Numerous studies suggest that olive oil, one of the foundations of the heart-healthy Mediterranean diet, may also be good for the brain. Now researchers are uncovering reasons why the aromatic oil, part of the traditional diet of Mediterranean countries like Italy, Greece and Spain, may help protect against Alzheimer’s disease and other forms of dementia.
In one study, scientists at the University of Louisiana College of Pharmacy tested a component of olive oil called oleocanthal on the brains of mice that had been bred to develop a disease resembling Alzheimer’s in people. The substance, they found, appears to help speed up the removal of beta-amyloid, the toxic protein that builds up in the brains of Alzheimer’s victims, forming gummy plaques. The findings appeared in the journal ACS Chemical Neuroscience.
Study author Amal Kaddoumi noted that Alzheimer’s affects about 30 million people worldwide, but that the prevalence is lower in Mediterranean countries. Other research has shown that some of olive oil’s benefits are a result of an abundance of antioxidants and monounsaturated fats, which are good for the heart. Other research has shown that heart-healthy fats protect blood vessels throughout the body, including in the brain, thereby helping to ease the damage of Alzheimer’s and other forms of dementia.
In the latest study, Dr. Kaddoumi and colleagues tracked the effects of oleocanthal on brain cells, both in the laboratory and living mice. They found that it consistently boosted production of two proteins and key enzymes believed to be critical in removing beta-amyloid from the brain. "Extra-virgin olive oil-derived oleocanthal associated with the consumption of a Mediterranean diet has the potential to reduce the risk of Alzheimer’s disease related neurodegenerative dementias," their report concludes.
In another study, researchers at the German Research Center for Food Chemistry reported that some of olive’s oil benefits may derive from its effects on appetite. They found that compared to other fats, olive oil made people feel fuller after a meal. As a consequence, they tended to eat less and not gain weight.
For the study, the German researchers recruited 120 healthy volunteers and had them eat yogurt every day for three months. Unknowingly, some ate yogurt laced with butter, lard, olive oil or canola oil, another heart-healthy fat. They found that unlike the other groups, those eating the yogurt containing olive oil tended to eat fewer calories the rest of the day and did not gain weight.
The researchers found that it didn’t even require actual olive oil to induce feelings of satiety. Just adding an aromatic extract that imparted the scent of olive oil to the yogurt led to less food consumption during the day. Those eating the olive oil scented food tended to eat, on average, 176 fewer calories a day. That did not occur among those eating yogurt with a canola oil scent.
The findings may help to explain why a Mediterranean diet rich in olive oil, along with fruits and vegetables and modest amounts of red wine, may help to promote good health. Other studies have shown that keeping weight down in middle age lowers the risk of Alzheimer’s in old age.
Many factors may contribute to problems with thinking and memory in old age. Food and diet is likely just one contributing factor. But a growing body of evidence that people who follow a Mediterranean diet may lower their risk of developing Alzheimer’s and other forms of dementia, as well as heart attacks, strokes and other illnesses as well.
Source: “Olive-Oil-Derived Oleocanthal Enhances β-Amyloid Clearance as a Potential Neuroprotective Mechanism against Alzheimer’s Disease: In Vitro and in Vivo Studies”ACS Chemical Neuroscience, Feb. 15, 2013. German Research Center for Food Chemistry.