快猫短视频

鈥淚N THE emergency room, the doctor took us aside and told us to prepare
ourselves. He said that Aaron was probably going to die. Then he added: `You do
know, Mrs Oaten, that if your son had been wearing a cycling helmet he would
almost certainly not have suffered brain damage?鈥� It was 1986. I had no idea
that Aaron should have been wearing a helmet.鈥�

Aaron survived but suffered profound brain damage that left him without
speech. Now aged 27, he is confined to a wheelchair. Rebecca Oaten has since
campaigned to raise awareness of helmet safety for cyclists in New Zealand,
where she and her son live. In 1994, the New Zealand government made helmet use
mandatory for cyclists. And this month a team of scientists from New Zealand and
Britain published the results of a study dramatically vindicating her campaign.
They conclude that the law has produced a 19 per cent drop in head injuries
among cyclists鈥攁 huge figure for safety campaigners, who struggle to shave
percentage points off accident rates.

The implication seems clear: wear a helmet and the risk of head injury
plummets, so any sensible government should make their use mandatory. Yet if the
British Medical Association is to be believed, there is another side to the
story. Had a law been in place in New Zealand at that time, Aaron would probably
have foresaken cycling鈥攁nd instead risked a heart attack in later life as
a result of his sedentary lifestyle. The BMA said as much in a report last
year.

Loopy as it sounds at first, the BMA鈥檚 argument does have some sense on its
side. Nonetheless, this stance caused a storm in public health circles. In
Britain, the government is determined to quadruple the amount of cycling by
2010, and other countries are carefully watching its example. Hospitals are
worried that if this policy succeeds they will have to deal with a corresponding
increase in head injuries and associated deaths, unless more cyclists wear
helmets.

But the BMA insists it has simply applied logic to an important public health
issue. In July 1990, after several years鈥� campaigning to raise the awareness of
cycle-helmet safety, the Australian state of Victoria made it compulsory for
cyclists to wear a helmet. According to Max Cameron, a researcher at Monash
University Accident Research Centre in Clayton, Victoria, and one of the prime
movers behind the introduction of the law, it had two major effects. The first
was a 70 per cent reduction in the number of cyclists going to hospital with
head injuries. 鈥淔rom the road safety point of view, the argument is over,鈥� says
Cameron. Other states in Australia soon followed Victoria鈥檚 lead, and helmets
are now mandatory in most of them.

But the BMA points to Cameron鈥檚 other prominent finding: a 36 per cent
reduction in the overall number of cyclists, and an even bigger drop among
teenagers. 鈥淚t was very significant,鈥� says Cameron. 鈥淲e鈥檝e been unable to secure
the funds to repeat our counts so we just don鈥檛 know whether the numbers of
teenagers ever returned.鈥�

There is no available evidence of similar drops in the numbers of cyclists in
New Zealand or in the various states in the US where certain age groups are
required to wear helmets. Nonetheless, the BMA sees the findings from Victoria
as a powerful warning. There is clear evidence that just 15 minutes鈥� cycling
every day can dramatically improve the cardiovascular system. A reduction in the
number of cyclists in Britain would be extremely worrying, the BMA believes, as
encouraging cycling is an important part of its drive to cut coronary heart
disease. Heart disease is the cause of around 22 per cent of all deaths in
Britain鈥攁 toll that dwarfs cycling-related fatalities.

Vivienne Nathanson, who is responsible for science ethics and health policy
at the BMA, says that it came to its decision by balancing the risks of head
injury against the increased levels of heart disease that a mandatory helmet law
would cause. But this logic has stunned many public health experts, including
Robert Ekman of the Swedish Bicycle Helmet Initiative. 鈥淭he assumption is that
if people don鈥檛 cycle, they don鈥檛 do anything,鈥� he says. 鈥淏ut how does the BMA
know this? There is plenty of other exercise people can do.鈥� Even Nathanson
accepts that there is no research linking a fall in the number of cyclists with
increased cardiovascular disease. If other evidence came to light the BMA would
take note, she says 鈥淲e鈥檙e not closed-minded on this issue.鈥�

Dorothy Robinson, a statistician at the University of New England, New South
Wales, also casts doubt on the importance of helmets. Safety experts expected
that when helmet use became mandatory in Victoria there would be an immediate
and substantial increase in the number of cyclists wearing them, and this should
have resulted in a correspondingly sudden drop in the number of serious head
injuries. But instead the the study shows a steady decline. 鈥淪omething else must
be responsible鈥攑erhaps better driving,鈥� says Robinson.

Researchers on both sides of the debate agree that good data is hard to come
by. Even counting the number of cyclists is a difficult task. The studies have
to be done on the same day of the week, at the same time in the same season, and
even then the rates vary according to the weather. 鈥淐ycle studies are
notoriously difficult to do,鈥� admits Cameron.

The difficulty of obtaining and handling data, and then distinguishing
between good and bad results, is common to many areas of public health research.
To tackle this problem researchers set up the Cochrane Collaboration, an
international organisation that assesses healthcare studies according to strict
criteria, collates those that measure up, and publishes a report of the results.
Its review of helmet safety, published last year, came to a clear conclusion:
鈥淗elmets reduce bicycle-related head and facial injuries for bicyclists of all
ages involved in all types of crashes, including those involving motor
vehicles,鈥� it says.

Diane Thompson, a researcher at the Harborview Injury Prevention and Research
Center in Seattle, and one of the authors of the Cochrane Collaboration鈥檚
review, likens the debate to the one that raged over lung cancer in the 1970s
and 80s. 鈥淭here were numerous papers showing the link between cancer and
smoking, but the tobacco companies were always able to pounce on the one or two
studies that showed no correlation.鈥� The BMA is unlikely to relish being
compared to tobacco barons in this way.

Thompson wants to see helmet-wearing eventually made mandatory, but admits
that laws can鈥檛 be implemented from a standing start. Only when a relatively
large proportion of cyclists use helmets voluntarily will it be possible to
enforce such as law. In Britain, car drivers were only compelled to wear seat
belts after years of campaigns promoting their use. A pitifully low 18 per cent
of British cyclists wear helmets at present, so there鈥檚 a lot of educational
work still to do. The Bicycle Helmet Initiative Trust, based in Reading, says it
has had significant local success in its efforts to increase this figure. But
while the government supports the trust, it does not back a cycle helmet
law.

For Rebecca Oaten, though, the issue is clear-cut. 鈥淢y son鈥檚 life has been
ruined by brain damage that a helmet law could have prevented. It just breaks my
heart to think that others might have to go through the same suffering.鈥