Inflammatory bowel disease (IBD) is a multifactorial disorder influenced by host genetics, immune dysfunction, intestinal microbiota, and environmental factors like diet. Over the past century, soybean oil (SO) has increased in the American diet, paralleling the increased incidence of IBD in the US.
Consuming soybean oil has been connected to obesity, diabetes, autism, Alzheimer’s, anxiety, and sadness. Additionally, the large intestine is chronically inflamed in ulcerative colitis (IBD), an inflammatory bowel disease. In the lab, Mice fed a diet rich in soybean oil for up to 24 weeks were investigated in the gut by researchers at the University of California, Riverside.Â
They discovered that colitis-causing conditions included a decline in helpful bacteria and an increase in dangerous bacteria, notably adherent invasive Escherichia coli.
Soybean oil is currently the most popular cooking oil in the United States. It is becoming more popular in other nations, particularly Brazil, China, and India. Soybean oil was produced as a byproduct of the increasing trend in growth in the United States in the 1970s for use as animal feed. Soybeans, a good source of protein, are simple and inexpensive to raise.
The researchers challenged the decades-old belief that many chronic diseases are caused by eating too much-saturated fats from animal products and that unsaturated fats from plants are always healthier.
They discovered that consuming a lot of soybean oil promotes the formation of adherent invasive E. coli in the gut. This bacterium uses linoleic acid as a carbon source to meet its nutritional needs. Furthermore, numerous helpful bacteria in the stomach are unable to survive linoleic acid and die, resulting in the growth of dangerous bacteria.
She said, “While our bodies need 1-2% of linoleic acid daily, based on the paleo diet, Americans today are getting 8-10% of their energy from linoleic acid daily, most of it from soybean oil; excessive linoleic acid negatively affects the gut microbiome.”
In humans, adherent invasive E. coli has been linked to IBD. A diet high in soybean oil has been observed to promote the growth of dangerous bacteria in the gut, such as adherent invasive E. coli. The combination of good bacteria dying and harmful bacteria multiplying makes the stomach more vulnerable to inflammation and its consequences.Â
Linoleic acid causes the intestinal epithelium to become porous, which is essential for gut health. When this barrier is breached, it can increase permeability or leakiness, allowing toxins to leak out of the stomach and enter the bloodstream, dramatically raising the risk of infections and chronic inflammatory disorders like colitis.
Toxicologist Frances M. Sladek, a cell biology professor and co-corresponding author on the study, recalls how saturated fats were related to heart disease in the late 1950s.
She noted that every animal requires linoleic acid in their diet, but just because something is required does not mean that a lot of it is good for you. Several membranes in the body, for example, require linoleic acid to operate properly. Future research is needed to identify the safe level of daily linoleic acid ingestion.
She said, “Since studies showed that saturated fats can be unhealthy, it was assumed that all unsaturated fats are healthy. But there are different types of unsaturated fats, some healthful. For example, the unsaturated fat fish oil is well known to have many beneficial health effects. Therefore, people assumed that soybean oil is safe and healthier to consume than other types of oils, without actually making a direct comparison as we have done.”
According to Sladek and Deol, olive oil is healthier because it contains less linoleic acid. Olive oil, the foundation of the Mediterranean diet, is thought to be highly healthy; it causes less fat, and we have now discovered that, unlike soybean oil, it does not enhance mice’s susceptibility to colitis. James Borneman, a co-corresponding author on the paper and a microbiology and plant pathology professor at UCR, specializes in gut microbiota.
Most processed foods in the United States contain soybean oil, which may explain why many Americans consume more linoleic acid than is advised. Because soybean oil is relatively inexpensive, it is used in most restaurants in the United States. Try to avoid IBD by staying active.
Researchers advised, “Try to stay away from processed foods,” “When you buy oil, make sure you read the nutrition facts label. Air fryers are a good option because they use very little oil.”
The result shows that the naturally high LA content of soybean oil may be contributing to the rise in IBD in the United States through a variety of mechanisms involving the gut microbiota and host cells and by fostering an immunoreactive environment typical of IBD by both increasing pro-inflammatory and decreasing anti-inflammatory molecules. Future research is still needed to ascertain the intricacies of this mechanism.
Journal Reference:
- Poonamjot Deol, Paul Ruegger, et al. A diet high in linoleic acid dysregulates the intestinal endocannabinoid system and increases susceptibility to colitis in Mice. Gut Microbes. DOI: 10.1080/19490976.2023.2229945