Lapses in memory? Trouble concentrating? Junk food could be to blame. In a new study from the University of New South Wales in Australia, researchers show that a diet high in fat and sugar may restrict cognitive abilities after just one week. The discovery could help improve the current understanding of how obesity and excessive weight gain affect the body.
For some time, researchers have suspected a link between obesity and psychiatric complications like depression. However, it has not been clear whether unhealthy eating habits actually affect the brain. The new study, which is published in the journal Brain, Behavior, and Immunity, sought to clarify this by evaluating cognitive changes in rats fed a diet high in sugar and fat.
For one week, subjects were assigned one of three meal plans: a healthy diet; an unhealthy diet emphasizing cake, chips, and biscuits; or a healthy diet taken with sugar water. The first and the second meal plan represented the control and treatment group respectively. The third plan was an experimental diet aimed at isolating the effect of excessive sugar intake.
The team found that, in both the treatment and the experimental group, subjects exhibited cognitive impairments after only one week. These impairments typically manifested as a reduced ability to recognize certain objects. According to senior author Margaret Morris, the results suggest that even a temporary diet high in sugar and fat may have alarming consequences. "What is so surprising about this research is the speed with which the deterioration of the cognition occurred,” she said in a press release. “Our preliminary data also suggests that the damage is not reversed when the rats are switched back to a healthy diet, which is very concerning.”
In addition, these rats had signs of inflammation in their brain’s hippocampal area — a cerebral center associated with spatial memory. This suggests that the inflammatory responses recorded in obese people may not be limited to fat tissue. “We know that obesity causes inflammation in the body, but we didn’t realize until recently that it also causes changes in the brain,” Morris added.
Junk Food and Your Mind
The new study is not the first to implicate unhealthy eating in adverse psychiatric outcomes. In an earlier study from the University of Toronto, researchers show that advertisements and symbols associated with McDonald’s, Wendy’s, and other fast food restaurants actually impair our ability to savor the moment. These establishments, they argue, “undermine the surplus time they permit” by instilling a type of chronic impatience in their customers.
Hopefully, Morris’ and her colleague’s new paper will help more people realize the many consequences of excessive sugar and fat intake. “We suspect that these findings may be relevant to people,” Morris told reporters. “While nutrition affects the brain at every age, it is critical as we get older and may be important in preventing cognitive decline. An elderly person with poor diet may be more likely to have problems. ”