The coronavirus pandemic has somewhat turned the world’s attention to the immune system, the body’s defence mechanism against disease-causing bacteria, viruses and other organisms that we touch, ingest and inhale every day.
Several studies have stressed the importance of a strong immune system to the human body.
According to the Heart Foundation, New Zealand, when a foreign microbe gets into the body, the body puts up a defence.
Although the immune system is not always successful in preventing microbes from entering the body, it can help to quickly recover from the illness.
According to medical scientists, one of the best ways to stay healthy and boost the immune system is to eat healthy because what one eats is the major factor that determines how healthy one will be.
Eating healthy, antioxidant-rich foods such as fruits and vegetables, whole grains, and lean protein is an important part of maintaining good immune system and health to ward off infection and illness.
The following 10 foods can boost your immune system, although the list is not exhaustive.
Honey’s antioxidant and antibacterial properties help improve the digestive system and boost immunity. It is a powerhouse of antioxidants, which are effective for the removal of free radicals from the body. According to Delhi, India-based nutritionist Anshul Jaibharat, one can start one’s day by adding a spoonful of honey and lemon juice to a cup of warm water. One can drink this cleansing tonic before breakfast to reap honey’s amazing health benefits.
Garlic’s scent tips you off to its many health benefits. The pungent aroma comes from sulphur compounds, including allicin. Scientists believe that allicin may block enzymes involved in infections; some studies suggest that swallowing garlic may ward off colds.
Garlic can be cooked with other foods, although some people can stomach eating a bit like a pill, followed by milk or water. Research has also linked garlic intake to a lower risk of stomach, colon and oesophagus cancers. For a flavour and immunity boost, add garlic to marinades, roasted vegetables or grain bowls.
Half a grapefruit has more than 60 per cent of your daily vitamin C content, and eating grapefruit may also help the body absorb other essential nutrients, such as iron. People who regularly consume foods containing vitamin C may have slightly shorter colds or milder symptoms. For a healthy morning treat, broil grapefruit with a little cinnamon sugar.
Ginger, which is sometimes recommended to treat nausea, is high in both antioxidants and anti-inflammatory properties. A recent review of 60 studies found that ginger might have beneficial effects on ailments like obesity, heart disease and diabetes. It also contains immune-system-supporting compounds like beta-carotene and capsaicin.
You can toss freshly ground ginger into a tofu stir-fry or sip it in your tea.
Lemons are high in compounds called bioflavonoids, which kill cancer-causing free radicals. They also provide vitamin C (you can meet half your daily requirement from one fruit), so adding lemon juice to your meals is an easy strategy for protecting yourself against colds and other infections.
One simple way to work in a daily dose of vitamin C is to drink lemon water, either chilled or warm. A squeeze of lemon also makes steamed veggies tastier.
People who eat an apple a day use fewer prescription medications, according to a 2015 study. And regular apple eaters report fewer asthma symptoms, according to research conducted by a group of researchers in the United Kingdom.
Apples are also high in fibre, which can help reduce the inflammation common during infections. They are also a superfood when it comes to satiety.
To turn apples into a more energising snack, slice one up and enjoy with a spoonful of peanut or almond butter. Buy organic or wash well before eating: a recent study found that a little water and baking soda remove pesticide residue from the fruit.
Chicken soup helps soothe cold symptoms, likely because the warm broth can thin nasal mucus so it can clear more easily. Soup in general hydrates, making it a smart meal pick when you’re sick. If you want, you can spice up your chicken soup with nutrient-dense foods like carrots, onions and fresh herbs.
Additionally, foods high in protein, such as lean meats and poultry, are high in zinc–a mineral that increases the production of white blood cells and T-cells, which fight infection. Other great sources of zinc are oysters, nuts, fortified cereal, and beans.
Mushrooms may be a potent weapon in warding off colds, flu, and other infections. Studies done on fresh mushrooms, dried mushrooms, and extracts have shown that mushrooms such as shiitake, maitake, and reishi have antiviral, antibacterial, and anti-tumour effects.
Berries are rich in vitamin C and bioflavonoids, phytochemicals found in fruits and vegetables that may work as antioxidants and prevent injury to cells.
