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What is the relationship between pesticides for GMOs and the decline in bee populations?


Bryan Danforth, PhD

There is both a short and a long answer to this question. First, the short and simple: No evidence exists to support the claim that GMO crops themselves have a negative impact on bee populations.

However, the long answer is that there is evidence that neonictinoid pesticides (which are either sprayed on crops, or applied as seed coatings) are seen as a contributing factor to the decline in bee populations. One must consider, however, that currently approved GE crops are modified to either provide protection from pests (for example, using Bacillus thuringiensis, or Bt) or tolerance to herbicides (for example, “Round-Up Ready”)—neither related to neonictinoid pesticides.

Additionally, it’s also important to note that some recent studies have pointed to the indirect effects of Round-Up Ready crops on bees, demonstrating that the reduction in weeds and adjacent non-crop plants leads to reduced pollinator abundance.

The bottom line is that the major causes of bee declines are a combination of (1) heavy pesticide use in agricultural settings, independent of GMOs, (2) habitat simplification and the absence of floral diversity in and around heavily-agricultural areas, and (3) the most likely contributor, heavy pathogens loads from the many viruses, bacteria, fungi, and microsporidia that infect the domestic honey bee.

For more information, I would refer you to the Xerxes Society website on pollinator conservation

Bryan Danforth, PhD, Professor, Cornell Department of Entomology. Research focuses on the phylogeny, evolution, population, genetics, and conservation of bees.

What is recombinant bovine somatotropin hormone, and why do some of the dairy products in my fridge have labels saying they don’t contain it?


Dr. Dale Bauman, Dr. Alice Callahan, and Joanna Lidback

We asked 3 scientists to each answer this question:

Scientist #1: Dr. Dale Bauman, Ph.D. is Liberty Hyde Bailey Professor Emeritus in the Department of Animal Science and the Division of Nutritional Sciences at Cornell University. His research on metabolic regulation of nutrient use has led to development of new technologies and commercial practices, including recombinant bovine somatotropin hormone. Dr. Bauman was elected to the National Academy of Sciences. He served on various USDA Advisory Committees, and was President of the American Society for Nutrition.

I’d specifically like to tackle the first part of this question, and explain what recombinant bovine somatotropin (rbST)—also called recombinant bovine growth hormone (RBGH)—is. At the most basic level, Bovine Somatotropin (bST) is a protein hormone produced in the pituitary gland of a cow’s brain. bST is responsible for the regulation of milk production in lactating dairy cows. This occurs through coordination of the cow’s metabolism, such that the nutrients she consumes through her feed are efficiently used to produce milk.

Recombinant-DNA technology has allowed for the commercial production of bST, known as rbST. What results is a biologic equivalent to the natural, pituitary-derived bST. It is of value to note that because of this equivalence, there is no test that can identify if the milk did or did not come from cows supplemented with rbST.  As a result, instead of a label identifying “rbST-free” milk, the FDA has required the label to include the disclaimer statement that, “No significant difference has been shown between milk derived from rbST-treated and non-rbST-treated cows.”

Among one of the first proteins produced through biotechnology application, rbST has been marketed for 28 years (24, United States). As of 2014, more than 35 million dairy cows have received rbST supplementation, representing a supply of over 80 billion gallons of milk. rBST’s contribution to improving productive dairy cow efficiency (milk output/resource input) is one reason that today’s carbon footprint per gallon of milk production is only one-third of that in the 1940s.

Additional information can be found here


Scientist #2: Dr. Alice Callahan earned a B.S. in Animal Science from Cornell University and Ph.D. in Nutrition from the University of California, Davis. She writes about science, nutrition, and parenting on her blog, Science of Mom, and in her first book, to be published by Johns Hopkins University Press in 2015.

With every trip to the grocery store, we are confronted with a dizzying array of food choices. We may have different priorities as we approach these decisions, but we all agree that we want our food to be safe. In the dairy case, some products are labeled as being from farms that pledge not to use recombinant bovine somatotropin (rbST). The use of rbST has proven to be controversial, but scientific evidence is reassuring that it doesn't compromise the healthfulness or safety of dairy products.

From a nutrition standpoint, studies show that the use of rbST doesn't change the nutrient composition of milk. All milk is a valuable source of calcium, vitamin D, potassium, high-quality protein, and many other nutrients. A common safety concern about rbST is that it might alter the concentrations of hormones in milk, particularly somatotropin, also called growth hormone, and another hormone called IGF-I.

There are several reasons why we don't need to worry about growth hormone in milk, regardless of the use of rbST. First, rbST treatment doesn't actually increase growth hormone in milk. Second, growth hormone is a protein, and like all food proteins, it is broken down in the human digestive system. (This is why diabetics have to inject insulin; if they drank it, it would have no effect.) Finally, growth hormone is species-specific, so bovine growth hormone doesn't have biological activity in the human body.

Growth hormone also stimulates the production of another hormone called IGF-I. This is of greater concern because the human and bovine versions are identical, making bovine IGF-I potentially biologically active in humans. The use of rbST in cows can cause a small increase in IGF-I in milk, although concentrations are still within a normal range for cow's milk and human breast milk. Most IGF-I in milk seems to be broken down by the human digestive system, but small amounts may be absorbed. However, this amount would be tiny compared to natural production of IGF-I by the human body. It has been estimated that the increase in IGF-I in milk from cows treated with rbST would be less than 0.09% of daily human production of the hormone (and that's assuming that a person drank 1.5 L of milk per day, all from cows treated with rbST, and absorbed all the IGF-I in it). Despite many studies, there is no evidence for a link between IGF-I in milk and cancer or diabetes.

