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Press releases Saturday 22 December 2007

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(1) Top doctors call for tougher measures to reduce alcohol related harm
(2) Marathons cut risk of fatal vehicle crashes
(3) High altitude football teams have significant advantage over lowland teams
(4) Active computer games no substitute for playing real sports
(5) Airport security measures not backed by solid evidence
(6) Many common medical beliefs are untrue
(7) New slang words doctors use
(8) Humour develops from aggression caused by male hormones

Also in this week's Christmas issue of the BMJ ...
Chocolate industry delivers major blow for medicine
Using chocolate bars to explain bone structure not justified
Are magical powers inherited?
Champagne: the safer choice for celebrations
Should hospitals restrict visitors?

Doctors writing in this week's Christmas issue of the BMJ call on the government to introduce tougher measures to reduce alcohol related harm.

Ian Gilmore, President of the Royal College of Physicians and Nick Sheron, a liver specialist at Southampton University Hospital argue that measures favoured by the government and the alcohol industry - namely education and public information - have not generally been shown to change drinking behaviour or to reduce harm.

Instead proven measures, such as increasing the price of alcohol, banning alcohol advertising, and reducing the availability of alcohol, should be considered.

Alcohol is certainly a major health problem, they write. The Cabinet Office reported up to 150,000 hospital admissions and 15-22,000 deaths overall in 2003, with an 18% increase in deaths directly attributable to alcohol between 2002 and 2005, and more people dying from alcohol related causes than from breast and cervical cancer, and MRSA combined.

So do we have a duty to seek to reduce the health burden to society from alcohol or is this giving in to the 'nanny state' they ask?

They point out that damage to third parties from exposure to alcohol misuse dwarfs that from smoking. For example, drinking alcohol is a factor in over half of violent crimes and one third of domestic violence.

Furthermore, evidence shows that the most effective and cost effective measure is to increase the price of alcohol. Between 1980 and 2003 the price of alcohol increased by 24%, but disposable income increased by 91%, making alcohol 54% more affordable in 2003 than in 1980.

To suggest, as producers and retailers do, that increasing the price of alcohol would not reduce alcohol related harm goes against not only the evidence but also the fundamental principles of marketing, they argue.

Banning alcohol advertising and restricting opportunities to purchase alcohol are also effective, although less so than tax and early intervention, as has been the case with smoking. One wonders, conclude the authors, how many more lives will be damaged by alcohol in the UK before our Governments decide to tackle the problem with measures that are likely to work.

Another article in this week's Christmas issue of the BMJ reveals that the ancient Greeks had a sophisticated understanding of the effects of alcohol, both in moderation and excess.

Contact:
Ian Gilmore, President of the Royal College of Physicians, London, UK
Email: ian.gilmore@rcplondon.ac.uk  

(2) Marathons cut risk of fatal vehicle crashes
(Competing risks of mortality with marathons: retrospective analysis)
http://www.bmj.com/cgi/content/short/335/7633/1275

Organised marathons are not associated with an increased risk of sudden death, despite the media attention they attract. In fact, marathons lower the risk of fatal motor vehicle crashes that might otherwise have taken place if the roads had not been closed, finds a study in this week's Christmas issue of the BMJ.

Millions of people take part in organised sporting events on a regular basis, yet the outcome for a few participants is sudden death. These deaths attract widespread media attention, such as the high publicity given to deaths that occur in marathon runners.

In contrast, sudden deaths from motor vehicle crashes occur more than a hundred times each day in the United States alone and tend to be under-reported in the media. Yet no previous study has explored the extent to which marathons might actually decrease mortality.

So researchers examined marathons throughout the US to test whether the total number of sudden deaths changed when roads were closed to traffic and opened to marathon running.

They randomly selected 26 established marathons involving more than 3 million participants over a period of 30 years. Each marathon had at least 1,000 participants and took place on United States roadways from 1975 to 2004. Sudden cardiac deaths following each marathon were recorded and compared to motor vehicle deaths during the same hours one week before and one week after each marathon.

