Antioxidant-Rich Rambutan For Skin Health

Overview

The rambutan (Nephelium lappaceum) is a tropical fruit tree indigenous to the Malay Archipelago region, which includes Indonesia, Malaysia, southern Thailand, and parts of Asia. It is also grown commercially in India and Sri Lanka. This tree thrives in humid environments with high annual rainfall between 250 to 350 cm. The fruit resembles a litchi in shape and texture. Its outer covering is distinctive, with numerous long, thick hairs that can be yellow, pink or red. Inside the hairy peel is a single oval or round edible seed with opaque white flesh that is firm in texture.¹

Due to its high nutritional profile, rambutan offers a variety of health benefits and antioxidant properties. In this article, we will explore how rambutan improves skin health by providing a source of antioxidants.

The benefits of rambutan

The rambutan is a rich source of bioactive compounds in its peel, seed, and pulp. The rambutan fruit possesses an appealing flavour, aroma, and sweetness, making it a juicy and desirable treat. It is a nutritious source of:¹ 

• Carbohydrates
• Sugars
• Vitamin C
• Minerals (e.g., niacin, iron, calcium, and copper)
• Fibre
• Protein

Rambutans can be consumed fresh or processed into dried fruit pulp, jams, jellies, fruit concentrates, and other products. While most rambutan varieties yield sweet fruits, some cultivars produce sour varieties. The sweet ones are eaten fresh, while the sour ones are canned or used to make jams, jellies, juices, and even pharmaceuticals in major producing countries such as Malaysia and Thailand.

Research has revealed that the peel of the rambutan fruit is a rich source of various phytonutrients, including:¹ 

• Tannins
• Saponins
• Flavonoids
• Geraniin

Additionally, the seeds contain several phenolic compounds, such as ellagic acid, corilagin, and geraniin, which may offer potential health benefits. Rambutan seeds are also a source of essential minerals such as:¹

• Calcium
• Zinc
• Iron
• Magnesium 
• Manganese

The studies on the diverse bioactive compounds in rambutan reveal various beneficial properties for health and disease prevention:¹

• Antidiabetic, antimicrobial, and anti-obesity effects
• Potential in mitigating metabolic syndrome
• Potential to increase sperm count
• Antioxidant properties restore oxidative stress biomarkers and provide safety against lipid and glucotoxicity
• Ability to increase red blood cell and haemoglobin counts
• Anticancer activity by hindering the growth of cancer cells
• Anti-hypercholesterolemia effect, reducing cholesterol levels
• Wound healing, anti-inflammatory, and free radical scavenging properties

Understanding free radicals and antioxidants

While oxygen is essential for life, it can cause harmful effects on the human body under certain circumstances. Many of these potentially detrimental effects occur due to reactive oxygen species (ROS), which are chemical compounds formed through normal metabolic processes or exposure to external sources like:

• X-rays
• Ozone
• Cigarette smoke
• Air pollutants
• Industrial chemicals

Antioxidants are stable molecules that can neutralise and reduce the damaging capacity of rampaging free radicals. Some antioxidants are produced naturally during metabolism, while others come from the diet. Although the body has enzymatic systems to scavenge free radicals, the principal dietary antioxidants are vitamins E, C, and β-carotene, which must be obtained from food sources.³

A balance between free radicals and antioxidants is crucial for proper physiological function. When free radicals overwhelm the body's ability to regulate them, oxidative stress can adversely alter lipids, proteins, and DNA, contributing to various diseases. Therefore, supplementing with external sources of antioxidants can help combat oxidative stress. While synthetic antioxidants are harmful, the search for effective, non-toxic natural compounds with antioxidant activity has intensified recently.³

Antioxidants and skin health

In humans, the ageing process is due to intrinsic (internal) and extrinsic (external) factors. Intrinsic ageing is a natural, progressive, and irreversible degeneration of tissues that occurs over time. It is due to metabolic oxidative damage and free radical oxygen species. The rate of intrinsic ageing varies among individuals based on their unique genetic makeup. On the other hand, extrinsic ageing is the compounding effect of external factors on intrinsic ageing, such as:⁴

