Boosting Immunity with Functional Foods: Strengthening the Body's Defense Systems

August 22, 2023

The Covid-19 pandemic revealed the limited understanding of immunity that most people have. There was so much ambivalence around the conversation of immunity, or the idea that your body has in-built mechanisms to prevent or limit an infection after catching the virus once. 

Just like the rest of the systems in your body, your immune system works on feedback loops – if you serve it well, it will serve you well. So, let’s take a brief dive into this magical defense system and learn how to strengthen it with the right nutrition! 

A primer on the immune system

First, let’s understand that there are two types of immunity: innate immunity and acquired immunity. Your innate immunity is the one that you are born with; it is your body’s first line of defense against germs entering the body. It acts very quickly and has a similar response to all microorganisms. For instance, it takes only a few hours to detect and destroy any bacteria that has entered your body through a small wound. 

Whereas acquired immunity takes over when the innate immune system is not able to destroy the germs. It consists of specialised cells that target the type of microbe that is causing the infection. It also has memory cells to remember the germs so that it can fight the infection when the pathogen hits again. This memory is also why you can catch some illnesses only once in your life. 

However, the innate immune system still plays a crucial role to initiate and direct the adaptive immune responses, and to remove the pathogens targeted by them. Since the adaptive immune system takes 4-7 days to do its job, the innate immune response steps in to control infections during this period. 

What are the signs of a weak immune system? 

Most people associate weak immunity with just catching a fever or cold too often. But immunity is all-encompassing: feeling fatigued, having digestive issues like constipation, delayed wound healing, skin issues like psoriasis, eczema, and acne are also signs of a weakened immune system. These issues indicate that your immune system is having a tough time dealing with the toxins and pathogens in your surroundings. Now, let’s look at some ways in which you can boost your immunity!

Boost your immunity with functional foods

Garlic and Ginger

Garlic enhances the functioning of the immune system by stimulating certain cell types that help fight viruses and other microbes. One of the most important components in garlic is allicin, which is known to be a powerful antioxidant and fight against several bacterial and fungal infections. Similarly, ginger acts as an anti-oxidant and the most relevant compound found in it is gingerol that exhibits antimicrobial and antiviral properties. 

Vitamin D

Vitamin D has the ability to regulate immunity through effects on both the innate and adaptive immune systems. Various immune cells contain vitamin D metabolizing enzymes and receptors. It also pairs well with vitamin A to boost immunity. Vitamin D3 is its naturally occurring form and is synthesized in the skin by exposure to sunlight. It is obtained in diet chiefly through fish liver oils and salt water fish. Make sure to soak yourself in the sun for at least 30 minutes a day and remember that sunscreen use also prevents the synthesis of vitamin D in the skin. 

Antioxidant vitamins 

Vitamin C, E, and A act as powerful antioxidants and are known to enhance resistance against infectious microbes such as bacteria, viruses, and parasites. A lack of these nutrients in the diet can weaken the immune system, and ultimately, its ability to defend the body against diseases.

Food sources rich in antioxidants:

  • Vitamin C - Citrus fruits, tomatoes, red and green peppers, broccoli, strawberries, amla, and kiwifruit. Many of the best sources of vitamin C include fruits and vegetables that are eaten raw. 
  • Vitamin A - liver or liver products, organic free range eggs, A2 dairy milk, organic grass fed butter, ghee, carrots, lettuce, and tomatoes.
  • Vitamin E - avocado, mango, red bell pepper, asparagus, and pumpkin. 


Zinc affects multiple aspects of the immune system, from the barrier of the skin to gene regulation within white blood cells (WBC) called lymphocytes. Zinc deficiency also affects the development of acquired immunity by inhibiting the growth and functions of certain WBCs. Some foods rich in zinc include beef, lamb liver, pork liver, chicken heart, turkey neck, crab, oysters, and lobster. Some vegetarian sources include beans, lentils, chickpeas and pumpkin seeds and zinc supplements. Make sure to have enough protein in your diet to enhance zinc absorption. 

Healthy gut = healthy immune system

Keeping the gut healthy influences the immune system and virtually every aspect of your health. A diet rich in fiber and resistant starch, bone broth, probiotics and fermented foods, and a variety of colorful fruits and vegetables can help promote gut health.  

Medicinal Mushrooms 

Several mushrooms like lion’s mane and shiitake have immunological benefits. But if you are looking to specifically target the immune system, then reishi mushrooms are the way to go as they potentiate and stimulate the production of different immune cells in the body. 

Including these foods in your diet along with enough movement and exercise can help you enhance your immune system. We will end this article with a pro tip - ensure your toxin levels are low as an overload of toxins in the body compromises the immune system. All in all, working on your health holistically can strengthen this master defense system in your body. 


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  1. Vitamin D and Immune Function - The National Library of Medicine

Priyanka Gulati

Priyanka is a journalism graduate with a passion for truth-seeking. She is a conspiracy realist and developed an interest in nutrition science after waking up to the war on health. She is also an activist and has worked in the social sector and rural journalism. In her free time, you will find her getting into rabbit holes and drowning in books to understand the matrix!

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