crowded places to prevent COVID-19 transmission.
Limit alcohol consumption, parties, and large gatherings to curb the spread of COVID-19, which is transmitted via respiratory droplets and direct contact with contaminated surfaces.
PhD. MD. Nguyen Thanh Ha (Department of Clinical Nutrition - National Lung Hospital)
Source: https://bvcmay.thuathienhue.gov.vn/kien-thuc-y-khoa/bi-quyet-dinh-duong-du-phong-lay-nhiem-covid19.html