In the long-running debate about whether organic food is more healthy and nutritious than the conventional variety, the press has shown a preference for covering research rejecting the averred value of organics.

Such was the point of a clever, but incomplete piece of criticism that appeared in The New York Times’s weekly Science Times section on Tuesday. Using a head-fake lede, the paper’s Kenneth Chang reports that:

A team of scientists laboriously reviewed decades of research comparing organic fruits and vegetables with those grown the usual way. They found that, as many had suspected, the organic produce, farmed without synthetic fertilizers or pesticides, was more nutritious, with more vitamin C, on average, and many more of the plant-defense molecules that in people help shield against cancer and heart disease.

That is probably not the study you heard about.

The findings, by scientists at Newcastle University in England, appeared in April 2011 and barely made a ripple in the news media or in the public consciousness.

But last month, after a team from Stanford University conducted a similar review of many of the same studies, they came to opposite conclusions — and set off a firestorm.

It’s an excellent point, and crafty setup, but the piece isn’t the mea culpa that it should be. Chang goes to blame the “chasm” between the low coverage of positive results and high coverage of negative results on the different ways scientists conduct broad reviews of the scientific literature, called meta-analyses:

The way the data from various studies is divvied up or combined in a meta-analysis can make a big difference in the conclusions. In the organic food research, some studies reported many measurements, some only a few. Some included several crops grown over multiple years, while others looked at only a few samples.

While that’s true, and the messiness of science can be a confounding factor for journalists, it does not explain the “chasm” in coverage or the “mixed messages” described in the headline of Chang’s story. The more likely cause of those problems is the media’s penchant for counterintuitive, gotcha-style conclusions. Organics are assumed to be healthier, so it’s catchy when someone says they’re not.

Chang, who is a top-flight reporter, was one of the many people who contributed to the rash of overly confident stories last month about organics being no healthier than conventional foods, and while his attempt to make amends is appreciated, this isn’t the first time that the press has fallen head over heels for negative results.

When a study funded by the UK’s Food Standards Agency (FSA) concluded in 2009 that “there are no important differences in the nutrition content, or any additional health benefits, of organic food when compared with conventionally produced food,” it got reams of coverage. Yet reporters basically ignored the final results of a four-year study funded by the European Union that had been published two months earlier and come to the opposite conclusion. To be fair, that investigation, which spanned four years and involved 36 research institutions, drew some attention in 2007 when it released interim results of its work, but mostly short articles that said the findings contradicted the FSA, which was skeptical of organics back then, too.

The research concluding that some organics may have health benefits above and beyond their conventional cousins is every bit as robust as the research arguing that those advantages aren’t particularly large or widespread. But the media have shown a clear preference for the latter, and it’s not because of the different methods that scientists use. It’s because of the media’s own biases.