Genetically modified organisms, or GMOs, are one of those topics everyone seems to have a vocal opinion on: depending on who you talk to, they're either the key to feeding our growing population, or the ultimate threat to society.

Now, a two-year analysis of almost 900 journal articles on the past 30 years of genetically modified, or engineered (GE), crop use has weighed in on the debate, concluding that there is no evidence that GE crops are unsafe to eat, or do damage to the environment.

But it also showed little support for claims that they've significantly boosted crop yields or improved economic outcomes for farmers, suggesting that we're still a long way off finding the best way to use and disseminate the technology.

The 400-page report was conducted by 20 scientists, and commissioned by the US National Academies of Science, Engineering, and Medicine, as part of an attempt to figure out how to regulate crops and GM food going forward.

Whether you like it or not, the reality is that since the 1980s, scientists have been genetically modifying crops to enhance their favourable characteristics, such as vitamin content, yield, and/or pest-resistance.

This is simply a faster and more precise version of selective breeding, which humans have been doing for millennia - dramatically altering what food crops look like in the process.

But because many of these GM seeds contained all-new DNA code that could, in theory, be patented and sold back to poor farmers at a higher cost, many have been concerned about their presence in our farms and fields. Not to mention the fact that they haven't been around long enough for longitudinal studies to be conducted on the long-term effects they have on our health or the surrounding environment.

Despite that, a lot of research over the years has concluded that GM crops are safe and can greatly benefit humanity - but that's done little to relieve the public's concern.

Which is one of the reasons that this new analysis was commissioned. It looked into several aspects of the debate, and trawled more than 900 articles, along with hours of expert testimony and public submissions, to come to the following conclusions:

Health risks: "The committee carefully searched all available research studies for persuasive evidence of adverse health effects directly attributable to consumption of foods derived from GE crops but found none."

Beyond that, there was also evidence that GE crops had actually benefitted human health by reducing insecticide poisonings, and helping to increase vitamin levels in developing countries.

Effects on the environment: "The use of insect-resistant or herbicide-resistant crops did not reduce the overall diversity of plant and insect life on farms, and sometimes insect-resistant crops resulted in increased insect diversity."

One of the biggest concerns has been that genetically engineered genes will spread into the wild population - and while studies have shown that this can occur, there have been no adverse effects reported from this gene flow, the report concluded.

Impact on farmers: "The committee examined data on overall rates of increase in yields of soybean, cotton, and maize in the US for the decades preceding introduction of GE crops and after their introduction, and there was no evidence that GE crops had changed the rate of increase in yields."

And while some GE crops made more money for farmers, they also came with extra training and infrastructure requirements, which could be expensive and outweigh any savings. 

 "If GE crops are to be used sustainably, regulations and incentives are needed so that more integrated and sustainable pest-management approaches become economically feasible," the committee reports

Tl;dr: All our evidence so far suggests that GE crops are safe for humans and the environment, but may not be as awesome as we thought when it comes to helping us grow more food. 

When it comes to regulation, the report concluded that the lines are now being blurred between GE crops and conventionally bred crops, thanks to new technologies in both fields, and in the future, we're going to need to come up with different ways to categorise and regulate both products. 

As Wayne Parrott, a professor of crop and soil sciences from the University of Georgia, who wasn't involved in the committee, told the Genetic Expert News Service: "The inescapable conclusion, after reading the report, is the GE crops are pretty much just crops. They are not the panacea that some proponents claim, nor the dreaded monsters that others claim."

It's unlikely this report will resolve the debate either way, but at least it's keeping the evidence-based conversation going, and that's the only way to move forward.