Wednesday, February 20, 2013

NIGERIA: Fresh Concerns Over Tainted Palm Wine

Dangerous drug, heavy metals contaminate commercial product

It is replete with yeast, vitamins C, A and B. Palm wine is used in ethno-medicine as a prophylactic against malaria and also used to increase milk flow in postpartum mothers; and a mixture with bitter leaf for treating measles, small pox and chicken pox.
But recent studies suggest that “processed” palm wine is often tainted with chemicals and heavy metals and could be one of the major causes of rising liver and kidney failures, cancers, and hypertension in the country. CHUKWUMA MUANYA writes.

 Image: Nazereth House

PALM wine is a sweet, effervescent drink obtained from the fermented sap of the tropical palm tree (Elaeis guineensis) and raphia palm trees (Raphia species). Palm wine is used in ethno-medicine as prophylactic against malaria and also used (mainly that of E. guineensis) to increase milk flow in postpartum mothers.

Medicinal herbs can be infused in palm wine to remedy a wide variety of physical complaints and are used to drink some medicines, like the exceptionally bitter ones, such as the mixture with sequestered extracts of Vernonia amygdalina (bitter leaf); the mixture is rubbed on the body together with drinking a glass daily in the course of curing measles, small pox and chicken pox.

The results of nutritional value of palm wine published in Economic Botany showed that while palm wine is an important source of nicotinic acid or niacin (the water-soluble B vitamin), and vitamin C, previous studies appear to have overestimated its value as a source of protein, thiamin, and riboflavin.

Some eye doctors and optometrists say as yeast is good for the eyes, likewise palm wine helps in enhancing sight, but with a word of caution from the World Health Organisation (WHO): Fermented palm wine should be taken with caution as it contains high quantity of alcohol which can be injurious to organs of the body like liver, kidney and eyes.
Unfermented palm wine, it was reported, contains good amount of yeast, though there are other formulated yeast tablets. It is also beneficial to the body as well.

Medical experts warn that other precautionary measures that must be observed when considering drinking palm wine to enhance the sight is that it must not be the adulterated type.

Indeed, due to its growing commercial value, palm wine has become an object of mass adulteration with saccharine and untreated water, to improve the taste, and is often tainted with salicylates and heavy metals when prepared in commercial quantities.

Several studies have linked salicylates and heavy metal poisoning to the rising incidences of organ failures such as liver and kidney, hypertension and cancers.

Saccharine is an artificial sweetener. It is used to sweeten products such as drinks.
Studies in laboratory rats during the early 1970s linked saccharine with the development of bladder cancer in rodents. As a consequence, all food containing saccharin was labeled with a warning.

However, in 2001, the United States Food and Drug Administration (FDA) and the state of California reversed their positions on saccharine, declaring it safe for consumption.
A new study published in African Journal of Food Science found traces of salicylate in samples of some of the regularly sold palm wine but not in the freshly tapped.

The study titled: “Meddling with a cultural heritage: Traces of salicylate in adulterated palm wine and health implications” was conducted by researchers from Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria; and School of Mathematics and Natural Science, Thohoyandou, Limpopo Province, South Africa.

Salicylate (Salicylic acid) a common pain reliever or an analgesic was a powder extracted from the bark of willows to treat pain and reduce fever. In the year 2004, the United States poison center reported over 40,000 exposures to salicylate-containing products. Besides the aspirin, a common source of salicylate, various other sources of salicylate poisoning are an excessive application of topical agents, ingestion of salicylate containing ointments, use of keratolytic agents or agents containing methyl salicylate. Most of these preparations are liquid, highly concentrated and lipid soluble, and, therefore, they are able to provoke a severe, rapid salicylate poisoning.

According to the study, “the toxic effects of salicylate are complex. These could be life-threatening or even lead to mortality. Ingestion of salicylic acid tablets is the most common cause of salicylate poisoning.

“In a child, moderately severe poisoning is achieved by the ingestion of 240 mg kg-1. In adults, 150 to 300 mg kg-1 is moderately toxic while greater than 500 mg kg-1 is potentially lethal. Its overdose stimulates the respiratory centre, inhibits citric acid cycle, stimulates lipid metabolism and inhibits amino acid metabolism.

“Clinical effects are nausea, vomiting, acute renal failure, gastrointestinal bleeding and epigastric discomfort. Symptoms of mild poisoning are dizziness, sweating and vomiting. Severe poisoning is characterized by respiratory alkalosis and metabolic acidosis.”
The researchers concluded: “The presence of salicylate in the regularly sold palm wine as opposed to the freshly tapped is certainly a result of adulteration of the product. To avoid salicylate poisoning and high alcohol intake, we advocate consumption of freshly tapped, unadulterated palm wine. Moreover, palm wine and some other traditionally fermented drinks have provided basic food and drink in many African countries. It is thus a commodity with economic, social and cultural value and hence should be maintained in its original unadulterated form.”

Another study published in African Journal of Biotechnology found heavy metal contamination of bottled palm wine in Benin City.

The study is titled “Some mineral profiles of fresh and bottled palm wine – a comparative study.”

The researchers from the Faculty of Science, University of Benin, Edo State concluded: “From the results obtained in this study it is clear that except for copper (Cu), all the minerals analysed were either not detected in unprocessed palm wine or were present at much lower levels than in the bottled analogues. This strongly suggests that most of these minerals might have resulted from contamination during the bottling process, most likely from the dilution water. This deduction is supported by a recent finding, which indicates that the ground water in Benin City is contaminated with unaccepted levels of lead (Pb), cadmium (Cd), chromium (Cr) and zinc (Zn).

“In addition, ground water is a major source of industrial and public water supply, not only in Benin City, but also in many parts of Nigeria. The variabilities in the levels of the various minerals may be attributable to non- uniformity in water quality among the bottling outfits, as well as likely differences in palm wine handling. In view of the toxicities of Pb and Cd, this study has underscored the need for optimum water quality in the palm wine bottling industry.”

The researchers wrote: “The World Health Organization (WHO) recommended limits for Pb and Cd in drinking water are 0.10 and 0.003 ppm, respectively. Thus the levels of these metals in some of the bottled palm wine samples are potentially toxic. Sources of human exposure to Cd include atmospheric, terrestrial and aquatic routes; as well as phosphate fertilizer. The most severe form of Cd toxicity in humans is “Itai-itai”, a disease characterized by excruciating pain in the bone.

--------------Chukwuma Muanya, Guardian, Thursday, February 21, 2013
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