Friday, November 20, 2015

Dear Christie Brinkley: We Aren’t Guinea Pigs

This letter is co-written by Mommy, PhD and BioChica (Dr Alison Bernstein and Dr Layla Katiraee. For more information about the authors, please see the end of the letter). Dear Christie,

We read this week about your new book and watched your interview on FOX Business. As scientists and science communicators, we are concerned that, while your motivations to help people eat healthy diets is honorable, your knowledge of genetic engineering, pesticide toxicity and the agricultural industry is not accurate. We are part of a group of moms (#Moms4GMOs) who also want to make healthy choices for ourselves and our families. We have previously reached out to other celebrities who are using their public platforms to spread misinformation and fear about the food supply in the US.

In our original letter, we addressed many of the concerns that you and others have raised about genetically engineered crops and pesticides. We hope that you will take the time to read the letter and the references we provided. There are a couple of points that were highlighted in your interview that we would like to discuss briefly here.

Colony Collapse Disorder is caused by many things, but GMOs are not one of them.

As you may know, much of our food relies on pollination by bees, so the health of these insects impacts all of us. Colony collapse disorder affecting honey bees is a topic of much controversy. This phenomenon is defined by the USDA as “a dead colony with no adult bees or dead bee bodies but with a live queen and usually honey and immature bees still present”. There are many theories on what may be causing CCD; the primary culprits seem to be parasites like the Varroa mite and flowerless landscapes, together with other factors, including exposure to pesticides and stress due to transportation. However, exposure to GMOs does not rank among the possible reasons underlying CCD.

Attempts to link GMOs to CCD have commonly focused on two factors: glyphosate and worm-resistant traits. Glyphosate, which is an herbicide used with some varieties of GMOs and is commonly used in gardens and parks around the country, has been examined to determine if it impacts honeybee health. A recent study examined the impact of the commercial formulations of 42 common pesticides on honeybees at concentrations actually used in the field. Due to the popularity of glyphosate, this herbicide was also included in the study. The study concluded that, while some pesticides are extremely toxic to bees, glyphosate was not harmful to their health.

Worm-resistant corn (commonly referred to as Bt-corn) is designed to kill the larval stage of many damaging insects, such as caterpillars, as they chew on the corn leaves. These crops have also been studied to determine if they impact honeybee health: a meta-analysis published several years ago concluded that their research “support[s] safety assessments that have not detected any direct negative effects” of the trait on the honeybee.

For more information on the science of CCD, we recommend these articles:

GMOs are the most tested and regulated food items: we are not guinea pigs.

The term “GMO” is commonly used to denote a crop or ingredient that is made using a laboratory technique known as “transgenesis”. But there are many different types of GMOs: non-browning apples, nutrient fortified rice, virus-resistant papayas, herbicide-tolerant soy, and pest-resistant corn. These cannot all be lumped into a single category. To underscore that the process is irrelevant and it is the trait that is important, herbicide-tolerant sunflowers have also been developed using traditional methods by the German chemical producer BASF and Dupont. By current rules, herbicide-resistant crops developed with targeted genetic engineering undergo extensive testing prior to being sold, while herbicide resistant crops developed by traditional breeding require no testing. In fact, genetically engineered food items are the most tested and regulated food in the market. No other foods undergo premarket approval by the EPA, FDA and USDA.

The sheer volume of data and number of studies on different traits used in biotech crops may surprise you. As a simple exercise, searching the NIH’s database of scientific studies for “MON810”, which is the trait that gives corn resistance to worms, identifies over 170 studies that have examined this trait. These range from multi-generational feeding studies to molecular analyses of the protein that makes the corn resist worms. Thousands of scientists around the world are dedicating their efforts to the development and testing of these crops, which defies notions implying that these crops are released into the market without being thoroughly tested.

For information about studies on GMOs and worldwide approvals of genetically engineered crops, check out these two databases.

The US food supply is safe, regardless of the breeding or farming method used.

We read about your adoption of an organic diet over concerns about possible links between GMOs and pesticides to sterility and breast cancer. Pesticides are important tools in agriculture, which farmers use judiciously depending on many factors including the type of pest and the type of crop, among many others. It is important to know that organic food production uses pesticides as well, and that pesticide residues in the US on non-organic produce are far below safety limits, but we have no data to compare it to for residues on organic produce. Furthermore, there’s no conclusive evidence suggesting that adopting an organic diet is significantly healthier (see meta-analyses here and here, and here and here for discussion of this research). Each pesticide has its pros and cons, and not using any pesticide at all can have significant consequences, including lower crop yields.

