While adequate sleep, movement, and coping strategies lay the foundation for strong immunity, nutrition arguably plays the biggest role in decreasing susceptibility to infectious disease.
Businesses have shut their doors, students have moved to virtual education, and medical facilities have ramped up their staff. Yet, one piece of the pandemic puzzle that is notably absent from the public conversation is how to bolster immune function so that your body can effectively fight off COVID-19, should you be exposed.
Each time you eat, the body is flooded with substances that either increase or degrade the immune response. By removing foods that deplete immune system resources (e.g., sugar, alcohol, and refined carbohydrates) while simultaneously incorporating ones that shore up immune defenses, the body’s white blood cells receive the nourishment that they need to promote optimal immune system function.
The following is a list of 10 immune-boosting foods that radically escalate the immune system’s ability to destroy pathogens. In combination with good hygiene, these foods can bolster your immune system’s ability to maintain health.
1. Broccoli Sprouts
Packed with powerful antioxidant properties and other nutrients, broccoli sprouts are optimal for boosting immune health. Broccoli sprouts contain extremely high levels of sulforaphane, which not only has impressive anti-carcinogenic capabilities, but can fight off a common infection, detoxify environmental chemicals, combat autoimmune diseases, and even protect your brain after serious injury. Sulforaphane has been found to influence the epigenetic layer of certain parts of DNA that influence a number of disease-fighting functions.
In one human study, individuals living in a congested area infamous for its toxic air found that ingesting broccoli sprouts resulted in excretion of far larger quantities of airborne chemicals than a control group.
2. Matcha Green Tea
Matcha green tea is loaded with powerful plant-based antioxidants known as polyphenols. Studies suggest that a particular type of polyphenol found in matcha green tea, called catechins, may kill influenza (flu) viruses. One researcher summed up matcha tea’s superhero powers as follows, “GTCs [Green tea catechins] have been reported to provide various health benefits against numerous diseases. Studies have shown that GTCs, especially epigallocatechin-3-gallate (EGCG), have antiviral effects against diverse viruses.”
To ensure that your matcha tea is free from heavy metals, always purchase tea leaves grown in Japan, where soil quality is controlled.
Throughout history, garlic has been used to prevent and treat various diseases. Recently, garlic has made a bit of a comeback as research has elucidated its antiviral, anti-microbial, and anti-tumor capabilities.
One study evaluated garlic’s effectiveness in treating a strain of coronavirus known as infectious bronchitis virus (IBV). It was found that garlic had inhibitory effects on IBV. Other studies found that garlic reduces the risk of becoming sick, as well as how long you stay sick. It can also reduce the severity of symptoms.
The way garlic is prepared can alter its health benefits. The enzyme alliinase, which converts alliin into the beneficial allicin (the main active component in garlic), only works when not deactivated by heat.
Ginger is a great way to boost your body’s immune response and is commonly used to increase gut health, prevent the common cold, and reduce inflammation. Fresh ginger also contains a medicinal component known as gingerol that is known to inhibit viral activity in the human respiratory syncytial virus (HRSV). It is worth noting that the active components of ginger may work symbiotically with other components in the whole food source to exert their positive effects.
5. Olive Leaf
While you might not find an olive leaf in your pantry, it is readily available via herbal supplementation. The leaves of olive trees (Olea europea) contain substances called elenoic acid and calcium elonate that have been identified as powerful inhibitors of a wide range of viruses including influenza, herpes, polio, and coxsackie viruses. These substances block the production of enzymes that allow viruses to replicate, which is why an olive leaf is great for its immunity-boosting properties.
Propolis is a compound produced by bees from the sap on evergreen trees. It has been used for centuries to fight infections and aid in a plethora of healing processes. Current research suggests that propolis may also possess antiviral properties. Propolis can be eaten as a whole food but is most often found as a capsule or tincture supplement.
7. Reishi Mushrooms
Ancient manuscript as far back as 25 CE describes the use of reishi mushrooms (sometimes referred to by the Chinese name Lingzhi) as potent medicinal tools. In the Chinese history book, Hanshu, reishi is referred to as the “Mushroom of Immortality.”
Modern research reveals that reishi mushrooms may kill cancer cells, boost immune function, and inhibit bacterial as well as viral growth. Researchers have suggested that reishi mushrooms have, “positive health benefits, including anticancer effects; blood glucose regulation; antioxidant, antibacterial, and antiviral effects.” Reishi mushrooms are too chewy to be eaten raw so they are best consumed in tea or powdered form.
High in vitamin C, berries are full of bioactive compounds, known as polyphenols, that neutralize harmful free radicals, bacteria, and viruses. In a 2017 review in the Journal of Functional Foods, “Research indicates that components of berry fruits may inhibit replication of [viruses] both directly and indirectly, e.g. by blocking surface glycoproteins of influenza virus and stimulating the immune system of the organism.”
A specific class of polyphenol, anthocyanins, have been touted as a “valuable resource of antiviral substances." Topping the list of high anthocyanin berries are blackberries, raspberries, and wild blueberries. Frozen berries retain their anthocyanin values for up to three months so these are a viable choice.
9. Pepitas (pumpkin seeds)
Pepitas contain a wide array of vitamins and minerals (vitamin C, vitamin B, vitamin E, zinc) known to support immune health. In addition to minerals, these mighty seeds are also packed with cell-protective antioxidants. The lignans in pumpkin seeds (including pinoresinol, medioresinol, and lariciresinol) have also been shown to have antimicrobial, and especially anti-viral, properties. To maintain potency, pepitas should be eaten raw.
10. Coconut Oil
Now is the time for you to swap your olive oil for coconut oil, as this is one of the best foods for the immune system. In a formal statement published by Ateneo de Manila University (the Philippines), Dr. Fabian Dayrit from the university and Dr. Mary Newport of Spring Hill Neonatolody (U.S.) proposed the efficacy of coconut oil as a potential agent in the fight against COVID-19. They explained that coconut oil, and more specifically the lauric acid within it, causes disintegration of the virus envelope; inhibits the replication of virus cells; and prevents the virus from binding to the host agent. Though clinical trials have yet to take place, the takeaway message is that coconut oil can act as a powerful ally in protecting your body from viruses, including COVID-19.
Now that we have listed some of the best foods for the immune system, you can begin integrating them into your diet each day. Through this, you provide yourself with the boost that you need to fight infections and keep your body functioning at optimal capacity. Incorporating immune-boosting foods rich in vitamin C, nutrients, and healthy fats will keep you healthy and support your blood cells in protecting your immune system. Together with good hygiene and social distancing practices, these immune-boosting foods are simply good medicine.
*Editor’s Note: The information in this article is intended for your educational use only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition and before undertaking any diet, supplement, fitness, or other health programs.