Boosting Immune Response With Dragon Fruit

The immune response is the way your body defends itself from foreign substances, such as bacteria and viruses. It essentially protects us from any harm and is therefore a crucial system within the human body, without which we would not survive.

Certain foods have been found to help boost this immune response, aiding this system to protect you more efficiently. One particular food that has been recently receiving attention for its unique appearance and ‘immune boosting’ effects is the dragon fruit.

This article will describe in detail how this fruit helps our immune response function to the best of its abilities, and how to incorporate dragon fruit into our diet.

Understanding the immune response

Before we delve into how dragon fruit helps our immune response, we will first outline how this system works.

Functions and components of the immune system

As mentioned above, the immune response is your body’s defence system, whose job is to attack anything that does not belong in the body, to prevent and limit infection and illness.¹

Examples of foreign harmful substances to which the immune system reacts include (but are not limited to):¹

• Bacteria
• Viruses
• Fungi
• Parasites
• Cancer cells

The immune system can distinguish between healthy cells that belong in the body and these foreign harmful substances through antigens. An antigen is a particle that does not belong in your body, found on the foreign substance itself, but not on healthy, normal cells.² Antigens act as signals to trigger the immune response. Once the immune system identifies these antigens, a variety of immune cells team up to travel to the foreign substance, attack and eliminate the danger.¹

There are various types of immune cells which play unique, essential roles in the elimination of foreign harmful substances. These cells are called white blood cells, and they can be broadly compartmentalised into two categories:

Innate immune cells

These white blood cells are the first cells in line to respond to any harmful substance in the body. They are the first to attack, and they also signal other immune cells to come to the site of infection and help them kill the harm.¹

Adaptive immune cells

These white blood cells are the second responders to the attack.¹ Once they have found the foreign substance, they are stimulated to make antibodies. These are particles/chemicals that then travel through the blood to find and attach themselves to antigens of the harmful foreign substances.² Antibodies are specific, meaning an antibody can attach to only one type of antigen.

This means adaptive immune cells make millions of antibodies, each specific for different antigens of different infections and germs. Once specific antibodies attach to their paired antigens on the harmful substance, they neutralise the germ (essentially stop it from invading the body) and flag it so other immune cells can come to kill it. Once a specific type of antibody is made, the immune system will remember it and store it in its ‘memory bank’, so the next time the same germ tries to invade the body, the immune system will react quicker by producing the specific antibodies quicker. This is called immunological memory.³

Once the foreign substance has been killed by the white blood cells, the immune system must also be able to end the ‘attack’ to preserve any surrounding healthy cells that do belong in the body.¹

Importance of the immune system

Your immune system is strong and healthy is vital⁴, for the following reasons: 

• When your immune system is strong, you are likely to recover from injuries or infections in a much quicker manner
• When someone does catch an infection, a strong immune system can help lessen any symptoms they may feel
• You do not get sick as often
• Less fatigue
• Healthier hair and nails
• Clearer skin, as the stronger immune system is fighting off any bacteria that leads to acne

Hence, it is highly recommended to try to keep your immune system as strong as possible, and one way to do so is through eating certain foods known to boost it.

An overview of the dragon fruit

The dragon fruit is a sweet-tasting fruit native to Central and South America, where they are commonly known as pitaya or pitahaya. The fruit grows on an unusual species of cacti, known as climbing cacti, that do not resemble the spiky, bulbous appearance of a typical cactus. Although they do not have any bark or foliage, these cacti tend to look like trees in that their branches and roots grow in an upward direction, finding other plants to cling to. Eventually, their branches bend down, almost like a weeping willow tree, and at their ends, dragon fruits can grow.⁵

Although originating from Central and South America, the fruit is now grown around the world, with its top supplier actually being Vietnam. Pitayas prefer dry tropical and subtropical climates, with their ideal temperatures being between 21°C and 29°C.⁵

There are five different types of dragon fruit you can find, all of which have edible black seeds:⁵

• White dragon fruit – These fruits have a pink skin and white flesh (the inside of the fruit). They are the most common dragon fruit available and sold
• Red dragon fruit – These fruits have a deep red skin and flesh. These are much sweeter tasting compared to the white dragon fruit. Eating this fruit will most likely stain your fingers
• Pink dragon fruit – These fruits are very similar to the red variety, but with a pink skin and flesh. It is sweeter than the white variety, and less richer in taste than the red variety
• Yellow dragon fruit – These fruits have a yellow skin and white flesh, particularly native to South America. Their texture is the firmest of the dragon fruit types, and its taste is known to be the richest and sweetest of them all
• Sour dragon fruit – This is the rarest variety of dragon fruit, most commonly found in Central and South America. These fruits resemble the white dragon fruit, but are instead sour in flavour. They are considered the juiciest of all varieties, and their seeds have a nutty flavour

It is possible to find dragon fruit with a blue or green skin, however these are not edible. Their skin colour indicates that the fruit is not ripe, and they will eventually turn either red, pink or yellow once fully grown and mature. This is when they are ready to be consumed.⁵

How does the nutritional content of the dragon fruit boost the immune system?

There are a variety of nutrients found in the dragon fruit that have been found to help boost immune response, protecting us more from illnesses and infections.

