The first study to use human volunteers to test the ability of extra virgin olive oil (EVOO) to delay the onset of Alzheimer’s disease has yielded exciting results. It shows that a long-term diet rich in EVOO containing a medium to large amount of natural phenolic compounds can help protect against Alzheimer's disease and mild cognitive impairment.

Known as MICOIL, this was the first investigation worldwide to use human volunteers to consider the effect of long-term use of EVOO on patients with mild cognitive impairment (MCI). MCI includes a decline in thinking skills and in some cases memory problems that are worse than what is expected with normal aging. MCI is quite often a step on the way to Alzheimer’s disease or another type of dementia. There is currently no cure for either MCI or Alzheimer's--only symptomatic treatment for Alzheimer's. So the global fight against Alzheimer's focuses on the early detection and management of the amnesic stage of MCI.

MICOIL brought together Greek researchers from Aristotle University of Thessaloniki, Alzheimer Hellas, the World Olive Center for Health, and the University of Athens; they worked with Greek extra virgin olive oil donated by Yanni’s Olive Grove.

The MICOIL researchers knew that an earlier long-term trial with 285 study participants with a high vascular risk resulted in better mental function for those who followed a Mediterranean diet rich in extra virgin olive oil (50 ml daily), compared to the control group. With this in mind, the MICOIL study examined a key element of the Mediterranean diet, extra virgin olive oil; in the second part of the study, two specific types of EVOO were compared with a “regular” Mediterranean diet.

Dr. Anastasia Pantazaki, a professor in the Chemistry Department at Aristotle University, explained to Greek Liquid Gold that the first part of the MICOIL study was designed to test the hypothesis that giving a substantial amount of extra virgin olive oil to people with mild cognitive impairment could help prevent their progression toward severe Alzheimer's disease. The answer appears to be yes.

In addition to the cognitive impairment that is evident to many people and may be professionally evaluated using neuropsychological tests, another symptom of Alzheimer’s disease is a change in certain "hallmark" proteins in the body. The change in these proteins (compared to the normal situation of a healthy person) can be measured in the blood or the cerebrospinal fluid.

With their pilot study of 108 individuals, the MICOIL team found that MCI patients who consumed 50 ml of EVOO daily for one year had decreased levels of the Alzheimer's "hallmark" proteins in their blood. On the other hand, in a control group of MCI patients who did not consume a specific amount or type of olive oil, after one year the levels of these “hallmark" proteins were almost as high as those of patients suffering from Alzheimer's.  

This very important finding indicates that long-term EVOO consumption by individuals who do not yet have full-blown Alzheimer’s disease (those with a condition such as MCI, or even healthy people) may help prevent the progression to Alzheimer's. Researchers also mentioned possible ways that could occur: via the fibrinolytic system and the antioxidant mechanism that intervenes due to the high phenolic content of the EVOO. Phenolic compounds such as oleocanthal are natural substances that have antioxidant, anti-inflammatory, and neuroprotective effects, as well as other likely health benefits.

Published in the Hellenic Journal of Nuclear Medicine in 2019, the article about the initial MICOIL study findings titled “Administration of the extra virgin olive oil (EVOO) in mild cognitive impairment (MCI) patients as a therapy for preventing the progress to AD” won the second prize at the 5th International Medical Olympiad sponsored by the Greek Ministry of Health and the Medical School of the University of Thessaloniki.

That part of the MICOIL study suggested an important benefit of EVOO. In the second part of the study, scientists explored the question of whether high phenolic and moderate phenolic EVOOs had different effects on MCI, compared to each other and to a typical Greek Mediterranean diet without any specific olive oil use. Focusing on amnesic type mild mental disorder (mild cognitive impairment - aMCI), MICOIL researchers sought to determine whether high phenolic early harvest EVOO and moderate phenolic EVOO could act as natural remedies to help fight the aMCI that is usually a precursor to Alzheimer's disease. AMCI includes memory loss and an inability to perform complex daily activities.

