According to a study in Endocrinology, soybean oil may cause genetic changes that lead to neurological conditions such as autism, Alzheimer’s disease, anxiety and depression.
Researchers compared mice that were fed three different diets high in fat: soybean oil, soybean oil modified to be low in linoleic acid, and coconut oil.
Results showed that a diet high in soybean oil—whether modified or unmodified—had significant effects on the hypothalamus and caused dysfunction in genes, particularly those associated with oxytocin production. Levels of oxytocin, the “love” hormone that promotes mother-child bonding and is important for maternal health, dropped in mice who were fed soybean oil.
The research also found that the soybean oil diet affected about 100 other genes, which could have consequences for proper brain function and diseases such as autism or Parkinson’s disease.
The same research team found in an earlier study that soybean oil contributed to obesity, diabetes, insulin resistance and fatty liver in mice.
Importantly, researchers note that the study does not prove that soybean oil causes these diseases, and they have not yet identified which chemicals in the oil contribute to the changes found in the hypothalamus. However, their study rules out linoleic acid and stigmasterol, a cholesterol-like chemical natural to soybean oil.
Their future research will focus on identifying specific compounds at fault.
“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.
While the research used male mice only, and effects may be different on humans, the study authors recommend reducing consumption of soybean oil. Their caution does not extend to other soy products, such as tofu, soy milk and edamame.
Deol, P., et al. 2020. Dysregulation of hypothalamic gene expression and the oxytocinergic system by soybean oil diets in male mice. Endocrinology, 2020. doi: 10.1210/endocr/bqz044.