The potential effect of dietary oils on emotional behavior

A study in PLOS ONE examining laboratory mice demonstrated a link between a diet rich in oils and the reduction of anxiety and depression symptoms.

Dr. Keiko Kato, whose research was funded in part by Kyoto Sangyo University in Japan, conducted the study to evaluate the effectiveness of dietary oils on emotional behaviors. Kato was interesting in expanding on earlier research, noting that “few studies have compared dietary oils containing saturated and unsaturated fatty acids with regard to their effects on emotional behaviors using the same experimental model.”

It has been demonstrated that dietary fatty acids play a role in neurological health, assisting with the regulation of the limbic system and cortical functioning. Serotonin production, for instance, is dependent on omega-3 fatty acids. By investigating how laboratory mice respond to a diet rich in oils, researchers may be able to more fully understand the role of dietary oils in human diets.

In the study, mice in the experimental group were fed 1 of 3 combination oil rich diets, while control group mice were fed a rodent diet comprised primarily of carbohydrates and protein. Beginning at 9 weeks of age, mice were subjected to behavioral tests assessing anxiety (measured with an auditory fear conditioning test) and depression (measured with a forced swim test). To evaluate activity, exploration and acclimation, an open field test was utilized.

Kato’s results indicated differences in treatment between wild type mice (“WT,” or mice that occur in nature) and sialyltransferase ST3Gal IV-knockout mice (“KO mice,” genetically altered mice where a specific gene, in this case, ST3Gal IV, has been “knocked out”).

Most notable are the findings that a diet comprised primarily of triglycerides improved anxiety and depression symptoms, such as contextual fear in WT mice and tone fear in KO mice; these data are inconsistent with studies linking saturated fatty acids to coronary artery disease and some tumors in humans.

As noted by Dr. Kato: “the POP-SOS diet (primarily triglycerides) in the present study alleviated mouse anxiety and depression symptoms in the presence of a stressor. Thus far, little is known about the effects of triglycerides, including the effects of saturated fatty acids on emotional behaviors. The present study shows that a mixture of palmitic acid, stearic acid, and oleic acid is suitable for alleviating anxiety symptoms in a rodent model, and represents an important advance in understanding the neural effects of dietary triglycerides.”