The same comparisons were then replicated for state counties that were outside the marathon route to check for spillover in traffic flow.

Over the 30 years there were 26 sudden cardiac deaths, equivalent to a rate of 0.8 per 100,000 participants or about two deaths per million hours of exercise. But because of road closure, 46 motor vehicle fatalities were prevented, equivalent to almost two lives saved that would have otherwise occurred.

The reduced risk could not be explained by re-routing traffic to other regions or days and was consistent across different parts of the country, decades of the century, seasons of the year, days of the week, and race characteristics.

The data show that the final 1.6 km of the marathon accounts for almost half of the sudden cardiac deaths, so the authors suggest the last half of the marathon (and the last 1.6 km in particular) is the priority for paramedic staffing and ambulance preparedness.

The results also indicate that, for participants, the final sprint with sudden cessation may be more dangerous than generally realised, they conclude.

Contact:
Professor Donald Redelmeier, Department of Medicine, University of Toronto, Ontario, Canada 
Email: laura.bristow@sunnybrook.ca 

(3) High altitude football teams have significant advantage over lowland teams
(Altitude and athletic performance: statistical analysis using football results)
http://www.bmj.com/cgi/content/short/335/7633/1278

Football teams from high altitude countries have a significant advantage when playing at both low and high altitudes, finds a study in this week's Christmas issue of the BMJ.

In contrast, lowland teams are unable to acclimatise to high altitude, reducing physiological performance.

At altitude, lack of oxygen (hypoxia), cold and dehydration can lead to breathlessness, headaches, nausea, dizziness and fatigue, and possibly altitude sickness. Activities such as football can make symptoms worse, preventing players from performing at full capacity.

In May 2007, football's governing body, the Federation of International Football Associations (FIFA), banned international matches from being played at more than 2500 m above sea level. So Patrick McSharry, a research fellow at the University of Oxford, set out to assess the effect of altitude on match results and physiological performance of a large and diverse sample of professional footballers.

He analysed the scores and results of 1,460 international football matches played at different altitudes in 10 countries in South America spanning over 100 years.

Four variables were used to calculate the effect of altitude and to control for differences in team ability (probability of a win, goals scored and conceded, and altitude difference between home and away team venues).

Altitude difference had a significant negative impact on performance. High altitude teams scored more and conceded fewer goals as altitude difference increased. Each additional 1,000m of altitude difference increased the goal difference by about half of a goal.

For example, in the case of two teams from the same altitude, the probability of the home team winning is 0.537. This rises to 0.825 for an altitude difference of 3,695m (such as high altitude Bolivia versus a sea level opponent Brazil) and falls to 0.213 when the altitude difference is -3,695m (Brazil versus Bolivia).

The surprising result is that the high altitude teams also had an advantage when playing at low altitude, so benefiting from a significant advantage over their low altitude opponents at all locations.

There is still some debate over the best strategy for low altitude teams to employ when playing at high altitude to deal with this disadvantage.

He suggests that assessing individual susceptibility to altitude illness would facilitate team selection.

Contact:
Patrick McSharry, Research Fellow, Systems Analysis, Modelling & Prediction, Department of Engineering Science, University of Oxford, UK  
Email: patrick@mcsharry.net 

(4) Active computer games no substitute for playing real sports
(Energy expenditure in adolescents playing new generation computer games)
http://www.bmj.com/cgi/content/short/335/7633/1282

New generation active computer games stimulate greater energy expenditure than sedentary games, but are no substitute for playing real sports, according to a study in this week's Christmas issue of the BMJ.

Young people are currently recommended to take an hour of moderate to vigorous physical exercise each day, which should use at least three times as much energy as is used at rest. But many adolescents have mostly sedentary lifestyles.

Time spent in front of television and computer screens has been linked to physical inactivity and obesity.