• Ultraviolet (UV) and infrared radiation
• Environmental pollutants
• Harsh chemicals
• Disease processes cause Inflammation

Excessive oxidative stress can be highly detrimental to skin cells, triggering inflammation and accelerating the visible signs of premature skin ageing. Oxidative stress accelerates the collagen breakdown, causing sagging skin lines and wrinkles. Free radicals cause skin inflammation, clogging pores and triggering pimple formation. Ultraviolet (UV) light exposure induces the formation of free radicals in the skin, which can contribute to premature ageing and skin cancer development.⁵

Antioxidants combat free radical damage and promote healthy skin. They achieve this by influencing intracellular signalling pathways involved in skin damage, protecting against photodamage, and preventing wrinkles and inflammation. Fruits and vegetables serve as the most critical dietary sources of antioxidants. The skin is the largest body organ and greatly benefits from a healthy diet rich in antioxidants. Since the skin receives up to one-third of the body's total blood circulation, nourishing this vast organ from the inside out through a balanced diet is considered the best approach to improving skin health, complementing topical skincare products.⁴

Excellent antioxidant food sources for skin include blueberries, avocados, grapes (especially red/ purple), bell peppers (red and yellow), almonds, cashews, and walnuts. These provide antioxidants like anthocyanins, lycopene, beta-carotene, vitamin C, vitamin E, and selenium that neutralise free radicals, counter oxidative stress, reduce wrinkles, protect against UV-induced photodamage, and help fade hyperpigmentation for a brighter, more radiant complexion.⁵

Unlocking the antioxidant power of rambutan

Rambutan is a rich source of antioxidant compounds which reduce cellular damage. Rambutan fruit provides around 7.4 mg of vitamin C per 100g, making it a nutritious choice. Vitamin C, being an antioxidant, can combat free radicals. Scientists suggest that vitamin C contributes to fighting ageing by keeping white blood cells healthy. The natural antioxidants in rambutan and its lipid-containing components like oils, fats, and butter, make these ingredients well-suited for moisturising creams and other skincare products, providing antioxidant benefits to the skin.¹

Rambutan also offers distinct health benefits and therapeutic properties when consumed as fresh fruit or juice and applied topically on the skin. It contains several essential amino acids that help to build healthy skin cells and suppress redness and swelling on skin exposed to harsh environmental conditions. Its high flavonoid content provides antioxidant properties that can:^7,8

• Combat free radical damage
• Diminish acne, scars, and dark spots
• Lessen skin irritation

Rambutan contains spermidine, a compound that aids in delaying the ageing process of skin cells. The carotenoid class of flavonoid plant antioxidants further plays a crucial role in reducing the appearance of wrinkles, fine lines, and sagging skin. Applying rambutan-infused creams, oils, and moisturisers can boost collagen production, a protein essential for maintaining skin elasticity and firmness.^7,8

A research study reveals antioxidant activities in various extracts from the peel and seed portions of rambutan.⁶ The findings show that the peel extracts exhibited more potent antioxidant activities than the seed extracts. The study highlights the significant antioxidant potential residing in the often discarded peel of the rambutan fruit. Leveraging this byproduct as a source of natural antioxidants could have valuable applications, given the importance of antioxidants in various industries and health domains.⁶

Summary

The rambutan is a nutritious tropical fruit, native to Southeast Asia. It is packed with bioactive compounds exhibiting remarkable health benefits. Rich in vitamins, minerals, and antioxidants like vitamin C, carotenoids, and flavonoids, rambutan possesses antidiabetic, antimicrobial, anti-obesity, and anticancer properties. Its antioxidant prowess helps combat oxidative stress, increases red blood cell count, and promotes wound healing. The colourful fruit is eaten fresh or processed. Extracts from the peel and seeds also demonstrate potent antioxidant activities useful for mitigating ageing, inflammation, and skin ailments. Rambutan's diverse phytochemicals make it a promising natural source for nutraceutical and cosmeceutical applications, providing multifaceted benefits for overall health and skin rejuvenation.