This was surprising. A study suggests that just a few days eating a high fat diet weakens brain function. Further, this study suggests that a high fat diet affects physical performance too.

Who would have thought that a few days on a high fat diet could affect your memory? As if we needed another reason to make us feel guilty eating high fat foods.

The published study was on rats, but according to the NYT, an unpublished follow-up study in humans (healthy young men) show the same thing.

The researchers trained rats to navigate a complex maze that contained 8 different food rewards within it. After the rats had mastered the maze, half were given a high fat diet (55% fat) the rest remained on a regular diet (7.5% fat).

After only 9 days on high fat diet, the rats were not performing as well in the maze test, as they had previously. Those rats remaining on regular diet continued to perform well.

It had previously been shown that a long duration high fat diet reduced brain function in memory and learning tasks in humans and rats (Neurobiol. Aging, 26 Suppl 1 42-5 & 46-9, 2005). However, now it appears that the weakened brain function starts pretty quickly.

The rats on the high fat diet also ran 35% less time on a treadmill after 9 days on the diet.

This fast, and big change, in activity level indicates that a decline in physical performance on a high fat diet is due to some rapid internal change in the body, not purely weight related. The researchers showed that the level of a protein called uncoupling protein 3 (UCP3) increased in the muscle of the rats.

The researchers do not give an explanation for the effects of high fat consumption on brain function.

So this raises the question in humans. Does simply binging on high fat foods make you stupider?

Is the high fat effect reversible? If so, how long does it take to reverse?

Should you eat a low fat diet for a week or two before an important exam or other activity that requires learning and/or critical thinking?

Was I stupider after my recent vacation than I was before, since I ate a lot more rubbish than usual?

photo credit: tsuihin – TimoStudios ©

[tags]high fat diet, brain function, memory, maze, physical performance, activity level, uncoupling protein, UCP3[/tags]