Obesity has been associated with so many degenerative diseases such as diabetes, cancer, high blood pressure, kidney failure, heart attack and stroke; but recent study suggests that a meal of Ogbono soup could be the weight loss recipe the world has been waiting for. CHUKWUMA MUANYA reports.
CAN eating Ogbono soup help overweight persons shed some kilos, reduce abdominal fat, lower their cholesterol and chances of developing diabetes, heart diseases, cancer, stroke, kidney failure, high blood pressure?
A new study published last month in Lipids in Health and Disease suggests that an extract derived from the seed (Ogbono) of West African mango may help overweight people shed kilograms, lower their cholesterol and chances of developing degenerative diseases.
Researchers in other studies found that the fruit of Irvingia gabonensis could be used to reduce abdominal fat, and stop diarrhoea and ulcer.
Lab research has shown that extracts from the plant's seed may inhibit body fat production, through effects on certain genes and enzymes that regulate metabolism.
A person is said to be obese when the ratio of the weight in kilogrammes over the height in square metres, that is the Body Mass Index (BMI), is more than 30; overweight when the BMI is between 25 and 30; and healthy weight when the BMI is between 20 and 25.
The seed of Irvingia gabonensis is the basic ingredient of the popular tasty delicacy, Ogbono soup. The fruit looks like mango; but leaves a bitter after taste. The seed, slimy when it touches water, is used in cooking Ogbono soup.
Botanically called Irvingia gabonensis, West African mango or Wild mango is a fruit commonly eaten in Nigeria, and indeed the whole of West Africa. It is also called native mango, bush mango, dika nut tree, and dika bread tree.
In Nigeria, it is pekpeara in Nupe; ugiri (tree or fruit) or ogbono (kernel or seed) in Igbo; oro (the tree) or aapon (the kernel) in Yoruba; ogwi (the tree or fruit) in Benin; goron or biri in Hausa; uyo in Efik.
Irvingia gabonensis belongs to the Irvingiaceae family of plants. The tree attains a height of up to 30 meters and about 1.0 metre in girth when fully developed.
The leaves are simple and alternate, up to 10 cm long with deciduous stipples up to 1.2cm long, which leaves encircling scares on the branchlets.
Flowers are tiny, white to greenish and appear in clustered axially racemes. The flowers are very sweetly scented. The fruit is slightly flattened, ellipsoidal drops with fibrous mesocarp and stony endocarp.
In the species "gabonenesis" of Irvingia, well-defined intraspecific taxa have been recognized; thus there are: Irvingia gabonensis var. gabonensis and Irvingia gabonensis var excelsa. The pulp of the Irvingia gabonensis var excelsa is said to be eaten although it is bitter and acrid with the flavour of turpentine and slightly slimy. On the other hand, the pulp of the I. gabonensis var gabonensisis sweet, smooth in the mouth and has brittle pulp.
According to the current study, researchers at the University of Yaounde in Cameroon randomly assigned 102 overweight adults to take either the plant extract or a placebo twice a day for 10 weeks. The study participants did not follow any special diet and were told to maintain their normal exercise levels.
By the end of the study, the extract group had lost a significant amount of weight, an average of roughly 28 pounds, while the placebo group showed almost no change.
At the same time, they showed declines in "bad" Low Density Lipo-protein (LDL) cholesterol and blood sugar levels. High Density Lipo-protein (HDL) is the good cholesterol.
The study, titled "The effect of Irvingia gabonensis seeds on body weight and blood lipids of obese subjects in Cameroon," was conducted by Judith L Ngondi, Julius E. Oben, and Samuel R Minka of the Nutrition, HIV and Health Research Unit, Department of Biochemistry, Faculty of Science, University of Yaounde, Cameroon.
Dr. Julius E. Oben and his colleagues report the findings in the online journal Lipids in Health and Disease. The Fairfield, California-based Gateway Health Alliances, Inc. supplied the Irvingia gabonensis extract and partially funded the research.
The study is the first well-controlled clinical trial of the extract's effectiveness as a weight-loss aid, the researchers note. But the findings, they write, suggest that Irvingia gabonensis could offer a "useful tool" for battling the growing worldwide problem of obesity and its related ills.
A few patients on the extract reported side effects, including headaches, sleep problems and gas, but the rates were similar in the placebo group.
The findings, Oben's team concludes, should "provide impetus for much larger clinical studies."
