African Walnuts (Coula edulis) – Description |Health benefits | Constituents

African Walnut ( Coula edulis) is an evergreen plant commonly found in the western Africa. However, It is more common with these countries; Democratic Republic of Congo, Nigeria and Sierra Leone. In these regions, Walnuts are commonly used as food because of its numerous health benefits.

The nuts are commonly accessible as it is hawked in streets and markets. It has an amazing aroma and is sometimes a good source for food condiments.


The African walnut tree grows up to 25 m – 39 m in height with dense crowns. The wood is very hard, durable and resistant to termite and fungal attacks. Hence, It is one of the major source of Timber in the tropical forests.

Coula edulis has a yellowish green flowers with 4 or 5 petals. The leaves are alternately arranged, simple, oblong or elliptical in shape and usually measures 10-30 cm x 4 cm. The young leaves are usually covered with a brownish stellate hairs that is more prominent at the upper surfaces.

The Fruit of African walnut is an ellipsoidal drupe measuring 3-4 cm long, with an extremely hard kernel that is cracked to show a smooth greenish or reddish edible part..

Botanical name

Coula edulis Baill

Common names

  • African walnut
  • Gabon nut
  • Ukpa (Igbo)
  • Ekom (Ibibio and Efik),
  • Ivianlegde (Edo)
  • Asala (Yoruba)
  • Dibetou in Gabon and Ivory Coast
  • Mpengwa in Ghana

Scientific classification

  • Kingdom         Plantae
  • Phylum            Angiosperms
  • Class                Eudicots
  • Order               Santalales
  • Family              Olacaceae
  • Genus              Coula
  • Specie              C. edulis Baill

Chemical constituents of Coula edulis

Phenolic compounds, Vitamin C, Vitamin E, Phlobotannins, Flavonoids, Phenols and Glycosides.

Health Benefits of African walnut

African walnut tree is popularly known as a great source of Timber due to its high tensile strength and termite resistance. However, that is not the only use of this tree, the bark, leaf and fruits from African walnut have so many health benefits that are worth mentioning.

Usually, the fruit from the tree is edible and is sold at the roadside in some West African countries such as Cameroon and Nigeria. The leaf or bark decoction is also a source of herbal medicine used by many communities in treating different illnesses.

Nevertheless, the list of the health or medicinal uses in this post are going to be research based.

Nourishes the Skin and revive ageing cells

Coula edulis is a great source of phenolic compounds, vitamin C and vitamin E. This is a great source of antioxidant that helps to scavenge the free radicals in the body. It is also found that extracts from the dried seed of C. edulis have the ability to remove intoxication by heavy metals such as Lead and Arsenic poisnoning.1

Helps to ward off infections

Another important benefits of walnuts is its ability to help prevent and treat infections from bacteria and fungus. The extracts from the seed, leaf and bark have the ability to inhibit the growth of Staphylococcus, Candida and Pseudomonas. 2

Therefore, consumption of this fruit will serve a great purpose to keep someone free from microorganism in the environment especially maintaining oral hygiene.

Walnuts help in weight reduction and obesity

One of the most effective way to loose weight fast is to balance the calorie intake and the energy dissipated in a day. Walnut is a rich calorie food but studies have shown that the energy absorbed from eating walnuts is lesser that the total energy in the fruit itself.

An experiment published in Pubmed suggests that daily consumption of walnuts can reduce appetite and hence, food consumption in a group of obese patients. 3

Therefore, African walnuts will benefit those with history of type 2 diabetes mellitus and also those battling to reduce and watch their weight.

African walnuts helps to improves male sexual health

African walnut is one the ingredients in the preparation of the famous Tiger nut juice (Cyperus esculentus plus other ingredients). This juice have been used by many men as an aphrodisiac and also a way to improve the quality of their sperm.

Coula edulis nuts has the ability to improve sperm motility, vitality, and morphology. The research was observed in 117 men ranging from 21 to 35 years old. The result of the sperm quality after a continuous diet with walnuts was amazing .4

Walnuts benefits the functions of the brain

C. edulis is very rich in Polyphenolic compounds that helps to reduce the oxidation and inflammatory load on brain cells. Also, benefits of walnuts includes; improve in interneuronal signaling, increase neurogenesis, and enhance sequestration of insoluble toxic protein aggregates. 5

Therefore, walnuts are very essential in the reviving of neuro-degenerative diseases such as Dementia, Alzheimer’s and Parkinson disease.

African walnuts can prevent the risk of cancers

So many studies have proven walnuts to be a very good anti cancer agent. One of the studies, is to observe the health benefits of eating peanuts, walnuts and almond on the development of breast cancer.

The result shows that the consumption of these three plants can reduce he development of breast cancer by 2 to 3 times. 6

Reduces the risk of stroke

Researchers have identified biochemicals, including n–3 (ω-3) fatty acids, tocopherols and β-sitosterol which acts against excessive cholesterol that blocks blood vessels supplying oxygen and blood to the brain.

These lack of oxygen and blood to the brain is the primary cause of stroke. Hence, good and frequent eating of walnuts can prevent stroke.

In summary, there are other plethora uses of African walnuts that has not been documented. Therefore, the researches encourages us to incorporate walnuts into our routine diets as this can help out with so many help benefits.


here are other tropical plants with amazing health benefits

Fio Fio (Pigeon peas) – Cajanus cajan | 14 Interesting Medicinal Uses

Morinda lucida Benth – Description | Constituents & Medicinal uses


  1. Ita, Basil & Ndukwe, Gloria. (2017). Antioxidant Activity of Coula edulis Baill. Seed Extracts. European Journal of Medicinal Plants. 17. 1-7. 10.9734/EJMP/2016/30762.
  2. Bukola C. Adebayo-Tayo and Kola K. Ajibesin, 2008. Antimicrobial Activities of Coula edulisResearch Journal of Medicinal Plants, 2: 86-91.10.3923/rjmp.2008.86.91
  3. Farr OM, Tuccinardi D, Upadhyay J, Oussaada SM, Mantzoros CS. (2017).Walnut consumption increases activation of the insula to highly desirable food cues: A randomized, double-blind, placebo-controlled, cross-over fMRI study.10.1111/dom.13060 [pubmed}
  4. Robbins WA, Xun L, FitzGerald LZ, Esguerra S, Henning SM, Carpenter CL. (2012) Walnuts improve semen quality in men consuming a Western-style diet: randomized control dietary intervention trial. 10.1095/biolreprod.112.101634 [Pubmed]
  5. Poulose SM, Miller MG, Shukitt-Hale B. (2014). Role of walnuts in maintaining brain health with age.web.10.3945/jn.113.184838
  6. Hardman W. E. (2014). Walnuts have potential for cancer prevention and treatment in mice. The Journal of nutrition144(4 Suppl), 555S–560S. doi:10.3945/jn.113.188466