The Oyster Nut: The East African seed with big nutritional and traditional uses

It does not look much like the nuts most people know.

Oyster nut grows on a climbing vine in the Cucurbitaceae family, the same broad plant family that includes pumpkins and gourds.

The vine can climb high into trees and produces large, ridged fruits containing numerous flat seeds.

The species is native to eastern Tanzania and northern Mozambique and is cultivated in parts of Tanzania, Kenya, Uganda and elsewhere in East and southern Africa.

In Kenya, it has been documented in the Mt Kenya region, including Tharaka-Nithi, as well as the coast.

The “nut” is actually a seed

The edible part is the kernel inside the seed.

FAO describes the seeds as large, flat and oily, with a flavour comparable to Brazil nuts when roasted.

Traditional preparation involves washing, drying and removing the fibrous outer covering before the kernel is eaten.

The seeds can be eaten raw or roasted, incorporated into food or pressed for oil.

The plant itself is remarkably productive.

Its fruits can weigh up to about 15kg and may contain as many as 140 seeds.

The value of the oyster seed

Oyster nut has long been more than a snack.

Ethnobotanical research in northern Tanzania documented its use as food, cooking oil, medicine and in cultural practices.

In the study, cooking was the most frequently recorded use, followed by use by pregnant and breastfeeding women and consumption as a snack.

The researchers also recorded uses in soap and candle production and cosmetics.

The plant is particularly associated with maternal diets in parts of East Africa.

Some communities traditionally consume the nuts during pregnancy and after childbirth, including in foods prepared specifically for breastfeeding mothers.

Researchers have documented the long-standing belief that the nuts help stimulate breast-milk production.

That is a traditional use, not proof that oyster nut increases milk supply.

There is limited clinical evidence to establish the claim.

What is actually in oyster nut?

The seed is valuable principally because it is an energy-dense oilseed.

Older food-resource data put the kernel at roughly 27% protein and around 6% fat in one preparation, while other analyses of the seed and extracted oil report substantially higher oil content, illustrating how composition varies with the sample and processing method.

Research on oyster nut oil from Kenya found a substantial unsaturated-fat component.

A 2026 study of oil from Tanzania found 54.7% unsaturated fatty acids, dominated by linoleic acid, alongside several phytochemicals and measurable antioxidant activity in laboratory tests.

This is promising nutritionally, but laboratory antioxidant activity should not be presented as proof that eating oyster nuts prevents disease.

What are the health claims?

Traditional use has linked oyster nut with postnatal recovery, lactation, digestive problems, rheumatic or joint discomfort and general weakness.

Some communities have also associated the seed with male fertility and other health benefits.

The better-supported claim is more straightforward: oyster nut is a nutrient-rich food containing protein and substantial amounts of oil.

Claims that it treats disease, increases fertility or cures joint problems require clinical evidence that is currently limited.

The oyster nut oil

Oyster nut's value does not end in the kitchen.

Its oil has been used traditionally for cooking, soap, candles, cosmetics and massage products.

Researchers have also identified commercial potential because the plant can provide both food and an oil crop from smallholder farming systems.

One catch is storage.

Research comparing oyster nut oil with sunflower and flaxseed found that unrefined oyster nut oil had relatively poor keeping quality, making the roasted kernel or flour a potentially more practical form where storage conditions are limited.

Why is the crop neglected in EA?

Oyster nut has an unusual contradiction: it has been known and cultivated for generations, yet it remains a neglected crop.

Researchers describe it as underutilised despite its food, income and conservation potential.

Cultivation is declining in parts of East Africa, while traditional knowledge appears to be disappearing among younger generations.

That makes oyster nut interesting not because it is some newly discovered “superfood”, but because East African communities already knew its value long before it became a subject of nutritional research.

Today, the challenge is turning that knowledge into wider cultivation, better processing and a reliable market without losing the crop's place in the food traditions that kept it alive.

To get seedlings around Mt. Kenya areas, click here to reach a registered oyster nut nursery in Meru County ran by Kagene CBO.