Vitamins and antioxidants in dragon fruits

Vitamin C

One of the most abundant vitamins found in all varieties of dragon fruit is vitamin C. Vitamin C is an example of an essential vitamin, meaning that the body does not produce it naturally, but the vitamin is considered important for bodily functions.⁶ Hence, it is crucial to get your vitamin C through your diet – and dragon fruit is a perfect food to do so.

Vitamin C is able to help the immune system by accumulating itself in both innate and adaptive immune cells, in turn helping them effectively kill harmful substances.⁶ Also, the vitamin has been shown to help a specific type of immune cell, called T-cells, mature properly, in turn aiding the adaptive immune system to provide targeted responses to specific illnesses and infections.⁶ 

A further important way vitamin C helps boost our immune response is the fact it is considered a powerful antioxidant. An antioxidant is a molecule that protects the immune system by attacking harmful molecules called free radicals. Free radicals are little, unstable compounds that are highly reactive, which are found all around the body thanks to normal bodily processes and external sources including X-rays, cigarette smoke and industrial chemicals.⁷

If there is an abundant amount in the body, free radicals can cause severe impairment to the immune system by interacting with it and disrupting its normal responses to infections and illnesses. When this occurs, this is called oxidative stress, and this state has been linked to various chronic diseases, including diabetes, cancer and heart disease.⁷ As an antioxidant, vitamin C neutralises these free radicals, stopping them from disrupting the immune system and protecting us from such debilitating diseases.⁸

Other antioxidants

Other types of antioxidants which are found in abundance in dragon fruits are phytochemicals, which are naturally occurring chemicals produced by plants. Examples of such phytochemicals specific to dragon fruits include catechin, epicatechin, epigallocatechin, caffeine, and gallic acid.⁹ Not only do they act as antioxidants, they have also been found to directly reduce the chances of germs, such as bacteria and viruses, to grow in the body.¹⁰

Another particular type of antioxidant found specifically in the red variety of dragon fruits is betalains - natural red colour pigments.¹¹

Vitamin B

Dragon fruit is also an excellent source of vitamin B, which is another example of an essential vitamin that effectively boosts the immune response. It does so by aiding the production of new red blood cells, which carry oxygen to immune cells to help them work at maximum efficiency.¹²

Minerals in dragon fruits

Iron

Dragon fruit is one of the few fruits that are high in the mineral iron. Iron is necessary for immune cell replication and maturation, making it important for the generation of specific immune responses. Research has shown that people who suffer from iron deficiencies (lack of or shortage of iron in their body) are more susceptible to infection.¹³

Magnesium

Another mineral that is found abundantly more in dragon fruits compared to other fruits is magnesium. Magnesium helps the immune response by improving white blood cells’ functions of identifying and killing germs. Magnesium deficiency impairs the cells involved in the immune response.¹⁴

Incorporating dragon fruit into your diet

There are a variety of ways one can incorporate dragon fruit into their diet. The following are some common examples:

• Fresh fruit – The fruit is commonly eaten raw/fresh by itself. All one has to do is use a sharp knife, slice the fruit in half, and eat the fruit out of the skin using a spoon. Some people also peel the skin off the fruit entirely, slice the flesh into small pieces and refrigerate it, as it is recommended to eat the fruit when cold for its taste.⁵ It is important to note that the dragon fruit skin is not recommended for consumption. Besides its bitter taste, the skin may contain remains of pesticides (chemical substances used in farming which prevent any bug from eating the plant), which can be dangerous if ingested¹⁵ 
• Smoothies and juices – Dragon fruit can be an excellent addition to smoothies and juices. Other fruits they are commonly paired with include bananas, kiwis, lemons, mangoes, oranges, pineapples and strawberries⁵ 
• Supplements – If the fruit is not widely available in your area, you can also order dragon fruit extract supplements, which will still be rich in antioxidants, vitamins and minerals⁵ 

As the fruit is low in calories (60 per 100g, which is roughly the size of one dragon fruit), it makes for a perfect everyday snack. Although generally safe to eat, it is important to be cautious that there are possible side effects from overeating dragon fruit, including the following:

• Some people might be allergic to dragon fruit, as there have been some rare reported cases.¹⁶ If you know you are allergic to other fruits, such as kiwis or pineapples, then you could be at a higher risk of developing an allergy to dragon fruit. Symptoms to look out for minutes to hours after eating dragon fruit include itching, swelling of the tongue, rashes, difficulty breathing and vomiting
• Eating too much dragon fruit could lead to an abundance of iron within your body, which can sometimes have detrimental consequences. Iron overload can be associated with heightened susceptibility to infectious diseases, as these infectious cells feed off any free, excess iron to invade the body¹⁷
• Although antioxidants are important for our health, too many antioxidants (from overconsumption of dragon fruits) can be detrimental, as they could affect immune response mechanisms¹⁸ 

Summary

Developing and maintaining a strong immune system is crucial in defending us from various infections and illnesses, and specific foods help boost the immune response. Dragon fruits have recently gained interest as a potential “superfood” – it is low in calories and high in valuable nutrients which help improve our immune cells to defend our body from harm. It is a perfect food to incorporate into your diet, and incredibly tasty too!