Two Sneaky Ways Junk Food Weakens the Immune System

junk food weakens immune system, coronavirus

Junk Food is All Around Us

Junk food is the go-to food for many Americans. It is becoming a global staple as the obesity rate continues to rise worldwide. What is it about junk food that has hooked millions of people – taste, convenience, price? Likely, it is a combination of all three.

Food companies invest millions of dollars into research and development every year to study the driving influences of people and junk food. They also identify how to get consumers hooked.

Junk Food is Nothing But Empty Calories

Junk food is high in calories and has no substantial nutritional value. Therefore, it is low in nutrients like quality proteins, healthy fats, minerals, vitamins, and dietary fiber. These macro and micronutrients are necessary for many biochemical processes in the body.

Junk food includes both processed and fast food. Some include bakery items, candy, soft drinks, snacks, pizza, French fries, potato chips, and ice cream, among others.

Junk food is nothing but empty calories and has a reputation for being unhealthy. It is commonly associated with chronic health conditions like obesity, atherosclerosis, heart disease, type-2 diabetes, and high blood pressure. These are some of the most prevalent health conditions in the U.S. and globally.

Junk food is rich in added sugars, unhealthy fats, salt (sodium), chemicals, and preservatives that reduce the immune system response. Weak immune system responses make people more vulnerable to infections.

In this article, we look at how high junk food consumption can weaken the immune system response.

Two Sneaky Ways Junk Food Weakens Immune System Response


junk food weaken immune system, weight loss, immune system


1. Junk Food Robs the Body of Important Vitamins and Minerals Needed for the Immune System Response

Consuming junk and fast food can lead to a deficiency of many nutrients in the diet. One such nutrient is vitamin C, which can be lacking in people who eat a lot of junk or fast food. 


Vitamin C and sugar have nearly identical compound structures; they fight for entry into immune system cells. Therefore, too much sugar could limit vitamin C’s access to immune system cells.


Vitamin C boosts immunity by promoting the differentiation and growth of B and T cells. It may also reduce the life span of infectious conditions, like the common cold. 


A diet consisting of mainly prepackaged food and fast-food restaurants leads to a reduced intake of vitamins, antioxidants, and minerals like zinc, causing increased inflammation in the body.

2. The Immune System Sees Junk Food as a Threat

A high sugar intake alters how white blood cells respond to bacteria.

The high-[unhealthy] fat in junk food increases susceptibility to altered immune responses. Therefore, it can lead to an increased immune response even when it is not needed. In other words, the immune system is constantly fighting a perceived threat, whether or not there is one.

Generally, when the body gets exposed to an infection, an intracellular complex called an inflammasome becomes activated and causes widespread inflammation. As a result, this inflammasome remains alert to detect any incoming infection source so the body can eliminate it as soon as it arrives.

Persistent inflammasome activation can disrupt the human body and its functions.

Check out: Boost Your Immune System with These Powerful Foods

How does junk food play a role in the immune system?

Junk food affects the immune system by activating the inflammasomes, causing widespread inflammation in the body. Therefore, overconsumption of unhealthy food makes the body react like it is fighting infections. 


Several science magazines, including, reported on a study that revealed how too much junk food damages the immune system over time. According to researchers at Bonn University in Germany who analyzed mice, high consumption of junk food aggravates the body’s defense system, making it more hostile and aggressive. It could lead to inflammatory conditions such as type-2 diabetes and hardening of the arteries. 


The researchers also discovered that the aggressiveness does not immediately resolve when starting a healthy diet.


It will take time before the aggressiveness dies down, and proper regulation can occur. It is because innate immunity retains memories that keep the body in an attentive state. 


Generally, these immune cell memories fight secondary infections and protect the body. They result from epigenetic changes in the innate immune cells, known as innate immune training or reprogramming. 


An unhealthy diet also forces this immune system response and increases inflammation throughout the body. It can lead to chronic inflammation and the persistent inflammatory condition that promotes the development of type-2 diabetes and high LDL cholesterol. 

Atherosclerosis is also possible as a result of chronic inflammation. 


Chronic inflammation increases the size of atherosclerotic plaque. It may increase the risk of plaque rupturing and lead to clots that induce stroke or heart attack. 


To summarize, an unhealthy diet promotes chronic inflammation. 

3. Bonus: Junk Food Has Little to No Fiber

Junk food consists of refined and processed ingredients. In addition, it is low in dietary fiber. Dietary fiber may have a protective mechanism for the heart and may offer some protection against type-2 diabetes. Some studies have also shown that fiber may help reduce the risk of colorectal cancer.

Dietary fiber may also promote gut health. The human gut contains many microbes that help digestion, absorption, and detoxification. 

In the gut, healthy microbes get replaced by unhealthy ones, thus increasing overall gut health deterioration. What we eat affects our gut health; junk food hurts the gut microbiome. Therefore, experts recommend eating foods that promote the growth of healthy micro-organisms. 

Also, the gut plays a vital role in a healthy immune system. The micro-organisms in the gut make up roughly 75 percent of the immune system.

Junk food, Immune System Response, and Coronavirus/COVID-19

The coronavirus has shown us how a person’s most essential (sometimes overlooked) asset is their immune system.

Avoiding or severely limiting foods and beverages that weakens the immune system response is one of the best things to do in times of crisis.

So, while junk food is delicious, convenient, and affordable, it will not cover up the long-term harm it does to your body.

The deficiencies of antioxidants, minerals, and fiber, along with the inflammasome activation and innate immunity reprogramming, make a person’s body more vulnerable to infections and chronic inflammatory conditions that indirectly weaken the immune system.

Thus, it is better to adopt a healthier lifestyle, as this will benefit your immune system and overall health. 

Final Thoughts

I am sure you read all of this and said to yourself, “Okay, I get it. Junk food weakens my immune system response, so I need to avoid my favorite foods forever?!”

While health experts would like to say ‘yes, you are correct,’ they also understand that we are only human. 

Thus, to forgo junk food forever is impossible for most people (myself included). 

For this reason, many experts believe in the 80/20 approach. This approach is practical because it allows for some wiggle room for our favorite snacks and foods. 

The 80/20 concept requires the consumption of healthy foods 80 percent of the time while allowing for some unhealthy consumption 20 percent of the time. In this way, we do not feel deprived.

Our goal should be to strive to eat healthily most of the time. It helps fuel our bodies and strengthens our immune system responses.

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