Sugar can make you dumb, US scientists warn

I'm not sure the conclusion is valid from the study. There were 2 variables here, you can't tell which one caused the differences. The real question is, does it make you dumber than statin use.
http://news.yahoo.com/sugar-dumb-us-scientists-warn-190918006.html

Eating too much sugar can eat away at your brainpower, according to US scientists who published a study Tuesday showing how a steady diet of high-fructose corn syrup sapped lab rats' memories.

Researchers at the University of California Los Angeles (UCLA) fed two groups of rats a solution containing high-fructose corn syrup -- a common ingredient in processed foods -- as drinking water for six weeks.

One group of rats was supplemented with brain-boosting omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA), while the other group was not.

Before the sugar drinks began, the rats were enrolled in a five-day training session in a complicated maze. After six weeks on the sweet solution, the rats were then placed back in the maze to see how they fared.

The rest at the link.