7 Foods That are The Worst for Your Immunity

Aditi Shenai

May 12, 2022

A strong immune system is crucial for staying healthy. Sound sleep, exercise, and good nutrition are vital for the immune system. A deficit in the sleep cycle, adapting to a sedentary lifestyle, and consuming unhealthy food will weaken the immune system. In such testing times as the pandemic, it is vital to strengthen the immune system by staying away from the worst immune foods. When the immune system is powerful, it restricts the body from being easily susceptible to falling ill and fights viruses like a strong warrior during sickness. 

Nutrition indeed comes into the picture as a significant factor when the strength or weakness of the immune system is under question. It is up to people to maintain a healthy lifestyle by consuming whole, organic foods free from additives & chemicals. Such food helps in nourishing the body and truly supports the immune system with zero toxins. Choose to keep your immune system strong by avoiding the worst immune foods and adopting a healthy lifestyle. 

Relationship Between Food and Immunity

People might not be highly aware, but selective foods with low nutritional value can hamper their immune system. Foods high in calories and consisting of sugar, saturated fats & excessive salt have a hand in lowering the immune system’s capabilities. Hence, it is crucial to maintain a safe distance from the worst immune foods to lead a healthy life. 

Our immune systems correlate to our protein intake. Eating insufficient amounts of protein or foods with incomplete proteins, weakens the immune system and therefore the chances of getting infections and inflammation in the body, increases greatly. As per studies, the diet consumed by people significantly affects their immune systems. Nutrition can influence the microbiome, gut barrier functions, inflammatory processes, and functioning of the white blood cells. 

Dietary patterns and sedentary lifestyles are responsible for enhanced risk of diseases, allergies, and impaired immune response. Specific diets contain foods with increased fats (saturated), ultra-processed foods, and unhealthy calories. Thus, consuming wholesome diets containing fruits, vegetables, legumes, seafood, etc., is crucial to promoting healthy immune function.

 Foods That Ruine Your Immune System 

1. Selective Beverages 

All kinds of beverages like soda, sweetened tea, energy drinks, juices and especially alcoholic drinks are a few of the worst immune foods. They have a pretty negative impact on our bodies, and avoiding them is in the best interest of our health. These beverages enhance the stress hormone cortisol production and upturn blood sugar levels while interfering with the functioning of insulin, all of which can lead to a weak immune system. They are one of the worst immune foods as it also disrupts the circadian rhythm. Additionally, they target our sleep cycle, which affects our immune system. A chilled soda can seem perfect for a hot sunny day, but along with quenching your thirst, it cynically pokes at your immune system.

Sodas and a couple of fizzy drinks are only empty calories & hence account for zero nutritional benefits to your body. Also, even diet soda is not a safe option because it does not contain any beneficial nutrients. It leads to a deficiency of enough vitamin A, calcium & magnesium, which are essential for maintaining a sound immune system. These beverages also contain phosphoric acid. Therefore, it depletes the presence of magnesium & calcium in the body.

2. Sugary Goods 

White sugar or refined sugar is highly detrimental to our immune system. All the mouth-watering candies, chocolates, cakes, bread, doughnuts, biscuits & other desserts are full of white sugar. Try to eliminate this white sugar from your diet & go for healthier substitutes like jaggery, honey, coconut sugar, maple syrup etc. These food substances have equal calories but are undoubtedly healthier than white sugar. A rise in blood sugar levels after consuming candies or chocolates can cause an eruption in the immune pathways.

The production of free radicals leads to cancer, diabetes & cardiovascular diseases. Moreover, as per studies, consuming a sugary diet exacerbates oxidative stress, resulting from free radicals. All of these lead to the weakening of blood cells and inflammation. For example, ice cream is an eternal favourite. But, it is high in fat, cream & milk, which makes it top the list of saturated fats and sugar, spiking sudden blood sugar levels. Therefore, think long term where these sugary food items can gradually affect your immune system. 