Despite searching for information, we found little to no credible evidence linking sterility or breast cancer to GMOs. It is a basic concept of scientific research that, when examining a cause-effect relationship between two items, the null hypothesis is what you start with - that there is no connection between the two items. This means that until someone comes up with a study showing that A causes B, then the null hypothesis stands: A does not cause B. Without this important principle, you could propose any hypothesis and people would have to “prove you wrong”. Instead, the burden of proof falls on those proposing a relationship between two items; they must provide evidence for that hypothesis.

Additionally, hypotheses are not invented out of whole cloth; they are based on previous knowledge. In considering how seriously to take a hypothesis, scientists consider plausibility, possible mechanisms, and what we already know about the subject. When a hypothesis has no plausible biological mechanism by which A can cause B, based on everything that we already know about biology, the burden of proof is even higher on those proposing the relationship between A and B and these hypotheses are often dismissed. This requirement for proof underlies the popular phrase “extraordinary claims require extraordinary evidence”. In the case of GMOs, breast cancer, and sterility: despite many studies of the health effects of GMOs, there is no evidence for a link to breast cancer or sterility and no plausible mechanism to explain such a link. At a minimum, scientists would need to have seen an increase in these things since the introduction of the first GMO in 1996. However, neither breast cancer rates nor infertility have increased since 1996. Thus, scientists have no evidence that GMOs are in any way associated with breast cancer or sterility and no plausible reason to hypothesize that they are. All the current evidence shows that GMO food is as safe as non-GMO food.

In North America, we have the luxury of having an abundant food supply with many options and choices. This includes the choice of being able to avoid GMOs entirely by adopting an organic diet, which excludes  genetically engineered crops and ingredients derived from them. However, in areas of the world where such abundance does not exist, GMOs can be extremely beneficial. GMOs may not solve world hunger, eliminate global warming, or ward off pests, but these crops will help us as we face these challenges. Disregarding an entire set of tools, based on the fears and privilege of those of us fortunate enough to have these choices, restricts the ability of farmers and scientists around the world to find solutions to real problems in agriculture.

Farmers have written about how they make their choices regarding pesticide use, and we encourage you to check out these resources:

To learn about the benefits of GMOs, see:

Talk to farmers and scientists about genetic engineering

From our original letter:

“Please, don’t co-opt motherhood and wield your fame to oppose beneficial technologies like genetic engineering. Certain celebrities have misled thousands of parents into thinking that vaccines are harmful, and we see the same pattern of misinformation repeating itself here. When GMOs are stigmatized, farmers and consumers aren’t able to benefit from much-needed advancements like plants with increased nutrients, or plants that can adapt to changing environmental stresses.

We, like millions of other Americans, line up to see your movies, and respect your occupation. Though our jobs differ, we share a common goal: to raise healthy, happy, successful kids. As moms we feel it is our responsibility to use the best available information to protect our children’s health, and to let the best science inform the choices we make for our families. We ask you to take the time to learn about how genetic engineering is being used by farmers, and the potential it has to help other moms raise healthy, happy, successful kids.

You have the opportunity to influence millions of people, so please use that influence responsibly, and ensure that your advocacy is supported by facts, not fear.”

We would like to extend the same invitation to you: talk to scientists, talk to farmers, talk to the experts in these fields. Arm yourself with knowledge, not fear, to help you make informed, healthy choices.

Alison and Layla

About the letter writers:



  1. This comment has been removed by the author.

    1. Could you please edit your post so that is readable. I can't understand your second sentence.

  2. As a scientist and professor who has been involved with human studies on pesticides and health outcomes for almost 3 decades, I agree with most of your assertions. However, I would say that pesticide residues on food are "below EPA-allowed levels" rather than saying they are "safe." Besides being more technically correct, these allowed levels are considered safe based upon the information available when those levels were derived; however, new data may suggest they are not as safe as previously thought. Hopefully, these new data will translate into policy/regulation. Lots of human data suggest these allowed levels, for certain pesticides namely organophosphates, aren't safe, especially in fetuses.

    1. That's fair. And yes about OPs. The point here is more about a comparison. We have next to no data on the residues on organic produce. They don't have OPs (because they aren't allowed for organic certification) but we have no comparison for what residues are on organic produce. It all comes down to washing your produce, discarding outer leaves of leafy greens and things we should to on all produce to minimize exposures.

  3. This comment has been removed by the author.