Introduction
Each human being is gifted with five different senses, each of which has its own special function. These senses act as our guardians that help us to perceive, understand, and interact with the world around us. The health of our senses plays a vital role in maintaining well-being and quality of life. In this article, we will discuss the impact of eye health and how mangosteen, the queen of fruits, helps us maintain our health.
Eyes - the window to the soul, the window to the world
The eyes are one of five senses responsible for vision. They detect light and convert it to electrical signals, then send the information to the brain to generate visual images. Poor vision will hinder our daily activities and reduce productivity. That is why maintaining healthy eyes is important because they ensure clear vision, thus contributing to a better quality of life, which allows us to see and appreciate the world around us, enabling us to engage in activities we enjoy, such as reading, watching movies, or playing sports. Moreover, good eye health is closely related to mental well-being, as it allows for independence, social interaction, and overall confidence in one’s abilities.
There are hundreds of eye disorders and issues related to vision. According to The World Health Organization (WHO), the primary causes of vision impairment and blindness are refractive errors, cataracts, diabetic retinopathy, glaucoma, and age-related macular degeneration (AMD).1 All these conditions can occur at any age, but interestingly, except for refractive errors, the prevalence of the other four diseases occurs mostly in the group of elderly.
As The Centers for Disease Control and Prevention (CDC) reported, more than 4.2 million Americans aged 40 years and older are either legally blind (having best-corrected visual acuity of 6/60 or worse in the better-seeing eye) or with low vision (having best-corrected visual acuity less than 6/12).2 Cataracts have become the leading cause of vision loss in the United States, with an estimated 20.5 million cases in 2020, followed by AMD with a total number of cases of 1.8 million in the same year.2
Yes, those numbers are big and scary, yet ageing is a natural process that we cannot avoid. As we get older, the function of our bodies will gradually decrease and they will not function as prime as before. Although this process is inevitable, the good news is that we could slow down the process and we would never have to deal with these problems in the future if we know how to maintain the health of our eyes correctly.
The underlying cause of any age-related eye disease is oxidative stress. Compared to most other organs, the eye is particularly susceptible to oxidative stress because of its constant and cumulative exposure to light and high metabolism, involving high oxygen consumption. This combination of factors leads to the generation of reactive oxygen species (ROS) as byproducts that can trigger oxidative damage to ocular tissues. Recent works of literature and research indicate that the role of dietary antioxidants in the form of vitamins and minerals (vitamin C, vitamin E, carotenoids, zinc) and anti-inflammatory properties (omega-3 fatty acids) may improve the risk of age-related eye diseases.3,4
Mangosteen - the queen of fruits packs with antioxidants
How many of you have ever heard of mangosteen? For those of you who are not yet familiar with this name, mangosteen is a tropical fruit that usually grows in tropical Asian countries, such as Cambodia, India, Thailand, Malaysia, Sri Lanka, Vietnam, Philippines, and even Africa.5,6 The fruit, as many botanists believe, is a native plant of Indonesia.5,6 Dubbed as ‘The Queen of Fruits’, mangosteen is roughly the same size as a mandarin orange. The rind is thick and hard with a colour of maroon to purple (called pericarp) surrounding snow-white pulp (called aril) that is edible. Mangosteen has a juicy, fibrous, yet delicate texture with a sweet and tangy flavour and delightful smell which some people are crazily addicted to. A legend told that Queen Victoria once promised a reward of one hundred pounds sterling to anyone who could present her with a fresh mangosteen.
Mangosteen is not only delicious but also nutritious. Many thousand years ago, every part of mangosteen, including its rind, leaves, fruit, and bark was used as a natural source of medicine for its antioxidant, anti-inflammatory, immunomodulatory, and anticancer activities. The high nutrient value of mangosteen has drawn interest both in its country of origin and in Western countries, where it is esteemed as a functional food. Due to the high demand for this fruit, some origin countries, such as Indonesia, have been exporting the fresh fruit and its commercial products (extracts, juice, powder, capsule, and dried fruit) to many other countries such as China, Netherlands, Germany, Italy, Spain, and the UK.7
So what nutrients does mangosteen have and how would these benefit our eye health? Mangosteen contains various antioxidants and vitamins. The main nutrients that mangosteen has, benefiting our eye health are xanthones, vitamin C, vitamin E, and minerals.8
Xanthones
After doing many literature studies, most of them showed that in traditional medicine in Southeast Asia, the pericarp was mostly used to treat infection, wounds, inflammation, and diarrhoea. If you have not forgotten, the pericarp is the rind part of mangosteen that is thick and hard but is inedible. Although the technique of how the ancestors process the pericarp still remains unclear, many researches showed that this part of mangosteen is rich in xanthones.
Xanthones are the major phytochemical compounds, which all researchers in many studies agree are the secret behind the magic power of mangosteen. Phytochemicals are bioactive compounds produced by plants for their protection. There are various types of phytochemicals, but all of them serve as strong antioxidant agents.
