Extra-virgin olive oil may protect against cognitive decline, according to a new study recently published in the Annals of Clinical and Translational Neurology. The study, conducted by researchers at Temple University, concludes that extra-virgin olive oil contributed to the preservation of memory and helped protect against the development of classic markers of Alzheimer’s Disease in the brains of mice.
“Brain cells from mice fed diets enriched with extra-virgin olive oil had higher levels of autophagy and reduced levels of amyloid plaques and phosphorylated tau,” said Dr. Domenico Praticò, one of the lead researchers of the study. Autophagy is a process in which cells discard debris and toxins, such as amyloid plaques and tau tangles. Phosphorylated tau is a substance that causes neurofibrillary tangles. Scientists believe that these tangles contribute to the deterioration of nerve cell function in the brain, which in turn is responsible for symptoms of Alzheimer’s.
Dr. Pratico and colleagues used an established Alzheimer’s disease mouse model to study the effects of extra-virgin olive oil on dementia. In this triple transgenic model, the mice develop three important characteristics of the illness: memory impairment, amyloid plaques and neurofibrillary tangles. The team then divided the animals into two groups. They fed one group a regular chow diet, while they fed the second group a diet enriched with extra-virgin olive oil. They added the oil to the diets at the six-month marker, before Alzheimer’s symptoms developed.
At the nine and twelve-month checkpoints, mice received the olive oil-enriched diet performed better on working memory, spatial memory and learning ability tests. The scientists studied brain tissues from both groups after the experiment’s conclusion and saw significant differences in nerve cell appearance and function. The connections between neurons, known as synapses, were preserved in the group exposed to olive oil. Brain cells from the olive oil group also showed a boost in nerve cell autophagy activation, which is responsible for reduced levels of amyloid plaques and phosphorylated tau.
“Thanks to the autophagy activation, memory and synaptic integrity were preserved,” said Dr. Pratico, “and the pathological effects in animals otherwise destined to develop Alzheimer’s disease were significantly reduced. This is a very important discovery, since we suspect that a reduction in autophagy marks the beginning of Alzheimer’s disease.”
“Taken together,” the researchers wrote, “our findings provide strong experimental support for the translational value of extra-virgin olive oil as a therapeutic tool with potential disease-modifying activity for Alzheimer’s Disease since it beneficially influenced all three major aspects of the Alzheimer’s phenotype in the implemented disease model.”
Benefits of the Mediterranean Diet
The article also makes mention of the fact that Mediterranean diets are associated with a lower risk of Alzheimer’s and cognitive decline. Previous studies have shown that people in Mediterranean countries such as Italy and Greece have a longer life expectancy and lower instances of cardiovascular disease and dementia than populations where other diets are the norm. Mediterranean folks tend to eat large amounts of fresh fruit and vegetables, cereals, beans and legumes. Extra-virgin olive oil is a primary source of fat for people in that region.
“The thinking is that extra-virgin olive oil is better than fruits and vegetables alone,” said Dr. Pratico, “and as a monounsaturated vegetable fat it is healthier than saturated animal fats.”
It is clear that diet is extremely important to our overall well-being. Our diets not only supply us with the necessary energy required throughout the day, they also have long-term ramifications. Though this study by no means proposes that eating olive oil is a way to completely prevent dementia, it’s definitely food for thought. Maybe next time I need to buy cooking oil, I’ll reach for the olive oil first.