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More Evidence Suggests Marijuana Slows Alzheimer's

Up in Smoke: Marijuana Toasts Memory

Marijuana might contain compounds that slow memory loss in Alzheimer's patients, according to a new study that bolsters other research suggesting potential brain benefits of pot.

Old rats treated with a synthetic compound similar to marijuana got smarter, said Gary Wenk, study co-author and a professor of psychology at Ohio State University.

"The compound substantially improved the memories of the older rats," Wenk said. "These animals were able to hold on to key details of a specific task. Untreated older rats, on the other hand, were not."

The key seems to be in marijuana's anti-inflammatory effects.

"Inflammation in the brain is part of aging," Wenk said. "It happens to almost all of us as we age. But in some cases, this inflammation gets out of hand and causes serious damage."

Wenk notes that other studies indicate that people who regularly smoked marijuana in the 1960s and '70s rarely develop Alzheimer's disease. But there is of course a downside. Research has also shown that years of heavy marijuana use, consisting of four or more joints a week, can impair memory, decision making, and the ability to pay attention to more than one thing at a time.

"We don't use marijuana in our experiments because we're trying to find a compound that isn't psychoactive," Wenk said.

The synthetic marijuana-like compound used in the study, called WIN-55212-2, decreased inflammation in the brains of both young and old rats and helped them navigate a maze better.

The findings were presented today in Atlanta at the annual Society for Neuroscience meeting.

A separate study earlier this month found that the active ingredient of marijuana could be considerably better at suppressing abnormal clumping of malformed proteins in the brain that is a hallmark of Alzheimer's.

Robert Roy Britt
Rob was a writer and editor at Space.com starting in 1999. He served as managing editor of Live Science at its launch in 2004. He is now Chief Content Officer overseeing media properties for the sites’ parent company, Purch. Prior to joining the company, Rob was an editor at The Star-Ledger in New Jersey, and in 1998 he was founder and editor of the science news website ExploreZone. He has a journalism degree from Humboldt State University in California.