Are GM Foods Safe?

Many of us do not know that we have been eating genetically modified (GM) foods since their entry into the market in the 1990’s. Genetic modification is the transfer of one or more genes from one organism into the DNA of a different organism in order to create a new desired trait. Currently with food, this is usually done to create some supposed economic or environmental benefit, such as the ability for a crop to contain its own pesticide and therefore theoretically reduce or eliminate the need to spray pesticides on crop fields.

The Potential Risks of GM Foods

The most common GM foods that are in our stores right now are soybeans, corn, canola, cotton (used to make cottonseed/salad oil) and sugar beets (used to make sweeteners). Since their introduction into the market, there has been much debate regarding their safety. Currently the FDA, EPA and USDA consider GM foods safe. However there are a number of scientific studies, case reports and conflicts of interest in the research and regulatory agencies, as well as an overall lack of long-term research and human trials, which together cast doubt on these claims of the safety. The main human health concerns include the possibility for GM foods to cause (1):

  1. increased allergies and introduce toxins into the food supply
  2. increased spread of antibiotic resistance
  3. transfer of new (modified) genes and their components into the cells of our intestines
  4. changes in stomach and intestinal structure and metabolism
  5. changes in growth and development

Aside from possible public health concerns, there are also environmental, economic, agricultural and sustainability concerns which are beyond the scope of this article. For those who want to learn more about the potential human health risks of GM foods you can read “Genetically Modified Foods: Are They a Risk to Human/Animal Health?,” by researcher, Arpad Pusztai, Ph.D. So why is there doubt about the safety of GM foods if our government is telling us that they are safe?

How GM Foods Are Regulated

The FDA, EPA and USDA share oversight of genetically modified plant foods. Careful review of their respective safety regulations reveals exemptions and assumptions, which are questionable. In fact most GM crops regulated by the FDA are actually exempt from the need to prove safety and are “presumptively GRAS [generally recognized as safe] (2)” because they are considered to be substantially equivalent to their non-GM counterparts. Any safety data submitted to the FDA is therefore voluntary on the part of the industry. Crops modified to contain a pesticide within the plant itself, such as Bt corn, would fall under the regulatory domain of the EPA. The EPA also has a series of exemptions and assumptions that reduce the requirements for proof of safety and presume safety of the crop in the absence of adequate, scientific data (3). A good example of this is the case of Bt corn.

Bt Corn: An Example of Insufficient Safety Regulation and Testing

Bt corn is genetically modified to contain the bacteria, Bacillus thuringiensis (Bt), which produces a toxic protein that has been used as a pesticide. Because the bacteria was safely used as a pesticide spray for many years, its incorporation into the plant itself is assumed safe by the EPA. The EPA writes that “The basic premise relied on for the toxicology assessment is the fact that all the Bt plant-incorporated protectants are proteins. Proteins are commonly found in the diet and, except for a few well described phenomena, present little risk as a mammalian hazard. In addition, for the majority of Bt proteins currently registered, the source bacterium has been a registered microbial pesticide which has been approved for use on food crops without specific restrictions. (4)”

There are several flaws in these assumptions made by the EPA. First, just because something is a protein does not make it safe. There are many toxic proteins that we know about. Tetanus, botulism and diphtheria are all toxic proteins. The protein in this case, the Cry protein, is also a toxin to some organisms, which is why it is used as a pesticide. These toxic proteins are not “commonly found in the diet.” Secondly, Bt toxin sprayed on the surface of the plant as a pesticide is not the same as Bt toxin being genetically incorporated into the plant. The crux of the safety testing depends upon isolating the different proteins between the non-GM version of the food and the GM version. However, what proteins are produced by a plant’s DNA actually varies a little depending on the environmental conditions in which the plant is growing. Additionally, over time the DNA of the plant can change and mutate, again possibly changing the proteins produced by the plant. This means we cannot be entirely certain what proteins the new Bt gene will produced in the corn both now and in the future.

However, because of these assumptions, the EPA required only superficial safety testing. The safety studies cited looked at acute toxicity of Cry proteins in mice and some allergy, digestion and breakdown characteristics of the Cry proteins in vitro (in a test tube). All the studies cited in the document are unpublished. None of the animals in the studies were even fed Bt corn. No long term testing was done on animals or humans. Therefore one really should question, in this example, if there is adequate proof of safety.

Industry Driven Testing & Unpublished Data

Additionally, safety studies on GM foods are usually done by the very industry that is developing the new GM crop and seeking to profit from its development. These studies are often restricted from being published and therefore not subject to the usual scrutiny of the general scientific community and their attempts to replicate results. This begs the question as to whether these safety studies are good science or even science at all. Even if we assume that the science is good and was done in good faith, the required testing is inadequate. No long-term testing is being done on animals. No testing is being done at all on humans. No long-term studies have been done that look for the possible development of new diseases or an increased incidence of known diseases due to introduction of GM foods into our food supply. Therefore, many agree that there is insufficient evidence to prove that GM foods are safe.

Chinese Medicine & Modern Nutritional Health

Chinese Medicine has always viewed food as medicine and recommends a varied diet of fresh, locally grown, organic and unprocessed foods, which include fresh whole grains, vegetables and fruits with a small amount of meat and dairy. A varied diet means that you eat a variety of different foods, thus assuring you get a diverse range of vitamins, proteins and minerals while reducing your chances of developing food allergies or intolerances due to overexposure. Unprocessed foods means that the food should be as close to its natural state as possible while avoiding pre-cooked and pre-packaged foods, preservatives, additives and processes which denature or change the quality of food such as microwaving. We believe that it would also be prudent to avoid foods that have been genetically modified, especially in children, elderly, pregnant women and those with chronic allergies, food intolerances, autoimmune conditions and infertility, until more rigorous safety testing is done.

Regardless of where you stand in the GM food safety debate, everyone should know what they are putting into their bodies. To help with that, we have included the “Non-GMO Shopping Guide” as well as a link to the guide as an iPhone app “ShopNoGMO.” This guide will explain which foods are genetically modified and how to avoid them, if you so choose.

  1. Pusztai, A. “Genetically Modified Foods: Are They a Risk to Human/Animal Health?” http://www.actionbioscience.org./biotech/pusztai.html. Date accessed: Oct. 25, 2010.
  2. Brackett, RE. “Bioengineered Foods.” U.S. Food and Drug Administration. June 14, 2005. http://www.fda.gov/NewsEvents/Testimony/ucm112927.htm. Date accessed: Oct. 25, 2010.
  3. U.S. Environmental Protection Agency. “Plant Incorporated Protectants.” http://www.epa.gov/pesticides/biopesticides/pips/index.htm. Date accessed: Oct. 25, 2010.
  4. U.S. Environmental Protection Agency. “BIOPESTICIDES REGISTRATION ACTION DOCUMENT: Cry1Ab and Cry1F Bacillus thuringiensis (Bt)Corn Plant-Incorporated Protectants.” http://www.epa.gov/oppbppd1/biopesticides/pips/cry1f-cry1ab-brad.pdf. Date accessed: Oct. 25, 2010.

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