A major review of genetically modified crop research confirms that after 25 years there have been no human health issues from GM crop consumption, and the technology is delivering improved environmental and economic outcomes to farmers globally.
John Caradus, CEO of AgResearch subsidiary Grasslanz, has recently had his review paper published in the New Zealand Journal of Agricultural Research.
He reviewed more than 800 studies conducted in the past two decades on GM technology’s impact on health, environment, economic production and social outcomes.
The paper, Intended and Unintended Consequences of GM Crops, concluded that the technology is a valuable option for delivering positive environmental and economic outcomes with risks that can and have been well monitored, quantified and mitigated.
“What I have tried to do is step back and say ‘What is in peer-reviewed literature to compare risk and benefits of GM crops their outcomes?’ This is why there are so many study references in there, I did not want to be seen to be cherry picking from the work out there,” Caradus said.
Breaking down human/animal health, environment, economic and social impacts of the technology, the studies have generated a wealth of data and conclusions bought together under Caradus’s work, generally proving positive in their conclusions on the tech’s value.
Estimates are that as at 2018 there was 192 million hectares in GM crops globally, consisting of 32 different crop species with over 2000 GM foods approved in 43 countries, including NZ.
Economic studies showed between 1998 and 2018 the technology has returned US$225 billion (about $351b) to 17 million farmers, of whom 95% are in developing nations. On average crop yields have been increased by 34% in cotton, 12% in maize and 5% in soybeans.
In 2018 alone the on-farm benefit was calculated by one study to be US$19b, an additional 5.8% added to the global value of soybeans, maize, canola, and cotton crops.
The bulk (75%) of gains have come from improved production gains in GM crops and 25% from cost savings through less tillage and pesticide/herbicide use.
“There are some big numbers in here because you are talking about some really large broadacre crops like soybeans now grown with the technology,” Caradus said.
Estimates are there is at least a further US$65b that could still be accrued to the world’s developing farmers through use of the technology.
Countries such as Uganda, for example, have been shown to enjoy cost:benefit returns of up to 2.1 times by utilising GM corn that is resistant to drought and stem borer insects.
Toxicity risks of GM crops on human and animal health have been cited over the years as reasons for banning the crops’ use here.
However, Caradus said some earlier studies that indicated such risks have since been proven to be invalid, based on poor science and bad study design. None of the work he reviewed had found human or animal health compromised by GM food consumption.
“But unfortunately, those earlier studies have since become ingrained into some views of it.
“I am not saying we should throw the baby out with the bathwater and do away with checks and balances. But we also have to know that there are a lot of other treatments like synthetic chemicals that have had a lot more issues around them.”
Some crops, like Golden Rice that boosts the body’s vitamin A levels, have proven valuable in countries such as Philippines in helping improve consumer health.
One of the key negatives of GM tech raised in studies has proven to be the contribution of Roundup Ready crops to the development of glyphosate resistance in weeds.
Caradus said this has been the main negative around the seed technology – “but glyphosate resistance has also developed in spite of GM tech too”.
“But in those countries that have it, the degree of resistance may have been exacerbated by its use.”
However, overall, the environmental benefits of the technology have proven solid.
On average GM crop use has led to a 37% lower pesticide use, a 22% increase in crop yields and a 68% increase in farmer profits with the greatest gains again in developing countries.
Based on environmental indices, the GM crops delivered a 23% lower environmental impact than conventional, and 620 million kg less of crop sprays being applied between 1995 and 2015.
In 2010 alone 13 million hectares less land was needed to grow the equivalent amount of crops using conventional methods, averting emissions equivalent to 15% of all US car emissions in that year.
On a social level, many critics of Roundup Ready GM seed claimed its proprietorial demands had prompted increased suicides among farmers in India in particular.
This was not the case, and increased GM crop yields of 24% contributed to a 50% gain in profits for small farmers and stopped many falling below the poverty line.
Caradus said he hoped the extensive review would contribute to more informed, science-based discussion in NZ on GM use. He was encouraged by it ranking among the “top 4” papers in the NZ Journal of Agricultural Research in 2022.
“This is not really part of my job but there has been an injustice here with naysayers getting a platform, and that is just wrong.”
