November 2003

Genetically Modified Foods Have Serious Health Risks

The Science Behind the Anti-biotech Movement

by Jeffrey M. Smith

In the summer of 2002, the British government sponsored the first-ever research on genetically modified food (GMOs) using human subjects. Researchers fed seven volunteers a single meal of soy burgers and soy milkshakes. The soy was genetically modified, as are 80 percent of the soybeans planted in the US.

The volunteers were selected because they had all previously had their lower intestines removed and were using a colostomy bag — the bag collected digested material after it passed through the small intestine. Researchers were surprised to discover that in every case, a large amount of genetically modified DNA survived digestion and remained intact. (Biotech companies had insisted that DNA is broken down.) Moreover, the modified gene from the soybean transferred into DNA of bacteria inside the gut of three volunteers. Their intestinal bacteria, like GMO soybeans, contained a foreign gene that allowed the bacteria to survive a dose of weed killer. No one knows what the health consequences of this are.

Scientists are more concerned about a related danger. Most genetically engineered crops contain an antibiotic resistant marker (ARM) gene. These allow the cells to survive an otherwise deadly application of antibiotics. The ARM gene used in GMO corn, for example, confers resistance to the antibiotic, ampicillin. What if an ARM gene jumped from our corn muffins into our gut bacteria? Could bacteria in our body become resistant to antibiotics?

The British Medical Association thinks so and cited this serious risk as one of their reasons for wanting an immediate moratorium on genetically engineered foods. Likewise, when FDA scientists were asked in 1992 to approve ARM genes in the first GMO crop, a tomato (no longer on the market), they were against it. The director of the Division of Anti-infective Drug Products wrote in all capital letters: "IT WOULD BE A SERIOUS HEALTH HAZARD TO INTRODUCE A GENE THAT CODES FOR ANTI-BIOTIC RESISTANCE INTO THE NORMAL FLORA OF THE GENERAL POPULATION." Political appointees overrode the scientists’ recommendations and approved ARM genes, siding with the biotech industry that assured them that DNA was destroyed during digestion, and that genes could not transfer to gut bacteria.

Having disproved these assumptions, the soy burger study raises a more serious threat. Before inserting a foreign gene, engineers attach a promoter to keep the gene permanently switched on. Promoters overpower the cells’ regulatory system, which normally turn on genes only as needed. But promoters can sometimes unintentionally switch on other naturally occurring genes in the DNA, causing them to pump out potentially toxic or allergenic proteins. Scientists are afraid that if these promoters transferred to bacteria or internal organs, they might turn genes on at random or create unstable DNA.

Stanley Ewen, one of Scotland’s leading experts in tissue disease, believes that promoters might generate uncontrolled cell growth that could theoretically lead to cancer. Evidence of unusually high cell growth in the digestive tract of animals was discovered in three of the ten published animal feeding studies on GMO foods. (Two showed increased cell growth. One showed increased weight of the intestines. The other seven were not necessarily designed to detect such changes.) In addition to the cell growth, a study published in the prestigious Lancet found that young GMO-fed rats also had more sluggish immune systems, partial atrophy of the liver, and smaller brains, livers, and testicles. Researchers believe that the unstable, unregulated, and aggressive promoter may be the culprit.

In the absence of long-term safety tests, many people avoid eating GMO foods. The four main GMO crops (unless labeled organic or non-GMO) are soy, corn, cottonseed oil, and canola oil. Monsanto is now trying to introduce GMO wheat.

Jeffrey Smith is author of Seeds of Deception: Exposing Industry and Government Lies about the Safety of the Genetically Engineered Foods You’re Eating. To order, call 888-717-7000, or click here.