Scientists in America have found that oleocanthal - a compound which gives olive oil its peppery “bite” - helps to destroy the toxic proteins that are thought to cause Alzheimer’s disease.
The researchers believe that the naturally-occurring antioxidant could become a key ingredient in powerful new drugs to fight dementia, the Daily Express reported.
They also suggested that a Mediterranean diet could help people cut their risk of developing Alzheimer’s.
They noted that rates of the disease and other forms of dementia are far lower in Mediterranean countries, where extra-virgin olive oil is a staple part of the diet.
High consumption of oleocanthal is believed to help “shuttle out” destructive molecules of the protein amyloid beta from the brain.
The sticky protein forms harmful “plaques” which kill off nerve cells and eventually stop one part of the brain talking to the other, causing devastating symptoms such as memory loss and confusion.
Amyloid beta is thought to build up in the brain for at least a decade before the first outward signs of dementia are seen.
Finding ways of preventing it from forming plaques is seen as the key to wiping out Alzheimer’s.
In the latest study, scientists tested oleocanthal on mice and cells taken from them.
The compound was found to boost production of two proteins and key enzymes critical in removing amyloid beta from the brain by stopping it from clinging on to nerve cells.
The researchers believe that their findings also apply to humans.
"Extra virgin olive oil derived oleocanthal associated with the consumption of Mediterranean diet has the potential to reduce the risk of Alzheimer’s or related neurodegenerative dementias,” the paper quoted Dr Amal Kaddoumi, of the University of Louisiana as saying.
However, Dr Simon Ridley, head of research at Alzheimer’s Research UK, argued that finding out what elements of lifestyle affect our dementia risk is a real challenge, and at present there is no evidence that olive oil has a protective effect.
"The mice in this study were injected with oleocanthal but it’s still not known whether normal consumption of olive oil in cooking would have the same effect for people. Ultimately we’d need to see large—scale, controlled studies in people to determine whether oleocanthal or olive oil could hold promise as a treatment or prevention for Alzheimer’,” he stated.
But he noted that evidence has shown that a healthy, balanced diet can help lower the risk of Alzheimer’s, with regular exercise, not smoking, and keeping blood pressure and cholesterol in check.
Findings of the potential of olive oil are published in ACS Chemical Neuroscience, the journal of the American Chemical Society, also apply to humans.