tampabay.com

Got caffeine? Your brain may thank you

By LISA GREENE
Published September 14, 2006


TAMPA - Go ahead, drink that latte.

Caffeine might help prevent Alzheimer's disease - at least in mice, say researchers at the Johnnie B. Byrd Sr. Alzheimer's Center & Research Institute in Tampa.

Mice fed a steady diet of caffeine as they aged stayed mentally sharper and were less likely to develop protein in their brains linked to Alzheimer's, the researchers say in an article published in the journal Neuroscience.

"Oh, boy. The Starbucks people are going to like this," joked Dr. Kimford Meador, a neurology professor at the University of Florida.

But some researchers say people should think twice about getting that extra cup, said Dr. Ronald C. Petersen, director of the Alzheimer's Disease Research Center at the Mayo Clinic College of Medicine.

The study is "well done scientifically," Petersen said. But mice are mice.

"This is not a human study," said Petersen, also vice chairman of the Medical & Scientific Advisory Council of the Alzheimer's Association. "I would be cautious about implying that these results tell us we should all go out and drink five cups of coffee a day."

The mice got the human equivalent of five cups of regular drip coffee a day. The same amount of caffeine, about 500 milligrams, can be found in one or two cups of many premium coffees, said the study's lead author Gary Arendash, research professor at the Byrd Institute and the University of South Florida. Other USF researchers and scientists from the University of Pittsburgh also worked on the project.

Arendash became curious about how caffeine might affect Alzheimer's a few years ago, when he heard about a small Portuguese study asking people about their past caffeine consumption.

That study found people with Alzheimer's had drunk less caffeine over the past 20 years than people without the disease. But the study was small. Arendash wondered if similar results could be shown in mice.

Researchers chose 57 mice, most of which had been genetically altered, so that their brains produced high levels of beta amyloid, a protein linked to Alzheimer's.

Some of the mice got caffeine in their drinking water starting at 4 months old - the threshold of mouse adulthood - and continuing for five months. Other mice got plain water.

At the end of that time, the caffeinated mice performed better on tests designed to measure their memory and thinking.

The brains of the caffeinated mice also had lower levels of beta amyloid. Researchers believe the caffeine reduces the level of two enzymes that help form beta amyloid.

The results are interesting enough to prompt further study in people, Meador said. But designing such a study could be difficult and expensive. For that reason, Petersen said, he would like to see more animal studies confirming the results first.

But Arendash sees no reason why most people shouldn't drink coffee.

"We think this is one that should be in every adult's diet, as long as there are no health reasons to not take caffeine," he said.