Can Extra Virgin Olive Oil Protect Against Alzheimer Disease?

An Interview with Domenico Pratico, MD

Dr Pratico is Professor of Pharmacology, Immunology and Microbiology, Center for Translational Medicine, Temple University, Philadelphia, PA.

Nutrition and lifestyle are increasingly being explored to prevent and combat Alzheimer disease. Dr. Domenico Pratico and colleagues have published a new study exploring the link between extra virgin olive oil (EVOO) and Alzheimer disease that indicates it might be protective against the disease. Neurology Times invited Dr. Pratico to share highlights from the study and implications for prevention and clinical practice.

Neurology Times: Your study explored the effects of extra virgin olive oil on an Alzheimer disease-like phenotype in a mouse model. Can you briefly describe the study?

Dr. Pratico: We divided the triple transgenic mice aged 6 months (equivalent of 40-45 years for humans) into 2 groups: one was given a regular diet and the other the same regular diet that also contained EVOO for 6 months (which made their age equivalent of 60-65 years for humans). There was no difference between the groups in terms of the amount of food they ate and their body weight by the end of the study.

After 6 months, the animals were tested for memory and learning ability in 3 different tests: y-maze, fear conditioning, and Morris water maze. Next, they were euthanized, their brains isolated to study the nerve cells, the nerve connections called “synapses,” the amyloid plaques, and the tau fibrillary tangles (all of these are parameters used for measuring Alzheimer pathology in mice as well as in humans).

Neurology Times: Among your findings was a dramatic increase in nerve cell autophagy activation as well as reduced levels of amyloid plaques and phosphorylated tau. What are the implications of these results?

Dr. Pratico: Autophagy is a mechanism by which the nerve cells protect themselves from the presence and possible accumulation of toxic proteins and unwanted material (ie, cell garbage). Autophagy actually works like the garbage disposal in a sink. In Alzheimer disease, it is known that the activity and function of this system are reduced; as a result, the nerve cells in the patient’s brain have a progressive accumulation of amyloid proteins and tau tangles.

The group of animals receiving EVOO had a significant increase in the autophagy system, which explains the reduced amount of amyloid plaques and tau phosphorylated/tangles. The results are remarkable because for the first time we discovered that a natural product-EVOO-is able to do something that in the past only chemicals (some of which are very toxic) could do: activate autophagy.

Another remarkable result was the protective effect that the EVOO had on the synapse. Animals on the regular diet had a significant reduction in the synapse integrity/number, while animals receiving the EVOO had their synapse intact. In other words, the EVOO kept these connections healthy and functional so that learning and memory were well preserved.

Neurology Times: Why do you suppose EVOO has this effect? What are the potential mechanisms of action?

Dr. Pratico: Previous work has shown that EVOO can act as an antioxidant by blocking free radicals. Our study unveiled a new and important facet of EVOO-as an activator of autophagy. This new action can now better explain the benefits of EVOO that we are familiar with in population studies for dementia and Alzheimer disease in Mediterranean countries.

Neurology Times: Should clinicians recommend EVOO in patients as part of a prevention/treatment regimen?

Dr. Pratico: The clinical implication is that a daily intake of 2 tablespoons of EVOO could and probably should be recommended to patients as part of a prevention regimen. This intake should be seen as is a lifestyle change; it should be implemented for a long period of time (chronic use). Patients should be informed that EVOO could be used as source of fat intake instead of other fats such as butter (ie, dietary lifestyle change).

Neurology Times: Do you have follow-up research planned? If so, can you share what you’d like to further explore?

Dr. Pratico: Our study is focused on prevention; we started the treatment with EVOO in our animals when they were young/adult (6 months). Next, we want to test whether daily intake of EVOO has the same beneficial effects when it is started at a later (ie, 12months) after the disease is well established. This new study will more closely mimic the clinical scenario in which the typical Alzheimer patient presents, ie, after the disease has already started.

Neurology Times: Any advice for clinicians?

Dr. Pratico: If your patient manifests signs that are compatible with Alzheimer or is at risk for developing the disease, it would be appropriate to recommend the daily use of EVOO as part of a regular diet. After all, EVOO has been used for more than 2000 years so that EVOO, and its benefits are well established. In fact, it probably is a good idea to recommend its use to anybody, at risk for dementia or not.

References:

1. Lauretti E, Iuliano L, Praticò D. Extra-virgin olive oil ameliorates cognition and neuropathology of the 3xTg mice: role of autophagy. Ann Clin Transl Neurol. 2017;4:564-574.