Pesquisadores ingleses da Universidade de Oxford avaliaram 431 peças publicitárias de 104 diferentes produtos voltados ao esporte nos melhores magazines de esporte da Inglaterra e dos EUA. Os resultados apontaram que menos de 3% delas tinham respaldo científico. Além de uma constatação de informações duvidosas, o estudo dá uma espetada na autoridade de segurança alimentar européia, correspondente à ANVISA aqui no Brasil, órgão que regula esse tipo de publicidade. Os resultados da pesquisa foram publicados no British Medical Journal esta semana e esse também foi o conteúdo de um programa veiculado ontem pela BBC com o título “A Verdade dos Produtos Esportivos”.
Anúncios de distribuidores não foram incluídos, mas apenas os de fabricantes de produtos, como isotônicos, suplementos alimentares e acessórios esportivos. As empresas foram questionadas por email quanto às referências científicas que justificavam os anúncios de melhora de desempenho ou prevenção de condições clínicas com o produto.
Muitas empresas não tinham mesmo qualquer tipo de referência para apresentar, outras apresentavam, mas com evidências que não justificavam os anúncios, e apenas uma minoria de 2.7% tinha embasamento científico satisfatório de acordo com critérios objetivos baseados no Centro de Medicina Baseada em Evidências. Os resultados ainda mostraram que a maior parte das pesquisas que investigavam a eficácia desses produtos era patrocinada pelas próprias empresas interessadas.
Elenco abaixo alguns pontos que foram alvo de críticas por uma série de experts em medicina do esporte e publicados em outros sete artigos na última edição do British Medical Journal :
* promessas dos isotônicos – para o atleta de elite, esses produtos podem fazer a diferença, especialmente em provas de longa duração. Entretanto, para maioria dos que praticam atividade física de forma amadora, água é o suficiente e é bom lembrar que muitos dos isotônicos estão cheios de calorias. Existe um apelo de que os isotônicos têm menor risco de queda dos níveis de sódio, mas o que temos de evidências é de que qualquer líquido em excesso pode provocar essa condição clínica chamada de hiponatremia. Além disso, não custa lembrar que o corpo saudável tem um mecanismo preciso de controle dos níveis de eletrólitos no sangue e não é qualquer corridinha que é capaz de driblá-lo;
* outros “movimentos isotônicos” – a bebida oficial da Olimpíada de 2012 é o isotônico Powerade da Coca-Cola com a chamada “Ajuda a manter a resistência”. A gigante GlaxoSmithKline tem um programa de pesquisa com voluntários de 11 a 14 anos de idade para avaliar as vantagens de isotônicos sobre a água;
* hidratar muito antes mesmo de sentir sede – o excesso de hidratação tem suas repercussões negativas, assim como a desidratação. Beber à medida que se tem sede pode ser a melhor opção já que a sede é o melhor alarme que o corpo está precisando de hidratação;
* tênis especiais para cada tipo de pisada – o que faz mesmo diferença na incidência de lesões é a intensidade e tempo de treino/prova assim como o intervalo de recuperação. O tipo de tênis tem um valor irrisório, é o que aponta recente e maior pesquisa realizada sobre o tema;
* shakes de proteína – forma cara de tomar um copo de leite;
Por enquanto, o que a ciência endossa é que devemos nos exercitar regularmente, e se for com o pé no chão, que seja com um tênis confortável. Garantir também uma dieta balanceada e hidratação com água.
2 comentários
25 julho, 2012 às 9:46 pm
Angelita
Olá Ricardo,
Pode me dizer qual o artigo sobre os tênis específicos para cada tipo de pisada?
Desde já, agradeço. Abraço.
29 julho, 2012 às 5:26 pm
Ricardo Teixeira
Oi Angelita
Esta revisão Cochrane faz um apanhado das intervenções http://www.ncbi.nlm.nih.gov/pubmed/21735382
Veja tbem o press release do BMJ
Panorama Press Release “Striking lack of evidence” to back up claims for
popular sports brands
“Striking lack of evidence” to back up claims for popular sports brands
With the biggest sporting event in the world just a week away, a joint
investigation by the BMJ and BBC Panorama has found that there is “a
striking lack of evidence” to support claims about improved performance and
recovery for many sports products like drinks, trainers and protein shakes.
