With scientists on both sides of the GMO debate, how can you know who’s wrong or right?

posted in: Science | 47

People have lots of questions about GMOs. Here’s an interesting question posed by Micky about lists of signatures against GMOs:

Q: “Are these scientists all wrong, there are over 800 scientists who all believe GMOs are a bad idea. http://www.i-sis.org.uk/list.php How many scientist believe that GMOs are good and do all of these scientist work for big agro corporations?”

And here is my Answer to Micky’s question:

Scientific arguments are not settled by counting the number of people supporting an opinion. They start with a careful search for scientifically valid evidence, and they carry this forward with open-minded and careful logical reasoning and false conclusions are eliminated from the discussion. Good scientific reasoning also takes notice of the whole body of evidence on a topic, and updates the verdict as new evidence becomes available.

 The I-SIS website mentioned in the question has a public letter with over 800 signatories. Most scientists when making a scientific judgment don’t really care about such lists, and who signed the letter doesn’t enter into their thinking. It is quite right that they take this line.

 Albert Einstein said this best (quoting Michio Kaku’s article at Encyclopedia Britannica):

 “One Hundred Authors Against Einstein was (a short book) published in 1931 [which said the Theory of Relativity is wrong]. When asked to comment on this denunciation of relativity by so many scientists, Einstein replied that to defeat relativity one did not need the word of 100 scientists, just one fact.”

 So let’s take a scientific approach and look at what evidence is presented in the I-SIS  letter, and evaluate whether the claims it makes are true.

Definitely some of the letter is wrong or out of date. In the years since 2000, when the letter was signed, many more scientific publications on the topics have come out.

 These new publications have settled many of the questions that are raised in terms of whether GMO crops are bad. These publications (numbering thousands in total) involve many thousands of scientists.  About one in four of them, or even more, are not connected with commercial seed companies selling GM crops.

 The letter claims that “GM crops offer no benefits to farmers or consumers.”

 This claim ignores the huge benefits of insect protected biotech corn and cotton which save many farmers from unnecessary exposure to toxic pesticides. Insect protected GM corn is of special value to food consumers and farmers as reduces harm to animals and people from eating moldy insect damaged corn. Such damaged corn often contains residues of a cancer causing mold toxin called fumonisin that accumulates in mold affected grain. This benefit of safer corn is especially important for poorer people in developing countries in Latin America, Africa and in China where corn is a staple item in their daily diet.  Clearly, as the evidence stands today, the 800 letter signers are wrong about the benefits of crop GMOs.

White maize — mealies — is a staple food in Southern Africa.

 The letter at the I-SIS website also publicizes worries about the “spread of antibiotic resistance marker genes that would render infectious diseases untreatable, the generation of new viruses and bacteria that cause diseases, and harmful mutations which may lead to cancer.”

 There are good reasons for believing such risks are insignificant. Some of these reasons are explained at the following website entries (which I wrote with Professor Bruce Chassy):

Much of the rest of the letter is really about a somewhat different issue than whether GMOs are good or bad. For instance the letter ends with a plea for the wider use of alternative farming practices.

Quite likely, some of the scientists signing the letter at I-SIS may have changed their minds about GMOs in the years since 2000.

 Returning to the second question posed:  “How many scientist[s] believe that GMOs are good and do all of these scientists work for big agro corporations?”

 When asked this question, most scientists would say something like—not all GMOs are bad, and some GMOs are a really good idea.

 Most modern biologists know that GMOs have been a tremendous boost to scientific research. In basic biology research areas connected with medicine, cell biology and even zoology and evolution studies, GMOs are seen by almost all knowledgeable people as an extremely useful experimental tool, and they have accelerated progress in many areas of science – for example given us new ways of making insulin that is essential for treating diabetes, or tools for discovery of drugs to manage HIV virus infections. (I personally have done this type of work, and I know that genetic engineering methods have played a hugely important role in developing treatments for virus diseases such as AIDS or hepatitis).

 As far as how many scientists support crop GMOs that provide benefits to fight malnutrition, more than 6,500 scientists recently signed a petition to protest against destruction by activists of GM rice field trials in the Philippines. This rice has potential to prevent diseases that occur in people with vitamin A deficiency that is widespread in many regions where rice is a staple food. (See Global scientific community condemns the recent destruction of field trials of Golden Rice in the Philippines)

 There is a wide range of scientific investigations on seed breeding, food safety, and food improvement using GMO crops that have been and are currently being done outside seed companies. Many government-funded studies have been carried out in the EU for example

 I personally know many University and non-corporate scientists who are extremely enthusiastic about GM crops and are busy developing GM crops that help the poor. These include mineral and vitamin fortified crops that can alleviate micronutrient malnutrition.


If more people knew about the many non-commercial research GMO crop efforts which are deliberately targeted to help the poor, I am sure they would get wide support inside and outside the academic community from both scientists and non-scientists.  They certainly dispel the impression that GMOs are only of interest to large seed companies.

(Original Post at GMO Answers website)

Follow David Tribe:

David Tribe is an applied geneticist, teaching graduate/undergrad courses in food science, food safety, biotechnology and microbiology at the University of Melbourne.