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Story | Research
30 April 2020

Op-ed: Food for thought on how to reinforce your immune system amid coronavirus


Image source: dotshock, via Shutterstock

Dr M. Walid Qoronfleh, Director of Research and Policy at the World Innovation Summit for Health, QF’s global health initiative, on how our diet and lifestyle can help us defend ourselves against COVID-19.

By any name, it is scary and downright frightening. Coronavirus, novel coronavirus disease (nCovide-19), coronavirus disease (Covide-19) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

As you read this, you will be acutely aware that the COVID-19 pandemic is a colossal global health challenge. The outbreak is testing public health systems and governments. Certainly we need to follow and adhere to guidelines by the World Health Organization, our health ministries and government officials, and take common sense precautions. However, you may ask yourself this question: How can I further protect myself, and keep myself healthy?

At the outset, let us be clear and debunk many unsubstantiated claims on the internet or social media; there is no food, herb, or supplement that prevents coronavirus disease or guarantees super-protective immunity against it, according to the US Federal Trade Commission and the US Food and Drug Administration. Indeed, monumental and heroic efforts are under way to deliver solutions ranging from diagnostics to developing drugs, antibodies, and vaccines.

The reason COVID-19 is disseminating so fast and having such a significant impact on people worldwide is that we lack immunity to it.

Dr. Walid Qoronfleh

In short, the reason COVID-19 is disseminating so fast and having such a significant impact on people worldwide is that we lack immunity to it. Our immune systems have never been primed or exposed to it before.

However, there are ways to keep your immune system functioning optimally. By implementing some of these holistic steps to boost your immunity, you are taking measures that give you extra protection.

Sleep and stress

Sleep is a vital indicator of overall health and well-being. Both stress and sleep deprivation are extremely taxing on the immune system and reduces the body’s ability to respond against viruses and bacteria. For some people, this may lead to harmful habits, including excessive smoking, over-eating, and poor dieting, in turn negatively affecting the performance of the immune system.

According to Dr. Qoronfleh, sleep is vital in enabling the body to respond to viruses and bacteria. Image source: Dragana Gordic, via Shutterstock

People should aim for 7-8 hours of sleep each night or take 20-30 minute daily naps to mitigate lack of sleep. In addition, they can employ some calming or relaxing stress-reduction techniques. Spirituality, meditation, mindfulness exercises, and getting outside for walks are just a few examples of ways to manage stress and anxiety. Explore online options for workouts or live-streamed at-home practices. Connect with friends and loved ones via different social platforms. And curtail judging your feelings and thoughts.

Physical activity

Regular physical activity, as defined by the WHO, is not only beneficial to our overall health (by lowering the risk of chronic diseases) and to stress management (by biologically reducing stress hormone levels and stimulating the production of mood elevator hormones linked to emotions), but also it strengthens immunity.

Those who exercise frequently tend to experience a lower incidence of infection when compared to inactive and sedentary individuals.

Dr. Walid Qoronfleh

Actually, those who exercise frequently tend to experience a lower incidence of infection when compared to inactive and sedentary individuals.


Adequate daily fluid intake ranges from 2.7-3.7 liters. This covers fluids from water, other beverages and food. For water, that translates into consumption of at least two liters per day.

While this recommendation takes into consideration gender and age, it also proposes adjusting total fluid intake based on factors like heat, humidity, exercising, pregnancy, and breast-feeding. Your hydration status influences your energy level and organ functions like the kidney, and importantly improves immune functions – specifically the lymphatic system that helps combat infections. Even if you do not feel thirsty, it is imperative to set regular reminders to drink water. Trick yourself by making it flavorful and adding slices of cucumber, lemon or orange.

Reduce inflammation

Our immune system is triggered once it recognizes a germ or anything that is foreign to our body, which invariably elicits inflammation. Many phyto-compounds – naturally derived plant chemicals – like antioxidants and polyphenols in food possess anti-inflammatory effects.

It is sensible to limit the conditions – such as high blood pressure or high blood sugar – that might worsen the immune response. Studies show that a low-carb, moderate protein, higher fat diet effectively decreases blood sugar. Refined carbohydrates, sugar, processed and red meat, shortenings, and alcohol tend to overtax the immune system. Evidence from research suggests sugar may impair white blood cell function.

However, other evidence suggests acute rises in blood sugar may increase risk of infections and complications. In laboratory experiments, plenty of foods have been found to reduce inflammation, such as turmeric, nuts, berries, citrus, grapes, ginger, tea, various vegetables, dark chocolate, and fish, to name a few.

For diet and nutrition sources or recommendations, people need to follow the guidelines or recommendations of credible organizations that provide science- and evidence-based information.

Dr. Walid Qoronfleh

Eat healthy - diet and nutrition
For diet and nutrition sources or recommendations, people need to follow the guidelines or recommendations of credible organizations that provide science- and evidence-based information, such as the WHO and the Academy of Nutrition and Dietetics in the US. Balanced meals with the right portions of meat, vegetables, and fruits is a sure way to maintain health. This can be augmented with off-the-shelf vitamin and mineral supplements such as:

Vitamin A: It is essential for the growth, development and maintenance of epithelial cells, a type of cell that lines our surface body systems such as the skin, respiratory tract and gut. They form a barrier and act as the first line of defense against pathogen invaders. It also plays a critical role in enhancing immune function.
Vitamin A food groups are oily fish, egg yolks, cheese, liver, tofu, nuts, seeds, whole grains and legumes. Foods rich in beta-carotene, which the body converts to vitamin A, are dark, leafy green vegetables and orange and yellow fruits and vegetables.

