WebMD Newsroom

By Daniel J. DeNoon

SUGAR MAKES YOU STUPID has been in headlines this week.

The culprit of the week is fructose, better known to most of us as corn syrup (often called “high fructose corn syrup”), a common food additive.

“Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information,” UCLA researcher Fernando Gomez-Pinilla, PhD, said in a news release.

A glance at Professor Gomez-Pinilla’s resume tells me he’s a highly trained scientist. But a glance at his findings tells me his study was done on rats. And not just ordinary rats, but rats starved for omega-3 fatty acids.

That’s how science works, moving from the test tube to lower animals to higher animals to man. Media reports, however, make mice into men.

Rats deficient in omega-3 fatty acids are dumber than normal rats. Feeding them a lot of sugar for a long time makes them even more stupid. Giving them some omega-3 supplements counteracts these effects of sugar.

Does this mean sugar makes us stupid — and that it’s okay to eat lots of sugar if we take omega-3 supplements?

Rat brains and human brains have a lot in common. (Insert your favorite joke here.) But the jump from rats to humans is a long evolutionary leap.

That’s not obvious from the headlines you see every week. Last week, the headlines screamed that yogurt makes men manlier. Yet who was eating all that yogurt? Mice.

It may be that eating yogurt makes a sexy man out of a mouse. But don’t bet on it.

There’s a saying in biology: Mice lie. It means that many things discovered in rodent studies turn out not to apply directly to humans.

It’s intuitive to think that findings in mice, or rats, must apply to humans. It’s good science to confirm those findings in humans. That’s why we at WebMD are very cautious about declaring a cure for cancer, stupidity, or lack of manliness based on studies in mice. Or rats.

Or even in monkeys, who are a bit closer to men evolution-wise. The full saying is, “Mice lie. Monkeys exaggerate.”