It changes the mix of bacteria in the gut-known as the gut microbiome-which appears to affect the brain, including cognitive ability, memory and increased anxiety.
The diet also causes inflammation in the brain, and this could lead to depression and other psychiatric disorders, say researchers from Louisiana State University.
Thus far, the discoveries have been based on tests with laboratory mice, but the results are nonetheless worrying. Gut microbioma from mice given a high-fat diet were transplanted into other mice, which were monitored for any changes to their behaviour and cognition.
They quickly developed behavioural problems, including anxiety, impaired memory, and repetitive actions. The mice also showed signs of gut permeability and had markers of inflammation, including signs of inflammation in the brain.
(Source: Biological Psychiatry, 2015; 77(7): 607)