Designed by biotech giant Monsanto to combat corn root worm, MON863 was approved for food use in Australia in 2003, swiftly followed by New Zealand in April this year.
"No potential public health and safety concerns were identified during the assessment and no further data was deemed necessary or requested," said the Food Standards Australia New Zealand (FSANZ).
But the food agency points out this week that it has since been aware of an additional 90-day feeding study in rats that was provided by Monsanto to the German Competent Authority and subsequently assessed.
Media reports last week drew attention to this feeding study, suggesting it was actually an animal toxicity study. A conjecture rapidly corrected by FSANZ.
"This new study is not an animal toxicity study as originally reported in media releases. Animal feeding studies are designed to give general information about the normal growth and well-being of animals fed with GM food or feed and are therefore narrow in design, scope and interpretation," commented FSANZ.
Animal toxicity studies are designed to assess the potential for any adverse effects of a substance by assessing a wide range of concentrations and toxicological endpoints, added the authority.
Earlier this year in April, the European Food Safety Authority (EFSA) examined this same 90-day feeding study in rats, together with the supplemental analysis completed by Monsanto, and subsequently adopted a positive scientific opinion, concluding that the 'the placing on the market of MON863 is unlikely to have an adverse effect on human and animal health or the environment in the context of its proposed use.'
FSANZ clarified that it does not require feeding studies in animals, such as this 90-day feeding study in rats, to be submitted as part of an application to FSANZ for a GM food. Where GM varieties have been shown to be compositionally equivalent to conventional varieties, feeding studies using target livestock species 'will add little to a safety assessment and are generally not warranted,' explained the authority.
"In the case of MON863 corn, the extent of the compositional data, molecular characterisation and toxicity/allergenicity data was considered sufficient to establish the nutritional adequacy of the food," said FSANZ.
Canada, Japan, the Philippines and the US have all cleared MON863 for use in food, Europe has not.
In 2003 maize (Zea mays L.), or corn, was grown commercially in over 150 countries and worldwide combined production hit 638 million metric tonnes harvested from 143 million hectares. Major producers were the US, China, Brazil, Mexico, Argentina and France. Maize is grown primarily for its kernel, which is largely refined into products used in a wide range of food, medical, and industrial goods.