The investigation reveals new research carried out by the Oxford Centre for
Evidence Based Medicine and the BMJ, and published in the online journal
BMJ Open. It concludes that no sound evidence could be found to support
claims made by some of sport’s biggest brands and that it is “virtually
impossible for the public to make informed choices about the benefits and
harms of advertised sports products.”
The findings are also highly critical of the methods used by the European
Food Safety Authority (EFSA) to regulate these marketing claims. Dr Matthew
Thompson, Senior Clinical Scientist at Oxford University’s Department of
Primary Health Care Sciences, told the Panorama investigation these methods
are based on “very meagre” research, supplied largely by manufacturers
themselves. He would like to see “a more scientific and rigorous approach”
to assessing the basis of food claims in Europe.
Their findings are part of a joint investigation by the BMJ and BBC
Panorama which tests the science behind the marketing hype of this
multibillion-dollar industry and suggests we could be wasting our money on
these products.
Full details will be published on bmj.com and broadcast on Panorama “The
Truth About Sports Products” on Thursday 19 July at 8pm on BBC One.
The investigation also explores the role of sports drinks companies in the
“science of hydration” and questions their links with some of the world’s
most influential sports bodies in a bid to gain public trust in their
products and persuade ordinary people they need more than water when they
exercise.
But Arthur Siegel, Associate Professor of Medicine at Harvard University,
says we are being misled about the dangers of dehydration and industry
advice to “stay ahead of thirst” when, in fact, drinking too much of any
liquid can be fatal.
A team at Oxford University tested the evidence behind 431
performance-enhancing claims in adverts for 104 different sports products
including sports drinks, protein shakes and trainers.
If the evidence wasn’t clear from the ads, they contacted the companies for
more information. Some, like Puma, did not provide any evidence, while
others like GlaxoSmithKline – makers of Lucozade Sport – provided 174
studies.
Yet only three (2.7%) of the studies the team was able to assess were
judged to be of high quality and at low risk of bias. They say this absence
of high-quality evidence is “worrying” and call for better research in this
area to help inform decisions.
Many top sports scientists support this view. Professor Tim Noakes from the
University of Cape Town says that while sports drinks may be helpful for
elite athletes, the drinks companies rarely study ordinary gym goers. Many
also contain high levels of sugar.
Yet sports drinks like Lucozade, made by GlaxoSmithKline, and Powerade,
made by Coca Cola – the official drink of the 2012 Olympics – are sold in
supermarkets and will soon have the European stamp of approval that they
“help maintain endurance performance.”
GlaxoSmithKline also runs a school science programme, aimed at 11-14 year
olds, looking at things like the advantages of sports drinks over water, as
part of its involvement in the Olympic anti-doping operations.
Dr Matthew Thompson from the Oxford team is also concerned about rising
levels of obesity among children and young people. He says anything that
suggests sports drinks are good for us “could completely counteract
exercising more, playing football more, going to the gym more.”
But not only is industry telling us we need specially formulated drinks to
exercise, it is also telling us how to drink, with advice like “stay ahead
of your thirst” when the evidence suggests it’s best to drink when you’re
thirsty.
Some manufacturers have even suggested that sports drinks can protect
against the effects of hyponatremia (a drop in the body’s salt levels
caused by over-drinking) when experts are clear that drinking too much of
any liquid can be dangerous.
The Oxford team were also unable to find good quality evidence to support
claims that special trainers reduce injury, although for decades the
industry focus has been on creating specialised shoes which aim to reduce
the risk of injury by cushioning against impact and controlling pronation –
guidance which the NHS supports.
