Oriental Intervention for Enhanced Neurocognitive Health (ORIENT) Diet in Patients With Intracranial / Carotid Stenosis

Inclusion Criteria: * Patients aged ≥ 40 years * ≥ 50% stenosis in unilateral intracranial / carotid artery * Written informed consent available * Willingness to complete all assessments and participate in follow-up * Adequate Visual and auditory acuity to undergo neuropsychological testing Exclusion Criteria: * Previous history of major head trauma and any intracranial surgery * Intracranial abnormalities, such as intracerebral hemorrhage, subarachnoid hemorrhage and other space occupying lesions * Extrapyramidal symptoms or mental illness which may affect neuropsychological measurement * Severe loss of vision, hearing, or communicative ability * Nuts, berries, olive oil, or fish allergies * Patients presenting a malignant disease with life expectancy \< 3 years * Participation in an ongoing investigational drug study Exit Criteria: * Not meet the inclusion criteria * For any poor adherence, not comply with the requirements of the follow-up, or safety reasons determined by investigator * Any adverse or serious adverse events during the study period judged by Investigator