The immune system is your body’s natural defence system against diseases and germs. It is a network of biological processes that coordinate to respond to viruses, bacteria, and various pathogens when they enter the body. Like most things in the body, a healthy diet is crucial for a robust immune system. But, before we move on to the immune-boosting foods, let us understand how our immune system works.
How Does the Immune System Work?
Whenever a microorganism enters the body, the innate immune system gets alert and protects the system against them. These microorganisms include viruses, bacteria, fungi, worms etc. Skin, chemical barriers (proteins), white blood cells are the physical barriers against these infections.
Mucous membranes are the inner lining for the respiratory tract and gastrointestinal tracts. They secrete mucus which helps to trap small microorganisms and tiny particles. These tracts also have small hair-like projections that provide physical protection by trapping particles. In addition, the stomach has glands that produce hydrochloric acid (HCl). It is strong enough to kill any unwanted microorganisms and pathogens that might have entered the body with food.
The human body also produces specific antimicrobial proteins which contribute to the non-specific defence system. When a microorganism enters the body, it activates the production of these proteins. These proteins then break the infection and eliminate the harmful infectious agents.
The large intestine has colonies of healthy gut bacteria, which are suitable for the body and do not cause illness or diseases. These gut bacteria secrete various proteins, which enhance their survival chances by eliminating the harmful bacteria that might be bad for the body.
Role of Nutrients in Boosting the Immune System
The entire human body works in coordination with the minerals and vitamins we consume. Therefore, they play a vital role in building up our immune system. According to a study, the resistance is due to vitamin A, D, C, E, B6, B12 and minerals like zinc, iron, and selenium.
Compounds such as flavonoids, retinoids and antioxidants are present in various foods. These compounds make the immune system much more effective against multiple infections. On the other hand, minerals like iron, zinc, and selenium help stimulate the body’s response against infections by assisting the development and functioning of immunity cells.
The Best Immune-Boosting Foods
1. Citrus Fruits
Citrus fruits like grapefruit, oranges, tangerines, lemons etc., are packed with vitamin C. Vitamin C helps boost your immune system to fight against the common cold. In addition, it helps increase the number of white blood cells, which are the prominent infection-fighting soldiers. Our body absorbs vitamin C from citrus fruits easily.
Vitamin C is heat-sensitive. Therefore, you should consume these foods raw to get all the vitamin C benefits.
2. Red Bell Peppers
Red bell peppers are red because of the beta carotene present in them. They are a fantastic source of beta carotene and vitamin C. When you consume beta carotene, it converts into vitamin A inside the body. According to a study, vitamin A is an essential nutrient for the skin and eyes. The inner membrane of our eyes has vision cells. These cells require retinol (vitamin A) to function properly. Vitamin A helps improve cell health and life cycle, which results in improved vision.
Nutrition Value of Red Bell Pepper
100 grams of red bell pepper contains:
- Calories: 31 kCal
- Fat: 0.3 g
- Protein: 1 g
- Carbohydrate: 6 g
- Fibre: 2.1g
Broccoli is rich in vitamins and minerals. It has high amounts of vitamin A, C, E, dietary fibres, and other antioxidants.
Vitamin A is a superfood for the eyes, and it helps to improve eyesight by improving the functioning of the cone cells in the eyes. At the same time, vitamin C helps boost the cells against the common cold symptoms.
According to research, vitamin E is an antioxidant that prevents oxidative damage. Oxidative damage is the degradation of cells due to poor oxygen supply, which occurs because of increased free radicals. Free radicals are the compounds that bind to the blood oxygen and deprive healthy cells. Antioxidants help eliminate these free radicals, thereby decreasing oxidative stress.
Nutritional Value of Broccoli
For 100g of broccoli:
- Calories: 34 kCal
- Carbohydrates: 6.64 g
- Protein: 2.82 g
- Fibre: 2.6 gm
The best way to consume broccoli is by steaming the vegetable and having it in salads or with other steamed vegetables. This way, almost all of the nutrients remain preserved.
Spinach is a superfood loaded with numerous antioxidants, beta carotene, and iron. These nutrients help to boost the immune system and increase the body’s ability to fight infections.
Spinach is an excellent source of iron. Iron is essential for the body to produce healthy immune cells and proper maturation. According to a study, iron plays a vital role in boosting immunity and fighting infections. It also aids haemoglobin production. Haemoglobin is essential in the blood for healthy oxygen transport to various cells and organs in the body.
Nutritional Value of Spinach
100 grams of raw spinach contains:
- Calories: 23kCal
- Protein: 2.86g
- Fibre: 2.2gm
- Carbohydrates: 3.6gm
- Calcium: 99mg
- Iron: 2.71mg
The best way to get all the nutrition value of spinach is to cook it as little as possible. This way, the body absorbs retinol (vitamin A) easily.