The recently published article "A randomized clinical trial of Greek High Phenolic Early Harvest Extra Virgin Olive Oil in Mild Cognitive Impairment: the MICOIL pilot study" in the Journal of Alzheimer's Disease discusses encouraging results. MICOIL showed that long-term intervention with early harvest extra virgin olive oil containing a high concentration of natural phenolic compounds or with a later harvest EVOO with a moderate concentration of phenols was associated with a significant improvement in cognitive function compared to the control group, who followed the Mediterranean diet using olive oil they bought themselves. (The store-bought olive oil that researchers tested had “very low” levels of phenolic compounds, as Dr. Magda Tsolaki, a professor in the Department of Neurology at Aristotle University, reported to Greek Liquid Gold.)

More specifically: after 12 months of follow-up, the study of 60 people with MCI revealed better performance in the treatment groups consuming 50 ml daily of specific high or moderate phenolic EVOOs in comparison to the Mediterranean diet control group. Participants consuming the high phenolic early harvest EVOO, Yanni’s Finest, achieved better performance than the other two groups in most of the cognitive areas. Those eating the moderate phenolic EVOO, Yanni’s Selected, also did better than participants in the control group.

This suggests that high phenolic extra virgin olive oil can have a particularly beneficial effect on cognitive function in people with aMCI. The Yanni’s Finest EVOO used in the MICOIL study had 975 mg/kg total measured phenolic compounds according to the NMR measurement method, while Yanni’s Selected had 271 mg/kg.

"To date, there is no other study that has examined in such detail the effects of extra virgin olive oil on the elderly with mild cognitive impairment as an effective solution for cognitive impairment," according to Tsolaki. Based on this study’s data, she told Greek Liquid Gold that EVOO appears to be “a very good solution” until a medication becomes available that gives better results. For this reason, she recommends that anyone concerned about getting Alzheimer’s consume 50 ml/day of high phenolic or moderate phenolic extra virgin olive oil.

This is not hard to do. Study sponsor Evi Psounou Prodromou of Yanni’s Olive Grove explained that Yanni’s Finest EVOO is a well balanced early harvest EVOO with medium intensity, while Yanni’s Selected is medium fruity and less pungent, milder, with no bitterness, since it is made from riper olives. As Prodromou explains, the careful production of EVOO from unripe green olives tends to yield high phenolic oils.

For consumers seeking products containing even more healthy components, Yanni’s Olive Grove has developed a food supplement based on early harvest high phenolic Chalkidiki EVOO enriched with the antioxidants Vitamin E and Vitamin K, as well as omega fatty acids. This supplement helps maintain normal blood pressure and blood cholesterol levels, helps protect cells from oxidative stress, helps promote necessary blood clotting, and benefits the bones. Called MICOIL, the supplement is awaiting final clearance from the Greek National Drug Organization and is expected to be available in pharmacies in Greece and abroad in spring 2021.

The scientific journal article about the first part of the MICOIL study was written by E. Tzekaki, M. Tsolaki, A. Pantazaki, G. Geromichalos, E. Lazarou, M. Kozori, and Z. Sinakos at Aristotle University of Thessaloniki. The scientific team for the second part of the study consists of Professor Magda Tsolaki of the Department of Neurology of Aristotle University, and the researchers Eftychia Lazarou, Machi Kozori, Niki Petridou, Irene Tabakis, Ioulietta Lazarou, Maria Karakota, Iordanis Saoulidis, and Eleni Melliou, as well as Prokopios Magiatis, Associate Professor in the Department of Pharmacy at the University of Athens. The sponsoring company that donated all the extra virgin olive oils used in the study was Yanni's Olive Grove from the family of Yannis Prodromou in Nea Potidea, Chalkidiki, Greece.  

Thanks to Yanni’s Olive Grove for the photos used with this article.

All businesses, organizations, and competitions involved with Greek olive oil, the Mediterranean diet, and/or agrotourism or food tourism in Greece, as well as anyone else interested in reaching readers interested in these topics, are invited to consider the advertising and sponsorship opportunities on the Greek Liquid Gold: Authentic Extra Virgin Olive Oil website. The only wide-ranging English-language site featuring news and information from the Greek olive oil world, greekliquidgold.com has helped companies reach out to consumers in more than 200 countries around the globe.