Soybean oil is everywhere in American life. Websites run by everyone from doctors to random vegans tout it as a healthier alternative to vegetable oils, with some folks claiming unique health benefits ranging from lower blood sugar to X-ray vision.
Okay, maybe not X-ray vision, but a quick web search will show you what I mean.
Your fast-food is fried in it, since it is polyunsaturated and not a trans-fat. It’s in thousands of packaged and processed foods, all with the blessing of the USDA and other agencies. It’s even fed to livestock, unless they are the free-range, grass-fed or organic variety. Soybean oil is far and away the most widely produced and consumed oil in the entire USA, according to our pals at the US Department of Agriculture.
It’s universally accepted by food agencies, health gurus and other “trustworthy” sources as healthy and good for you.
So what’s the problem, you ask? Well, how about genetic changes to the brain, specifically the hypothalamus? How do you feel about obesity, diabetes, insulin resistance and fatty liver disease? Are you a fan of neurological problems like depression, anxiety, Alzheimer’s and even Parkinson’s disease?
Health food, indeed. Eat up, America!
The very same research team that revealed a link between soybean oil consumption and obesity, diabetes, fatty liver and insulin resistance in 2015 and again in 2017 now has something new to say. According to new research by the University of California Riverside team, soybean oil may lead to changes in the brain that affect neurological conditions such as autism, depression, anxiety and even Alzheimer’s disease.
The team published their research in the journal Endocrinology this month.
In their study, they fed mice three different high-fat diets. One was soybean oil-based, one was coconut oil-based and the last was high in soybean oil which was modified to be low in linoleic acid. This last one was the soybean oil used in the 2017 study.
What they found was that both soybean oil-based diets had profound and significant effects on the hypothalamus. This is important because, well, important stuff happens in the hypothalamus.
“The hypothalamus regulates body weight via your metabolism, maintains body temperature, is critical for reproduction and physical growth as well as your response to stress,” said Margarita Curras-Collazo, a UCR associate professor of neuroscience and lead author on the study.
The problems discovered by the UCR team were genetic. Specifically, a number of genes weren’t functioning correctly in the soybean oil-fed (SOF) critters. One crucial genetic change was the dysregulation of the gene responsible for production of oxytocin, often called the “love hormone.” In the SOF mice, oxytocin levels in the hypothalamus were suppressed.
The problems don’t stop there, however. About 100 other genes were affected by the soybean oil diet. The ramifications of this finding extend to brain function and energy metabolism, as well as problems like autism and Parkinson’s disease. Currently, this is only a linkage. There is no evidence yet that soybean oil causes these diseases and conditions.
Another thing to remember is that these findings apply to soybean oil only. Other soy products, as well as other vegetable oils, were not involved in this research.
“Do not throw out your tofu, soymilk, edamame, or soy sauce,” said Frances Sladek, a UCR toxicologist and professor of cell biology. “Many soy products only contain small amounts of the oil, and large amounts of healthful compounds such as essential fatty acids and proteins.”
Before you panic, it’s important to remember that this research was done on mice. While human and murine brains are similar in many ways that make them suitable for research, mouse studies don’t always translate to similar results in humans.
Another limitation of this study is that it used only male mice. Studies on female mice will be needed, given the importance of oxytocin to maternal health and its promotion of mother-child bonding.
Researchers could rule out linoleic acid as the culprit for the genetic brain changes, since both soybean oil-based diets caused the disruptions. They also ruled out stigmasterol, which is a cholesterol-like compound occurring naturally in soybean oil. Other than those conclusions, they were unable to isolate which chemicals were responsible for what they observed.
An important area of the team’s future research, then, will be identifying the compounds responsible for the negative effects.
“This could help design healthier dietary oils in the future,” said Poonamjot Deol, an assistant project scientist in Sladek’s laboratory and first author on the study.
“The dogma is that saturated fat is bad and unsaturated fat is good. Soybean oil is a polyunsaturated fat, but the idea that it’s good for you is just not proven,” Sladek said.
Coconut oil would seem to be a better choice, having produced very few changes in the hypothalamic genes.
“If there’s one message I want people to take away, it’s this: reduce consumption of soybean oil,” Deol said about the most recent study.
Obesity, diabetes, insulin resistance, fatty liver and now neurological disorders. It might be time for the “health gurus” and the food agencies to admit that they really have no idea whether soybean oil is okay for you to consume. Of course, that would mean some of those gurus would lose their “guru” status and taxpayers might question what we’re paying government food bureaucrats for.
The rest of us, however, might be healthier for it. And that should be all that matters.
Keep the faith and keep after it!
Journal Reference – Poonamjot Deol, et al., Dysregulation of Hypothalamic Gene Expression and the Oxytocinergic System by Soybean Oil Diets in Male Mice. Endocrinology, 2020