The new generation of wireless based computer games is meant to stimulate greater interaction and movement during play, so researchers at Liverpool John Moore's University compared the energy expenditure of adolescents when playing sedentary and new generation active computer games.

Six boys and five girls aged 13-15 years were included in the study. All were a healthy weight, competent at sport and regularly played sedentary computer games.

Before the study, each participant practiced playing both the active and inactive games.

On the day of the study, participants played four computer games for 15 minutes each while wearing a monitoring device to record energy expenditure.

The participants first played on the inactive Project Gotham Racing 3 game (XBOX 360). After a five minute rest, they then played competitive bowling, tennis and boxing matches (Nintendo Wii Sports) for 15 minutes each with a five minute rest between sports. Total playing time for each child was 60 minutes.

Energy expenditure was increased by 60 kcal per hour during active compared with sedentary gaming.

However, energy expenditure during active gaming was much lower than authentic bowling, tennis and boxing, and was not intense enough to contribute towards the recommended amount of daily physical activity for children.

When translated to a typical week of computer play for these participants, active rather than passive gaming would increase total energy expenditure by less than 2%.

Contacts:
Gareth Stratton, Professor of Paediatric Exercise Science, Liverpool John Moore's University, Liverpool, UK  
Email: g.stratton@ljmu.ac.uk 
or:
Professor Tim Cable, Liverpool John Moore's University, Liverpool, UK  
Email: t.cable@ljmu.ac.uk 

(5) Airport security measures not backed by solid evidence
(Did you pack your bags yourself?)
http://www.bmj.com/cgi/content/short/335/7633/1290

There is no solid evidence that the huge amounts of money spent on airport security screening measures since September 11th are effective, argue researchers in this week's Christmas issue of the BMJ.

Most screening programmes around the world are closely evaluated and heavily regulated before implementation. They rely on sound scientific and cost-benefit evidence before they are put into practice. Is airport security screening an exception, ask Eleni Linos and colleagues?

They reviewed evidence for the effectiveness of airport security screening measures, comparing it to the evidence required by the UK National Screening Committee criteria to justify medical screening programmes.

Despite worldwide airport protection costing an estimated $5.6 billion every year, they found no comprehensive studies evaluating the effectiveness of passenger or hand luggage x-ray screening, metal detectors or explosive detection devices. There was also no clear evidence of testing accuracy.

The US Transportation Security Administration (TSA) defends its measures by reporting that more than 13 million prohibited items were intercepted in one year. But, argue the authors, there is no way of knowing what proportion of these items would have led to serious harm.

This raises several questions, they say, such as what is the sensitivity of the screening question: 'Did you pack all your bags yourself?' and has anyone ever said 'no'? What are the ethical implications of pre-selecting high risk groups? Are new technologies that 'see' through clothes acceptable and what hazards should we screen for?

While there may be other benefits to rigorous airport screening, the absence of publicly available evidence to satisfy even the most basic criteria of a good screening programme concerns us, they write.

They call for airport security screening to be open to public and academic debate. Rigorously evaluating the current system is only the first step for building a future airport security programme that is more user-friendly, cost-effective and, ultimately, protects passengers from realistic threats, they conclude.

Contact:
Eleni Linos, Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA  
Email: elinos@hsph.harvard.edu 

(6) Many common medical beliefs are untrue
(Medical myths)
http://www.bmj.com/cgi/content/short/335/7633/1288

• Should we drink at least eight glasses of water a day?
• Does shaving hair cause it to grow back faster or coarser?
• Does reading in dim light ruin your eyesight?

These are just some of the common medical myths that are unproven or untrue, according to a study in this week's Christmas issue of the BMJ.

Researchers in the United States selected seven medical beliefs, espoused by both physicians and members of the general public, for critical review. They then searched for evidence to support or refute each of these claims.

The quality of evidence was taken into account and instances in which no evidence supported the claim were noted.

The results show that all of these medical beliefs range from unproven to untrue. For example, they found no evidence supporting the need to drink eight glasses of water a day. In fact, studies suggest that adequate fluid intake is often met by the consumption of juice, milk, and even caffeinated beverages. Clinical evidence also points to the dangers of drinking excessive amounts of water.

The belief that we only use ten percent of our brains is refuted by studies of patients with brain damage, which suggest that damage to almost any area of the brain has specific and lasting effects on mental, vegetative, and behavioural capabilities, say the authors. Brain imaging studies also show that no area of the brain is completely silent or inactive.

The belief that hair and fingernails continue to grow after death may be an optical illusion caused by retraction of the skin after death, they add. The actual growth of hair and nails requires a complex interplay of hormonal regulation not present after death.

Again, illusion may be to blame for the belief that shaving hair causes it to grow back faster, darker, and coarser, they say. The stubble resulting from shaving grows out without the finer taper seen at the ends of unshaven hair, giving the impression of thickness and coarseness.

Finally, expert opinion is that reading in dim light does not damage your eyes, and there is little evidence to support beliefs such as banning mobile phones from hospitals on the basis of electromagnetic interference.

Despite their popularity, all of these medical beliefs range from unproven to untrue, say the authors. They suggest that physicians should constantly evaluate the validity of their knowledge.

Contact:
Rachel Vreeman, Research Fellow, Children's Health Services Research, Indiana University School of Medicine, Indianapolis, USA  
Email: rvreeman@iupui.edu 

(7) New slang words doctors use
(Pimp my slang)
http://www.bmj.com/cgi/content/short/335/7633/1295

Medical language and slang is constantly evolving and this week's Christmas issue of the BMJ takes a look at the new words hospital doctors are using on the wards. Dr Paul Keeley, a consultant in palliative medicine lists the following words, and others, as ones which doctors would do well to familiarise themselves with: Disco biscuits: otherwise known as the class A drug, ecstasy. The phrase might be used by an A&E doctor, for example, "the man in cubicle three looks like he's taken one too many disco biscuits." MacTilt: The tilting of the head by a Macmillan nurse, a specialist palliative care nurse. It is intended to convey sympathy and understanding. Hasselhoff: An injury with a bizarre explanation presenting to Accident and Emergency. Named after the former Baywatch actor David Hasselhoff who suffered a freak injury in 2006 when he hit his head on a chandelier while shaving. The broken glass severed four tendons and an artery in his right arm. Testiculation: The holding forth with expressive hand gestures by a consultant on a subject on which he or she has little knowledge. Blamestorming: A session of mutual recrimination during which a multidisciplinary team attempts to apportion blame for a glaring error. Agnostication: The (usually vain) attempt to answer the question, "How long have I got, doc?"

Contact:
Dr Paul Keeley, Consultant in Palliative Medicine, Glasgow Royal Infirmary, Glasgow, Scotland  
Email: paul.keeley@northglasgow.scot.nhs.uk 

(8) Humour develops from aggression caused by male hormones
(Sex, aggression and humour: responses to unicycling)
http://www.bmj.com/cgi/content/short/335/7633/1320

Humour appears to develop from aggression caused by male hormones, according to a study published in this week's Christmas issue of the BMJ.

Professor Sam Shuster conducted a year long study observing how people reacted to him as he unicycled through the streets of Newcastle upon Tyne. What began as a hobby turned into an observational study after he realized that the huge number of stereotypical and predictable responses he received must be indicative of an underlying biological phenomenon.

The study was an observation of people's reactions to a sudden unexpected exposure to a new phenomenon - in this case unicycling, which at the time few had seen. He documented the responses of over 400 individuals, and observed the responses of many others.

Over 90% of people responded physically, for example with an exaggerated stare or a wave. Almost half responded verbally - more men than women. Here, says Professor Shuster, the sex difference was striking. 95% of adult women were praising, encouraging or showed concern. There were very few comic or snide remarks. In contrast, only 25% of adult men responded as did the women, for example, by praise or encouragement; instead 75% attempted comedy, often snide or combative as an intended put-down.

