One of the most important factors that can help to prevent or cure a disease like the Covid-19 coronavirus or any of its variants is efficient nutrition, meaning eating healthy food in reasonable quantities. It is very important to know what kind of food to eat and what not to eat before, during, and after an infection.

“The main function of the human immune system is to protect the body from diseases, toxins, cancer cells, and foreign bodies. There are many factors that affect the functions of the immune system, the most important of them being food,” said nutritionist and head of the food industries department at Egypt’s National Research Centre Ahmed Mohamed Saeed.

He added that a lack of nutrients or malnutrition could lead to immune deficiency, and an excessive food intake could lead to other diseases that affect the functions of the immune system. 

Many foodstuffs such as fruit and vegetables and foods rich in nutrients such as amino acids, vitamins, minerals and bioactive substances contribute to strengthening the immune system. One of the most important food sources that help to support the immune system are functional foods. These contribute to preventing, mitigating, or treating diseases and strengthening the immune system, Saeed said.

“Functional food is the concept of food being not only necessary for survival, but also being a source of mental and physical well-being and contributing to the prevention and reduction of the risk factors for many diseases or the promotion of certain physiological functions such as those of the immune system,” he added.

 Consuming these different sources of food could help in the production of immune cells and antibodies, he said.

“Vitamins like A, B6, B12, folic acid, C, D, and E and micro-elements like zinc, copper, selenium and iron have been shown to play key roles in supporting the immune system and reducing the risk of infection. Other nutrients such as amino acids and omega-3 fatty acids also play an important role,” Saeed said.

 Gut bacteria play a role in regulating the immune system, and they can help to restore its functioning especially among elderly patients. 

Among the foods that can contribute to strengthening the immune system, Saeed picks out yoghurt as a great source of protein that can help to maintain healthy bones and skin, which is the first barrier against infection. Citrus fruits such as oranges or grapefruits are full of Vitamin C, which is known to support immunity. Women should get 75 mg of Vitamin C per day, while men should get 90 mg. It helps the body to repair tissues and maintain a healthy skin and blood vessels. It is also an important antioxidant, a substance that prevents cell deterioration and improves immune function.  

Green leafy vegetables like spinach and kale are rich in Vitamin A, which is important for immune function. Men need 900 mcg of Vitamin A each day, while women need 700 mcg. Red peppers are particularly beneficial for immune health due to their content of Vitamins A and C. Green tea is rich in antioxidants and polyphenols, the first helping to prevent cell damage. Ginger has antioxidant and anti-inflammatory properties. Garlic is also good since it contains allicin and antioxidants that help fight infection and support the immune system.  

Turmeric supports the immune system because it contains curcumin, which is the ingredient that gives it its dark yellow colour. Curcumin has the ability to modulate the immune system by activating immune-related cells.

When it comes to combatting the coronavirus, Saeed also sees a role for food. “Yoghurt is one of the best foods that can be eaten during an illness because it is soft and filled with protein. Ice cream may also be a good option, but use caution if a person has diabetes. Ice cream contains glucose and protein, which helps patients to maintain their weight, bearing in mind that most people with coronavirus lose weight,” he said.

“Patients should also be given a lot of fluids, especially soup that contains protein (chicken or meat) and vegetables that help provide the body with the nutrients it needs while fighting off an infection. Any type of pasta eaten with a type of protein (meat in tomato sauce) is a good meal, especially after symptoms begin to subside. Fruit and cooked vegetables in all their forms, especially broccoli and cabbage, are also very useful foods.”

“Try a vanilla or chocolate protein shake, which is also light on the stomach. Whole grains such as oats, plain popcorn, brown rice, and whole wheat bread are also good,” he said. 

On the other hand, there are also foods to avoid. “Avoid eating avocados because they are a fatty fruit rich in histamine. For a patient to recover faster, it is best to avoid bread with gluten (an ingredient found in wheat flour), since this causes inflammation that can lead to an increase in mucus production. Eliminate sugary foods from the diet because they will make recovery times longer. Sugar causes inflammation that can impair the production of the white blood cells that fight infection,” Saeed said.

 “Fried food like French fries causes inflammation in the body, which is especially harmful when you are sick. Whole milk yoghurt has been shown to stimulate mucus production. Drinking coffee is a very bad idea. Caffeine is a diuretic, which means it dehydrates your body faster, and that’s even more harmful if you’re experiencing other symptoms like a fever or an upset digestive system. Pizza can also make cold symptoms worse, so it’s a triple threat to recovery efforts. The gluten, the carbohydrates in the dough, the fat and dairy products, and the histamine in the tomato sauce will all make you feel sluggish and tired.”

After the recovery of a patient from the coronavirus, the focus should be on healthy foods that strengthen the body’s immunity and restore strength. Protein of various types should be eaten, like milk and its derivatives and animal proteins, in order to regenerate tissues. Starches from bread, rice, and potatoes can help to restore energy. Fruit and vegetables are also good because they provide the body with vitamins and minerals.

In short, a variety of foods of good quality and in appropriate quantities should be eaten in this phase to help a patient recover.

Food tips to avoid Covid-19

According to nutritionist Ahmed Mohamed Saeed, certain foods and other activities can help to protect us against the Covid-19.

His advice includes: 

- Eating more fruit and vegetables. 

- Getting enough sleep. 

- Making sure you eat enough protein.

- Not skimping on foods - that contain probiotics.

- Managing stress. 

- Getting enough vitamins through your diet. 

- Being active in moderation. 

- And quitting smoking.

*A version of this article appears in print in the 24 February, 2022 edition of Al-Ahram Weekly.