Eating for Immunity
Strengthen your body’s ability to fight back this season with the latest scientific research and our curated immune-boosting recipes.
Now that we’re in the middle of winter’s germy worst, protection against infection is top of mind. And because this year’s flu season is compounded by the unknowns of the COVID-19 virus, supporting immune function has never been more important. While researchers are still puzzling out the details of this novel coronavirus, one thing’s universally accepted: Diet and nutrition are crucial for supporting the immune system, helping to inhibit prolonged inflammation and helping to boost your body’s resistance to infection.
Much research suggests that deficiencies in micronutrients like zinc, selenium, B vitamins and vitamins A, C and E may alter immune responses, potentially increasing the risk of infection and slowing recovery. But excessive amounts of certain nutrients can impair immune function, so focusing on a balanced diet rich in nutrient-dense foods is a smart approach. Plus, whole foods contain an array of vitamins and minerals as well as other compounds like antioxidants, healthy fats, probiotics and beta glucans that may help support immune health.
Newer research also suggests the proper diet can help ensure your body’s in the optimal state to work to resist COVID-19. Check out some highlights from the World Health Organization’s September 2020 recommendations.
- Eat fruits daily, for a total of four servings per day.
- Emphasize fresh vegetables – five servings a day – and legumes. To get the most nutrients out of fresh veg, avoid overcooking.
- Stick to whole, unprocessed grains like oats, brown rice or quinoa.
- Add nuts like almonds, pistachios and walnuts.
- Minimize meat; eat red meat once or twice a week and poultry two or three times a week.
- Avoid refined sugar; excessive amounts may impair white blood cells and increase inflammation.
- Stay away from sodas and juices, and stick to water – ideally, eight to 10 cups a day – to facilitate nutrient transport and get rid of waste products.
- Maintain a healthy lifestyle including exercise, stress reduction and adequate sleep. Ready to put these nutrients into action on your plate? Start with these easy, nutrient-dense recipes that focus on infection protection.
Related: The Benefits of Taking a Probiotic
Salmon is loaded with omega-3 fats, found in studies to reduce inflammation, inhibit viral replication, protect against infection and support immune response. EPA and DHA, the forms of omega-3s found in salmon, appear to especially impact the body’s inflammatory response – one of the first immune responses – to help prevent overstimulation and help foster balanced, modulated immunity. And salmon is rich in astaxanthin, an antioxidant that also may play a role in modulating the immune response. Salmon also contains folate and is high in vitamin B12, both of which are important for immunity. There is evidence that folate and B12 play a role in the production and activity of white blood cells and other compounds necessary for proper immune function; inadequate levels of folate and B12can dramatically alter immune response and lower your resistance to infection.
Olive oil contains a variety of compounds that research suggests have antioxidant and antimicrobial effects – especially oleuropein and hydroxytyrosol. These may help reduce inflammation, protect against infection and support the immune system. Studies also found that oleuropein had significant antiviral activity against common viruses that cause a variety of respiratory illnesses.
Quinoa contains a variety of phenolic acids, flavonoids and other compounds that may have antimicrobial, anti-inflammatory and immune-supportive effects.
Research has found that shiitake mushrooms are rich in substances that activate immune cells, including lymphocytes, macrophages and natural killer cells, and may have antiviral and antibacterial properties that could help reduce inflammation and support immune health. In one study, people who ate them daily showed improvement in immunity and had decreased markers of inflammation.Important active compounds in mushrooms, called beta glucans, have been shown to activate and stimulate different immune responses. Several studies reported beta glucans may have antiviral effects, potentially protecting against and reducing the effects of influenza infection. Other research suggests beta glucans, especially from shiitake mushrooms, may help prevent and treat recurrent respiratory tract infections.
Oats also contain beta glucans, which may further enhance immune response, and eating oats may improve the body’s resistance to viral infections. Some research also suggests a possible cancer-preventive effect of oat beta glucans.
Leafy greens are rich in a variety of nutrients that support immune health, especially carotenoids; a number of studies suggest dietary carotenoids may enhance immune response, protect against viruses and other pathogens, and help prevent infections.
Brazil nuts are one of the best dietary sources of selenium, a trace mineral that supports and may enhance immune response, potentially boosting the body’s resistance to viruses and its ability to fight infection. Brazil nuts also contain zinc, which plays a role in the production of white blood cells that destroy bacteria and viruses; in some studies, even mild deficiencies increased the risk of infection. As well, in studies, zinc appeared to protect against respiratory viruses and reduce the length and severity of infections. But too much zinc can suppress the body’s immune response. While it’s not a concern with whole foods, do be cautious with supplements and stick to the directions on the package or check with your doctor.
Acorn squash & leafy greens are rich in beta-carotene, a carotenoid antioxidant that’s converted by the body to vitamin A. This nutrient plays a critical role in immune support, and there’s evidence that it may enhance the activity of white blood cells, antibodies, natural killer cells and other immune system responses. Halibut also contains zinc, immune-supportive omega-3s and selenium as well as iron – key in chemical reactions that generate compounds that help protect against infection from bacteria, viruses and other pathogens.
