A recent study has revealed that daily consumption of Extra Virgin Olive Oil (EVOO) may improve brain connectivity and functionality of the blood-brain barrier (BBB) in humans with mild cognitive impairment (MCI). The research also indicated potential benefits in terms of brain health due to the monounsaturated fats in olive oils, including Refined Olive Oil (ROO). However, EVOO's superior effects can be attributed to its phenolic compounds.
A number of studies have considered the effect of extra virgin olive oil (EVOO) on memory function in mild cognitive impairment (MCI) in mice and now, for the first time, a study has been conducted that reviews the direct impact on the brain in humans.
Multiple studies have suggested that following a Mediterranean eating pattern improves cognitive functioning and slows the progression of Alzheimer’s disease (AD). It is no coincidence that one of the main elements of the Mediterranean eating pattern is olive oil.
EVOO is a high-quality oil, rich in monounsaturated fatty acids and phenolic compounds. The phenolic compounds have an antioxidant function and protect cells against oxidative damage, providing many health benefits. Substantial evidence has shown that the development of AD involves a dysfunctional BBB. Aging and the presence of vascular conditions, including high blood pressure, atherosclerosis, type 2 diabetes, high cholesterol and cardiovascular diseases, can adversely impact the structure and functioning of the BBB. First time hearing about the BBB? Take a look at this video, which briefly explains what the BBB is and how it functions.
“A recently published study has illustrated the effects of EVOO on the brain confirming that it improves the functioning of the blood-brain barrier (BBB) and enhances brain connectivity.”
The endothelial cells of the BBB strictly control what enters the brain from the bloodstream, and any changes in the functioning of the BBB may allow toxic molecules to enter the brain and impair the expulsion of new or existing toxic molecules.
This could lead to oxidative stress, neuroinflammation, disturbances of the functional brain network and the impairment of blood flow to the brain, which could lead to MCI. MCI could advance to AD and related dementias.
Thus, ensuring the integrity of the BBB is an important therapeutic target for the prevention, or delay, in the onset of AD and other dementias. The study aimed to assess the effect of EVOO on people with MCI and provide a comparison against the effect of refined olive oil (ROO), which didn’t contain any phenolic compounds.
The effect of olive oil intake on BBB function, as well as the effect on brain function was evaluated. Additionally, cognitive function changes and AD blood markers were assessed. Twenty-six men and women with MCI, aged between 55 – 75 years, were randomised to receive either 30 ml of EVOO or 30 ml of ROO daily (raw, not cooked) for 6 months.
The findings of this study demonstrated that the daily consumption of EVOO over 6 months may well enhance the functional connectivity of the brain and reduce BBB permeability. On the other hand, ROO did not alter permeability of the BBB or brain connectivity, however it did offer improvements in the clinical dementia rating scores and increased functional brain activation to a memory task. Interestingly, both oils reduced Aβ 42 /Aβ 40 and p-tau/t-tau ratios, which are associated with an increased risk of MCI and AD. Somewhat surprisingly, both olive oils were found to offer benefits for the brain and may assist in the prevention of the onset of AD, illustrating the role of the monounsaturated fats they contain (e.g., oleic acid) on brain health. The differing effects of EVOO and ROO can be attributed to the presence, and role, of the phenolic compounds found in EVOO.
As with all studies, the results need to be interpreted together with the limitations of the study. The sample size was small and there was an absence of control groups for comparative purposes, such as participants who did not receive olive oil or those with normal cognitive functioning of the same age as the participants receiving the intervention. The treatment time was also relatively short, and studies held over a longer duration are needed to assess the effect of long-term ingestion of olive oil on the brain and its impact on cognitive function.This may offer an opportunity to better differentiate between the effects of EVOO and ROO. That being said, this was a pilot study and offers valuable information to pave the way for future research.
CLICK HERE to learn about how to use EVOO and how much to use.
For more information on the study, refer to the reference below.
So, what is the takeaway message?
The Mediterranean Diet (MD), characterized by a combination of antioxidant-rich foods and anti-inflammatory effects, stands out as one of the healthiest dietary patterns globally. Focusing on overall high-quality food patterns, the MD includes generous amounts of extra virgin olive oil (EVOO), plant-derived foods, moderate wine consumption, and limited intake of certain foods. Beyond nutrients, the MD’s health benefits stem from a holistic approach, encompassing cooking techniques, eating behavior, lifestyle, and sociocultural aspects. Extensive research indicates the MD’s protective effects against various health conditions, including heart disease, obesity, diabetes, cancer, cognitive decline, and chronic kidney disease. The PREDIMED trial demonstrates its sustainability and effectiveness in preventing cardiovascular disease, while its mechanisms involve positive impacts on blood pressure, insulin sensitivity, lipid profiles, inflammation reduction, and more.
REFERENCES
- Kaddoumi A, Denney TS, Deshpande G, et al. 2022. Extra-virgin olive oil enhances the blood–brain barrier function in mild cognitive impairment: A randomized controlled trial. Nutrients, 14(5102). Available here.
Nicola Royce
Registered Dietitian,
Postgraduate Diploma Diabetes,
Masters in Nutrition
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