Food labels can be overwhelming, but science can help us understand what they do and don't mean. In the case of rbST, national and international food safety organizations periodically review this evidence and agree that milk from cows treated with rbST is safe to drink.


Scientist #3: Joanna Lidback is a first-generation dairy farmer (45-cows) in northeast Vermont, as well as a mother of two. In addition to being an active partner on the farm, she works full-time with Farm Credit, and as vice president of her county Farm Bureau. In July, she was called on to testify before the House Agriculture Committee hearing on he Societal Benefits of Agricultural Biotechnology. She holds a bachelor’s degree from Cornell University, and an MBA.

Recombinant bovine somatotropin (rBST) is a tool to increase a cow’s milk production. We would give it to a cow if her milk production was lagging for whatever reason – perhaps she had been injured or sick and upon return to good health, we could help her get back to her normal production levels with rBST. Another way to use rBST would be to administer it to all or most cows on a regular basis in order to boost production across the whole herd. While many see the use of rBST as an example of “big agriculture” practices in a negative way, the reality is that is can be used by all sizes of farms. In particular, its use could help small or resource-limited farms boost their production in a way that does not harm the cow, makes better use of existing resources and does not require expanding the actual herd size by number of cows including additional capital investment and other costs of business growth, (i.e., greater inputs, labor challenges and regulatory issues).

Our milk cooperative has asked us to not use it anymore. This way, our milk is more marketable to processors who may want to use a label on their end product that reads “made from cows not treated with rBST.” This label, driven by the marketplace, does not convey anything about the safety of the product but rather production methods. Consumers, not understanding the science behind rBST and being driven by fear stirred up by anti-agriculture activists, rejected this technology for no sound reason. It has no adverse effect on human health. Milk that is from cows treated with rBST is just as safe as that from those that are not. At the end of the day, compositionally, milk is milk; there is no significant difference between the level of hormones found in milk based upon production methods – either using rBST or not, and that includes organic milk as well.


How do GMOs affect farmers’ abilities to save seeds, and what impact does this have?


Edward Mabaya

There is no tool in biotechnology that affects a farmers’ ability to save seed. However, certain technologies are proprietary and the intellectual property rights (IPR) within each country do govern what seed farmers can save. It is important to decouple the technology from the IPR.

There are many new GMO technologies that have been developed through public research (CGIARs and National Agricultural Research Organizations). These technologies should soon be coming to market, and can be used without restrictions. In the case of Africa, the public should familiarize themselves with the excellent work of the African Agricultural Technology Foundation, a not-for-profit organization that “facilitates and promotes public/private partnerships for the access and delivery of appropriate agricultural technologies for sustainable use by smallholder farmers in Sub Saharan Africa.” It is also important to note that patents to the currently popular GM technologies (Round Up Ready and Bt) will be expiring in the next two years, making them publicly available.

Last and most importantly, farmers are willing to buy seed each year when they see the value. In most cases, the benefits of purchased seed to the farmer do outweigh the cost. Indeed, most farmers do not save seed for the numerous hybrid varieties that are currently on the market. The idea of farmer-saved seed is only important to open pollinated varieties (such as beans and small grains) that can retain genetic purity over a couple of generations.

Instead of focusing on farmers’ ability to save seed, we need to shift our attention to ensuring that smallholder farmers have access to the affordable, appropriate, and high quality seed at the time of planting.

Dr. Edward Mabaya is a Research Associate in the Emerging Markets Program of the Charles H. Dyson School of Applied Economics and Management at Cornell University, and the Assistant Direct at the Cornell International Institute for Food, Agriculture, and Development. His research focuses on food marketing and distribution, seed systems, and agribusiness management.


Tags: seed

How do GMOs affect low FODMAP diets?


Ruth MacDonald

The short answer to this question is – not at all! A low FODMAP diet (FODMAP = fermentable oligo-Di-Monosaccharides and polyols) is a clinical approach to the management of inflammatory bowel symptoms. FODMAPs are carbohydrates found in foods that are poorly digested and therefore are available for fermentation by colonic bacteria. Not all carbohydrates fit this category – in fact most commonly consumed carbs (starches and sugars) are readily digested. And most people tolerate these food components very well. However, in some individuals, excess intake can lead to symptoms of diarrhea, constipation, gas, bloating or cramps. FODMAP carbohydrates are found mainly in fruits, wheat, beans and dietary fiber sources (whole grains). Some people with lactase deficiency will be unable to digest lactose from milk, so dairy products would fit this category for those individuals. Relative to genetically modified foods, the main components in the food supply that are derived from GMO crops are corn oil, corn starch, corn sweeteners, soy protein, soy oil and sugar from sugar beets. These ingredients from GMO plants are not different chemically or nutritionally from conventionally grown plants, therefore there is no concern about avoiding GMO foods or ingredients specifically. Corn sweetener and sugar, which both contain the same amount of fructose, when consumed in high quantities may need to be monitored in sensitive individuals – this would be true for these ingredients from either conventional or GMO derived plants. Wheat, beans, fruits and vegetables grown in the US have not been genetically modified using biotechnology, but these foods may trigger symptoms in sensitive individuals. Hence, GMO foods or food ingredients do not play a role in FODMAP diets and there is no need to avoid these products.


Dr. Ruth MacDonald is Professor and Chair of the Food Science and Human Nutrition Department in the Iowa State University’s College of Agriculture and Life Sciences. Dr. MacDonald holds a Ph.D. in Nutrition and Food Science from the University of Minnesota, and is a member of the American Association for Nutritional Sciences, the American Association for Cancer Research, Sigma Xi, and the Institute for Food Technologists.



Tags: diet, FODMAP

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