The researchers wrote: "A recent in vitro study indicates that IGOB131, a seed extract of the traditional West African food plant Irvingia gabonensis, favourably impacts adipogenesis (the formation of fat or fatty tissue) through a variety of critical metabolic pathways.
"This current study was aimed at evaluating the effects of IGOB131 on body weight and associated metabolic parameters in overweight human volunteers. The study participants comprised of 102 healthy, overweight and/or obese volunteers randomly divided into two groups. The groups received on a daily basis, either 150 mg of IGOB131 or matching placebo in a double-blinded fashion, 30-60 minutes before lunch and dinner. At baseline, four, eight and 10 weeks of the study, subjects were evaluated for changes in anthropometrics and metabolic parameters to include fasting lipids, blood glucose, C-reactive protein, adiponectin, and leptin.
"Significant improvements in body weight, body fat, and waist circumference as well as plasma total cholesterol, LDL cholesterol, blood glucose, C-reactive protein, adiponectin and leptin levels were observed in the IGOB131 group compared with the placebo group.
"Irvingia gabonensis administered 150 mg twice daily before meals to overweight and/or obese human volunteers favourably impacts body weight and a variety of parameters characteristic of the metabolic syndrome. This is the first double blind randomised placebo controlled clinical trial regarding the anti obesity and lipid profile modulating effects of an Irvingia gabonensis extract. Irvingia gabonensis extract may prove to be a useful tool in dealing with the emerging global epidemics of obesity, hyperlipidemia, insulin resistance, and their co-morbid conditions."
Until now, dietary fibres are frequently used for the treatment of obesity. Conventional dietary and behavioural treatment have failed in long-term management. Dietary strategies used to manage obesity include the use of high fibre, low carbohydrates and fats diet.
Beneficial effect of dietary fibre in the management of obesity is not well established, since their mechanism of action is not known. The discovery of new medicinal plants has led to the creation of potential drugs that modify feeding behaviour and metabolism and may therefore have application in weight management.
In an earlier study by the researchers published in 2005, a total of 40 obese subjects aged between 19 and 55 years were selected from a group responding to a radio advertisement. After physical examination and laboratory screening tests, diabetics, pregnant and lactating women were excluded. None of these subjects took any weight reducing medication and none was following any specific diet. The purpose, nature and potential risks of the study were explained to all patients and a written informed consent was obtained before their participation. The local research ethics committee approved the experimental protocol.
The study was as a randomised, double blind placebo-controlled crossover design, and consisted of a four-week treatment period. Subjects were given two different types of capsules containing 350 mg of Irvingia gabonensis seed extract (active formulation) or oat bran (placebo). Three capsules were taken three times daily, one-half hour before meals (a total daily amount of 3.15 g of Irvingia gabonensis seed extract) with a glass of warm water. Capsules were identical in shape, colour and appearance, with neither patients nor researchers knowing what capsule they received.
During the experimental period, subjects were examined weekly, with their body weight, body fat, waist and hip circumferences recorded each time. Subjective findings such as increased or decreased appetite, feeling of lightness and gastrointestinal pains were individually noted. Side effects of the active extract, if any were also solicited and noted during each visit. The subjects were also interviewed about their physical activity and food intake during the trial, and were instructed to eat a low fat diet (1800 Kcal) as well as keep a record for seven consecutive days (using household measurements).
According to the researchers, the soluble fibre of the seed of Irvingia gabonensis like other forms of water-soluble dietary fibres, are "bulk-forming" laxatives. Irvingia gabonensis seeds delay stomach emptying, leading to a more gradual absorption of dietary sugar. "This effect can reduce the elevation of blood sugar levels that is typical after a meal."
Controlled studies have found that after-meal blood sugar levels are lower in people with diabetes given glucomannan in their food and overall diabetic control is improved with soluble fibre-enriched diets according to preliminary and controlled trials.
One double-blind study reported that glucomannan (eight-13 grams per day) stabilised blood sugar levels in people with the insulin resistance syndrome. Like other soluble fibers, Irvingia gabonensis seed fibre can bind to bile acids in the gut and carry them out of the body in the faeces, which requires the body to convert more cholesterol into bile acids. This can result in the lowering of blood cholesterol as well as other blood lipids.
Controlled double-blind studies have shown that supplementation with several grams per day of soluble fibre significantly reduced total blood cholesterol, LDL cholesterol, and triglycerides and in some cases raised HDL cholesterol, these being comparable with effects noticed with Irvingia gabonensis.
The researchers concluded: "Considering the wide use of Irvingia gabonensis in the preparation of various dishes in Cameroon, its use should be further encouraged for the purposes of control of dietary lipids as well as for weight reduction."
It has been shown that people with excessive abdominal fat (big belly) is a risk factor for heart disease, stroke, diabetes, and other serious conditions. This is because abdominal fat is one of the risk factors associated with Syndrome X (also called metabolic syndrome or pre-diabetes).
Abdominal fat is linked to leptin (an hormone) resistance. New research shows leptin's role in reducing the risk.
According to a new article published at brighthub.com, the fruit of a plant called Irvingia gabonensis may be the answer to control leptin resistance.
Leptin is an hormone that signals the brain when no more food is needed. Under regular circumstances there is a tight control of this hormone production but when things go wrong there is an over production and as with insulin resistance the body loses the ability to regulate the important functions where leptin participate (appetite suppression and fat metabolism).
According to the study, Irvingia gabonensis seem to lower the levels of CRP (C-reactive protein) in the body and hence reduce leptin resistance. A double-blind study (cited by the article) involved more than 100 overweight individuals with abdominal fat who took 150mg capsules of extract from this plant or a placebo twice a day before meals for ten weeks. The group that took the plant extract had an average weight loss of 28 pounds and their waistlines decreased by an average of 6.7 inches.
The researchers concluded: "Although more studies are needed, especially long term, it is good news that a plant may help millions of people struggling with weight problems and the health risks associated with being overweight."
Nigerian researchers have found that the crude methanol extract of Irvingia gabonensis exerts healing effects on gastrointestinal motility and indomethacin-induced gastric ulceration.
According to the study published in Pharmaceutical Biology by Y. Raji, I.A. Ogunwande, J.M. Adesola and A.F. Bolarinwa, the extract (50, 100 and 200 mg/kg, p.o.) exhibited dose-dependent inhibition of indomethacin-induced gastric ulceration that seems to be stronger than cimetidine (50 mg/kg).
The study is titled "Anti-Diarrhegenic and Anti-Ulcer Properties of Irvingia gabonensis in rats."
A significant decrease in gastric acid secretion with concomitant increase in intragastric mucous secretion was produced by the extract at all doses studied.
Gastrointestinal motility was significantly reduced in the extract-treated rats. Acute toxicity studies showed there were no deaths either 24 hours or seven days after the application of the extract up to 1600 mg/kg.
The results show that Irvingia gabonensis possesses anti-diarrhegenic and anti-ulcer properties. The anti-ulcer property probably act via a reduction in gastric acid secretion and an increase in the intragastric mucous secretion.
According to The Useful Plants of West Tropical Africa by H. M. Burkill, Irvingia gabonensis is a large tree reaching 35 metre height in the western part of West Africa, but less in the east, high buttresses, sometimes to six metre, straight bole to one metre diameter, less in the East, slightly fluted, carrying a dense compact crown, of the evergreen dense rain-forest from Senegal to West Cameroons, and widely dispersed from Sudan to Uganda and Angola. Forms are recognised by Africans.
In Liberia there are two: One small-leaved with inedible seeds, and the other larger-leafed and edible seeds. In Nigeria var. gabonensis has sweet edible fruit-pulp, and var. excelsa. It has bitter inedible pulp but is slimy and is added to soup for this quality. In Lower Dahomey, a variety with a thick edible pulp is cultivated. In Ivory Coast large-leaved and small-leaved forms are given separate vernacular names, the former being considered inedible, which differences on taxonomic standards, however, appear untenable.
Nevertheless, the distinction between edibility and inedibility is of basic pragmatic importance, and this and other distinctions recognised by countrymen in the field merit serious study to gain a proper understanding. In Igalaland (Nigeria), as no doubt elsewhere, it is considered one of the most important trees of the bush, and individual Igala lay claim to the produce of a tree by farming around it or by clearing the land beneath.
Sap-wood is light brown, and heart-wood a slightly darker or greenish-brown. The wood is very hard, and not easy to cut limiting its usefulness where only simple implements are available. It is very heavy and durable, but its weight is said to preclude it from all but the most rugged construction-work, example, for railway-ties, etc. It is immune to termite attack and is used for house-building. Canoes can be made from the trunk, and pestles for yam-mortars. There is a fine moderately close grain and a good polished finish can be achieved. It is suitable for boards, planking, ships' decking, paving blocks, and the like.
