Immune system and its functions:
The immune system is the body's defence mechanism against infection-causing pathogens. It is a network of cells, organs, tissues and proteins that function collectively to fight against any foreign particle entering the body. The immune system keeps a track of every germ it has ever defeated, hence it can identify and destroy that microbe in future, the moment it re-enters the body. A healthy immune system ensures quick recovery from injuries, strengthens the functioning of white blood cells, regulates the body’s pH and maintains ideal gut health and hormonal levels.
Types of immunity:
- Innate immunity: It is a general, in-born immunity that develops in a human by the time of birth. For example- skin acting as a shield to block germs from entering the body.
- Adaptive immunity: Adaptive or active immunity is the one that develops throughout our lives. A case in point is vaccination, which exposes us to certain antigens, ensuring immunity against a particular disease.
- Passive immunity: Passive immunity can also be called “borrowed immunity” from another source which lasts for a short time. For example, antibodies present in a mother's breast milk give the baby a temporary immunity to ward off infections and diseases.
Factors that can impair immune system activity:
- Old age: Ageing is often associated with micronutrient deficiencies, which may cause a decline in immune function.
- Environmental factors: Toxins like smoke, excessive alcohol and air pollutants can suppress the normal functioning of immune cells.
- Improper diet: Malnutrition or inadequate diet can disrupt the production and activity of immune cells and antibodies.
- Chronic diseases: Long-term illness or autoimmune disorders can attack and damage the immune cells of the body.
- Chronic mental stress: Stress releases a hormone called cortisol which suppresses inflammation, which is needed initially for the activation of immune cells and functioning of white blood cells.
- Insufficient sleep and rest: The body releases Cytokines during sleep that help fight infections and repair and revive the body.
Dietary and lifestyle changes for improved immunity:
1. Vitamin A: Beta carotene, converted into Vitamin A in the body, is a powerful antioxidant that lowers inflammation and boosts immune function by increasing disease-fighting cells (White Blood Cells). A deficiency of this vitamin can thus increase the risk of infections and delay the recovery process when you fall sick. Foods that contain vitamin A include sweet potatoes, carrots, green leafy vegetables, pumpkin, cantaloupe and mango.
2. Vitamins C and E: These two micronutrients are high in antioxidant content that help destroy free radicals and support the body’s natural immune response. Vitamin C rich sources include red bell peppers, oranges, strawberries, kiwi, lemon, guava and amla. Foods rich in vitamin E are almonds, sunflower seeds, hazelnuts, peanut butter, spinach, and broccoli.
3. Vitamin D: Also known as the sunshine vitamin, vitamin D reduces the risk of viral and respiratory tract infections and helps prevent other chronic diseases like hepatitis and cardiovascular diseases. Add foods like salmon, tuna, mackerel, fortified cereals, cheese, eggs and milk to your diet as they are rich in vitamin D
4. Zinc: Zinc helps boost the production of white blood cells (leukocytes) that fight against disease-causing microbes. Dietary sources of zinc include cashews, oysters, mushrooms, pumpkin seeds, sesame seeds and lentils, yoghurt and chickpeas, among others.
5. Selenium: Selenium is an important nutrient for keeping infections at bay and helps in speedy recovery from any infection or inflammation. Fish, poultry, tofu, cottage cheese, brazil nuts, whole wheat pasta and bread are few examples of selenium-rich foods.
6. Omega-3 fatty acids: The EPA and DHA in fish oil help reduce inflammation and boost the functioning of WBC’s. Omega-3 rich dietary sources include salmon, tuna, flax seeds, walnuts, almonds and avocados.
7. Proteins: Proteins help fight bacterial and viral infections, thereby strengthening immunity. Whey protein is a complete protein that provides all the essential amino acids to our body. Protein-rich foods you should add to your diet include lean meats, quinoa, soy products, paneer, nuts and seeds, broccoli and many more.
8. Proper sleep: Our bodies need adequate sleep to recover and revive, insufficient sleep can thus suppress the functioning of the immune system. Have at least seven hours of sound sleep every night to keep your immunity strong.
9. Avoid processed, packaged and preserved foods: These foods contain high levels of refined sugar and salt that can trigger inflammation in the body and weaken the gut health, thus leading to suppressed immunity.
10. Lifestyle factors: Limit alcohol intake and smoking as they can impair the immune system’s response to pathogens, making you more susceptible to infections.
11. Stress: Stress leads to the release of cortisol hormone, which can decline the functioning of lymphocytes (immune cells). This can adversely affect the immune system's ability to fight off antigens.