Examining DNA derived from GM foods: Scientists probe how it penetrates the body's cells

22 Jan 2019 --- Toxicologists, including scientists from the Far Eastern Federal University (FEFU), studying the potential risks of genetically modified (GM) products have published a review on the fate of the DNA derived from GM food and how it can survive during digestion and penetrate into the cells of the body. One of the key findings is that the micro-ribonucleic acid – one of the main molecules in cells of living organisms – of GM foods that were treated with insecticides and antiviral sprays can affect genetic processes in the bodies of those who consume it.

The review comes during a time of heightened focus on GM foods and how they are regulated and labeled around the world. 

According to the review data, the DNA of GM products can survive “harsh processing and digestive conditions.” Some can get into the human body, combining with the DNA of bacteria in the gastrointestinal tract (GIT). Scientists have discovered the presence of such DNA in the bloodstream and tissues of humans and animals.

Speaking with NutritionInsight, Dr. Muhammad Amjad Nawaz, a visiting scientist at the “Nanotechnology” Research and Education Center (REC) operating at FEFU, explains the driving factors behind the research.

“As the global commercialization of GM food and feed is on the rise, so is the interest in the fate of GM-derived extracellular DNA in the body of the consumer. This has triggered us to want to understand precisely how the GM-food based extracellular DNA is degraded in consumer’s body, whether it is stable, if it has any mutagenic potential and if it could have chances of expression,” he muses. 

“Average consumers of GM food are mostly unaware of its consequences on their health as it is not only the GM-food derived extracellular DNA (including miRNAs) which consumers should be aware of, but also the intense amount of the herbicides and insecticides used for the GM food production (particularly here, we refer to the intense use of herbicides on GM crops).”

The review comes during a time of heightened focus on GM foods and how they are regulated and labeled around the world. 

“Furthermore, most of the consumers are unaware of the fact that there is compelling evidence that food ingested siRNA molecules can target homologous sequences in the consumer and affect gene expression,” he says.

“Although we have not found evidence of any effect of DNA of GM products on the human genome, we can safely say that micro-ribonucleic acid (one of the main molecules in cells of living organisms, in addition to DNA and proteins) of the plant food treated with insecticides and antiviral sprays, enters the body of its consumers and can affect genetic processes. This question would be worth exploring further,” adds Dr. Nawaz. 

Another argument for GM food is that some believe they can help mitigate the challenges of feeding the world’s growing population, which is set to reach 9.8 billion by 2050. Another school of thought is that GMO crops may be necessary to counter the onset of climate change where extreme weather events are expected to impact yields more in the future. 

What does the review note?
Scientists examined the ways and mechanisms by which foreign DNA can survive during digestion and penetrate into the cells of the body of the consumer. In particular, researchers are interested in the region of the GIT as the hot spot for horizontal gene transfer of GM crop DNA into gut-bacteria. 

Such a transfer can potentially lead to dysbacteriosis and ill-health, as well as subsequent mutations, notes the review, which follows previous research in 2017 when researchers published two reviews of the scientific papers on the GM crop cultivation impact on the environment, ecosystem, diversity and the health of animals and humans.

“There is evidence that small fragments of dietary DNA (including that of GM food) can survive digestion and reach the bloodstream. However, the presence of intact genes still remains an unanswered question. Following the transfer of plant food DNA to gut bacteria or somatic cells of consumers, the fate of DNA (in terms of expression) is a poorly explored area which needs further explorations,” notes Dr. Nawaz.

“More comprehensive research is needed on the fate of GM diet-based DNA with long-term exposure. The off-target effects from the ingestion of novel siRNAs present in GM-food or foliar insecticidal or antiviral spray applications, cannot be ignored and thus should form an integral part of the risk assessment of these products.”

The broader debate of GM products
As consumers are becoming increasingly mindful about exactly what is in their food and where it comes from, transparency has become a must for suppliers. Innova Market Insights has noted strong growth of non-GMO claims in new food and beverage launches over the past five years, with a CAGR of 30 percent (2013-2017). However, for suppliers not switching to non-GMO, how the presence of GMOs or Bioengineered (BE) Foods is labeled could have a profound effect on their business.

The debate on the potential effects of GM food continues to gather pace and so the timing of this new review is even more significant. In the US, for example, food labeling, GMOs and BE will be among the big debates of 2019 and will likely be on the agendas of companies, suppliers and manufacturers closely monitoring how government policies will continue to play out under President Trump. This also comes at a time when the Trump Administration’s food and nutrition policies are under close scrutiny for favoring big business over consumer protection and transparency. 

Earlier this month, the US government was criticized for creating a “loophole” in standards in terms of how food products are labeled. US policymakers new rules mean that GMOs in many foods will go undisclosed, leading to concerns of “anti-transparency” towards consumers who might be confused about what exactly is in their food. 

Major players in the food industry, including the Environmental Working Group and Sustainable Food Policy Alliance (SFPA), which includes companies such as Danone, Mars, Nestlé and Unilever, believes that the US Department of Agriculture’s (USDA) final National Bioengineered Food Disclosure Standard, falls short of consumer expectations.

In November 2018, the Washington DC-based Pew Research Center looked into consumer understanding on matters such as genetically modified (GM) ingredients, illustrating how, against the backdrop of ongoing developments in food science, US consumers have their own set of interconnecting beliefs about food issues.

Seven-in-ten US consumers believe science has mostly had a positive effect on the quality of food. However, when asked about an area where new developments in biotechnology are changing the possibilities for how foods are grown and consumed, roughly half (49 percent) believe that foods with GMO ingredients are worse for health when compared to non-GM foods. 

In addition, research last summer by the International Food Information Council (IFIC) Foundation found that the presence of references to “bioengineered” (BE) foods on labels can lead to an increase in consumer concerns, especially regarding human health. This also impacts the likelihood they will purchase as well as the price consumers are willing to pay for a product containing GMOs.

Dr. Nawaz is continuing to work alongside a group of colleagues to study the effects of GM products on human and animal health.

The article has been published in the journal Food and Chemical Toxicology. 

By Gaynor Selby