Sports injury expert, Professor Irene Davis of Harvard University argues
that “there is no evidence for prescribing [tailored] footwear”. This view
is supported by evidence from a recent study by the US military – the
biggest sports footwear study of its kind. Soldiers were divided into two
groups – one of which was prescribed neutral shoes and the other received
shoes tailored for their feet. “They found absolutely no difference
between the groups in terms of injury patterns”, says Professor Davis.
Benno Nigg, a leading expert in the biomechanics of running shoes who has
worked with the major sports brands for over four decades, also told
Panorama that his recent research confirms that “the most important
predictors for injuries are distance, recovery time, intensity and those
type of things.” Shoes, he says, are “minor contributors.”
Similarly, Carl Heneghan, who led the research team at Oxford Univeristy
found “no evidence” to support claims that protein shakes or supplements
boost performance and recovery any more so than eating a diet that’s rich
in protein and carbohydrates. Nutritionist, Professor Mike Lean describes
protein shakes as “a rather expensive way of getting a bit of milk.”
“These misleading messages filter down to everyday health advice by
company-sponsored scientists who advise high-profile sports bodies,”
explains Deborah Cohen, BMJ Investigations Editor. “For instance, fear
about the dangers of dehydration has become gospel and now influences what
and how we drink when we exercise. It’s a triumph of marketing over
science.”
The investigation concludes: “For now, the evidence we do have seems to be
leading us to a rather common sense and affordable solution. Eat a well
balanced diet, drink water, find some comfy shoes, and get out there and
exercise regularly.”
Contacts:
Deborah Cohen, Investigations Editor, BMJ, London, UK
Tel: +44 (0)20 7383 6183; Mobile: +44 (0)7554 334 958
Email: dcohen@bmj.com
Amanda Hearn, Publicist BBC News and Current Affairs (BBC Panorama)
Tel: +44 (0)7720 671 396
Email: amanda.hearn@bbc.co.uk
Dr Carl Heneghan, Director of the Centre for Evidence-Based Medicine &
Clinical Reader, University of Oxford, UK
Tel: +44 (0)1865 289 299; Mobile: +44 (0)7896 258 823
Email: carl.heneghan@phc.ox.ac.uk
Dr Matthew Thompson, Senior Clinical Scientist and GP, Department of
Primary Health Sciences, University of Oxford, UK
Tel: +44 (0)1865 226 750; Mobile: +44 (0)7787 537 450
Email: matthew.thompson@dphpc.ox.ac.uk
Professor Tim Noakes, Discovery Health Chair of Exercise and Sports
Science, Department of Human Biology, University of Cape Town and Sports
Science Institute of South Africa
Email: timothy.noakes@uct.ac.za
Links to full articles under embargo:
Research: The evidence underpinning sports performance products: a
systematic assessment BMJ Open doi:10.1136/bmjopen-2012-001702
Clique para acessar o bmjopen001702.pdf
Feature: The truth about sports drinks
Clique para acessar o cohen.pdf
Feature: How valid is the European Food Safety Authority’s assessment of
sports drinks?
Clique para acessar o thompson.pdf
Commentary: Role of hydration in health and exercise
Clique para acessar o noakes.pdf
Feature: Forty years of sports performance research and little insight
gained
Clique para acessar o heneghan.pdf
Medicine and the Media: Miracle pills and fireproof trainers: user
endorsement in social media
Clique para acessar o socialmedia.pdf
Feature: Mythbusting sports and exercise products
Clique para acessar o myths.pdf
Feature: To drink or not to drink recommendations: the evidence
Clique para acessar o drink.pdf
Embargo: 00:01 hrs UK time, Thursday 19 July 2012
For more information please contact:
Emma Dickinson
Tel: +44 (0)20 7383 6529
Email: edickinson@bmjgroup.com
British Medical Association
BMA House
Tavistock Square
London
WC1H 9JP
For out-of-hours press enquiries telephone : 020 7383 6254
Email : pressoffice@bma.org.uk
http://www.bma.org.uk/mediacentre
http://twitter.com/thebma
http://www.youtube.com/bmatv
http://www.flickr.com/thebma
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