Neuroprotective Effects of Oleanolic Acid and Erythrodiol in Prodromal Alzheimer's Disease

Summary

Alzheimer's disease begins many years before memory problems become obvious. People in the early ("prodromal") stage have memory complaints but are still independent in daily life. At present there is no treatment that prevents this stage from progressing to dementia. Olive oil contains two natural compounds, oleanolic acid and erythrodiol. Earlier work by this research team suggests that these compounds may reduce inflammation and oxidative stress and may improve the way the body handles sugars and fats, processes that are also altered in Alzheimer's disease. This study will test whether consuming olive oils that contain these compounds delays the progression from prodromal Alzheimer's disease to dementia. A total of 120 adults aged 50 to 80 years with prodromal Alzheimer's disease will take part at three public hospitals in southern Spain. Participants will be assigned by chance to one of three groups and will consume 55 mL per day of one of three oils for 12 months: olive oil enriched with oleanolic acid, pomace olive oil (which naturally contains both compounds), or a standard commercial olive oil with very low levels of these compounds. Neither the participants nor the staff assessing them will know which oil each person is receiving. Participants will attend study visits at the start of the study and after 6 and 12 months. At these visits they will complete memory and thinking tests, a physical and nutritional assessment, and blood and urine tests.

Interventions

• Oleanolic acid-enriched olive oil · DIETARY_SUPPLEMENT

  Olive oil enriched with oleanolic acid (600 mg/kg), 55 mL/day for 12 months, consumed preferably raw and distributed across the three main meals.

• Pomace olive oil · DIETARY_SUPPLEMENT

  Commercial pomace olive oil, naturally containing oleanolic acid (180 mg/kg) and erythrodiol (670 mg/kg), 55 mL/day for 12 months, consumed preferably raw and distributed across the three main meals.

• Commercial olive oil 0.4 degrees · DIETARY_SUPPLEMENT

  Commercial olive oil 0.4°, with the same fatty acid composition but a very low content of minor bioactive components, 55 mL/day for 12 months, consumed preferably raw and distributed across the three main meals.

Published eligibility criteria

Verbatim from the registry. Only the site can decide how these apply to a specific patient.

Inclusion Criteria:

Men and women aged 50 to 80 years Diagnosis of prodromal Alzheimer's disease, meeting all of the following: memory complaints corroborated by a reliable informant; Mini-Mental State Examination (MMSE) total score between 22 and 30; Free and Cued Selective Reminding Test (FCSRT, picture version) total recall score of 46 or less; Clinical Dementia Rating Global Score (CDR-GS) of 0.5; functional independence in activities of daily living (Functional Activities Questionnaire total score of 8 or less); plasma p-tau 217 above 0.45 pg/mL measured by the Lumipulse method Ability and willingness to attend scheduled visits at the study center Adequate visual and auditory capacity to complete study evaluations Educational level sufficient to read and write Written informed consent

Exclusion Criteria:

Absence of a reliable informant Evidence, based on medical history or clinical evaluation, of a neurological condition other than Alzheimer's disease that could account for the cognitive impairment Clinically significant, advanced or unstable systemic disease that may interfere with cognitive evaluation Severe psychiatric disorders, including schizophrenia, bipolar disorder or active major depression History of alcohol or psychotropic substance abuse Pre-existing intellectual disability that precludes neuropsychological evaluation

Sites (1)

• Instituto de la Grasa, CSIC, Seville, Spain