Vitamin B: Several B vitamins – specifically members of the B-complex, in particular riboflavin, pyridoxine, folate, and cobalamin – contribute to our immunity by enhancing the immune response. Several research investigations have demonstrated the value of vitamin B-complex to overall health and how it promotes the defensive role, such as through its involvement in the synthesis of red and white blood cells.

Diet is also an important factor in maintaining our health, but advice needs to come from credible sources, Dr. Qoronfleh says. Image source: Zhenya Voevodina, via Shutterstock

Vitamin B food groups are poultry, fish, milk, yogurt, cheese, eggs, fortified cereals, legumes, green vegetables, citrus, berries, nuts, and seeds.

Vitamins C & E: As the body attempt to overcome an infection, it experiences oxidative stress; that is, generation of free radicals that damage tissue and affect immune health. Both vitamins C and E are well-known antioxidants. Undoubtedly, vitamin C is the most popular supplement. Some studies have shown that vitamin C does reduce the duration and severity of upper respiratory tract infections, including the common cold.
Vitamin C food groups are citrus fruits, berries, tomato, kiwi, peppers, and cruciferous vegetables. Vitamin E food groups are seeds, nuts, grains, dark leafy greens such as spinach, and cruciferous like broccoli.

Vitamin D: Vitamin D plays a number of significant roles in health, including with regard to the immune system. It enhances the activity of a number of white blood cells and decreases inflammation. Research suggests that vitamin D possibly protects against respiratory tract infections, and other studies noted that it increases antiviral treatment response to Hepatitis and AIDS. Our body is able to synthesize vitamin D upon exposure to sunlight, and it is also furnished from fortified foods.
Vitamin D food groups are fatty fish, liver, eggs, cheese, tofu, mushrooms and fortified foods such as cereals, spreads, and dairy products.

Micronutrients: Examples of essential micronutrients are iron, copper, zinc, and selenium. They play a crucial role in immune cell development and communication, and as antioxidants an important role in anti-inflammatory response. Compared to other minerals, perhaps zinc gets the most attention for its antiviral defense properties. Numerous studies have indicated that zinc may protect or reduce infection duration against respiratory tract infections.
Micronutrient food groups are meat, poultry, fish, nuts, seeds, legumes, wholegrain cereals, avocado, quinoa, and dried fruits.

The immune system is a complex network affected by many factors. A holistic approach that emphasizes the connection of mind, body, and spirit is indispensable.

Dr. Walid Qoronfleh

Probiotics: Recent research has established that the intestinal bacteria influence our body’s immune response to infection and maintaining overall health. The food you eat has a big impact on the diversity of the microbes in the gut. While the intricate system interactions are not well understood, the probiotic bacteria do produce chemicals that regulate the immune system and support immunity functions.
Food groups are fermented dairy products, aged cheeses, fermented vegetable-based foods, fermented drinks, and sourdough bread.

Other Supplements: Black elderberry and Echinacea exhibit powerful anti-microbial and anti-inflammatory properties. They are among few supplements that have been displayed to improve immune health and may have mild protective antiviral effects against several respiratory viruses, including respiratory syncytial virus and rhinoviruses or relief treatment from common cold symptoms. Often, these are sold as liquid extracts or capsules. However, convincing evidence in humans varies.
The immune system is a complex network affected by many factors. A holistic approach that emphasizes the connection of mind, body, and spirit is indispensable.

A number of different foods and nutrients are involved in supporting our immune systems capacity to perform perfectly so that we are capable to fight infections. Be proactive to minimize exposure to undesirable chemicals – such as chlorinated drinking water, polycyclic aromatic hydrocarbons, pesticides, heavy metals, air pollution, and food additives – that can suppress or potentially devastate your immune system.

Physical activity also strengthens immunity, Dr. Qoronfleh explains. Image source: SewCream, via Shutterstock

In your diet and lifestyle:

  • Consider engaging in meditation and other spirituality activities.
  • Avoid junk food and other foods that are high in fat, sugar and salt. Opt for a properly cooked meal and try to consume small portions throughout the day. And do not overeat.
  • Eat a Mediterranean-type diet that is rich in vegetables, whole grains, and fish, and low on red meat and processed foods.

  • Maintaining a balanced diet, getting enough sleep, reducing stress and anxiety, engaging in regular physical activity, and not smoking are some of the most important ways of helping to keep your immune system healthy and diminishing your chances of infection and diseases.

As for nutrients and supplements, we do not have evidence that they can prevent or treat viral infections per se. Definitive recommendations are awaiting well-designed, conducted clinical trials.
But supplements offer incremental benefit for immune health, so abide by the recommended daily allowance and check with your doctor. Massive or mega-vitamin doses could pose serious health risks. The supplements should not and cannot be used as a replacement for a healthy diet and lifestyle.
I wish you all good health – and urge you to act to boost your immunity.

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