How Diet, Exercise, Stress Affects Immune System: Doctor Explains

Your immune system protects you from various diseases, including COVID-19.

Shubhangi Shah
Written by: Shubhangi ShahPublished at: Feb 14, 2022Updated at: Feb 14, 2022
How Diet, Exercise, Stress Affects Immune System: Doctor Explains

Among the many things that the COVID-19 disease has taught us is how important it is to keep our immune system strong. Not just COVID-19, a strong immune system protects you from a plethora of microorganisms and the diseases they cause. Hence, it is crucial to keep it strong. Apart from diseases and medicines that directly impact it, basic aspects such as diet, exercise, and even stress affect it. During the pandemic, we took a proper diet specifically to boost our immunity. So, how do these aspects affect our immune system? What are the ways to strengthen it? To get answers to these questions, Onlymyhealth spoke to Dr. Abhinav Kumar – Associate Consultant, Gastroenterology & Hepatobiliary Sciences, Fortis Escorts Liver & Digestive Diseases Institute.

What Impact Does Food Have On Immune System?

Proper nutrition is needed for all the cells in your body to function optimally, which includes your immune system cells. 

  • Apart from that, certain micronutrients and dietary supplements play a key role in developing and maintaining an effective immune system throughout your life. These include:
  1. Vitamin A
  2. Zinc

Poor diet can harm the immune system

(Photo Credit: Freepik)

Both these micronutrients “regulate cell division,” explained Dr. Kumar, and are essential for a proper response within the immune system. Even a minor deficiency of zinc in the body can have a major impact on the immune system, the doctor explained.

  • Similarly, selenium, which is present in trace amounts just like zinc, has a major impact on a range of body proteins. Hence, poor selenium levels can increase your risk of a range of diseases, from cancer to cardiovascular illnesses.
  • Undernutrition also impairs the immune system.
  • Other than these, obesity and overnutrition are strongly associated with chronic inflammation and metabolic perturbation. They increase your risk for a range of chronic illnesses, from type-2 diabetes and stroke to chronic liver disease. 

A Western diet characterized by high sugar content, trans and saturated fats is not good for the body. At the same time, it is low in complex carbohydrates, fiber, micronutrients, and other essential nutrients like polyphenols, omega-3 fatty acids, and polyunsaturated fatty acids (PUFA). Juxtaposed to the Western diet, the Mediterranean diet is rich in fruits, vegetables, nuts, legumes, and healthy fats. It is associated with a reduced risk of chronic diseases such as cardiovascular disease, cancer, and Alzheimer’s.

Also read: Never Take Vitamin C and Zinc Together, Public Health Expert Explains Why

Impact Of Physical Activity On Immune System

Physical inactivity can harm the immune system

(Photo Credit: Freepik)

Just like food, the immune system is highly receptive to exercise. Moderate-to-vigorous intensity exercise for even less than an hour a day is good for the immune system. Regular activity has also been shown to have anti-inflammatory effects. Hence, working out is another key to a strong immune system.

Impact Of Stress On Immune System

Stress has earned a bad reputation despite it being a crucial response to promote survival during a fight or flight situation. Some amount of stress is fine, however, an excessive amount of it can have a detrimental impact on your health, including the immune health:

  • During the time of stress, your body is exposed to a stream of stress hormones that suppress the immune system.
  • Not just that, people suffering from depression have a higher level of systemic inflammation.
  • Chronic stress also affects a variety of clinically meaningful immune parameters, such as susceptibility to infectious diseases, the ability of the body to fight off pathogens, wound healing, antibody response to vaccines, and various inflammatory processes. These, in turn, increase a person’s risk of person to a host of diseases, such as cardiovascular diseases, diabetes, certain cancers, autoimmune diseases, etc.
Chronic stress can harm the immune system
(Photo Credit: Freepik)

Diseases That Affect The Immune System

Other than lifestyle factors, several diseases and medications also suppress the immune system.

  • Autoimmune diseases are a set of illnesses in which the immune system attacks its cells. Diseases include:
  1. Lupus
  2. Rheumatoid arthritis
  3. Type-1 diabetes
  • Several bacterial and viral infections also harm the immune system. Such infections include HIV (human immunodeficiency virus) that can develop into AIDS (acquired immune deficiency syndrome)
  • Diseases such as lymphoma, leukemia, and sickle cell disease can also suppress the immune system.
  • Other than these, several medications can also suppress the immune system. Immunosuppressants are the class of medicines specifically designed to suppress the immune system. These are prescribed to treat an autoimmune disease or during an organ transplant to prevent the body from rejecting the organ.

How To Strengthen The Immune System?


As lifestyle factors can contribute to a weakened immune system, you can develop a healthy lifestyle to prevent the same.

  • Have a proper, well-balanced diet to keep infections at bay. Have enough protein, along with vitamin A and zinc.
  • A poor diet can cause inflammation, which in turn causes oxidative stress. It, in turn, can affect the immune system. Hence, eat anti-inflammatory and antioxidant-rich food. Vitamin C, E, polyphenols, and carotenoids have these properties.
  • Similarly, have vitamin D and fiber for a strong immune system.
  • Exercise regularly.
  • Since stress is also a factor for the suppressed immune system. Hence take steps to manage that. Yoga and meditation are known to work well.
  • Connect with people.
  • Exercise to blow off the steam.
  • Insufficient sleep can also contribute to stress. Hence, get the requisite 7-9 hours of sleep every night.

Hence, as you saw, lifestyle factors such as food, physical activity, stress, and rest have a huge impact on your immune system. Being your body’s defense against infections, you need to have strong immunity. Hence, take the requisite steps to strengthen it by eating healthy, exercising plenty, and managing stress. These will play a huge role in keeping infections at bay.

(With inputs from Dr. Abhinav Kumar – Associate Consultant, Gastroenterology & Hepatobiliary Sciences, Fortis Escorts Liver & Digestive Diseases Institute)

Photo Credit: Freepik