Financial conflicts of interest were found in 40 percent of published research articles on the genetically modified crops, also known as GMO crops, French researchers said this week.
The findings in the December 15 edition of the US journal PLOS ONE focused on hundreds of research articles published in international scientific journals.
"We found that ties between researchers and the GM crop industry were common, with 40 percent of the articles considered displaying conflicts of interest," said the study.
Researchers also found that studies that had a conflict of interest were far more likely to be favorable to GM crop companies than studies that were free of financial interference.
The study focused on articles about the efficacy and durability of crops that are modified to be pest resistant with a toxin called Bacillus thuringiensis.
Thomas Guillemaud, director of research at France's National Institute for Agricultural Research (INRA), told AFP that the team originally looked at 672 studies before narrowing down to the pool to 579 that showed clearly whether there was or was not a financial conflict of interest.
"Of this total, 404 were American studies and 83 were Chinese," he said.
To determine whether there was a conflict, researchers examined the way the studies were financed.
Conflicts of interest were defined as studies in which at least one author declared an affiliation to one of the biotech or seed companies, or received funding or payment from them.
"The most important point was how we also showed there is a statistical link between the presence of conflicts of interest and a study that comes to a favorable conclusion for GMO crops," Guillemaud said.
"When studies had a conflict of interest, this raised the likelihood 49 percent that their conclusions would be favorable to GMO crops."
Among the 350 articles without conflicts of interest, 36 percent were favorable to GM crop companies.
Among the 229 studies with a conflict of interest, 54 percent were favorable to GM companies.
"We thought we would find conflicts of interest, but we did not think we would find so many," Guillemaud said.
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