Higher reported saturated fat and refined sugar intake is associated with reduced hippocampal-dependent memory and sensitivity to interoceptive signals

Francis, H.M., & Stevenson, R.J. (2011, October 24). Higher reported saturated fat and refined sugar intake is associated with reduced hippocampal-dependent memory and sensitivity to interoceptive signals. Behavioral Neuroscience. Advanced online publication. doi: 10.1037/a0025998

The hippocampus is a very important structure in regard to learning and memory.  The article I found suggests that a diet high in saturated fat and refined sugar (abbreviated as HFS), can reduce the effectiveness of the hippocampus.

Research has shown that amnesic patients who had attained bilateral hippocampal damage readily eat a 2^nd meal presented to them 15 minutes after they finish eating another meal.  They don’t have the memory for what they have already eaten. If the damage in the hippocampus can result in altered eating patterns, can a “damaged” diet, so to say, result in an altered or less effective hippocampus?

Seemingly, yes. Recent shows that the typical Western diet, which is high in saturated fats and refined sugars, disrupts hippocampal structures. Rodents fed this type of diet showed impaired performance on learning and memory tasks.

In the current study, researchers tested for association between an HFS diet and hippocampal sensitive neuropsychological task performance in human participants.  The researchers gave the participants a Dietary Fat and Sugar Questionnaire that assessed how often the participants at 24 common high fat, sugar, or both foods such as several types of meat, cheese, butter, eggs, pancakes, white bread, soft drinks, etc.  The participants also took the Marlowe and Crowne Social Desirability Scale, a measure researchers chose to use to try to determine if participants were telling the truth or trying to answer in a socially desirable way about their diet patterns. Participants also took the Three Factor Eating Questionnaire which measured their cognitive restraint, disinhibition, and hunger, and completed demographics.

Next they were subjected to hippocampal function tests on the computer. They listened to an audiobook story, and were the suddenly asked to type everything that they just heard. They were asked to do this same thing again 20 minutes later, after distractions.

Regression analyses revealed that diet was the highest predictor of hippocampal function among many other factors.

The major weakness noted in this study is that the participants retrospectively estimated how often they ate certain foods.