Candlenut, Light for Health

By Pharm. Ngozika Okoye MSc, MPH, FPCPharm

(Nigeria Natural Medicine Development Agency)

Email: ngozikaokoye@yahoo.com

Aleurites moluccana

Aleurites moluccana (Fam. Euphorbiaceae) does not have widely used traditional names in Nigerian languages because it is not native to West Africa. However, in regions where it is traded, people refer to it descriptively – goro mai or kifi goro in Hausa; aki oku, aki okuku, aki okummanu in Igbo; and agbon inu, eku ile oyinbo or oro imole in Yoruba. Common English names include Belgaum walnut, candleberry, country walnut, Indian walnut, Jamaican walnut, and Singapore nut. The tree originates from Indonesia but is now cultivated in the West Indies and South America, especially Brazil.

Constituents

The nuts are primarily composed of fibre, fats, protein, and carbohydrates, along with phytochemicals and minerals. The phytochemicals include flavonoids, saponins, polyphenols, coumarins, and triterpenoids, which are responsible for many of the plant’s traditional medicinal uses. Significant amounts of potassium, phosphorus, iron, zinc, and copper are present, as well as vitamins A, E, and C. Phorbol esters are also present.

Preparations

The fruits, leaves, and seeds are available in fresh or dried form. The seed oil is also commercially available. The seed can be boiled, crushed, or ground before use. It is sometimes used for thickening, flavouring, and seasoning.

Pharmacological actions and medicinal uses

The fruits, leaves, and seeds are used in traditional Asian medicine for treating various health issues, including headache, fever, inflammation, gonorrhoea (a sexually transmitted infection), and constipation, and for lowering blood cholesterol levels. The seed is claimed to be useful for arthritis, baldness, cellulite, constipation, haemorrhoids, improving skin conditions, suppressing appetite, and assisting smoking cessation. Candlenut is also used for asthma and constipation.

Its high fibre content may help relieve constipation and promote regular bowel movements. The potassium content may help lower blood pressure, and the nut may also increase “good” cholesterol (HDL). Compounds such as saponins, flavonoids, and polyphenols in the oil have been linked to immune-boosting effects. The oil contains melatonin, a hormone that helps regulate the sleep–wake cycle.

The inner seed is the most commonly used part of the plant and is often sold as a food additive, natural laxative, or weight-loss supplement. Candlenut oil (kukui nut oil) is a popular ingredient in moisturisers, creams, and hair products due to its emollient properties, high fatty acid content, and antioxidants. It helps hydrate the skin, soothe eczema and psoriasis, reduce signs of ageing, and promote hair growth. The oil also helps keep hair moisturised and nourished, treats dandruff, and supports hair growth.

However, no published studies are currently available to confirm any of the claimed health benefits.

Adverse effects

Raw candlenut is poisonous and can cause symptoms such as abdominal pain, vomiting, and diarrhoea when ingested. In rare cases, it can cause cardiac dysrhythmias. Some individuals may be allergic to the leaves or seeds. The seeds should be avoided during pregnancy and lactation, in young children, the elderly, and in patients with liver, heart, or kidney disease.

Economic uses and potential

The candlenut tree is a tropical species with numerous uses, including as a source of fertiliser, dye, tattoo ink, and fuel. Its high oil content allows the nuts to be strung together and used as traditional candles. The oil is also used in the production of paints and varnishes. The seed is considered a promising source of commercial biodiesel due to its high oil yield and favourable fatty acid profile. The nut husks can be used to produce ink and a black dye for tattooing. Candlenut costs about $16.44 per 300 g, or N7,000 per kg. It has strong prospects in the pharmaceutical, cosmetics, and building industries.

References

Lawani O, and Winter M. (2022). Heart Block Initiated by Candlenut Ingestion. Case Rep Cardiol. 30 May; 2022:3679968. doi: 10.1155/2022/3679968.