Dirt from Easter Island could contain the key to stopping a decline in cognitive skills in Alzheimer's patients, according to new research from The University of Texas Health Science Center in San Antonio.
The scientists behind the study fed mice rapamycin, which comes from bacteria in the Polynesian island's soil, and found the drug boosted memory and learning abilities. Significantly, it appeared to prevent and even reverse mental aging in older mice.
Veronica Galvan, an assistant professor of physiology at the university and a key researcher of the study, said the drug wasn't enough to make an old brain young again, but could push mice to perform substantially better in tests designed to gauge mental acuity.
The team of researchers studied how the mice performed in tests that measured long-term memory, spatial memory, motivation, emotionality and reactivity. Not only were the mice generally smarter after a steady diet of rapamycin, they seemed more relaxed.
"What you see is … less anxiety than is normal, and you see less depressive-like behaviour," she said. "That is pretty remarkable."
Dr. Galvan said depression, anxiety and cognitive skills are closely related. She said that while depression can affect "the motivation component of reasoning or memory," anxiety can impair learning, motor skills and overall cognitive ability.
"That is something we can all relate to," she said. "For example, you don't perform as well in an exam if you just had a car accident or something."
Dr. Galvan said the results were a significant development but just one part of a broader inquiry into the ways rapamycin can influence aging.
She said the risk for Alzheimer's disease, Parkinson's disease and dementia is largely a function of how old a person is.
"Forget about what you eat or what you do. All of that is very important, but if you look at those risks, everything is dwarfed by the aging component," she said, adding that rapamycin seems to help control just that. "For the first time in history we have a drug, a way, to modify the aging process."
Because rapamycin is already approved by the U.S. Food and Drug Administration for use by transplant patients and in conjunction with other cancer treatments, Dr. Galvan said it was likely that clinical trials to test the results of this research on human subjects would be approved in the future.
"I think that we will know whether this is something that might work in humans in five to 10 years at most," she said.