In a media briefing held March 20, 2020, World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus gave advice for individuals around the world who are "adjusting to a new reality" during various levels of quarantine imposed to slow the spread of novel coronavirus (COVID-19).[i]
"During this difficult time, it's important to continue looking after your physical and mental health. This will not only help you in the long-term, it will also help you fight COVID-19 if you get it," Ghebreyesus said, before offering five solid steps that virtually everyone can take to boost immunity and stay healthy not only during this pandemic but also after it ends.
1. Eat a Healthy and Nutritious Diet
This helps your immune system to function properly, Ghebreyesus noted.[ii] Indeed, whole foods are a powerful force to boost your immune function, including plenty of fruits and vegetables, which are rich in vitamins, antioxidants and other phytochemicals.
Flavonoids, for instance, found in berries and onions, among other produce, reduce the incidence of upper respiratory tract infections,[iii] while vitamin C, found in foods like broccoli and kiwi, exerts anti-viral immune responses[iv] as well as has antioxidant, immunomodulatory and anti-infectious effects.[v]
Fermented foods and beverages, such as yogurt and kefir, are also beneficial. Consuming a probiotic drink has been found to reduce the incidence of influenza in children[vi] while eating yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus augmented natural killer cell activity and reduced the risk of catching the common cold among the elderly.[vii]
Specific superfoods, like turmeric and its active ingredient curcumin, garlic and mushrooms, can further support your immune system health.
2. Limit Your Alcohol Consumption and Avoid Sugary Drinks
Excess alcohol consumption affects booth innate and adaptive immunity, leading to a significant weakening of your defenses and heightening the risk of infections.[viii]
Avoiding not only sugary drinks but sugar in general will also benefit your immune function, while a high sugar intake is associated with an increased mortality risk from all causes.[ix]
3. Don't Smoke
"Smoking can increase your risk of developing severe disease if you become infected with COVID-19," according to Ghebreyesus.[x] If you need help quitting smoking, there are many natural strategies that may help, many of which can easily be done while you're at home.
Exercising at moderate intensity for five minutes can temporarily reduce your desire to smoke along with tobacco withdrawal symptoms,[xi] for example, while continued physical activity can help you to quit in the longer term, possibly by improving your mood and self-efficacy.[xii]
Fresh lime can also help to cut cravings,[xiii] while acupuncture, self-massage, essential oils (including black pepper essential oil) and mindfulness training can help with smoking cessation.
WHO recommends 30 minutes of physical activity a day for adults and one hour a day for children. "If your local or national guidelines allow it, go outside for a walk, a run or a ride, and keep a safe distance from others. If you can't leave the house, find an exercise video online, dance to music, do some yoga, or walk up and down the stairs," Ghebreyesus said.[xiv]
Exercise boosts your immune system in multiple ways, including causing white blood cells, which fight disease, to circulate more rapidly, allowing them to detect illnesses sooner.
The rise in body temperature that occurs when you break a sweat during your workout could also help your body fight off infections, similar to the effects of a fever.[xv] In a review published in Exercise and Sport Sciences Reviews, it's further noted:
"[M]oderate intensity exercise reduces inflammation and improves the immune response to respiratory viral infections.
We hypothesize that acute and chronic moderate exercise induces a level of stress hormones that down-regulates excessive inflammation within the respiratory tract and aids in activating innate anti-viral immunity … "[xvi]
In addition to regular exercise, you'll also want to be sure you're not sitting too much. "If you're working at home, make sure you don't sit in the same position for long periods. Get up and take a 3-minute break every 30 minutes," Ghebreyesus advised.[xvii]
Indeed, excess sitting is a risk factor for disease in its own right and has even been linked to an increased risk of death from all causes.[xviii]
5. Look After Your Mental Health
If you're feeling excessively stressed or anxious over COVID-19, the blow this stress has to your immune system may increase your risk of infection.[xix] So Ghebreyesus' advice to protect your mental health is wise:
"It's normal to feel stressed, confused and scared during a crisis. Talking to people you know and trust can help. Supporting other people in your community can help you as much as it does them.
Check in on neighbors, family and friends. Compassion is a medicine. Listen to music, read a book or play a game. And try not to read or watch too much news if it makes you anxious. Get your information from reliable sources once or twice a day."[xx]
These tips are especially pertinent during a pandemic, but remember that supporting your immune health is something that can be done year-round. The more you lead a healthy lifestyle, the better prepared your body will be -- on a physical, mental and emotional level -- to deal with external stressors or pathogens.