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The oil was added to the first group’s diets when the mice were six months old, before Alzheimer’s symptoms could appear.
While there was no difference in overall appearance between the groups, at age nine months and 12 months, mice on the olive oil-enriched diet performed significantly better on tests that evaluated working memory, spatial memory and learning abilities, researchers said.
When the team studied the brain tissue from both groups of mice, they noticed “dramatic” differences in nerve cell appearance and function.
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In addition, compared to the mice that didn’t receive the oil, the brain cells of rodents in the oil group showed a dramatic increase in nerve cell autophagy activation.
Autophagy is essentially our body’s way of recycling and cleaning itself; the process gets rid of dead or diseased cells and controls inflammation and immunity.
“This is a very important discovery, since we suspect that a reduction in autophagy marks the beginning of Alzheimer's disease,” senior investigator Domenico Praticò said.
When the autophagy was activated, memory and synaptic integrity were preserved.
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The next step, Praticò said, is to investigate how introducing extra-virgin olive oil to the same mice at 12 months (after they’ve developed plaques and tangles) affects them.
“We want to know whether olive oil added at a later time point in the diet can stop or reverse the disease,” he said.
Read the full study.
Alzheimer's Disease, a fatal form of dementia, is the sixth leading cause of death in the U.S., affecting an estimated 5.4 million Americans, according to the Atlanta-based Centers for Disease Control and Prevention.
Scientists don’t completely understand the cause of the disease, but believe a combination of genetic, environmental and lifestyle factors are involved.
The disease destroys brain function and leads to memory loss, language difficulty, depression among other destructive abilities. One of the most harmful aspects of Alzheimer’s is memory loss.
Learn more about Alzheimer's at CDC.gov.