Never before has health been more important.
Understanding how to keep your immune system healthy is key to preventing infection and disease. Your immune system comprises a network of physical and biochemical processes that keep invading pathogens at bay.
One of the best ways to boost your immune system naturally is to eat nutritious food, exercise regularly and live a balanced lifestyle.
However, with the wide-spread COVID-19 pandemic, it is important to remember that no supplement, diet or lifestyle modification can protect you from COVID-19 other than social distancing and proper hygiene practices. It is important to remember that no supplement will cure or prevent disease.
Instead, we are providing a list of ways you can boost your immune system naturally with well-researched and evidence-based findings.
Here are seven ways to boost your immune system naturally
1) CHOOSE NUTRIENT-DENSE FOODS
Your immune cells require adequate nutrition to function optimally. Undernutrition or malnutrition is well understood to impair immune function. During periods of infection, the body demands increased energy to respond rapidly and fight against pathogens.
Some micronutrients play particular roles in the development and maintenance of a healthy immune system. For example, vitamin A and zinc regulate cell division and the rapid release of immune cells to strengthen the immune response (1).
Therefore, it is essential to choose nutrient-dense foods rich in vitamins and minerals, including foods like leafy greens, nuts and seeds, strawberries, oily fish like salmon and sardines, quinoa, barley, mushrooms, sweet potatoes and bell peppers (2).
Reduce the intake of low nutrient-dense foods like table sweeteners, candy, sweetened beverages, baked goods, desserts, processed foods and snacks (3).
During the COVID-19 outbreak, it is essential to reduce your visits to the grocery store. Focus on buying foods that have a long shelf life.
Here is a list of nutrient-dense foods that stay fresh for a month or more:
- winter squashes like pumpkin, spaghetti squash, acorn squash (best stored on the counter)
- beets (best stored in the fridge)
- carrots (best stored in the fridge)
- sweet potatoes (best stored in a dry, dark and cool place like the pantry, cellar, basement or garage)
- potatoes (best stored in a dry, dark and cool place like the pantry, cellar, basement or garage)
- cabbages (best stored in the fridge)
- onions (best stored in a dry, dark and cool place like the pantry, cellar, basement or garage)
- oranges (best stored in the fridge)
Stock your freezer with these nutrient-dense foods:
- anti-oxidant rich berries (strawberries, blackberries, blueberries)
- leafy greens (kale, spinach, brussels sprouts, broccoli, cauliflower)
- vitamin C rich bell peppers (red, yellow, and green)
- fatty fish rich in omega-3 like wild salmon
2) TAKE IMMUNE-BOOSTING SUPPLEMENTS
Vitamin and minerals fuel our cells. A healthy and balanced diet contains an abundance of nutrients that support a healthy immune system. Despite that, diet alone may not be enough to meet optimal nutritional levels.
For example, an essential immune-boosting nutrient, vitamin D, is found to be deficient across all age groups worldwide, even in countries with mandatory food fortification.
In Europe, the United States, and Canada, 35% of those aged 50 and older have one or more micronutrient deficiencies. At the same time, lower food intake in older populations leads to a lower intake of nutrients like calcium, iron, zinc, vitamin B and vitamin E (4).
Young adults require a sufficient amount of antioxidants like vitamin D, vitamin C, selenium, and zinc to combat oxidative stress and reduce the risk of infections. However, older adults lose their ability to produce antioxidants on their own. For instance, vitamin D synthesis is 75% slower in people aged 65 and older compared to younger adults aged 19 to 50 (4). Hence, supplementation warrants adequate nutrition levels to foster a healthy immune system.
Here are supplements that are known for their immune-boosting properties. The recommended daily allowance (RDA) for adults is listed below (5).
- Vitamin B6 | 3 mg to 6 mg
- Vitamin B12 (methylcobalamin) | 100 mcg to 400 mcg
- Vitamin B9 (folate) | 400 mcg to 900 mcg
- Vitamin C | RDA: 1000 mg
- Vitamin D | RDA: 1000 IU to 4000 IU depending on blood levels
- Zinc (gluconate/picolinate) | RDA: 15 mg to 40 mg of elemental zinc
- Selenium | RDA: 55 mcg
- Medicinal mushrooms (i.e. turkey tail, chaga, reishi, lion’s mane, cordyceps) | Taken in tincture, tea or supplement form. Dosage varies depending on the supplement form and its concentration.
3) EAT PROBIOTICS EVERY DAY
Probiotics are live microorganisms that have health benefits when consumed. You can find probiotics in fermented foods, fermented drinks and in supplement form.
Maintaining a healthy balance between good and bad bacteria is key to a robust immune system. The gastrointestinal (GI) tract houses trillions of bacteria; it cultivates a vibrant ecosystem that is responsible for regulating the immune system (6).
Probiotics signal the immune cells to activate regulatory T cells and the production of IgG – an antibody found in all body fluids that protect against bacterial and viral infections. These healthy bacteria also curb infections by preventing the growth of harmful gut bacteria (7).
