The Van Eenennaam review of animal feeding data fails to counter primary research findings and doesn't show GMO safety
Criticism continues to pour in from scientists of the former Monsanto researcher Alison Van Eenennaam's review of animal feeding data, which concluded that GMOs are safe. Here's the latest compilation of critics' points.
Review of paper by Alison Van Eenennaam and AE Young (2014): Prevalence of impacts of genetically engineered feedstuffs on livestock populations. J Anim Sci, 92:4255-4278 – A compilation of critiques by scientists
GMWatch, 23 October 2014
Van Eenennaam has a conflict of interest - she is at the University of California, Davis, which has a Seed Biotechnology Center which has received funding from biotech companies like Monsanto. The University runs a student Fellowship funded by Monsanto.
The attorney and food writer Michele Simon called the University of California at Davis "a research incubator for Big Biotech". She cited a press report saying that biotech companies have helped pay for laboratory studies, scholarships, post-doctoral students’ salaries, professors’ travel expenses, and even the campus utility bill.
Van Eenennaam implied in a radio interview on Australia’s ABC Radio National’s Bush Telegraph program (23 October 2014) that her study – which is no more than a review of others’ studies – counters Dr Judy Carman's toxicology study on pigs. However, in contrast with Carman's study, none of the studies Van Eenennaam looked at fed a diet containing three GM genes at once, looked at stomach inflammation, and weighed the uterus. So she cannot compare her study to Carman's.
The studies that Van Eenennaam reviewed generally measure very gross measurements such as body weight and death rates, designed to reassure farmers that if they feed GM feed to their animals, the animal will gain sufficient weight to sell the animals at market. They are generally not toxicology/health studies. These sorts of studies are very poor measures of health, particularly for people who eat these crops. The studies she looks at rarely look inside organs or measure things in blood. They generally do not look at health outcomes, such as allergies, reproductive rates, rates of cancer or toxic effects such as the effect of the diet on liver, kidneys, the heart, diabetes risk, immune function, rates of infections and so on.
Even with body weight measures, there is a problem – the view in these studies is that a heavier animal is a healthier animal. Yet we have a problem with obesity in many countries and the health outcomes associated with that, which clearly shows that a heavier person is not a healthier person. And even if you stay the same weight but some of your muscle turns into fat – that is not healthy either. But most of the studies she has reviewed are not interested in those “subtleties”.
Carman's measurements of performance indicators like feed intake and body weight in pigs fed GM feed showed that there was no difference between the GM-fed and the non-GM-fed pigs. Only by looking more deeply did Carman's team find problems.
Van Eenennaam's argument implies that you can decide that animal or a person does not have diabetes, heart disease, allergies, reproductive problems, toxicity or cancer simply by weighing them. You don’t need, for example, a physical examination, blood tests or imaging such as an ultrasound or MRI.
Van Eenennaam gives a table summarising 10 studies on pigs. Clearly written in that table is that different studies show that there were changes in blood biochemistry, haematology, immune function, intestines (histology), kidney weights, liver weights and gut bacteria in pigs fed GM feed. But then she concludes that these studies show that eating GM crops caused no adverse effects in the animals.
In the radio interview, Van Eenennaam stated that proteins are all digested in the gut and material does not enter the tissues of the body. Yet the studies she reviews clearly also show that GM DNA can at least be found throughout the intestinal tract, when the GM industry and food regulators have been saying for years that this doesn’t and can’t happen. And she ignores the Aris and Leblanc study on Canadian women showing DNA from Bt toxin (perhaps from GM crops) in blood.
On the program, she claimed that Carman's pig study cannot claim that there was an increase in inflammation in the stomach of pigs without doing histology. She is essentially stating that if you do a study on animals, you do not need to do histology to prove that animals are healthy, but if you find harm then you have to do histology to prove it. This is double standards writ large. Jack Heinemann used this argument on his recent blog. As far as we know, there is no single properly conducted histology study on rats fed crops containing three main GM genes.
Van Eenennaam looks at country-wide livestock production data for chickens and cows/cattle but does not look at pigs. Given that the spread of PRRS (Porcine Reproductive and Respiratory Syndrome) through pigs in the USA over the last few years is likely to have affected livestock production data for pigs, this indicates a selective use of data in her report.
Van Eenennaam argues that animal feeding studies (randomised controlled trials: RCT) should not be used and that there is good information from looking at overall production data on animals in the USA (the latter is called an ecological study design). Epidemiologists know that, of all the study designs, an RCT is the highest study design you can have while an ecological study design is the poorest. She is therefore arguing that good quality, controlled-for data from RCTs should be ignored in favour of data from a much poorer study design that adds in much more variability/noise into the data.
For example, lots of other things have changed in livestock production since GM crops started to be fed to farm animals. The genetics of animals have improved (eg an increase in artificial insemination using sperm from male animals with superior characteristics) and animal husbandry practices have changed. These changes could be masking any adverse effects of GMOs on health of animals. She acknowledges that there has been an improvement in genetics over that time but does not consider the possibility that this may be masking any effects from GM feed.
In addition, livestock are raised for slaughter for a much shorter time period than their natural lifespans, so the exposure periods that they are subjected to is comparable to short-term (acute) or subchronic studies in terms of length. Even dairy cows are now kept on CAFOs for only a few years (about 3-5) compared to much longer normal lifespans.
In the US, beef cattle headed for slaughter spend 6-8 months of their 11-15 months on earth on (non-GM) pasture, and consuming grass/legume forages — i.e. essentially no GMOs, at least not until RR alfalfa came on the scene (still, a small share at most). They would be shifted to an around 50% GMO diet for the last 3-5 months of their life, a time period when they are subjected to many health interventions, including drugs and hormones, in addition to consuming GM corn/soy/alfalfa.
Essentially no livestock in the US live out a normal life, other than perhaps sows and boars, and some bulls.
The best model for the adverse impacts of GM food in the US may be dogs and cats. These companion animals are showing emerging yet unexplained trends of obesity/diabetes/cancer.
In conclusion, Van Eenennaam's review does not counter Carman's toxicology feeding study on pigs and does not prove GMO safety.