ST. LOUIS -- Olive oil, a staple of a Mediterranean diet, reverses memory loss and improves learning, a study in an animal model at Saint Louis University found.
|Susan Farr, Ph.D.|
"Our research strengthens the case for olive oil," said Susan Farr, Ph.D., research professor of geriatrics at Saint Louis University School of Medicine. "Our research with mice lends credibility to the idea that extra virgin olive oil is really good for you and could even help if you already have some mild dementia. The take home message is to use extra virgin olive oil in your cooking."
The Mediterranean diet has long been associated with good health -- reduced heart disease, fewer cases of cancer, less obesity and a reduced risk of Alzheimer's disease. Farr wanted to test one of the most critical parts of the Mediterranean diet -- extra virgin olive oil (EVOO) -- to see if it improved memory, learning and thinking.
As the first oil pressed from olives, extra virgin olive oil is particularly healthy because it retains rich antioxidants called polyphenols.
Farr compared three types of fat -- EVOO, coconut oil and butter -- in mice that have an age-related impairment in learning and memory that is similar to Alzheimer's disease. EVOO is a monounsaturated fat known to boost good cholesterol and lower bad cholesterol. Both coconut oil and butter are saturated fats that increase bad cholesterol and reduce the good.
The mice were divided into four groups and received either EVOO, EVOO that was enhanced with extra polyphenols, coconut oil or butter for four weeks. During the experiment, the mice took tests of recognizing objects and navigating a maze that indicate memory and learning. In addition, their levels of oxidative stress in the brain were assessed.
The mice that were given EVOO with extra polyphenols did the best. They had the most improved learning, thinking and memory, and less oxidative brain damage than the other mice. The mice that consumed EVOO fared better than the other mice; the mice that consumed coconut oil had improved memory but no better learning than did the mice fed butter.
"Olive oil reversed the signs of memory deficiency in mice that represent a model of early Alzheimer's disease," Farr said. "This stands to reason. People in the Mediterranean region who eat a lot of olive oil have fewer cases of heart disease and Alzheimer's disease."
Farr previously studied the effect of fish oil, found in another staple of the Mediterranean diet, in mice that have a model of Alzheimer's disease.
"It also works to improve thinking skills," Farr said. "You'd probably want to cook your fish in extra virgin olive oil."
The research, which was supported by the VA Medical Center in St. Louis, is published electronically ahead of the print edition of the Journal of Alzheimer's Disease.
Established in 1836, the School of Medicine has the distinction of awarding the first medical degree west of the Mississippi River. The school educates physicians and biomedical scientists, conducts medical research, and provides health care on a local, national and international level. Research at the school seeks new cures and treatments in five key areas: infectious disease, liver disease, aging and brain disease, cancer and heart/lung disease. The school's department of internal medicine celebrates its centennial in 2011.
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