Unhealthy healthy soya oil

December 2021

In a curious chain of reductionist science, assumption, generalisation, extrapolation and failure to investigate ambiguous data, the western diet shifted from traditional, saturated animal fats to novel unsaturated vegetable oils in the space of a very few decades. Studies in the 1950s and 1960s linked the saturated fats in a typical American animal-based diet to increased risk of cardiovascular disease. This led to a dogma that all saturated fats are unhealthy and so, conversely, all unsaturated fats are healthy. Similarly, this logic extended to whatever is healthy for the heart is healthy for the rest of the body too.

As a result, soyabean oil has moved from having a negligible presence in the diet to constituting more than 60% of the edible vegetable oil which people are now eating instead of animal fats. Key to this shift, were US government subsidies to soya growers which helped soya to become a leading commodity crop. These subsidies later enabled the adoption of GM Roundup Ready soya in American agriculture too.

Soya oil is now ubiquitous in modern processed foods, margarines, salad dressings and snack foods, and is the oil of choice in many restaurants and fast food establishments.

When obesity and associated diabetes and heart disease started to skyrocket despite that 'healthy' oil in the diet, scientists looked for another reductionist culprit to blame, and singled out 'linoleic acid', a fat constituent present at high levels in soya oil.

Not wanting to relinquish its hold on the lucrative soya market, the biotech industry created 'Plenish' soya beans genetically transformed for low linoleic acid oil. Plenish is marketed as "the healthy option".

However, when the reductionist mindset is ditched, the science tells a different story.

Studies which fed soya oil to a laboratory strain of mouse widely used as a model for diet-induced obesity, found worrying disease markers in two key glands in the body, the liver and the hypothalamus.

Why disease markers in the liver and hypothalamus are of such concern:

The liver is responsible for many vital life functions, including the regulation of fats, proteins and carbohydrates, the storage of some vitamins and minerals, the synthesis of several blood constituents, and detoxification processes.

The hypothalamus, tucked in beneath the brain, is a major integrating link between the nervous and endocrine (hormone) systems. It controls, for example, our heart-rate and all the other muscles whose contractions we're not aware of in our digestive system, blood vessels, and eyes.

It regulates circadian rhythms, sleep and wakefulness, body temperature, thirst and hunger, memory and learning, growth, sexual behaviour, blood pressure, and defensive reactions such as fear and rage, and more.

While there is some evidence that dietary (conventional) soya oil reduces heart disease, and it seems that oil from GM 'Plenish' soya does, indeed, induce less obesity and insulin resistance than 'conventional' soya oil, the study identified much the same disease markers in animals fed either of the oils. It's clear that linoleic acid does not play a role in the adverse effects of soya oil, and contrary to the widely held belief that soya oil lowers blood cholesterol levels, neither test oils had any such effect.

Fat accumulation in the livers of the test mice were observed, along with altered function of genes linked to detoxification, diabetes, inflammation, and energy metabolism. Also, several cancer-promoting genes were up-regulated while several cancer-inhibiting genes were suppressed.

In the hypothalamus, more than 100 genes had significantly changed function. These included genes associated with inflammation, nerve function and insulin control. Up-regulation was observed in genes linked to schizophrenia, depression, anxiety, pain and autism, and the expression of a gene known to be predictive of Alzheimer's disease was also increased.

The authors point out the implications of their findings: soya oil may well be promoting a wide range of modern chronic diseases plus mental health issues. There is clearly a need for "careful evaluation of the extensive use of soybean oil-based food products, including infant formula, animal feed and other processed foods" (Deol 2020).

The take-home message from the authors is "reduce consumption of soybean oil".

OUR COMMENT

The inescapable conclusions from this 'healthy' food fiasco are that a healthy nutritional profile can only be determined by holistic studies, not by looking at single isolated components, and that risk assessment shouldn't be based on single health/disease parameters. Whole life-cycle feeding studies on an established animal model and comprehensive, in-depth investigation of all changes in all organ systems are essential for our safety.

The possibility that the genetic modification itself, or the chemical applications to the crops in the field, may have compromised the findings was not explored. In fact, none of the papers clarify the origin of the two soya oils fed to the mice.

One test oil was derived from Plenish GM soya. Besides genetic modification to change its oil composition, Plenish has been engineered for tolerance to sulfonylurea herbicides, and the crop will have been sprayed with some such formulation.

The other test oil is described as 'conventional', but US soya crops have, for many years, been overwhelmingly GM strains tolerant to glyphosate-herbicide and these would seem to be the new 'conventional'. GM soya sprayed with glyphosate is what's available for experimentation, so it may well have been what was used.

Neither herbicide is likely to end up in the extracted oil, but undisclosed toxic adjuvants added to the sprays to promote their herbicidal action might have.

Both GM soyas were created using micro-particle bombardment which is notorious for random collateral damage to the genome, and science has shown that artificial mutagenic techniques induce heritable stress responses [1]. It's unlikely both GMOs ended up with exactly the same DNA damage, but the assault may have triggered the same stress response in both which could alter oil quality.  

On the other hand, it may be the case that soya oil is intrinsically bad for humans and we shouldn't be eating it in any form, and certainly not feeding it to our livestock and infants (just to fill the coffers of the biotech industry): suggest that to your regulators in government.

Background

[1] STRESSED PLANTS, STRESSED PEOPLE? - GMFS Archive, June 2010 (Doc)


SOURCES:

• Kyle J. Mamounis, et al., 2017, Linoleic acid causes greater weight gain that saturated fat without hypothalamic inflammation in the male mouse, Journal of Nutritional Biochemistry 40

• Carlos Alberto Soares da Costa, et al., 2011, Abdominal adiposity, insulin and bone quality in young male rats fed a high-fat diet containing soybean or canola oil, CLINICS 66(10)

• Poonamjot Deol, et al., October 2017, Omega-6 and Omega-3 oxylipins are implicated in soybean oil-induced obesity in mice, Nature Scientific Reports

• Poonamjot Deol, et al., January 2020, Dysregulation of Hypothalimic Gene Expression and the Oxytocinergic System by Soybean Oil Diets in Male Mice, Endocrine Society

• Poonamjot Deol, et al., July 2015, Soybean Oil Is More Obesogenic and Diabetogeneic that Coconut Oil and Fructose in Mouse: Potential Role for the Liver, PLOS ONE

• "Healthy" soybean oil causes genetic changes in the brain linked to neurological disease, GM Watch, 4.02.20
  

  
  
  
  Picture: United Soybean Board, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons