WALNUT
They are enveloped in a black thick wall, they are white to creamy snack with a bitter after taste. African walnut is in seasonal. The cooked nuts containing the edible seeds are common articles of trade in Nigeria. Most Nigerians eat African walnut just as a snack, but researchers suggest the meal and indeed the whole plant could be the panacea to several diseases.
Researchers have demonstrated how extracts of walnut reduce the risk of breast cancer; boosts fertility and cognitive skills; and stop diarrhoea, fibroids, and disease pathogens such as Candida albicans (thrush), Staphyloccocus aureus, Bacillus subtilis, Aspergillus niger and Pseudomonas aeruginosa.
Nigerian researchers have shown that African walnut has a high potential as an antimicrobial medicinal plant for dug resistant strains; while their United States counterpart found that walnut consumption may provide the body with essential omega-3 fatty acids, antioxidants and phytosterols that reduce the risk of breast cancer.
Botanically called Tetracarpidium conophorum or Plukenetia conophora, African walnut belongs to the family Euphorbiaceae. In Nigeria, it is called asala or awusa in Yoruba; ukpa in Ibo; and okhue or okwe in Edo.
According to a study presented recently at the United States American Association for Cancer Research yearly meeting, mice fed the human equivalent of two ounces (56.7g) of walnuts per day developed fewer and smaller tumours.
Associate professor of medicine at Marshall University School of Medicine, United States, Elaine Hardman, said that while her study was done with laboratory animals rather than humans, people should heed the recommendation to eat more walnuts.
Hardman said: "Walnuts are better than cookies, French fries or potato chips when you need a snack. We know that a healthy diet overall prevents all manner of chronic diseases."
Hardman and colleagues studied mice that were fed a diet that they estimated was the human equivalent of two ounces of walnuts per day.
A separate group of mice were fed a control diet. Standard testing showed that walnut consumption significantly decreased breast tumor incidence, the number of glands with a tumour and tumour size.
"These laboratory mice typically have 100 per cent tumour incidence at five months; walnut consumption delayed those tumours by at least three weeks," said Hardman.
Molecular analysis showed that increased consumption of omega-3 fatty acids contributed to the decline in tumour incidence, but other parts of the walnut contributed as well.
"With dietary interventions you see multiple mechanisms when working with the whole food," said Hardman. "It is clear that walnuts contribute to a healthy diet that can reduce breast cancer."
The Nigerian researchers led by E. O. Ajaiyeoba and D. A. Fadare of the Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Oyo State, found that African walnut has a high potential as an antimicrobial medicinal plant. They examined the antimicrobial potential of extracts and fractions of the African walnut.
The researchers in the study published in
African Journal of Biotechnology wrote: "This is therefore improving the value of the plant. It is reported to be useful in the folklore in the treatment of dysentery. This investigation therefore justifies its
ethnomedical use, having displayed activities with the human pathogenic micro-organisms that were used in this study.
"The need for development of newer antimicrobial chemotherapeutic agents is imperative. This is because there is increasing treatment failure rates of microbial infections due
to drug-resistant antibiotics. The most active fraction in the present study, the ethyl acetate fraction of the leaf methanol extract, has a
very high potential as a source for drug discovery for antimicrobial
agents. This is being investigated by our group and the results will be
presented in due course."
According to the Medicinal Plants of Nigeria- South West Nigeria Volume 1 compiled and published by Nigeria Natural Medicine Development Agency (NNMDA), Victoria Island, Lagos, walnut seeds are used in the treatment of fibroid. The leaf juice is drunk to mitigate prolonged and /or constant hiccups. Seeds are chewed to improve spermatozoa count in men. The leaf juice is used to improve fertility in women and also to regulate menstrual flow.
In southern Nigerian ethnomedicine, African walnut is used as a male fertility agent and the leaves are used for the treatment of dysentery and to improve fertility in males. The oil from the nut has found use in the formulation of wood varnish, stand oil, vulcanised oil for rubber and leather substitute. Most of the studies on the plant have been on the nutritive value of the seeds, which is a snack and delicacy.
Walnuts are one of the best plant sources of protein. They are rich in fiber, B vitamins, magnesium, and antioxidants such as Vitamin E. Nuts in general are also high in plant sterols and fat – but mostly monounsaturated and polyunsaturated fats (omega 3 fatty acids – the good fats) that have been shown to lower LDL cholesterol. Walnuts, in particular, have significantly higher amounts of omega 3 fatty acids as compared to other nuts.
Nuts in general are high in calories, so moderation is the key. The best approach is to reap the health benefits of eating walnuts but not add excessive calories to your daily intake. Therefore, instead of just adding walnuts to your current diet, eat them in replacement of foods that are high in saturated fats (such as cheese and meat) and limit your intake of these tasty treats to the recommended 1.5 oz per day. That is about 20 walnut halves.
Walnuts add a flavourful crunch to dishes. Here are some simple ideas to incorporate walnuts in your diet:
• instead of snacking on cookies, crack some walnuts open and eat them as snacks
• instead of using meat, toss toasted walnuts in your salad or pasta to add some crunch
• instead of layering pepperoni, use chopped walnuts in your pizza
• instead of eating bacons or eggs, use walnuts as a protein choice by sprinkling chopped walnuts in your oatmeal or breakfast cereal
Through many studies performed by various research institutions all over the world, the benefits of walnuts have now been discovered. Not only has the consumption of walnuts proven beneficial in lowering cholesterol levels, they have been also noted to reduce the risk of heart disease and inflammation.
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