Consuming extra virgin olive oil could help a person stave off dementia, a new study has found.
According to researchers at the Lewis Katz School of Medicine at Temple University (LKSOM), the Mediterranean diet has long been associated with various health benefits.
This is widely believed to be partly down to the common use of extra virgin olive oil in this part of the world, with scientists speculating it is better than fruit and vegetables alone and healthier than saturated animal fats as it is a monounsaturated vegetable fat.
New research has found that one benefit of extra virgin olive oil is its ability to protect against cognitive decline.
Research published in the Annals of Clinical and Translational Neurology showed that the ingredient reduces the formation of amyloid-beta plaques and neurofibrillary tangles in the brain - which are established markers of cognitive degeneration.
Scientists found that olive oil reduces brain inflammation and triggers autophagy, the process by which cells break down and intracellular debris and toxins, such as amyloid plaques, are cleared out.
LKSOM made the discoveries by testing mice that had been modified to develop dementia, half of which were fed a standard diet and half a diet rich in olive oil.
The olive oil was introduced into their diet when the mice were six months old, before any symptoms of cognitive degeneration began to emerge.
By the time the mice were nine months old and 12 months old, those on the extra virgin olive oil-enriched diet performed much better in memory, spatial memory and learning tests than the other group.
Nerve cell appearance and function was also found to be dramatically different in both groups.
Dr Domenico Praticò, a professor in the Departments of Pharmacology and Microbiology and the Center for Translational Medicine at LKSOM, described the findings as "exciting".
"Thanks to the autophagy activation, memory and synaptic integrity were preserved and the pathological effects in animals otherwise destined to develop Alzheimer's disease were significantly reduced," he commented.
"This is a very important discovery, since we suspect that a reduction in autophagy marks the beginning of Alzheimer's disease."
Dr Pratico and his team now plan to extend the research to see whether or not extra-virgin olive oil has a similar impact on mice when they are 12 months old, when plaques and tangles have already developed.
"Usually when a patient sees a doctor for suspected symptoms of dementia, the disease is already present," Dr Praticò said.
As a result, he wants to establish whether or not olive oil added at a later point in the diet could potentially stop or reverse symptoms of the disease.
Alzheimer's Research UK agrees that more tests will have to be carried out before it can be stated that olive oil could have similar benefits in people.
Dr Rosa Sancho, spokesperson for the group, commented: "Further studies will need to explore the reported effects of extra virgin olive oil before we could say that it holds specific health benefits beyond those of any other component of a healthy diet."
Speaking to the Sun, Dr Sancho said there is currently no certain way to prevent dementia.
However, she stated that evidence suggests the risk can be lowered with a healthy lifestyle including regular exercise, not smoking, eating a balanced diet and keeping weight and blood pressure in check.