Forget the damage to your waistline - over-indulging at Christmas could take its toll on your brain cells, too. Eating a diet loaded with saturated fat and sugar may have an immediate effect on the brain's cognitive ability and cause memory loss, a University of New South Wales (Australia) study has found.
''We know obesity causes inflammation in the body, but we didn't realize until recently that it causes changes in the brain,'' said Margaret Morris, the head of pharmacology at the University of NSW.
The team placed rats on a diet high in sugar and fat and compared their performance with rodents on a healthy diet. Researchers were able to ascertain that rats fed a diet high in fat and sugar had impaired memory after just a week. Interestingly, the results were similarly poor for the rats fed a healthy diet and given access to sugar water to drink. The cognitive impairment related to place recognition, with the animals showing poorer ability to notice when an object had been shifted to a new location. These animals also had inflammation of the hippocampal region of the brain, the part of the brain that is involved in memory forming and storing.
"What is so surprising about this research is the speed with which the deterioration of the cognition occurred," says Professor Morris. "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."
Researchers said ongoing work will attempt to establish how to stop the inflammation in the brain of animals with unhealthy diets.
"We suspect that these findings may be relevant to people," Professor Morris said. "While nutrition affects the brain at every age, it is critical as we get older and maybe be important in preventing cognitive decline. An elderly person with poor diet may be more likely to have problems," she said.
Researchers said this study builds on previous work that has implications for obesity.
"Given that high energy foods can impair the function of the hippocampus, if you eat a lot of them it may contribute to weight gain, by interfering with your episodic memory," Professor Morris said. "People might be less aware of their internal cues like hunger pangs and knowing when they have had enough," she said.
The findings of the study, recently published in the journal Brain, Behaviour and Immunity, could lead to a really big difference with how much motivation we have to change the dietary patterns that we have. Because losing one's memory is all about the impact that it has on us on a very, very day-to-day life and a very personal level. And having a diet that optimises one's memory is going to be something that we'll all be very, very keen to be following.