Equally striking, he says, was the repetitive and predictable nature of the comments from men; two thirds of their 'comic' responses referred to the number of wheels - "Lost your wheel?", for example.

Professor Shuster also noticed the male response differed markedly with age, moving from curiosity in childhood (years 5-12) - the same reaction as young girls, - to physical and verbal aggression in boys aged 11-13 who often tried to get him to fall off the unicycle.

Responses became more verbal during the later teens, turning into disparaging 'jokes' or mocking songs. This then evolved into adult male humour - characterized by repetitive, humorous verbal put-downs concealing a latent aggression. Young men in cars were particularly aggressive. Professor Shuster notes that this is the age when men are at the peak of their virility. The 'jokes' were lost with age as older men responded more neutrally and amicably with few attempts at a jovial put-down.

The female response by contrast, was subdued during puberty and late teens - normally either apparent indifference or minimal approval. It then evolved into the laudatory and concerned adult female response.

The idea that unicycling is intrinsically funny does not explain the findings, says Professor Shuster, particularly the repetitiveness, evolution and sex differences. Genetics may explain the sex difference but not the waxing and waning of the male response.

He says the simplest explanation for this change is the effect of male hormones such as testosterone, known collectively as androgens, which induce virility in men.

Particularly interesting for the evolution of humour is, he says, the observations that initial aggressive intent seems to become channeled into a verbal response which pushes it into a contrived, but more subtle and sophisticated joke, so the aggression is hidden by wit. The two then eventually split as the wit takes on an independent life of its own.

Contact:
Professor Sam Shuster, Honorary Consultant, Department of Dermatology, Norfolk and Norwich University Hospital, University of East Anglia. 
Email: sam@shuster.eclipse.co.uk 

Also in this week's Christmas issue of the BMJ ... (9) Chocolate industry delivers major blow for medicine
http://www.bmj.com/cgi/content/full/335/7633/1287
In 2001, the BMJ reported that two chocolates in the Celebrations assortment (Teasers and Truffles, Masterfoods UK) could be used to accurately assess testicular volume. Once a boy's testicle is the size of a Teaser, it can be safely assumed he has embarked on puberty. But now the manufacturer has changed the shape of both these chocolates. This is a major setback for paediatric endocrinology, say the researchers, and they call for the original design to be reinstated.

(10) Using chocolate bars to explain bone structure not justified
http://www.bmj.com/cgi/content/full/335/7633/1285
Doctors often use the finely honeycombed structure of a Crunchie (Cadbury Trebor Bassett) chocolate bar to illustrate healthy bone and use the coarser structure of an Aero (Nestle UK) chocolate bar to illustrate abnormal osteoporotic bone. But researchers show that a Crunchie is more likely to fracture than an Aero. They suggest that using chocolate bars to explain bone structure to patients oversimplifies the situation.

(11) Are magical powers inherited?
http://www.bmj.com/cgi/content/full/335/7633/1299
An analysis of the Harry Potter novels of J K Rowling suggests that magic shows strong evidence of heritability. Specific magical gifts, such as the ability to speak to snakes, predict the future, and change hair colour, all appear heritable.

(12) Champagne: the safer choice for celebrations
http://www.bmj.com/cgi/content/full/335/7633/1281
Champagne, not beer, should be the celebratory beverage of choice for celebrations, says a doctor after treating an Australian Rules football player who inadvertently swallowed a beer bottle cap while celebrating his team's victory.

(13) Should hospitals restrict visitors?
http://www.bmj.com/cgi/content/full/335/7633/1316
Following reports of a hospital banning children from visiting their sick parents at Christmas over fears of infections, two doctors take a historical look at hospital visiting policies and discuss what might be considered the optimal pattern of visiting.

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