Introduction

Welcome to the vibrant world of rambutan and the potent compound it contains - lycopene. Originating from Malaysia, the rambutan tree yields a delectable fruit with a striking red exterior and a sweet, tangy pulp. Beyond its visual allure, rambutan houses a nutritional powerhouse, especially in its seed. Nestled within rambutan is lycopene, an effective antioxidant found in various red fruits and vegetables. While tomatoes often steal the spotlight, this article delved into the lesser-known lycopene haven that is  rambutan and explore the potential health benefits it brings. Join us on a journey to uncover the nutritional marvels of rambutan and the unique aspects of lycopene it harbours. From its benefits for cardiovascular health to its skin-loving properties and even its role in cancer prevention, the lycopene in rambutan emerges as a versatile ally to overall well-being.

What is rambutan and lycopene?

Rambutan

The rambutan is a member of the soapberry family that originates from Malaysia. The tree is widely cultivated for its fruit, which shares the same name: rambutan. It is characterised by its vibrant red hue, its velvety, hair-like spinterns, and boasts a delicious, tangy pulp.¹ Rambutans are rich in lycopene, an organic compound that is considered a tetraterpene and a carotene. It can be found in many red fruits and vegetables and is thought to give them their vibrant colours.²

Nutritional profile of rambutan

The seed of the rambutan is rich in protein (~8%-12%), fat (~33%-39%), and fibre ~12%). The primary fatty acids present in the rambutan seed include palmitic, stearic, oleic and arachidonic acids. In Malaysia, rambutan seeds are ground into fine powders and utilised as a form of local medicine, as they are known to contain compounds with antidiabetic properties.³

Lycopene

In order for our body to absorb lycopene, it needs to be mixed with bile salts and fat to form tiny structures called micelles. Eating lycopene in the presence of fat and also cooking it can help our intestines absorb it better. While lycopene is not vital to our bodies, it is often in our diet. On average, people get about 5.3 milligrams of lycopene per day.⁴

A study conducted in Indonesia looked at the carotenoid content in 18 different common fruits. Lycopene was among one of the carotenoids discovered. While they highlighted significant variation in the compounds even in the same species of fruit, rambutan contains a high lycopene count.⁵ While lycopene has been shown to be present in rambutan, the most bioavailable form of it is found in tangerine tomatoes. This is because tangerine tomatoes have a more specific kind of lycopene (tetra-cis-lycopene) that dissolves well in fats.⁶

Health benefits of lycopene in rambutan

Antioxidant properties

Lycopene is a powerful antioxidant with a study finding it to be the second most potent carotenoid⁷. Age-related memory and cognitive issues are common in ageing brains due to oxidative stress. Previously, research has delved into how adding lycopene to one’s diet lowers oxidative stress, reduce inflammation in the brain and mitigate the accumulation of substances linked to age-related illnesses⁸. Additionally, lycopene pigment effectively enhances the activity of antioxidant enzymes, reducing inflammatory substances in the blood and can affect specific genes associated with antioxidants and inflammation in the hippocampus of animal models.⁹ 

Anti-inflammatory effects

Studies have found lycopene to have anti-inflammation properties as it gets rid of harmful oxygen species by neutralising them. Additionally, lycopene can enhance the body's defence system against harmful molecules to help prevent inflammation.¹⁰

Cardiovascular health

Lycopene can lower the total amount of cholesterol, especially the type, as well as thiobarbituric acid-reacting substances, which are harmful compounds found in your blood. As well as this, it helps in reducing VLDL and triglycerides which are fats that are harmful to your heart. Finally, lycopene can increase the levels of good cholesterolwhich can provide additional heart protection. Together, lycopene can elicit all of these things and act as a cardioprotective agent for our hearts.¹¹

Lycopene and skin health

Lycopene is thought to have great benefits for skin health. There has even been scientific research into the advantages of using lycopene to protect against sun damage. One study investigated whether lycopene supplements from tomatoes and lutein can protect the skin from damage caused by sunlight. Participants took the supplements for 12 weeks and the researchers measured the effects on genes related to sun damage. The result shows that the supplements essentially prevented the increase in certain genes related to sun damage, regardless of when it was taken.¹²

Anti-cancer 

In more recent studies, lycopene has been explored in human cells as a protective agent against various types of cancer. There is some evidence from systematic reviews that shows eating lycopene may have a small link to a lower risk of prostate cancer.¹³ As lycopene is known for its potent antioxidant properties, it has been trialed to reduce exposure to oxidative stress as a means of slowing down the growth of ovarian cancer. Research has shown that it significantly reduced the spread of ovarian cancer in mice models when used as a preventative agent. When combined with chemotherapy, lycopene was found to reduce the number of rapidly dividing cancer cells and decreased the expression of a biomarker associated with ovarian cancer.¹⁴ This study suggests that lycopene can interfere with the mechanisms involved in the development of ovarian cancer. 

Incorporating rambutan into a healthy diet

There are many ways to incorporate rambutan into your diet: 

• Fresh rambutan fruit: the simplest way is to eat it as it is. Cut open the fruit and enjoy the juicy white flesh from the seed 
• Rambutan fruit juice: you can even make refreshing rambutan fruit juice by blending it with coconut water and straining out any solids
• Rambutan in cooking: you can elevate your desserts by adding sweet and juicy rambutan fruit whether it’s a fruit tart or diced up to add to a Thai curry 
• Supplements: while these aren’t rambutan supplements, lycopene supplements are readily available to buy on the internet to reap many benefits discussed in this article and even more
• See Klarity Health’s Library to read more about the Health Benefits of Rambutan Fruit 

There is no recommended daily intake for lycopene currently as it is found in varying concentrations from a plethora of different foods. From current studies, it is thought that around 8-21 milligrams per day seem to yield the most benefits.¹⁵

Potential concerns and side effects

Lycopene is generally safe and present in many diets. However, some individuals may experience intolerance or allergic reactions to dietary lycopene, leading to symptoms such as diarrhoea, nausea, stomach pain or cramps, gas and loss of appetite.¹⁶

As well as this, lycopene could potentially elevate the risk of bleeding when taken alongside anticoagulant drugs. Moreover,as it can help lowering blood pressure,¹⁷ interactions with medications affecting blood pressure may occur. Lycopene might also influence the immune system, nervous system, sensitivity to sunlight, or medications used for stomach issues.¹⁶

Another important consideration is that many scientific studies measuring the efficacy and health benefits of lycopene are based on different modes of ingestion. The measures of lycopene in rambutan will differ from those studies in tomatoes and further those in dietary supplements. 

Conclusion

In conclusion, the the abundance of lycocene in rambutan presents a captivating narrative of health and nutrition. As we explored the potential benefits, from antioxidant prowess to cardiovascular support, it is evident that lycopene holds promise for our well-being. As you embark on your journey of incorporating rambutan into your diet, remember the various ways it can be savoured - from the simple joy of relishing the fresh fruit to the exotic twist it lends to desserts and savoury dishes. With every exploration, a note of caution arises. While lycopene showcases its myriad of benefits it is essential to navigate potential concerns and side effects. Let the colourful allure of rambutan and the antioxidant might of lycopene guide us towards healthier, more informed choices.