Respiratory Health Benefits Of Dragon Fruit

Introduction

Dragon fruit, also known as pitaya, originates in Central South America but is now cultivated worldwide, particularly in Southeast Asian countries. It gained popularity in Vietnam when it was imported by the French over a century ago. Its scientific name derives from the Greek word ‘hyle’, meaning woody and the Latin words ‘cereus’ meaning waxen, and ‘undatus’ which refers to the wavy edges of its stems.¹ Dragon fruit belongs to the genus Hylocereus and is a member of the Cactaceae family. They are different varieties, with the species H. undatus having red peel and white flesh, while H. polyrhizus and H. costaricensis have both red peel and red flesh.²

Dragon fruit has recently obtained recognition in the scientific community, revealing its potential health benefits. Its phytochemical contents are associated with anti-inflammatory and antioxidant properties, and it may also be beneficial for conditions such as diabetes, cancer and cardiovascular diseases. Additionally, pitaya has been found to support the preservation of natural gut microbiota. Its bioactive nutrients include vitamins, potassium, betacyanin and gallic acid, among others.² While research into the full range of its potential benefits is ongoing, its positive impact on human respiratory health is increasingly evident. Below is a review of some of the most prominent nutrients found in this superfruit and their effects on fundamental respiratory mechanisms.

Nutrition profile of dragon fruit

Antioxidants

The main bioactive compounds of the fruit include terpenoids and different polyphenolic groups such as phenolic acids, flavonoids (e.g. myricetin, quercetin), tannins and betalains (specifically betaxanthin and betacyanin).³ These natural compounds have shown the ability to provide defence against various human diseases.⁴

The comparison of dragon fruits harvested in Israel and Thailand indicated a significant difference in the therapeutic profile of the plants; fruits from Israel had higher concentrations of antioxidant compounds compared to those from Thailand. This indicates that factors such as environmental conditions, cultivation methods, storage and processing may influence the pharmacotherapeutic potential of these plants. Generally, existing literature supports these findings, ascribing antioxidant activity to compounds like gallic acid and acetylcoumarins, which are also present in the phytocomposition (with phyto meaning plant) of red dragon fruit.³

Vitamins

Dragon fruit is abundant in several vitamins, with vitamin C concentration reaching a maximum level of 6 mg per 100g. Additionally, it contains vitamin E (tocopherol) at 150μg/100g and vitamin K1 at 25μg/100g.⁵

Existing scientific literature underscores the differences in the concentration of vitamins among various dragon fruit species. Notably, the H. polyrhizus species is distinguished by its high vitamin C content.⁶ Further investigations into red dragon fruit’s developmental stages demonstrated fluctuations in vitamin C levels.⁷

Ultimately, a specific study delved into the influence of the fermentation process of dragon fruit wines, revealing a substantial increase in vitamin C concentration, up to 24%, when fermentation occurred in 25°C.⁸

Other bioactive compounds

Dragon fruit, like many other fruits, contains a substantial amount of sugars including glucose, fructose, mannose and sucrose among others. Interestingly, white and yellow pulped fruits from Israel tend to have higher sugar levels, while red pulped fruits are richer in phenolic components.⁶

The red-fleshed dragon fruit variety, H. polyrhizus, is particularly notable for its amount of dietary fibre content, comprising mostly insoluble but also water-soluble fibres, totalling 69.3%. Furthermore, it contains pectin (10.79%), highlighting its potential for various nutritional applications.⁶

In addition, dragonfruit is a source of essential minerals, including calcium, magnesium, potassium and phosphorus. These minerals are found in both the pulp and peel of the Hylocereus genus, further augmenting the fruit’s nutritional value.⁶

Respiratory health benefits of dragon fruit

Effects on the immune system

The immune system of a healthy individual serves to eliminate external threats, such as pathogens and toxins from the respiratory tract, by activating the innate or adaptive immune system while also ensuring the proper operation of regular functions.⁹ Dragon fruit’s positive impact on the immune system has been demonstrated by analysing the effects of consuming pitaya oligosaccharides in drinking water, revealing that 4 g/day increased immunoglobulin A (IgA), an antibody involved in the immune response of mucosal membranes to foreign substances.¹⁰

Polyphenols, which are also abundant in dragon fruits, have proved their consequential impact on various immune cells, in vivo and in vitro.¹¹ Although there is evidence suggesting the correlation between the dragon fruit’s components and immune modulation, further research is needed need to comprehensively understand the precise mechanisms at play, specifically in the context of this tropical fruit.

