CANDLENUT TREE: USES AND HEALTH BENEFITS OF THE CANDLENUT TREE

CANDLENUT TREE, ALEURITES MOLUCCANA

The candlenut tree is known by many other names, including the Indian walnut tree, the varnish tree and candleberry. In Hawaiian it is known as kukui. It is a member of the Euphorbiaceae or spurge family of plants, and so is related to petty spurge, Sun spurge and so on, as well as to French and Dog’s Mercury, poinsettia, the castor bean tree, yucca and Croton tiglium (the jamalgota producer).

  It is native to the Pacific Islands and is sometimes used in agroforestry to protect avocado trees, mango trees and others from inclement weather. It can grow to heights of 66 feet, although is usually a little smaller. It is also native to the Indian subcontinent, Myanmar and parts of South East Asia. It was introduced to the Caribbean islands, the US, the Virgin Islands and Sri Lanka, among other countries. It is useful as a windbreak and can be pruned so that it forms a living hedge.

  The Hawaiian name for this plant means lighting and this is what the oil from the candlenut has traditionally been used for. It seems that no part of this tree goes to waste, as the husks are used to produce a black dye used in tattooing, or used for decorative items, for example filled with home-made candles. The shell contains seeds which are fleshy to leathery in texture, and it feels a little like a walnut shell. The husks and seeds are woven into traditional leis (garlands) in Hawaii and the flowers and leaves may also be included in these. It is the official state tree of Hawaii.       

  The name of the genus, Aleurites means “flowery” in Greek and this is a reference to the young leaves and flower buds, which look as though they have a fine dusting of flour over them. The flowers usually bloom in spring, although in some places they bloom at any time of year.

  The oil can be used like linseed oil (from flax seeds) and is used to oil surfboards in Hawaii. This oil was useful when the early people of that island used the latex from the breadfruit tree to trap birds, so that they could pluck feathers from them to make their ceremonial cloaks. After they had taken the feathers they needed, they would remove the sticky gum from the birds’ feet with oil from the candlenut tree and release them.

  All parts of the tree are toxic, but the bark, seed, leaves and flowers are all used in traditional systems of medicines in areas where the tree grows. The raw seeds are toxic and have a purgative effect, but the seeds may be roasted and powdered to use as a condiment mixed with salt, seaweed, and chilli peppers. This is called “inamona” in Hawaiian.

  The shells and seeds are also used to make jewellery, and may be varnished or unpolished. The oil is used in the cosmetics industry and can also be used as fuel in diesel engines after chemical modification. It is also used as a base for paint and varnish. The trunks of the trees are made into canoes, which are short-lived as the wood is not very durable. Another use for the wood is to make fishing net floats. After the oil has been extracted from the seeds, the leftover seed cake is used as animal fodder.               

  The oil from the candlenut is an irritant and is used on the scalp to promote hair growth. The pulped seed kernels are used in poultices to relieve headaches, fevers, swollen joints and sores and ulcers on the skin. In Java the bark decoction is given for dysentery, while the hot leaves are used for headaches and gonorrhoea for which purposes they are applied topically to the body.

  The leaves and bark have been found to have antiviral and antibacterial properties, while the methanol extract of the leaves has hypolipidemic effects. The leaves have pain-killing properties believed to be due to their flavonoids content.

  The nuts from the tree may be used in cooking as a substitute for macadamia nuts, but should not be eaten raw as they contain saponins and other toxic substances.