3. Fried Foods 

As per studies, fried foods are one of the worst immune foods. They are full of fats, and they enhance bad cholesterol. They also have the power to trigger inflammation which is an automatic attack on the immune system. Getting rid of this worst immune food item can help restore the body’s natural defence mechanism. Additionally, fried foods accumulate a lot of acrylamide, a hazardous carcinogen. Carcinogen enhances the risk of cancer. 

Fried foods can be addictive but terrible for the immune system due to their sky-high grease and fat levels. They are the primary cause of high blood pressure, shooting cholesterol levels and thus, a weak immune system. To defeat the worst immune food, you have to get rid of your oily food intake and opt for roasted, sautéed, air-fried or baked goods for satiating your cravings.

4. Red Meat 

Be it beef, pork or lamb – all of them cause your blood cholesterol to shoot up with its high levels of saturated fats. If you eat them regularly and in very high quantities, it significantly harms the immune system. In addition, it causes damage to heart health. Red meat is known to trigger dangerous reactions for weakening the immune system. It happens due to natural sugar present in red meats that the body finds impossible to digest. Sugar gives rise to many other health concerns, with an increased risk of cancer being one of the top ones. However, red meat also contains several nutrients. The trick is to eat them in moderation. Also, how you cook affects its nutritional value. 

5. Processed/Packaged Foods 

Many foods labelled as “natural” products contain vast amounts of refined sugars, carbohydrates & hidden flavours. On the other hand, processed foods like cereals and bread comprise immune-suppressing sugar. It is any food which comes in packets, has more than one ingredient & has been cooked & modified mechanically. Consuming packaged foods can lead to chronic irritation in your body and comprises toxins with no possible nutritional gains. It only equates to poor health and an impaired immune system because of ingredients like white flour, preservatives, and additives with more calories and fewer nutrients. Further, it leads to inflammation, insulin resistance and weight gain.

6. Excessive Stawberries

Starwberries are enjoyed across the globe as a part of your breakfast or midday snack. However, strawberries release a component called histamine, which leads to congestion and is the substance responsible for allergies. In addition, there can be an increase in the sinus problem with a rise of histamine in your body. 

Excess histamine in the body disrupts the immune system to believe that certain substances are harmful and lead to allergic reactions. It can cause discomfort in your nose region, constant wheezing, headache etc. However, berries are only unhealthy if you overeat them. Moderate consumption is healthy.

7. Unripe Bananas 

Even the fruits supposed to be healthy comprise natural sugars that negatively affect the immune system. It also negatively influences gut health, especially when the bananas are not ripe. When fruits and vegetables tend to be unripe, they contain high amounts of lectin harmful to the body’s immune functions.

Best Foods for Immunity

Now that we know what kinds of food are worst for the immune system, it is our responsibility to take care of our health by opting for the types of food which are best for our immunity like:


Blueberries are rich in antioxidants, especially anthocyanins (flavonoid). As per studies, flavonoids play a significant role in the respiratory tract’s immune defence system. It prevents damage to cells and keeps harmful pathogens away. Blueberries also contain vitamins such as vitamin C, vitamin A, potassium, dietary fibre, and manganese which play an additional role in improving the body’s immune system.

Dark Chocolate

Dark chocolate is an immunity booster as it contains an antioxidant called theobromine. Theobromine aids in shielding the body cells from free radicals. However, it should be eaten in moderation as its calorie content is high. Consuming cocoa boosts natural immunity and boosts the immunological response caused by vaccination, giving you better protection from influenza virus infection and related symptoms. 


Your immune system operates better if you minimise the quantity of active free radicals in the body. Curcumin is turmeric’s principal active ingredient. According to research, it has a high disease-fighting capacity and usefulness in treating colds and flu.

Curcumin’s ability to act as an anti-inflammatory renders it an effective immune-boosting treatment. Likewise, turmeric is an antioxidant which improves the immune system and prevents the development of chronic illnesses. 