The oxidative stress is preceded by an inflammation process. Overproduced free radicals from UV light, pollutants, or waste products in our bodies react with the ocular cells, causing impairment of their function. Thus, the combination of inflammation and oxidative stress underlies any cause of age-related eye diseases. As antioxidant agents, the role of xanthones is to eliminate any free radicals and suppress oxidative reactions, resulting in the decreased reaction of inflammation.
Vitamin C and vitamin E
The tangy flavour of mangosteen has reminded us of an orange which is known for the high source of vitamin C. Yes, mangosteen contains plenty of vitamin C. Recent studies showed that one hundred grams of mangosteen contains approximately 2.9 milligrams of vitamin C.6,8 Vitamin C has many roles in maintaining good eye health.
The first is promoting collagen synthesis. Collagen is an important structural component of blood vessels, determining the elasticity of vessels. In the process of ageing, especially if you have a history of diabetes, your blood vessels will become stiffer and weaker than normal, therefore they are prone to rupture. The retina contains central vision, rich in cells that are responsible for our visual ability and blood vessels. Any damage in the retina could lead to vision loss as happens in diabetic retinopathy and AMD. Thus, consuming enough vitamin C daily would help to increase the elasticity of blood vessels, preventing vision loss from progressing fast.
The second is a ‘sunscreen’ agent. Similar to sunscreen, vitamin C protects the lens of our eyes from UV light, which is the main risk factor for developing cataracts. Long exposure to UV light increases oxygen demand, thus generating reactive oxidative species (ROS), leading to oxidative stress that would damage the ocular (eyes) tissues. Furthermore, both vitamin C and vitamin E in mangosteen act as antioxidant agents that protect the structure of our eyes from damage.
Minerals
Mangosteen contains a lot of minerals that are significant for our bodies’ metabolism. Among these minerals, zinc is important in maintaining the health of our eyes. Similar to vitamins, zinc plays a crucial role in eliminating free radicals and oxidative stress. Zinc also plays a role in cell signalling, helping the nerve-impulse transmission from the eyes to the brain to go in accordance with their natural behaviour.
Conclusion
As part of the natural process, ageing will certainly happen and our bodies will not function as prime as when we are young. Compared to most other organs, eyes are more susceptible to changes due to old age. Inflammation and oxidative stress are the basic causes of any age-related eye diseases. Even though we cannot reverse this process, we could still ‘age like fine wine’ if we maintain a healthy-balanced lifestyle. Recent studies show that mangosteen, the queen of tropical fruits, is rich in antioxidants, vitamins, and minerals that are essential for good eye health. Both antioxidants and vitamins act as anti-inflammatory properties, thus protecting the eyes’ structure against oxidative stress. All these nutrients will also promote good blood circulation to the eyes, making sure that every part of the eyes gets enough oxygen and nutrients needed. However, having a good diet alone is not enough. Incorporating good habits on top of a healthy diet, such as routine eye exam checkups and tapering down screen time plays a vital role in maintaining our vision acuity. To conclude, the eyes are our window to the world. Therefore, we are obligated to maintain their Health.
Reference
- Vision impairment and blindness [Internet]. [cited 2024 Feb 15]. Available from: https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment
- Common eye disorders and diseases | cdc [Internet]. 2023 [cited 2024 Feb 15]. Available from: https://www.cdc.gov/visionhealth/basics/ced/index.html
- American Academy of Ophthalmology [Internet]. 2023 [cited 2024 Feb 23]. Diet and nutrition. Available from: https://www.aao.org/eye-health/tips-prevention/diet-nutrition
- Lawrenson JG, Downie LE. Nutrition and Eye Health. Nutrients. 2019 Sep 6;11(9):2123. doi: 10.3390/nu11092123. PMID: 31489894; PMCID: PMC6771137.
- Bi C, Xu H, Yu J, Ding Z, Liu Z. Botanical characteristics, chemical components, biological activity, and potential applications of mangosteen. PeerJ [Internet]. 2023 May 9 [cited 2024 Feb 23];11:e15329. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10178281/
- Bhat R, Paliyath G. Fruits of tropical climates: biodiversity and dietary importance. In: Encyclopedia of Food and Health [Internet]. Elsevier; 2016 [cited 2024 Feb 23]. p. 138–43. Available from: https://linkinghub.elsevier.com/retrieve/pii/B9780123849472003378
- Kementerian Luar Negeri Repulik Indonesia [Internet]. [cited 2024 Feb 23]. Consulate general of the republic of indonesia in penang malaysia. Available from: https://kemlu.go.id/penang/en
- EL-Kenawy AEM, Hassan SMA, Osman HEH. Mangosteen(Garcinia mangostana L.). In: Nonvitamin and Nonmineral Nutritional Supplements [Internet]. Elsevier; 2019 [cited 2024 Feb 23]. p. 313–9. Available from: https://linkinghub.elsevier.com/retrieve/pii/B978012812491800045X