Carrots are full of nutrients that provide many health benefits and boost your immune system at the same time. In addition, they are rich in vitamin A and dietary fibre.
Vitamin A helps improve your eyesight as it is a retinoid vital for the cone cells in the eyes. It is also one of the main micronutrients crucial for developing the cells that produce mucus. As per a study, vitamin A also has many anti-inflammatory properties. These antioxidants help enhance immune function and show therapeutic effects in treating various infections.
The dietary fibre present in carrots helps keep the gut clean and healthy, promoting the growth of good bacteria. Good bacteria can help maintain the number of harmful and good gut bacteria in the intestine. As a result, it can reduce infections.
Nutritional Value of Carrots
100 grams of carrots contain:
- Calories: 41 Kcal
- Protein: 0.93gm
- Carbohydrates: 9.58gm
- Fat: 0.24g
- Fibre: 2.8gm
- Calcium: 33mg
- Vitamin A: 835µg
- Vitamin K: 13.2µg
- Sodium: 42mg
Turmeric is an essential ingredient in many Asian recipes and is widely used in and out of the kitchen. It has many therapeutic effects and is very beneficial for health. You can consume it with food or can apply it topically. It has a bright yellow colour and has anti-inflammatory properties. In addition, it helps treat the symptoms of osteoarthritis and rheumatoid arthritis.
According to research, turmeric has anti-inflammatory properties, which significantly decreases muscle soreness. It is because of a compound called curcumin which is present in turmeric. This compound also has positive effects on the immune system.
Nutritional Value of Turmeric
For 100g of turmeric:
- Calories: 312kCal
- Fats: 3.2g
- Carbohydrates: 67g
- Protein: 9.7g
- Iron: 55mg
- Calcium: 168 mg
- Vitamin B6: 0.1mg
- Vitamin C: 0.7mg
- Sodium: 27mg
Garlic has been used as both food and medicine for a very long time now. It has many health benefits. For example, it may reduce the risk of heart disease, improve cognitive health and enhance the immune system.
According to research, the various compounds present in garlic positively affect the immune system and can help to enhance it. It helps stimulate specific cells responsible for the first action against any infections or pathogens that enter the body.
Nutritional Value of Garlic
100 grams of garlic contains:
- Calories: 149 kcal
- Fats: 0.5g
- Carbohydrates: 33g
- Protein: 6.4g
- Calcium: 181mg
- Potassium: 401mg
- Iron: 1.7mg
- Magnesium: 25mg
8. Button Mushrooms
Button mushrooms are low in calories and rich in proteins, amino acids, vitamins, minerals and fibres. Research suggests that white button mushrooms may promote immune function by increasing the production of antiviral and other proteins released by cells while seeking to protect and repair tissue. In addition, antioxidants like selenium support immune function and help protect body cells from disease-causing damage. Mushrooms are also a rich source of vitamin D, which is critical for the immune system.
Button mushrooms are specifically rich in Vitamin B complex such as niacin, thiamine, riboflavin. In addition, it is also an excellent source of zinc and selenium.
Zinc and selenium are essential elements for building a healthy immune system. In addition, research suggests that mushrooms possess antitumor, antiviral and antibacterial properties. So it is because they can modulate the functions of the immune cells.
Nutritional Value of Button Mushrooms
One cup of button mushrooms (54g) contains:
- Calories: 17 kcal
- Fats: 0.3g
- Carbohydrates: 4g
- Protein: 0.8g
- Dietary fibre: 2.1g
- Sugar: 1g
- Potassium: 273mg
- Vitamin D: 4.8mcg
9. Greek Yoghurt
Greek yoghurt is a highly nutritious food supplement. It is high in milk proteins, vitamin D, calcium and gut bacteria. The gut bacteria are essential for maintaining a friendly environment for other good bacteria in the gut and help in better absorption of food.
The gut bacteria can help reduce the number of harmful bacteria significantly. As a result, it helps reduce the chances of catching an infection and other digestive disorders.
Nutrition Value of Greek Yoghurt
In a 100g pack of Greek yoghurt, there are:
- Calories: 117 kcal
- Fats: 9.19g
- Proteins: 10.05g
- Carbohydrates: 5.04g
- Sodium: 55mg
- Calcium: 131mg
- Vitamin C: 0.8mg
Salmon falls in the category of fish. It is rich in proteins, vitamin D, B6, omega-3 fatty acids, and magnesium.
Vitamin D is essential for a healthy immune function and the bones. In addition, vitamin D is capable of activating the immune cells. According to research, vitamin D deficiency may increase susceptibility to infections.
