In recent years, there has been an accumulation of evidence in the literature supporting the neurological benefits of the Mediterranean diet, in which extra-virgin olive oil (EVOO) is the most representative component. In fact, according to a systematic review in Advances in Nutrition, a diet rich in EVOO is associated with better cognitive performance, particularly with a lower risk of developing Alzheimer’s disease (AD), mild cognitive impairment (MCI), and dementia. In a recent longitudinal brain imaging study published in Neurology looking specifically at AD biomarkers, the results showed that strong adherence to the Mediterranean diet (MeDi) provides 1.5 to 3.5 years of protection against AD in middle-aged adults compared to those with low MeDi adherence. Furthermore, an RCT in JAMA showed that following a MeDi － incorporating one liter per week of EVOO － was associated with improved measures of cognitive function in an older population compared with the controls who were advised to reduce dietary fat consumption.
New Findings Suggest EVOO defends against dementia
Findings from a recently published animal study in Aging Cell from Temple University’s Lewis Katz School of Medicine are the first to suggest that extra-virgin olive oil can defend against frontotemporal dementia, a specific type of neurogenerative disorder linked to tauopathy. The build-up and accumulation of these abnormal tau proteins in the brain lead to the decline in mental functioning seen in dementias. Symptoms of frontotemporal dementia generally involve personality and behavior changes, difficulties writing and speaking, and loss of memory and learning ability as it affects the areas of the brain near the forehead and ears.
In the study, human transgenic tau mice (hTau), which are engineered to develop beta-amyloid plaques and harmful tau tangle deposits, were given EVOO in addition to their regular chow diet starting at 6 months of age. The results of the study showed that 6 months of an EVOO-enriched diet significantly improved working, spatial, and learning memory, as well as hippocampal basal synaptic activity and short-term plasticity, and significantly reduced tau neuropathology among hTau mice. In fact, compared to mice that were not fed EVOO, the tauopathy-prone animals experienced 60% fewer tau protein deposits and greater than normal levels of complexin-1, the protein responsible for maintaining healthy neuronal synapse junctions where neurons meet and exchange information.
What’s the difference between EVOO and olive oil?
Extra-virgin olive oil is the juice of the very initial cold-pressed extraction process of olives and considered the gold standard in terms of health benefits. Compared with virgin, light, and classic varieties, EVOO is unrefined － thus retaining much more of its health benefits － and has the strongest flavor and aroma. Virgin and light olive oils are slightly lower in quality and have a more neutral flavor than EVOO, and classic olive oil is a blend of virgin and refined/processed oils.
EVOO is a superfood that is rich in polyphenolic compounds known for its cardio- and neuroprotective properties and has been shown to possess anti-inflammatory, antioxidant, and vasodilatory nutrients that lower the atherosclerotic burden and incidence of cardiovascular events such as heart attack and stroke among other metabolic conditions. 98-99% of the total weight of EVOO is primarily represented by fatty acids such as oleic and palmitoleic acids, with the remaining 1-2% comprised of polyphenolic metabolites, tocopherols, carotenoids, phytosterols and other minor constituents that may contribute to their beneficial effects.
It is important that your patients be made aware of the distinctions between the different oils and their potentially beneficial or detrimental effects depending on how they are used in cooking. EVOO should never be heated as it has a low smoke point and thus oxidizes at lower temperatures compared to other high-heat oils (e.g., avocado, coconut). EVOO is perfect for dressing salads or to drizzle on top of soups and steamed or roasted veggies for enhanced flavor, mouthfeel, and health benefits.