What is Immune System?

Overview

The immune system is the body’s tool for preventing or limiting infection. Its complex network of cells, organs, proteins, and tissues enable it to defend the body from bacteria, viruses, parasites, and more.

What Is Immunity?

Immunity refers to the body’s ability to prevent the invasion of pathogens which are the foreign disease-causing substances, such as bacteria and viruses. When we are exposed to these pathogens, the antigens attached to their surface stimulate an immune response in the body. An immune response is our body’s defense system to fight against antigens and protect the body.

Types of Immunity

There are several types of immunity. This includes

1. Innate Immunity

This is a general protection that a person is born with which is activated immediately when a pathogen enters the body. This includes physical barriers (skin, body hair), defense mechanisms (saliva, gastric acid), and general immune responses (inflammation).

2. Passive Immunity

This is the body’s capacity to resist pathogens by “borrowing” antibodies. The most common form of passive immunity is that which an infant receives from its mother during the last one to two months of pregnancy. During this time, the antibodies are transported across the placenta from mother to the baby.

3. Acquired (adaptive) Immunity

This is a type of immunity that develops from immunological memory. Once the body is exposed to a specific antigen, it develops antibodies against it and if next time the same antigen invades then the body already has antibodies to fight it off. Acquired immunity can occur from exposure to an infection, wherein a person gets a disease and develops immunity as a result. Acquired immunity also occurs from vaccination wherein the vaccine mimics a particular disease.

Factors that Affect our Immune System

Several factors like stress, age, body composition or our lifestyle can affect our immune system which in turn can affect our immunity.

1. Improper Sleep Cycle

The immune system is influenced by the sleep wake cycles. While we are sleeping we have decreased levels of stress hormone cortisol which can suppress the immune system. Getting adequate amount of rest every day is important in order to minimize the stress levels. Also, it can help increase signals that activate the immune system.

2. Elevated Stress Levels

When we’re stressed, the body produces stress hormone corticosteroid or cortisol which decreases the body’s ability to fight against infections making us more susceptible. Too much of stress can also lead to binge-eating on unhealthy snacks or consumption of alcohol which can lead to nutritional deficiencies and weaken our immunity.

3. Age

Immune system’s capacity declines we grow older, especially above 70 years of age. This is due to decrease in the production & functioning of T-cells due to degeneration of the thymus gland in the body.

4. Lifestyle Factors

Following a healthy diet and regular physical activity can result in a better immune function. Eating a balanced diet on a regular basis provides proper nourishment to the body and also prevents any deficiencies which may hinder the immune response. Exercising regularly also supports the immune system by increasing the number of fighter cells in the body.

5. Medications

Certain medications for autoimmune disorders, cancer, HIV or disorders with chronic inflammation like asthma, Crohn’s disease, rheumatoid arthritis etc can limit the immune response and weaken the body’s ability to fight against infections.

6. Body Composition

Too much or too little body fat can lead to suppression of the immune system. This is because excess weight gain can put you at the risk of developing health issues conditions like type 2 diabetes, hypertension & heart disease which can lead to a decrease in the body’s ability to fight against infections due to a weak immune response.

7. Unhygienic Behaviours

Cleanliness and following basic hygiene in simple daily habits is crucial as it helps in minimizing the chances of infections.

Immune System Disorders

When your immune system doesn't work the way it should, it is called an immune system disorder. This includes:

• Primary immune deficiency – In this you may be born with a weak immune system.
• Acquired Immune Deficiency – In this you may get a disease that weakens your immune system.
• Overactive Immune System – You may have an immune system that is too active and may react to environmental substances that are normally harmless. Having an allergic reaction is the most common example.
• Autoimmune Disease – Here you have an immune system that turns against you and the body attacks its own normal, healthy tissues.

Tips to Boost Immunity

A high functioning immune system is the key to staying healthy. For boosting immunity and to ward off most diseases and illnesses, there are several prescribed methods, some of which are listed below.

Foods that Boost Immune System

Regularly eating a variety of nutritious foods rich in vitamins and minerals, such as citrus fruits and spinach, can help boost your immune health. Foods that help boost immune system are:

• Citrus Fruits – Most citrus fruits are high in Vitamin C which helps to build-up immune system by promoting immune cell functions. It is believed that Vitamin C increases the production of white blood cells which are responsible to fight infections. Popular citrus fruits include: grapefruit, oranges, tangerines, clementines, lemons, and limes.
• Red Bell peppers - Red bell pepper is a rich source of Vitamin C. It contains about 3 times more vitamin C than an orange. Apart from that, it is also rich in Beta Carotene which is converted by the body into Vitamin A that helps to keep your eyes and skin healthy.
• Broccoli - Broccoli is one of the healthiest vegetables you can add in your diet. It is rich source of vitamins A, C, and E, as well as fiber and many other antioxidants.
• Garlic - Garlic is known to have immune-boosting properties and it’s a must have for good health. It is believed that it also slows down hardening of the arteries and lowers blood pressure.
• Fatty Fish - Eating food rich in omega-3 fats helps to keep our immune system in good shape and fatty fish are a good source of this anti-inflammatory fat. So consider eating mackerel, salmon, sardines, trout, herring, and tuna.
• Ginger - Ginger contains Vitamin C, magnesium, and potassium, and has multiple health benefits along with anti-inflammatory & antioxidant effects.
• Turmeric - The spice is touted for its ability to boost the immune system and act as an anti-viral.

Conclusion

If you want to boost your immune health, you may wonder how to help your body fight off illnesses. While bolstering your immunity is easier said than done, several dietary and lifestyle changes may strengthen your body’s natural defenses and help you fight harmful pathogens, or disease-causing organisms.

Frequently Asked Questions

1. Can immunity be boosted by food?

Yes, there are several food items which are naturally rich in the relevant vitamins, minerals, proteins and other nutrients which are essential to the proper functioning of the immune system.

2. How do I know if I have low immunity?

While there are comprehensive tests and health checks which can give you an understanding of the collective status of your immune system, some signs that one can look out for include; frequent cold and/or cough, feeling fatigued all the time, high stress levels, regular stomach or digestions related issues.

3. Is strong immunity related to age?

It is a known fact that aging reduces the responsiveness of the immune system. The lowered immunity levels may make you prone to external infections and other related ailments. Having said that, maintaining a healthy lifestyle has the power to offset several age-related issues.

4. Does walking boost immunity?

Yes, regular walking and other forms of mild exercise definitely boost immunity. Several studies recommend a minimum 150 minutes of walking or other exercises per week for a healthy body.

5. Does consuming sugar affect immunity?

High sugar intake is known to affect immunity adversely. It may also lead to weight-related ailments or lifestyle diseases like Type 2 Diabetes and even heart disease.

Source: Harvard Medical School, HealthLine, ClevelandClinic, ECampusOntario Pressbooks, Medium, HopkinsMedicine