What is the immune system?
The immune system is a host defense system that protects the body from bacteria, viruses, and other foreign invaders. It is a complex system with various cells, tissues, and organs working in collaboration to achieve one goal, i.e., protect the body from the effects of foreign invaders.
Our immune system includes skin, mucous membrane, bone marrow, and thymus – which produce leukocytes and white blood cells – spleen, lymph nodes, and tonsils. For more information on these organs, see the power of your immune system.
In this blog post, we are going to discover how our immune system responds to viral infections like COVID-19 and ways to strengthen immune system against coronavirus & other diseases.
Response to viral infection: Healthy vs dysfunctional immune system
When a virus enters a body, a strong, healthy immune system immediately identifies the foreign invader and sets into action to remove that virus. Cells that are infected by the virus are rapidly cleared by virus-specific T-cells that are attracted to the site of infection. The virus is inactivated by the antibodies that play a neutralizing role, and then other cells named as alveolar macrophages and apoptotic cells recognize the neutralized virus and engulfs it in the process known as phagocytosis. This leads to the clearance of viruses and therefore, recovery. In the case of COVID-19, this healthy response protects the lungs from excessive damage.
While all this is happening, the SARS-CoV-2 virus (the coronavirus) keeps spreading from one person to another via respiratory droplets. The signs and symptoms of the disease are not evident in the first 4-5 days, and the majority of the patients develop symptoms like fever and dry cough in 11.5 days of being infected. Mild symptoms are seen in the case of a healthy immune response.
In severe COVID cases, Acute Respiratory Distress Syndrome (ARDS) – a type of respiratory failure characterized by shortness of breath and rapid breathing – results in the death of the patient. Here aggressive inflammatory response and excessive release of cytokines (a group of proteins and chemical messengers that regulate the immune response) by the cells of the immune system lead to pulmonary edema, pneumonia, widespread infection, immune system suppression, and multi-organ damage due to sepsis, i.e., a life-threatening condition that results from the body’s response to inflammation. Studies show that COVID-19 causes sepsis in about 28% of the fatal cases.
Many people wonder why the coronavirus causes mild symptoms in some people whereas others suffer from severe symptoms like shortness of breath. The excessive release of cytokines (the cytokine storm) is thought to be the possible explanation in the case of serious symptoms.
Comorbidities and immune system
Comorbidity is the presence of one or more health conditions co-existing with the primary condition. For example, a patient who has COVID-19 and also suffers from heart diseases is said to have comorbid corona and heart disease. An important discovery in the case of microbial diseases has been the direct link between comorbidities and immune response.
Comorbidities like hypertension (high blood pressure), hyperlipidemia (presence of too many fats in the body), and diabetes have effects on the immune system. Some of these diseases, when uncontrolled, are linked to an exaggerated immune system response. So, individuals with comorbidities are more at risk of developing serious illness from coronavirus.
The best defense in the event of globally spreading coronavirus is to make sure that your chronic health conditions are under control. For example, people with diabetes must make sure that their sugar levels are well within the range. Similarly, if you have hypertension, try to keep your blood pressure under control.
Signs of a weak immune system:
If you have high stress levels, slow wound healing, you constantly catch colds, then you may have a weak immune system. Frequent diarrhea, gas, or constipation are also a sign of poor immune function. It is because 70 percent of the immune system is located in the digestive tract. The gut microbiota (microorganisms that live in the gut) helps in the regulation of immunity and any alteration causes immune dysregulation.
Strengthening the immune system
Although genetics plays a huge role in the working of your immune system, still, there are various ways to strengthen the immune system against coronavirus and other diseases.
Poor sleep, high stress levels, lack of physical activity, smoking, alcohol use, uncontrolled diabetes and hypertension, nutritional deficiencies, and poor diet, all play a role in the poor functioning of the immune system. Here’s what to do:
- Keep stress levels low. Breathing exercises, positive thoughts, and letting go of things can help you in keeping day-to-day worries of life at bay.
- Improve your sleep. A quality sleep for at least 7 hours a day has shown to provide health benefits.
- Improve your physical activity levels. If you are physically inactive, a 30-minute walk in that nearby park can be a good place to start. Similarly, jumping a rope is also a fun activity that won’t take a lot of time, but doing so regularly would definitely give a boost to your immune system.
- Try to quit smoking. Remember, second-hand smoking is as harmful as active smoking.
- Drink alcohol in moderation only. Excessive alcohol consumption has negative effects on the immune system. It can make people vulnerable to diseases like COVID-19. Individuals with heart disease and diabetes should drink even less as they are more prone to coronavirus complications.
- Avoid infections. Wash your hands after handling dirty items and by cooking your meat thoroughly.
- Pay close attention to nutritional deficiencies. Elderly are particularly prone to micronutrient deficiencies. A nutrient-rich diet consisting of unprocessed fruits, vegetables, legumes, seeds, nuts, proteins, healthy fat, and fibre is helpful in meeting nutritional needs. Although food is the best medicine, sometimes, dietary supplements help too. Discuss with your doctor if you are planning to take supplements,
- Take probiotics in your diet. Probiotics are good bacteria and yeast that help maintain gut flora. They give a boost to the immune system and prevent the growth of bad bacteria in your gut. Rich sources of probiotics are green banana, jamaica root, artichokes, asparagus, yogurt, kimchi, and kombucha.
- Increase the amount of vitamin-C-B6-and-E-rich foods in your diet. These foods include kiwi, orange, cantaloupe, berries, spinach, broccoli, carrots, nuts, chickpeas, green veggies, salmon, and tuna. Vitamin C, B6, and E protect against oxidative stress which translates into strong immunity.
- Adopt a positive attitude. Positive thoughts reduce stress and inflammation. They also increase resilience to infections. We realize that the COVID-19 pandemic is scary. With a lot of people getting infected, while some are taken to ICUs, it is only normal to be scared. But a positive thought like “I am safe at home with the people I love” is better than a negative thought like “I am not going to be OK.”
- Get vaccinated. While there are no vaccines for COVID-19 at present, there are other viral diseases, like influenza and hepatitis A and B, that can be prevented by vaccines.
A strong immune system can protect us against viral infections, like COVID-19. While the pandemic is scary, we can all improve our chances of staying healthy by strengthening our immune system against coronavirus and other diseases and keeping our comorbid conditions, like diabetes and hypertension, under control.