Kefir is rich in probiotics, beneficial bacteria that may enhance various aspects of the immune response and may play a role in the activity of macrophages, natural killer cells and other immune cells. Probiotics appear to have antibacterial and antiviral properties and may help protect against respiratory viruses, influenza and the common cold. A number of controlled trials suggest probiotics may reduce the incidence and/or severity of respiratory tract infections; other studies suggest probiotics may also help shorten their duration. Kefir is also an excellent source of calcium, and some brands may be fortified with vitamin D, which evidence strongly suggests is essential for a healthy immune system. Research seems to indicate that vitamin D plays a critical role in several aspects of the immune response, including increasing production of natural antibodies and enhancing activity of macrophages. A number of studies suggest vitamin D may help protect against influenza, pneumonia and the common cold, and other research links vitamin D with a reduction in respiratory tract infections. And other ingredients in this recipe, especially garlic and kale, may add even more immune support.
Garlic is rich in organosulfur compounds, especially allyl derivatives like alliin and allicin, which studies suggest support immune function and enhance the activity of macrophages, lymphocytes, natural killer cells and other cells of the immune system. Research strongly suggests that garlic has powerful antimicrobial properties that may help protect against a variety of bacteria, and it may have antiviral actions against influenza A and B, viral pneumonia and rhinovirus, the predominant cause of the common cold.
Yellow Onions are a good source of quercetin, a flavonoid compound that studies have found to possess powerful antioxidant, anti-inflammatory and antiviral properties. Quercetin appears to have a direct effect on immune cells, mainly leukocytes, and supports other functions of the immune response. In other studies, quercetin inhibited infection from influenza A viruses and prevented replication of respiratory viruses and other types of viruses.
Cauliflower is an excellent source of vitamin C, a versatile antioxidant for which there is strong evidence of antimicrobial activity and potential to enhance several components of the immune system, including natural killer cells and lymphocyte activity.
Related: 7 Immune-Boosting Foods to Get You Through Cold & Flu Season
Healing at Home
Diet, lifestyle and supplements can work wonders in supporting your immune system, but what happens if you do get sick? COVID-19 infection can be serious, requiring immediate medical attention and possible hospitalization. The good news: Most people who contract the virus will experience relatively mild symptoms that can be safely treated at home.
While there’s so much that’s not known yet, current studies suggest certain supplements may play a potential role in supporting your body during a mild case of COVID-19. Some that hold promise:
- In studies, sulforaphane has been shown to have anti-inflammatory and antiviral properties; researchers suggest it may have both preventive and curative effects against COVID-19, and it may help mitigate damage to the lungs.
- Vitamin C has antiviral properties and may help lower your susceptibility to lower respiratory tract infections from COVID-19.
- Vitamin D may help reduce the duration and severity of acute respiratory tract infection, and it’s especially important if you don’t get enough exposure to the sun during an illness or in the dark winter months.
- Selenium deficiencies are associated with a decrease in your body’s ability to fight infections and may increase the severity of viruses.
- Zinc supplementation may help lessen COVID-19-related symptoms like lower respiratory tract infection, and it also may aid in inhibiting replication of the virus. New research also suggests lower zinc levels may be linked with increased risk of death in COVID-19 patients.
- Iron deficiency is a risk factor for the development of acute respiratory tract infections, and anemia can be associated with severe COVID-19 infection.
Top Tips For Better Recovery
- Some studies found that honey safely treated mild coughs, and research suggests that manuka honey in particular may have more antiviral activity than other honey varieties.
- Try relaxation techniques to encourage deep breathing,help support respiratory health and aid in stress reduction – important since chronic stress dampens your body’s immune response.
- Eat a diet rich in antioxidants and anti-inflammatory foods to support your immune system and help quell inflammation associated with COVID-19.
- Exercise is important for immune health, but ease back into gentle movement after an infection. Experts suggest patients with mild symptoms wait two weeks after symptoms subside and they’ve been evaluated by a physician.
- Seek support: According to research, COVID-19 is linked to symptoms of depression in Americans. The CDC provides information on coping with stress and mental health issues during the pandemic: Coping with Stress
Za’atar Roasted Salmon with Warm Quinoa Salad & Yogurt Sauce
Za’atar is a Middle Eastern spice blend of savory dried herbs like oregano or thyme, and earthy spices like cumin, coriander and sumac. Here, we use it as rub over salmon and roast it for an incredibly flavorful recipe that your family will want to keep on repeat.
Get the recipe here.
Nut-Crusted Acorn Squash & Halibut in Mustard Spinach Sauce
Nut-crusted halibut and immune-supporting acorn squash make this gluten-free dish both healthy and delicious.
Get the recipe here.