It is yet another source of vitamin C. As per studies, broccoli contains potent antioxidants like sulforaphane which support immune system health. Broccoli is a nutrient-dense superfood that can help your immune system. One cup of broccoli juice has the same amount of vitamin C as an orange. Beta-carotene, potassium, magnesium, zinc, and iron are all abundant in vegetables. Thus, it is a good choice of vegetables for regular consumption.


Spinach enhances the functioning of the immune system. It comprises necessary nutrients & antioxidants like flavonoids, carotenoids, vitamin C & E. It strengthens the body’s immunity. As per research, flavonoids also aid in preventing the common cold in healthy people.


The coronavirus pandemic has succeeded in making people realise the significance of a robust immune system and has also given them enough reasons to appreciate their body’s natural defence mechanism in a better manner. Maintaining a healthy lifestyle can help your immune system. It includes avoiding meals and beverages heavy in sweeteners and salt and processed meats and fried foods, harming your immune system. To help your immune system, eat a well-balanced diet high in whole, nutrient-dense foods while avoiding ultra-processed foods.

Frequently Asked Questions (FAQs)

Q: What foods calm the immune system?

A: Calming foods for the immune system include omega-3 fatty acids like those in salmon and chia seeds. They help fight inflammation because healthy fats like olive oil and Omega 3 are anti-inflammatory. You can also opt for colourful fruits and vegetables to consume a variety of antioxidants, flaxseeds and spices like ginger, rosemary, basil and turmeric to quieten the immune system. 

Q: What are the signs of a weak immune system?

A: The signs of a weak immune system are infections, frequent colds, many digestive problems, delayed wound healing, skin infections, fatigue, delayed growth, blood disorders & autoimmune diseases. You may also feel very stressed and fatigued all the time 

Q: Does coffee affect the immune system?

A: When too much caffeine enters the body, it can diminish the abilities of the immune system to ward off infections. It also weakens its ability to remove damaged or abnormal cells—consumption of too much coffee results in higher cortisol levels, a stress hormone. 

Q: Can a 3 day fast reset your immune system?

A: When you fast for at least three days, the body produces new white blood cells, which help rejuvenate the immune system to fight infections. 

Q: Is rice anti-inflammatory?

A: Rice can be anti-inflammatory if you opt for whole grains like brown rice. They are high in fibre which aids in combating inflammation. 

Q: How long can you safely fast?

A: As a precautionary measure, you should always restrict your fasting period to 24 hours or less and keep a snack handy if you feel faint or dizzy. 

Q: How do you reset your immune system?

A: To reset your immune system, try getting enough sleep as both are closely connected. You should consume more plant-based foods and add healthy fats to your diet. Added sugars are to be limited while engaging yourself in moderate exercise. Remember to stay hydrated all day while checking your stress levels. 

Q: How do you build immunity against Covid?

A: You can build immunity against Covid -19 by taking vaccinations against the virus. Good immunity can also be built via a healthy diet and following good nutrition. It can surely decrease the likelihood of developing other health issues, including diabetes, a few types of cancer, heart diseases and obesity. 

Q: Can Covid trigger autoimmune diseases?

A: Covid- 19 can indeed cause dysregulation of the immune system via the development of the autoimmune phenomena. The consequence of this phenomenon is that it ranges from the production of autoantibodies up to the onset of rheumatic autoimmune disease. 

Q: Does fasting increase immunity?

A: Fasting stimulates the production of white blood cells. It aids in the regeneration of the entire immune system. Prolonged fasting levels initially break down the body into a couple of immune fighting white blood cells to strengthen the immunity.

About the Author

M.Sc in: Dietetics and Applied Nutrition from Manipal University. Worked: All over India and have been involved in helping set up nutrition departments in start ups. Interested in lifestyle based nutrition. Mantra: A healthy lifestyle isn't a choice to be made or discarded, it's a way of life!

Related Articles


Add Your Comment

Your email address will not be published. Required fields are marked *

Your health is our priority. Talk to one of our experts and get the best plan for you today.
Chat With Us