Probiotic foods with a long shelf-life:
- Pickles (Fermented in water and salt solution.)
- Cheddar and gouda (Make sure to look for live and active cultures on the food labels. Though most types of cheese are fermented, not all of them contain probiotics.)
4) GET MOVING!
Just like a nutritious diet, regular exercise is essential to a healthy immune system. Exercise improves the body’s ability to fight pathogens, enhance the production of antibodies and regulate inflammation.
It is interesting to note that moderate-to-vigorous exercise, of 60 minutes or less, has shown positive effects on long-term immune health. In contrast, prolonged endurance exercise, of 90 minutes or more, may reduce immune function (8).
To put it into perspective, 2% – 18% of elite athletes get sick when they compete due to increased workload, oxidative stress, and muscle damage. Intake of healthy carbohydrates and polyphenols alleviate those stressors by lowering stress hormones, white blood cells, and inflammation (9).
Overall, regular exercise has an anti-inflammatory effect, promotes heart health, and keeps the immune system function at peak performance.
With social distancing guidelines in place due to the COVID-19 outbreak, you are probably staying home most of the time, if not all the time. Social distancing doesn’t mean you can’t stay active, though.
Here are some ways to stay active at home during the COVID-19 outbreak:
- Challenge yourself to some press-ups, sit-ups, and planks.
- Dance to your favourite tunes.
- Join an online fitness class – You can find free classes hosted on Instagram and Facebook.
- Follow a work-out video on YouTube.
- Walk/run up and down the stairs.
- Other easy stair exercises.
- Increase playtime with your kids or pets at home.
5) GET MORE SLEEP
A good night’s sleep is often regarded as “the best medicine” when fighting an infection. Sleep affects a wide array of immune parameters, including white blood cell distribution and activity, regulation of inflammatory response, and the expression of immune-related genes. Adequate sleep reduces your chance of getting an infection and the duration it takes to recover from it. How many hours of sleep is considered healthy? Studies show that anywhere from 7 to 8 hours per night is a healthy amount (10).
Tips to a good night’s sleep:
- Reduce or avoid screen time before bed.
- Avoid stimulating music, movies or tv shows before bed. Instead, opt for something slow, calming, and light-hearted.
- Avoid eating a heavy meal three hours before bed.
6) REDUCE ALCOHOL CONSUMPTION
Excess alcohol consumption is associated with adverse immune-related health effects. Alcohol disrupts immune pathways that impair the body’s ability to defend against infections.
Alcohol alters the abundance of microbes in the gastrointestinal (GI) tract. The GI tract contains trillions of microorganisms that aid in a healthy gut and immune function. Alcohol also damages the lining of the GI tract, disrupting gut barrier function. When unwanted substances leak through the gut barrier, it may trigger an inflammatory response in the liver, which may lead to liver cirrhosis (11).
Canadian health experts recommend limiting alcohol consumption to two standard drinks per day for women and three standard drinks per day for men. For more information, check out this alcohol drinking guideline released by the Canadian Center on Substance Use and Addiction.
Skip the alcohol and choose this instead!
- Mix club soda with bitters and lime, mimicking the bitterness and fizz of beer.
- Make a mocktail. Try some of these healthy mocktail recipes.
- Try Kombucha. A naturally carbonated drink with trace amounts of alcohol (<0.5%). The sharp taste of kombucha mimics that of alcohol. It also contains beneficial bacteria that promote diverse gut microbiome.
7) STOP SMOKING
Cigarette smoke contains more than 7,000 chemical compounds. Many of which interfere with the immune system. According to the Center for Disease Control and Prevention, smokers’ overall health is worse and are sick more often than non-smokers. Smoking harms the immune system and makes the body less successful at fighting disease, especially viral and bacterial infections of the lung like pneumonia, influenza, and tuberculosis (12).
Tips for quitting smoking:
- Seek support through a therapist or your health care provider.
- Get advice from friends and family that have experience with quitting smoking.
- Try nicotine patches or nicotine gum.
- Curb cravings through exercise.
Protective measures against COVID-19
With these effective immune-boosting strategies in place, you may reduce your risks of contracting an infection. Nevertheless, it is imperative to practice these protective measures against COVID-19.
SOCIAL DISTANCING. Limit close contact with others. Keep a two-meter (or six feet) distance from one another.
REGULAR HAND-WASHING. Wash your hands for at least 20 seconds using soap and water; this is the single most effective way of reducing the spread of infection.
DISINFECT OFTEN. Regularly clean and disinfect frequently touched surfaces such as doorknobs, handles (toilet, car, fridge), cellphones, remote control, computer keyboard, counters, tabletops, bedside tables, and light switches.
BE MINDFUL. Avoid touching your face, eyes, nose, or mouth with unwashed hands.
AVOID TRANSMISSION. Cover your mouth and nose with a disposable tissue or the crease of your elbow when you sneeze or cough.
For more information on how to stay healthy and prevent the spread of COVID-19, visit the Government of Canada’s COVID-19 guidelines.