Salmon is also a rich source of protein which is an essential building block for the body and the muscles. The proteins made of amino acids can help stimulate specific immune cells.
Nutrition Value of Salmon
As per USDA, 85 gm of raw salmon fish contains:
- Calories: 121 mg
- Fats: 5.4g
- Sodium: 37.4 mg
- Carbohydrates: 0g
- Protein: 17g
Avocados are nutrient-dense foods that provide various vitamins, minerals and other minerals beneficial for the human body. In addition, avocados naturally contain 6g of fats per serving which can help increase the absorption of vitamin A, D and E, which are immunity-boosting nutrients.
Avocados are also rich in Vitamin B6, responsible for producing antibodies. Antibodies form whenever your body detects an infection or pathogen; they help eliminate the infection from the body.
Nutritional Value of Avocado
100g of avocados contain:
- Calories: 160 kcal
- Fats: 14.6g
- Carbohydrates: 9g
- Protein: 2g
- Vitamin C: 10mg
- Vitamin B6: 0.3mg
- Potassium: 485mg
- Magnesium: 29mg
- Iron: 0.6mg
- Vitamin A: 146mcg
- Calcium: 12mg
Beetroot has many essential vitamins, minerals, and antioxidants necessary for improving the immune system. In addition, beetroot contains vitamin C, zinc and iron. Vitamin C helps protect the body against cold symptoms, while zinc and iron help boost the immune cells.
Iron is also very essential for healthy blood circulation in the body. In addition, iron is helpful for various biochemical reactions of the immune cells. For example, it is associated with haemoglobin and helps transport it to healthy cells and organs.
Nutritional Value of Beetroot
100g of beetroot contains:
- Calories: 43kCal
- Fats: 0.2g
- Carbohydrates: 10g
- Protein: 1.6g
- Potassium: 325mg
- Vitamin C: 4.9mg
- Vitamin B6: 0.1mg
- Iron: 0.8mg
- Sodium: 78mg
Pomegranate has lots of antioxidants in the form of phenols. Antioxidants are essential for the body to reduce the oxidative stress caused by free radicals. Free radicals are compounds that bind to oxygen in the blood and prevent it from reaching the healthy cells in the body. As a result, it causes oxidative stress.
Pomegranate is also a good source of vitamin C, which makes up an essential part of the immune system. In addition, it has many anti-inflammatory effects on the body and improves the immune system.
Nutritional Value of Pomegranate
100g of pomegranate contains:
- Calories: 83kCal
- Fats: 1.2g
- Carbohydrates: 19g
- Protein: 1.7g
- Vitamin C: 10.2mg
- Potassium: 236mg
- Vitamin B6: 0.1mg
- Magnesium: 12mg
- Iron: 0.3mg
- Calcium: 10mg
Tomatoes is another immune boosting food and are a part of many dishes that we eat daily. You can consume them raw or cooked, in the form of soup or a salad. They are an excellent source of vitamin C. One medium-sized tomato contains up to 16 mg of vitamin C, which is more than enough for daily use. Vitamin C helps fight symptoms of flu by decreasing inflammation and other symptoms.
Nutritional Value of Tomato
100 grams of raw tomato contains :
- Calories: 18
- Water: 95%
- Protein: 0.9 grams
- Carbs: 3.9 grams
- Sugar: 2.6 grams
- Fibre: 1.2 grams
- Fat: 0.2 grams
Like citrus fruits and tomatoes, blueberries are also rich in antioxidants and vitamin C. It positively affects the immune system as it shows many anti-inflammatory properties. In addition, vitamin C makes up for a significant part of the immune system and can protect you against many infections.
Antioxidants are vital for the body to help eradicate free radicals and prevent oxidative stress. They also ensure a healthy oxygen flow to various body parts.
Nutritional Value of Blueberries
100 grams of blueberries contain:
- Calories: 57kCal
- Fats: 0.3g
- Carbohydrates: 14g
- Protein: 0.7g
- Vitamin C: 9.7mg
- Vitamin B6: 0.1mg
- Iron: 0.3mg
Foods to Avoid for a Healthy Immune System
1. White Bread
White bread has a high glycaemic index. That means it can convert complex carbohydrates into blood sugar (glucose) and increase blood sugar levels. Therefore, it is not healthy, especially for people having diabetes. It can also contribute to inflammation and weaken the body’s ability to heal and protect itself.
We all know that having too many sweets, sugar, and candies is not healthy for your body. It can also mess up your body’s immune system. Consuming too much sugar can counteract the body’s ability to fight pathogens, germs and bacteria.
