African walnut: The heal-all you must eat

For the younger generation, who may often seek validation from social media while holding the 21st century in their ‘e-palms’, African walnut may be relegated to the bottom of fruit options as some weird looking black fruit, only the old should relish. Ironically, the innumerable health benefits of this seemingly not so trendy and tasty fruit, surpasses all the likes one could ever get on social media.

Two years ago, a duo of teenagers developed a natural cure for halitosis, otherwise known as bad breath. The active ingredient of both their products (gum and mouthwash) was the walnut. That discovery, won Eveshorhema Sophia Samuel-Alli and Ibukunoluwa Ruth Oladeinde of Doregos Private Academy, Ipaja, Lagos, a Life Science Award of $1,000 in the Medicine and Health Science category, courtesy, Sigma Xi Scientific Research Society that year.

Enveloped in a thick black wall, the African Walnut, which has a creamy inner colour and a bitter after taste, has been described by experts as a wonder fruit, capable of curing a litany of diseases. The African walnut, locally called (Asala or Awusa in Yoruba; Ukpa in Igbo; and Okhue or Okwe in Edo) belongs to the botanical family Euphorbiaceae and is a highly versatile nut. Asides from its medicine and health uses, it serves a number of other uses such as furniture and dye making.

Last year, a research paper published in the Journal of Global Biosciences, itemized the many benefits of African walnut following the findings from a research work on the fruit titled “Studies on the Phytochemical and Nutritional properties of Tetracarpidium conophorum (black walnut) seeds.”

Based on the findings of researchers, Ojobor Chijioke, Anosike Chioma, both from the Department of Biochemistry, University of Nigeria, Nsukka and Ani Collins of the Department of Biological Sciences, University of Agriculture, Makurdi, the African walnut contains phytochemicals like alkaloid, saponins, glycoside and reducing sugar in high abundance. The study also showed that contained in the African walnut was also moderate amounts of soluble carbohydrate. However, other phytochemicals such as flavonoid and tannins were observed in trace amounts while hydrogen cyanide and terpenoid were not detected in the walnut samples.

According to the researchers, “phytochemicals are biologically active compounds, which contribute significantly to protection against degenerative diseases.” Flavonoids are known to have protective effects including anti-inflammatory, anti-oxidants, antiviral, and anti-carcinogenic properties.

“The presence of tannins in the walnut sample suggest that it could be used for healing of haemorrhoids and varicose ulcers in herbal medicine.”

Alkaloids are the most effective plant substance used therapeutically as analgesic, antimicrobial and bacterial properties. “This may probably be the reason walnut is believed to stop asthma (not acute asthma) and also a constipation cure for elderly.”

Also, the findings indicated that the high amount of saponins in the walnut samples points to the fact that walnut has a cytotoxic effect such as permealisation of the intestine. The presence of saponin, which gives the plant its bitter taste, has relationship with sex hormones like oxytocin which is involved in controlling the onset of labour in women and the subsequent release of milk.

While carrying out the vitamin analyses of the fruit, the researchers observed the presence of vitamins A, C and E in appreciable amounts and other vitamins like D, K, B1, B2, B3, B5, B6, B9 and B12, were found in trace amounts.  They discussed that the presence of such vitamins in walnut indicates that it can be used in the treatment of skin conditions, including eczema, pruritus, psoriasis and parasitic skin conditions. Also, it can be useful vitamin in the treatment of common cold and prostate cancer. The report also indicates that walnut could be used in treatment of indigestion, constipation and diarrhea. The exceptionally high content of vitamin E in walnut supports its use in Southern Nigeria ethno-medicine as a male fertility agent.

Based on the book, Medicinal Plants of Nigeria- South West Nigeria Volume 1, compiled and published by Nigeria Natural Medicine Development Agency (NNMDA), here are several other reasons why walnuts must be a part of every Nigerian’s diet.

Fertility purposes

In local ethnomedicine, walnuts are used as a male fertility agent; the  leaves are used to improve fertility in male and chewing the walnut improves sperm count. Eating around two handfuls of walnuts a day over a period of 12weeks will improve sperm health in young men. Walnut seeds are used to treat uterine fibroids and chewing walnuts helps prevent miscarriage.

For treatment of pain

The leaf juice of the African walnut is considered a headache cure in southern Nigeria and is used to improve and regulate menstrual flow. The leaf juice is drunk to mitigate prolonged and /or constant hiccups.

Cardiovascular benefits

African walnut helps prevent heart disease and is recommended for lowering cholesterol. Walnuts are rich in compounds such as omega 3 essential fatty acids that reduce hardening of the arteries, prevent erratic heart rhythms and keep them flexible. Walnuts also contain relatively high levels of L-arginine, an essential amino acid that is converted into nitric oxide, a chemical that helps to keep the inner walls of blood vessels smooth and allows blood vessels to relax.

Anti ageing benefits

African walnuts contain numerous antioxidants like vitamin E, melatonin, manganese, selenium, ellagic acid and about 16 different polyphenols. All these elements are known to prevent cellular damage; hence they help in the reduction of age-related diseases.

Cancer prevention

African walnuts contain multiple ingredients; omega-3 fatty acids, antioxidants, and phytosterols that, individually, have been shown to slow cancer growth.