Eat GMOs, get fat?

February 20, 2015 by Pat Thomas

Genetically modified food has been widely publicised as way to feed the world – but could eating it just make our ‘eating problems’ worse?

Since it has been shown GMOs don’t increase yields or make food more nutritious, and in fact may even contain higher residues of harmful pesticides, the mythology of feeding the world has taken quite a beating. No reputable scientist, or politician, would now use that notion as a justification for GMOs.

But in light of a series of studies in the medical journal the Lancet this week, showing that progress towards tackling obesity around the globe has been “unacceptably slow” and that in less than a generation, rates of child obesity have risen dramatically worldwide maybe it’s time to look at an often ignored adverse effect associated with GMOs.

Feeding the junk food industry – not the world

People don’t eat GMO ‘food’. Even in countries where GMOs are ubiquitous it is rare that consumers walk into a store and buy GMO ears of corn or soya beans. Instead GMOs are turned into ingredients for highly processed ready meals, pre-packaged foods and takeaways.

The main by-products of GMOs are fats and sugars. GMOs, when they’re not being turned into biofuels which feed no one, are being turned into oils (such as corn and soya and even cottonseed oil) and sugar syrups (such as high fructose corn syrup) and to a lesser extent sugar from GM sugar beets.

In other words, what GMOs have most successfully done is provide cheap unhealthy ingredients to the junk food industry. Consuming this food has resulted in multiple health deficits, of which obesity is just one.

Companies that produce these kinds of food may even be cynically maintaining the obesity status quo, particularly in children.

“Fat children are an investment in future sales,” said Tim Lobstein of the World Obesity Federation, a co-researcher on the Lancet series in a recent interview.

Lobstein argues that the food industry has a special interest in targeting children, since repeated exposure to processed foods and sweetened drinks in infancy builds taste preferences, brand loyalty and high profits.

Pesticide plants

Studies show that herbicide-resistant, (Roundup Ready) crops contain many times more of the herbicide glyphosate and its toxic breakdown product AMPA than non-GMO crops. This has led to some scientists calling GMO crops ‘pesticide plants’.

This is important not just because pesticide residues in foods are harmful but because glyphosate is also a hormone disrupter and a registered antibiotic.

It is known to devastate the population of good bacteria in the gut of animals studied and if this is also true in humans could have an effect on how well we absorb nutrients from our food, how well we digest proteins and ultimately how easy it is to maintain a healthy weight. This may be one factor behind the results seen in recent studies into GMOs and weight gain. 

Promoting weight gain

It’s easy to understand how eating junk foods could cause weight gain. But in Norway a group of scientist are finding that GMOs may promote weight gain in other less obvious ways. Their work shows that animals fed a diet of GM corn put on weight, were less able to digest proteins and suffered immune system problems.

The wide-ranging, decade-long international research project includes researchers from Hungary, Austria, Ireland, Turkey, Australia and Norway. Together the researchers are exploring the effects of GM food, studying the impact on rats, mice, pig and salmon.

“We are trying to identify which indicators we need to measure in order to explore unintentional effects from GM food,” explains lead researcher Professor Åshild Krogdahl of the Norwegian School of Veterinary Science.

“The findings could give us some understanding of the potential effects for these animal species as well as for humans”.

(Professor Krogdahl summarises her findings in a video at the bottom of this article).

As part of the project, a group of rats were fed corn which had been genetically modified for pest resistance. Over a period of 90 days they became slightly fatter than the control group of rats fed non-GM corn. The same effect occurred where rats were fed fish which, in turn, had eaten GM corn.

“If the same effect applies to humans, how would it impact on people eating this type of corn over a number of years, or even eating meat from animals feeding on this corn?”, he asks. “It is an interesting phenomenon and worth exploring further.”

Damage to the intestines

Examining the effects on salmon, the researchers found distinct differences between fish being fed GM food and those on a non-GM diet. Many of the changes were within ‘normal’ range, nevertheless the fish fed GM showed a distinct trend.

They were, said Krogdahl “slightly larger, they ate slightly more, their intestines had a different microstructure, they were less able to digest proteins, and there were some changes to their immune system. Blood samples also showed some change in the blood.”

This inability to digest proteins has important implications for health. The proper digestion of protein is necessary for many biological functions which include providing the body with amino acids.

If the link proves to be true it means that eating GMOs could be linked not only a rise in obesity, but to increases in many modern diseases such as diabetes, digestive disorders, inflammatory bowel disease, colitis, autism spectrum disorders (ASD) (ADD), autoimmune diseases, sexual dysfunction, sterility, asthma, COPD and more.

More organ damage

The subtle changes observed by the international study were found in a wide range of organs, including the digestive organs, liver, kidneys, pancreas, adrenal glands and reproductive organs.

Krogdahl points out that there’s nothing inherently unusual about physiological changes after food consumption, as this happens with non-GM food as well. The question is whether changes with a GM diet could be of a different category – potentially causing harm over the long term.

As well as examining salmon intestines after GM food consumption, the researchers also looked at the intestines of rats eating the salmon. The rats ate slightly more and grew faster than their GM-free counterparts, as well as showing signs of immune system disruption.

GM ‘drift’ into vital tissues

The work done by Krogdahl and her colleagues disproves another long held GM myth: that GMOs don’t survive the digestion process.

“A frequent claim has been that new genes introduced in GM food are harmless since all genes are broken up in the intestines. But our findings show that genes can be transferred through the intestinal wall into the blood; they have been found in blood, muscle tissue and liver in sufficiently large segments to be identified,” Krogdahl explains.

“The biological impact of this gene transfer is unknown.”

We should be very wary of all the unknowns associated with GMOs as well as mindful of the research that does exist.

The results of this and other studies into the risks posed by GM food demand that countries that have embraced GMOs over the last 18 years get them out of the food chain as soon as possible. In EU countries, where GMOs are not so widely consumed, they provide good reason to maintain a strict moratorium on GMOs in order to protect our health.

Professor Krogdahl summarises her findings linking GMO food with weight gain at a 2012 conference