Overview

Also known as lanzones or by its scientific name, Lansium domesticum, the langsat is an edible tropical fruit that originated in Malaysia but is now commonly cultivated in other parts of Southeast Asia, like Thailand, Indonesia, Vietnam and the Philippines.¹ Its tree requires a certain altitude, humidity, warmth and shade to prosper. The fruit is oval-shaped and found in clusters, similar to grapes. The peel is yellow and thin. The inner content comprises five to six pale, juicy, translucent segments. Seeds are found within these segments. The flavour is described as sour and sweet.² 

The two most common varieties are the wild type, which gives slender fruits with thicker skin, and duku, which offers fewer fruits to each cluster, more of an oval shape, with thinner and brownish skin.² 

Its benefits come from being a valuable source of vitamin A, complex B vitamins, vitamin C, antioxidants, phosphorus, calcium, iron, fibre and more. From its nutrients, langsat can promote wellness, mainly by supporting digestion, the immune system and skin health.¹

Nutritional composition of langsat

Vitamins and minerals

• High in vitamin A: significantly responsible for skin and vision health, besides immune system functions, male and female reproduction, and cell growth³
• Vitamin B1, also known as thiamin, is important for energy metabolism, which affects cell proliferation, development, and performance. It is recommended to be consumed frequently as it is stored for a short period within the body⁴
• Vitamin B2: known as riboflavin, is responsible for synthesising chemicals crucial to energy production, which affects cell metabolism, supporting the metabolisation of fats and drugs⁵. 
• Vitamin B3, also known as niacin, when absorbed, transforms into a molecule that triggers a variety of essential reactions for tissues to function effectively. It is involved in processes that capture energy provided by foods⁶
• Good source of vitamin C: a component known to support the immune system, building collagen, wound healing, protein metabolism, and iron absorption. Humans do not synthesise vitamin C, so it is advised to be consumed daily⁷
• Calcium: bone structure and body support, flexibility and movement⁸
• Phosphorus: present in a variety of forms and functions, it is important for accessing genetic information and regulating parameters that enable cell functions⁹
• Iron: oxygen carriage, muscle metabolism, physical development, tissue functioning, synthesis of specific hormones¹⁰

Macronutrients

• Rich in dietary fibre: Improves digestive health, sustained energy release, and control of blood sugar levels; nourishes beneficial gut bacteria¹
• Carbohydrates: natural sugars for quick energy

Antioxidants

Langsat fruit is a rich source of antioxidants such as polyphenols, carotenoids, and the previously mentioned vitamin C. Antioxidants are capable of protecting cells and genetic material from damage from specific reactive molecules. These harmful molecules are called free radicals, they can be generated either from external causes (pollution, smoke, UV exposure) or as a result of common reactions within the body. Free radicals can strongly attach to elements of cells and DNA, harming its structure and, most of the time, its function. Antioxidants are crucial to neutralising the action of free radicals.¹¹

Energy-boosting properties

Immediate energy boost

Langsat is composed of natural sugars, like fructose and sucrose, giving it a sweet taste. These sugars have a simple structure, so once consumed, they are readily available and require fewer reactions to break into useful molecules. This means that they are an immediate source of energy by providing a quick rise in blood glucose levels.^{12, 13} 

Sustained energy release

Langsat fruit is also well-balanced, with a significant amount of fibre, preventing sugar crashes. Dietary fibres help regulate the speed at which the nutrients are absorbed, slowing the release of sugar into the bloodstream. Glucose is then managed by insulin, a hormone responsible for capturing and guiding it to cells. The slow rise in blood sugar levels induces a stable recruitment of insulin and then a stable intake of glucose by tissues.¹³

The combination of natural sugar and fibre provides a rather safe energy boost. Still, as a fruit rich in sugar and carbohydrates, a spike in blood sugar levels can happen depending on the portion size. In the case of diabetes, it should be consumed in moderation.¹⁴

Vitality and overall well-being

Immune system support

Its considerable vitamin C content makes the langsat fruit a great supporter of the immune system. This vitamin is involved in wound healing, stimulating active defence blood cells and assisting immune response to infections.¹

Digestive health

As mentioned, langsat is rich in fibre, directly supporting digestive health. Fibers help regulate bowel movements, nourish gut microbiota, regulate blood sugar levels and prevent gastrointestinal disorders. A healthy digestive system combined with controlled release of sugar to the bloodstream provides proper nutrient intake and weight management, enabling fulfilment of the body's nutritional needs.^1,14

Skin benefits

The powerful association of antioxidants and vitamin A found within langsat makes it a great ally for skin health. These compounds reduce skin inflammation and cell damage, acting as a prevention for ageing, skin conditions and diseases. Vitamin C, besides being a source of antioxidants, is involved in the synthesis of collagen, which is responsible for skin elasticity and a youthful and healthy appearance.¹   

Some companies invest in skin care products derived from parts of the langsat peel or fruit. In Thailand, for example, it can be found as facial toners, wash cleansers, skin moisturisers and masks.¹²

Mental health

As a source of the B complex, especially B1, langsat can play a role in supporting mental health. Such vitamins are essential to neurological function. Synthesis of serotonin, a hormone that triggers positive feelings, depends on the presence of vitamin B1, for example. Deficiency in B vitamins is commonly related to cases of depression.¹

Research on cancer prevention and treatment

Studies point to extracts of the langsat leaves, fruit and seeds to contain compounds that, within the laboratory, present antitumor and antimutagenic activity. These results are still exploratory and non-conclusive but show evidence of a potential for cancer prevention or treatment in the plant’s composition.^15,16

Langsat in diet and lifestyle

Incorporation into daily diet

Langsat can be eaten purely fresh and raw, simply unpeeling it and removing its seed, but it is versatile and can be incorporated in salads, jams, juices or smoothies and even sweet treats such as ice cream and other desserts.¹

Summary 

The langsat, a fruit typical to Southeast Asia, is a source of a variety of nutrients recommended to be consumed daily for good health. Its nutritional value comes from significant amounts of vitamin A, vitamin C, complex B vitamins, antioxidants, dietary fibres, calcium, phosphorus and iron. For those components, the langsat is good for skin health, immune system support, mental health, and prevention of gastrointestinal disorders and disbalance, among other benefits. The wide range of health support enabled by the fruit's nutrients makes it a well-being promoter. If consumed within a balanced diet, langsat can be a rich and healthy source of energy. Its natural sugars provide quick fuel to the body’s tissues, while its fibre content helps control the release of glucose into the bloodstream. This combination results in a boost of energy in a sustained and safe way. For diabetics and people who need to manage their blood sugar levels, Langsat consumption, like any other fruit with a considerable amount of sugar, needs to follow professional advice for proper portion sizes. 

Overall, the langsat fruit is highly recommended for a healthy diet. It can be consumed raw, but also in salads, juices and desserts.