The Pharmaceutical Journal
Vol 272 No 7286 p196
14 February 2004

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Exploring Atlas's kingdom more
Beating bitterness more
Cannabis confusion more
Using exercise to ward off childhood obesity more

Exploring Atlas's kingdom

The ancient Greeks told strange tales of an island kingdom far out in the Atlantic Ocean. They called it Atlantis, after the Titan Atlas, who was reputed to rule over it. Plato in the fourth century BC was the chief source for the story, which was claimed to have been transmitted originally from Egyptian priests.

When the Athenians subdued the rulers of Atlantis, the island sank below the waves after violent earthquakes and floods had destroyed its inhabitants. Ever since, legends have abounded as to the exact whereabouts of the island, and controversy over this has raged since about 300BC. Modern speculation points to a massive eruption of a volcano on the island of Santorini in the late Bronze Age as the incident that provoked the Atlantis legend.

Now a team of underwater archaeologists from the University of Aix-en-Provence, led by Jacques Collina-Girard, is planning an exploration designed to determine whether an island called Spartel, west of the Strait of Gibraltar, holds the secrets of Atlantis. Reconstruction of the map of the western European coastline some 19 millennia ago, when the sea level was 130m lower than at present, indicated an archipelago that once occupied the spot. Evidence from local coral reefs suggested a rapid rise in sea level about the time stated by Plato.

Three archaeologists will explore the area in a manned submersible, paying particular attention to a hilly area lying between 55m and 200m below the surface. Sonar analysis and dating of sediment samples will be used in the investigation. If submerged caves can be discovered, sediments within them might reveal flint tools that will enable archaeologists to date the associated civilisation.

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Beating bitterness

The processing of food has a tendency to intensify any bitterness naturally present, and food manufacturers have therefore taken great pains to mask this bitterness by adding substantial quantities of sugar, salt and fats. Such additives are not calculated to improve health prospects, and an alternative method for reducing bitterness has been sought.

The development of bitter taste in a processed food depends upon a series of biochemical reactions on the part of the consumer. When the taste receptor cells in the mouth respond to bitterness they do so by releasing the protein gustducin, which then triggers a chain of reactions. It has been found during experiments at Rutgers University, Hew Jersey, that adenosine monophosphate in low concentration will bind preferentially to taste receptors and displace bitter substances ingested, so that gustducin release is prevented. When added to a food in a concentrations of some 400 parts per million, adenosine monophosphate is capable of preventing excessive bitter perception.

The bitter blocker has been cleared for use in the United States, and the way seems open for new and more powerful compounds to be developed. Their effect is not only to reduce bitterness but also to improve the taste of such commodities as roasted coffee and citrus fruits. The technique might prove useful in formulating some pharmaceutical preparations such as cough and cold remedies and drugs used to treat gastrointestinal ulceration.

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Cannabis confusion

Cannabis has now been reclassified in the UK from a class B to a class C Controlled Drug. With all the vague sequelae which that this relaxation of control has produced in terms of legal penalties, it is not surprising that attention has once again been directed to its possible virtues and its probable vices. The problem of cannabis has seen the publication of many books from 1938 to the present, none of them able to produce a definitive picture of the balance between therapeutic value and hazards.

In The Lancet for 31 January there is a commentary by David Sharp illustrating the complexity. The inconsistency and confusion of legislators, he writes, is seen on a global scale. Policies range from benign acceptance in the Netherlands to zero tolerance in Sweden. The UK practises nervous liberalisation. The US prescribes severe punishments.

The chemical complexity of cannabis makes it difficult to evaluate its possible value in the management of pain and multiple sclerosis, which is fiercely debated. Unfortunately there is some evidence of an association between cannabis consumption and the onset of schizophrenia, which has to be resolved in one way or another.

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Using exercise to ward off childhood obesity

In the 17 January issue of The Lancet there is a report of a measurement of total energy expenditure and physical activity in young children in Glasgow, which aims at developing a strategy for preventing further increases in childhood obesity and all the health-related hazards this involves. The authors of the report, from Glasgow and Aberdeen, stress that in recent years the prevalence of obesity among young children in the UK has increased strikingly, though not to the alarming extent that has been witnessed in the US. Public health authorities must make moves that will encourage an increase in physical activity, a reduction of sedentary behaviour, or both, in early life.

Investigations have indicated that young children typically spend only 20–25 minutes a day in moderate to vigorous physical activity, whereas present recommendations call for at least 60 minutes daily. The researchers measured total energy expenditure, physical activity and sedentary behaviour were measured in children aged three, and again when they were aged five.

The study found that the ratio of total to resting energy expenditure was 1.56 at age 3 and 1.61 at age 5. Moderate to vigorous physical activity was only 2 per cent of monitored time at age 3 and 4 per cent at age 5.

In a commentary on the results, in the same issue of the journal, James Hill, a nutritionist from Denver, US, states that it is extremely difficult, if not impossible, to maintain a healthy bodyweight when the level of physical activity is low. The modern environment encourages inactivity, to which children are not immune. Technological advances have eliminated many reasons for physical exertion.

Obesity is not solely the result of low activity, Hill writes, but arises rather from an imbalance between energy intake and energy expenditure, so that, to avoid obesity, a sedentary individual must also maintain a low energy intake.

Most people find it difficult to eat less, especially in an environment where tasty, convenient and inexpensive food is available. However, excessive gain in weight may be avoided by small changes in behaviour. Walking 2,000 additional steps daily and cutting energy intake by 100kcal daily could make all the difference. Such moves would be far easier than treating obesity once it is established.

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