Dean Rohrer

O Mito da Agricultura Biológica

STANFORD – Os produtos biológicos – desde alimentos até panaceias para cuidar da pele e cigarros – estão muito na moda, com o mercado global só de produtos alimentares biológicos a exceder anualmente os 60 mil milhões de dólares. As opiniões dos entusiastas biológicos parecem ser partilhadas pela Comissão Europeia, cuja opinião oficial sobre a agricultura e os alimentos biológicos é, “Bom para a natureza, bom para si”. Mas não existem provas convincentes de qualquer destas afirmações.

Uma meta-análise de 2012 sobre dados provenientes de 240 estudos concluiu que os frutos e vegetais biológicos eram, em média, não mais nutritivos do que os seus homólogos convencionais mais baratos; nem eram menos prováveis de estarem contaminados por bactérias patogénicas como a E. coli ou a salmonela – uma conclusão que surpreendeu até os investigadores. “Quando começámos este projecto”, disse Dena Bravata, uma das investigadoras, “pensámos que seria provável encontrar algumas conclusões que apoiassem a superioridade dos alimentos biológicos sobre os alimentos convencionais”.

Muitas pessoas compram alimentos biológicos de modo a evitar a exposição a níveis prejudiciais de pesticidas. Mas essa razão não é sustentada. Embora os frutos e vegetais não biológicos tenham mais resíduos de pesticidas, em mais de 99% dos casos esses níveis não ultrapassaram os conservadores limiares de segurança definidos pelos reguladores.

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