30 jul. 2009

Health claims for organic food can be damaging to good nutrition

Estimados:
Más debate en el Times de Londres. Esta vez se trata de un artículo de opinión escrito por el Science Editor. A propósito, ¿cuántos periódicos peruanos tienen uno en su planilla?. Pero este OpEd nos trae más carnecita.

Este estudio de la agencia de alimentos británica no es el primero en demostrar que no existe diferencia nutricional entre los alimentos orgánicos y los convencionales. Las agencias francesa y sueca ya habian concluido en lo mismo. Ademós, explica en lenguaje simple, las razones por la que los investigadores se vieron obligados a no considerar mas de dos tercios de los trabajos presentes en la literatura. Por ejemplo: si ud desea comparar la superioridad de un método de producción de tomates, orgánico vs convencional, en sus experimentos deberá usar la misma variedad cultivada en la misma granja y al mismo tiempo. En la gran mayoría de estudios promovidos por la Soil Association se comparaban rendimientos y aspectos nutritivos de cultivos de variedades diferentes cultivadas en diferentes partes de Inglaterra y en diferentes tiempos. No precisamente lo que un estudio científico requiere.

Finalmente, el editor termina con un párrafo que muchos de los pro-orgánicos de nuestro país debieran leer:
"...Science has made it clear that a diet rich in fruit and vegetables is good for you. But because organic food is so much more expensive families on a budget who choose it as a “healthy option” will often be able to afford less fruit and vegetables as a result...."

Esta es una buena razon económica en contra de los alimentos orgánicos, no creen?. Si las frutas y las verduras orgánicas son más caras, la gente de bajos recursos no podrán consumirlos en las cantidades que el doctor recomienda !! Personalmente, no tengo ninguna objecion en contra de los cultivos o alimentos orgánicos, lo que si me molesta son sus mayores precios al por menor que en mi opinión no se justifican. ASPEC tiene la palabra.

Saludos

Luis Destefano Beltrán, Ph.D.
From The Times

July 30, 2009
Health claims for organic food can be damaging to good nutritionMark Henderson, Science Editor The supposed health benefits of organic food are one of its great selling points. The evidence that it is any better for you than conventional produce, however, has always been weak. Several studies have suggested that certain kinds of organic foods contain greater concentrations of some nutrients. But the organic lobbyists who cite these are ignoring the bigger picture. For every paper that purports to show nutritional differences, there are many more that do not. The organic movement, like advocates of alternative medicines, tends to cherry-pick results while overlooking the balance of the evidence as a whole. Systematic reviews of all the evidence, such as the one conducted by the London School of Hygiene and Tropical Medicine, are thus the only fair way of assessing health claims. Like previous reviews by the French and Swedish food standards agencies, the school’s review found the claims unproven.

Research that appears to support health claims for organic food also suffers from a quality problem. Many studies lack proper controls or fail to detail the organic regime and crop variety being evaluated or the analytical techniques used for assessment. Studies that fail to meet these standards cannot provide useful evidence and are rightfully excluded from systematic reviews. It is no coincidence that the school had to throw out about two thirds of the available literature.

A further issue is that most organic research examines levels of certain nutrients, as with recent studies that have found high levels of flavonoid antioxidants in organic tomatoes and of omega-3 fatty acids in organic milk. Even if such results stand up to scientific scrutiny, they will not necessarily translate into a health benefit. To show that, you need to test foods on human beings, which has rarely been done to high standards. The school’s reviewers found only 11 papers with direct relevance to human health, of which five involved testing cell cultures rather than people. Of the six human studies, four included fewer than 20 participants, giving them little statistical power.

Science has made it clear that a diet rich in fruit and vegetables is good for you. But because organic food is so much more expensive families on a budget who choose it as a “healthy option” will often be able to afford less fruit and vegetables as a result. The health claims made for organic food are not just unfounded, they can actually damage good nutrition.

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