Relevant sections:

A research team from University of California, Riverside has been studying the impact of soybean oil for several years. They previously found that it induces diabetes and obesity in mice

And then:

it shows that when soybean oil is fed to mice it has major impact on their hypothalamus, an area of the brain crucial for regulating mood and behaviour.

Where it gets real interesting:

More worryingly, it even affected over 100 of the mice’s genes, including one for controlling oxytocin, the love and bonding hormone. Soybean-fed mice showed lower levels of oxytocin in the hypothalamus. Other genes affected had to do with metabolic and hormone pathways, including the insulin pathway, synonymous with diabetes. There was also upregulation of genes associated with anxiety, depression, and schizophrenia.

In summary: Soybeans make bug people.

Surprisingly proven by a Cuck'ifornia institute.