Moreover, the terpenoid lupeol present in the peel of H. polyrhizus fruit has also revealed immunomodulatory effects.⁶ This accentuates the potential health benefits of dragon fruit in regulating immune responses, even in individuals with other underlying chronic conditions.

Adequate consumption of vitamin C is essential for maintaining a vigorous immune response and reducing susceptibility to respiratory infections. While the exact mechanisms are still unclear, it is believed that vitamin C’s modulatory actions are responsible for immune-boosting effects.¹²

Antioxidant activity and anti-inflammatory properties

Polyphenols’ anti-inflammatory and antioxidant activity have been assessed based on their ability to suppress the production of reactive oxygen species (ROS), which are associated with oxidative stress.¹¹ This imbalance in the homeostasis of regular functions can hence be limited by polyphenols found in red-fleshed dragon fruit.¹³ Red dragon fruits, represented by a higher betacyanin content, which gives the fruit’s flesh its colour, were also associated with greater antioxidant activity.³

Specific compounds found in the pulp and peel of dragon fruit have displayed promise in blocking metabolic pathways in inflammatory responses. Extracts from both the flesh and peel of the fruit may also inhibit proinflammatory enzymes, leading to the assumption that dragon fruit may be a valuable tool for managing various inflammatory processes.⁶

Potential alleviation of asthma and allergies

Dragon fruit’s ability to boost immunity and reduce inflammation holds promise for addressing asthma and allergies. Asthma, characterised by chronic airway inflammation that impairs lung function, could potentially benefit from the antioxidant compounds present in dragon fruit and other fresh fruits, although more in-depth investigation is required.¹⁴ Researchers have acknowledged the association between high fruit consumption and a lower risk of asthma, specifically due to the presence of flavonoids.¹⁵

Accordingly, scientists believe that specific diets may influence the response to allergens and the course of allergic diseases in the respiratory system.¹⁵ One study exploring the benefits of tropical fruits highlighted the antiallergic properties of gallic acid, which is also present in pitaya. Gallic acid hinders the release of histamine, a chemical messenger responsible for triggering allergic reactions.¹⁶

Flavonoids such as quercetin and luteolin found in numerous fruits, including dragon fruit, have also demonstrated antiallergic properties and exert an overall regulatory action by mediating cells implicated with asthma and other bronchial allergic reactions.¹⁷

Incorporating dragon fruit into the diet

Consumption methods

All parts of the fruit are considered edible raw or may be utilised in different products. Red-flesh pitaya may be eaten after thorough washing. It can also be processed into powder, which has been found to have anti-diabetic and antihypertensive properties.⁶

Dried flowers of the dragon fruit can be used to produce a tea rich in antioxidants, while fresh buds of the plant can be cooked and consumed as vegetables.⁶

Dragon fruit pulp is commonly used for juices, jams, wines and fruit sorbets, contributing both flavour and nutritional value. The syrup extracted from the fruit is often added to various products, serving as a natural sweetener and colourant.⁶

The pectin-containing skin of the fruit can be used as a natural gelling agent in various food products, helping to thicken and stabilise them.⁶

The fruit’s seeds, rich in fatty acids, also have multiple uses and can be incorporated into ice cream and yoghurt preparations. They also possess a laxative and antilipidemic effect and may serve as a natural remedy for gastritis.⁶

Dietary considerations and precautions

It is essential to emphasise the importance of maintaining a balanced diet without excessive practices. If you are considering incorporating dragon fruit as a regular dietary supplement, it is advisable to consult with a medical professional beforehand.

If you are allergic to dragon fruit or have a history of allergies to fresh fruits, it is best to avoid consuming it. The presence of specific allergens in both white- and red-fleshed dragon fruit seeds has been corroborated and may explain the sensitivity present in some individuals.¹⁸

Excessive consumption of pitaya may lead to various side effects, including an upset stomach, hypotension and red-coloured urine.

Summary

In conclusion, by approaching dragon fruit consumption with moderation, awareness of personal health profiles, with special caution in case of allergies or hypersensitivity, and expert guidance, you may promote respiratory health effectively while enjoying the benefits of this superfood. Dragon fruit can be part of a preventive approach by supporting respiratory health. Optimal quality controls and production conditions will lead to maximum health benefits.

Always maintain balance in your overall diet and consult a nutritionist for personalised guidance. Seeking guidance from healthcare professionals or nutritionists ensures safe dietary choices and, in this case, will help you harness dragon fruit's potential for respiratory well-being.