3. Processed Food
Processed foods are high in salts, sodium and preservatives. According to research, fast food and processed food consumption two times a day show pronounced immune deficiencies.
4. Carbonated Drinks
Soda or cold drinks are full of sugar and preservative, and carbonated water. It can hurt your health and immune system. For example, the carbonated component can degrade the tooth enamel that protects the nerves and gums from various infections. It can also compromise the gastrointestinal lining, which has many adverse effects on gut health.
There are many ways to build your immune system naturally without taking additional supplements. Eating a healthy diet may help boost immunity. For example, many vegetables and fruits are full of vitamins and minerals, essential building blocks for the immune system. It is the body’s defence system.
Therefore, it is essential to have balanced meals packed with various veggies and fruits to get a full spectrum of nutrients.
Frequently Asked Questions
Q. How can I boost my immune system?
A. There are various ways to boost your immune system. However, the most effective way is to follow a balanced diet. You should add a variety of fruits and vegetables to your diet. They can give you all the minerals and vitamins essential for a healthy immune system.
Q. What are the top 10 immune-boosting foods?
A. Yoghurt, salmon, carrot, citrus fruits, spinach and button mushrooms are some foods that can help you boost your immune system because they are packed with the essential vitamins and minerals that the body requires. In addition, turmeric, garlic, tomatoes, avocados, and broccoli also serve the same purpose.
Q. What is the most potent immune booster?
A. As per the nutritional properties, spinach is one of the most potent immunity boosters. It is a superfood rich in vitamins and iron. In addition, it helps build the immune cells and ensure that they function correctly, making it a potent immune booster.
Q. What foods are antiviral?
A. Foods with antiviral properties include fruits, vegetables, fermented foods and probiotics, olive oil, fish, nuts and seeds, herbs, roots, fungi, amino acids, peptides, and cyclotides. In addition, regular moderate exercise may reduce viral risk and enhance sleep quality. One of the best antiviral foods is garlic. It has many anti-inflammatory and antiviral properties. In addition, it can treat certain infections and kill pathogens responsible for tuberculosis, pneumonia, herpes etc.
Q. What weakens the immune system?
A. Having too much sugar can compromise the immune system. It weakens the body’s ability to respond to infections and pathogen attacks. Besides this, smoking, alcohol, and poor nutrition may weaken your immune system.
Q. Which fruit is good for immunity?
A. Several fruits are good for boosting immunity. However, the best fruits for boosting immunity are citrus fruits. They are a rich source of vitamin C, which helps boost immunity. Another fruit that can help is blueberries. They are rich in vitamin c and contain antioxidants beneficial for the immune cells.
Q. Which vegetable is an immunity booster?
A. Broccoli is full of nutrients. It contains minerals that our body requires for a healthy immune system. In addition, spinach is an excellent vegetable for boosting immunity because it is rich in vitamin C. It also contains antioxidants and beta carotene, which may increase the infection-fighting capacity of the body.
Q. Is banana good for immunity?
A. Yes. Bananas are a rich source of iron, zinc, vitamin A and selenium. Our body requires all these nutrients to restore a weakened immune system.
Q. What three foods to never eat?
A. While a nutrient-dense, well-rounded diet supports your immune system, a diet low in nutrients and high in ultra-processed foods impairs immune function. Therefore you should avoid eating some foods. For example, white bread, processed foods and carbonated drinks are some foods you should avoid. These foods can severely compromise the immune system in the longer run.
Q. Does milk boost immunity?
A. Yes. Milk contains nutrients like probiotics, vitamin D and immunoglobulins that boost the immune system. They also reduce the risk of allergies. In addition, it can help reduce cardiovascular diseases and the chances of getting a stroke. Milk also has magnesium and potassium to help lessen blood pressure and increase blood flow to vital organs. In addition, vitamin D in milk helps in the healthy production of immune cells.
Q. Does boiled egg boost the immune system?
A. Yes. Eggs contain vitamin A, B12 and selenium, which build the immune system. These nutrients ensure that the immune cells work properly whenever the body comes in contact with an infection.
Q. Does chicken boost immunity?
A. Chicken cannot particularly help you boost your immunity as it is a rich bioavailable protein source. It can help you get overall better health which can lead to reduced risk of infections.
Q. What drinks boost your immune system?
A. Having turmeric milk is beneficial for the body as it has anti-inflammatory effects. You can also take probiotic drinks to increase the gut bacteria count, which can help improve the immune system.
Q. What are five ways to boost the immune system?
A. Being active, getting enough sleep, and taking additional supplements are some of the ways to keep yourself healthy and build resistance to boost your immune system. In addition, eating a healthy diet and being watchful of what you eat also helps.