Tests for paper manufacture have shown cellulose content 48 .8 per cent, fibre length 1.5mm, and the resultant dark brown paper to be inferior, rather weak and soft, and not bleachable.The bark-slash is brown with lighter brown to orange-yellow stripes or spots. A small amount of clear sap is expissated. This is said to be sweet though the bark itself is bitter and has the usual usage of bitter barks; in Sierra Leone it is ground up with water for rubbing on to the body for pains; in Ghana it is used in an enema for an unspecified purpose; in Gabon it is added to palm-wine to increase potency, and scrapings are taken in a baked banana or prepared in enemas to relieve diarrhoea and dysenter; in Congo (Brazzaville) the bark has use in mouth-washes for toothache, pulped on sores and wounds, internally as a purgative for gastro-intestinal and liver conditions, for sterility, hernias and urethral discharge, and is considered by some to be a powerful aphrodisiac and to be beneficial in cases of senility.
Tannin has been reported present in both the bark and the roots, also a strong presence of alkaloid in the bark, though none in the roots. Root and wood extracts have proved ineffective in avian malaria, though Igbo use a leaf-decoction as a febrifuge. A wax has been extracted from the plant, which has been found useful as an adjunct in making medicinal tablets. As already indicated above, the fruit is variable, with special forms. It is the most important part of the tree. It is a drupe, resembling a mango, with a fibrous pulp surrounding the hard-shelled nut. The pulp of some trees is edible with a turpentine flavour, and of others inedible, bitter and acrid. The edible ones are a source of vitamins. In the forest, animals readily search out the fruit for the pulp, but the seed is protected by its hard endocarp. The pulp is used at Lagos to prepare a black dye for cloth.
The kernel is an important source of vegetable oil. In season, the fallen fruits are collected in the forest and stacked till the pulp has rotted away. The nuts are opened and the cotyledons removed and dried. The cotyledons are a common item of market produce and are used in soups and as a food flavouring. They are said to have a pleasant taste with a lingering slight bitterness. They are rich in oil, but there is a wide variation in quantity and composition; even so they are considered a suitable source of industrial and edible oils.
Total fat content has been recorded as 54-68 per cent and a series of five analyses from Nigeria (in brackets) and central Africa gave the following assays: lauric acid 0-39 (39) per cent; myristic 31-69 (51) per cent; oleic 0-22 (10) per cent; stearic 0-4 (0) per cent and palmitic 0-65 (0) per cent.
The principal domestic use is for the preparation of odika, or dika bread, also known as Gabon chocolate. For this the cotyledons are ground and heated in a pot, lined with banana leaves, to melt the fat, and then left to cool. The resultant grey-brown greasy mass is dika bread. It has a slightly bitter and astringent taste with a more or less aromatic odour. Pepper and other spices may be added, and it may perhaps be subjected to woodsmoke. The end product may be made up into cylindrical packets wrapped in a basket-like or leaf-wrapping. It can be kept for a long time without going off and it is used as a food-seasoner.
An alternative method of preparation, more akin to the making of vegetable butters, is to take the fresh or stored cotyledons and pound them into a paste. This can be done in quantities according to the immediate requirement. A third preparation, known in Gabon as ov�ke, is to soak the kernels for 15-20 days till soft and then to knead them by hand into a cheese-like paste. A fourth practice is known in Sierra Leone, in which the cotyledons are dried and ground to a brown 'flour' in which form it can be stored for use as an additive to food as and when required.
The crude dika paste yields on heating or boiling 70-80 per cent of a pale yellow or nearly white solid fat, dika butter, which has qualities comparable with cacao-butter, and is, in fact, a possible adulterant or substitute for the latter in chocolate manufacture. Freed from its slight odour it can also be regarded as suitable for margarine manufacture. It is also suitable for soap-making. Following processes in which the fat is removed the residual cake, rich in protein, is a cattle feed-stuff similar to copra cake.
The following composition is recorded, crude protein 31 per cent, fat 10 per cent, carbohydrate 39 per cent, fibre three per cent and ash (minerals) six per cent. In Nigeria and Cameroon the split shells of the fruit are used in divination, if one falls convex side up and the other in reverse, the omens are good.
Nt37881
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