One cup of strawberries contains as much as 100mg of Vitamin C, which is nearly as much as a cup of orange juice. Dark berries such as blueberries are especially high in bioflavonoids. For an optimal immune system boosting effect, eat a bowl of mixed berries, or vary which berries you choose from day to day, rather than eating only one type.
Fish are rich in Omega 3 fatty acids and other healthy fats which help increase the activity of white blood cells. These Omega 3s may also play an important role in the production of compounds that regulate immunity in the body and help protect the body from damage from overreacting to infections.
The best way to get the omega 3 fatty acids – DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid)–is by eating fatty fish such as tuna, salmon, and mackerel. You can also get this omega 3s through krill oil capsules or algae supplements. Other sources of the omega 3 fatty acid ALA (alpha-linolenic acid) are flax seeds, flax oil, chia seeds, hemp seeds, and walnuts.
Meanwhile, one thing to keep in mind when choosing fish is that pregnant women and young children should avoid high mercury fishes like king mackerel, tilefish, shark, and swordfish.
Five additional tips to boost immune system
Although eating the above foods does not mean you may not get sick, medical experts have said taking the steps could dramatically strengthen the immune system and improve your overall health.
Apart from food, there are other activities that can help boost the immune system these crucial these times.
- Don’t smoke
Smokers have an increased risk of catching infections and suffering severe complications from them. Smoking damages the lungs and people with unhealthy lungs have been said to have a high risk of contracting coronavirus and other infections. Smoking is also the major cause of lung cancer and chronic obstructive pulmonary diseases such as chronic bronchitis and emphysema. Hence, you might want to desist from smoking, especially at this period of increased health risk.
- Get adequate sleep
Sleep is important for health in general, and as a bonus, it may also benefit our immune function. For instance, a study showed that those with insomnia had, on average, less immune response to the influenza vaccine, while another study in twins showed those with worse sleep had altered expression of genes related to immune function.
In another study, 153 volunteers were inoculated with the rhinovirus (the virus that can cause the common cold). It was found that those who slept less than seven hours were three times more likely to develop symptoms than those who slept more than eight hours.
Again, the science in this area may not be robust, but when it comes to overall health, proper sleep helps. In times like these, you should prioritise sleep hygiene.
If you’re isolated at home, that likely means more time on electronics like tablets, phones, and TVs. This may be a good time to invest in blue-light blocking glasses and to look for non-tech related activities to do in the evening, like puzzles, crosswords, or reading an actual book (not an ebook!).
- The right amount of exercise
Observational studies show that those who exercise tend to suffer fewer infections than those who do not. While those studies have confounding variables, the general consensus is that overall exercise is likely beneficial.
Stay active, but remember that now is not the time to start a new high-intensity exercise routine. If you already enjoy strenuous exercise, consider decreasing the frequency or intensity by 10-20 per cent (this is not scientifically backed but it’s recommended by some experts).
Also, try to focus on home or outside exercise. Shared gym equipment, like weights and cardio machines, may be surfaces that transmit the virus.
- Stress management
While acute stressors may temporarily enhance immune functions, chronic stressors can likely diminish immune function. Worrying about job loss, financial markets and debts, or focusing on the uncertainties of the future can raise cortisol levels, which may negatively impact on immune function.
While we can’t make this stressful situation disappear, we can all take measures to control our response to stress. Meditation, mindfulness exercise, and getting outside and going for walks are all examples of activities that can potentially lower blood pressure, blood sugar, and make your days much more pleasant.
- Drink alcohol in moderation
In times of stress, some people turn to alcohol as a coping mechanism. While meditation, nature walks, and mindfulness exercises are likely healthier ways of coping, for some, they aren’t enough, and alcohol adds a little something extra for them.
However, studies show a relationship between chronic heavy alcohol consumption and increased susceptibility to infections.
Perhaps most pertinent for the discussion about COVID-19, some of these studies showed an increased risk among heavy drinkers of acute respiratory distress syndrome, the lung complication responsible for most of the COVID-19 related deaths.
Hence, now is the time to limit your alcohol intake, with some medical experts suggesting two drinks for men and one drink for women per day.