Testing two doses of resveratrol

Inclusion Criteria: * Capable of providing informed consent (IC) and complying with study procedures * Stable on Levodopa and/or DA agonists for at least 4 weeks before enrollment * Clinical diagnosis of PD according to UK Brain Bank criteria and/or PD with Dementia (PDD) by MDS criteria (53-55). * MoCA≥18. * Hohn and Yahr stage 2 and 3 * Age of 55-85 years, medically stable * English Fluency Exclusion Criteria: * Known PD-linked gene mutations e.g. PINK-1, DJ-1, parkin, LRRK2 etc. * Clinical signs indicating syndromes or disorders other than PD including, Alzheimer's Disease (AD), corticobasal degeneration (CBD), supranuclear gaze palsy, multiple system atrophy (MSA), chronic traumatic encephalopathy (CTE), frontal dementia, history of stroke, head injury or encephalitis, cerebellar signs, early severe autonomic involvement * Any psychiatric diagnosis or symptoms, (e.g., hallucinations and suicidality, major depression, or delusions) that could interfere with study procedures * Medical history of liver or pancreatic disease, GI, ulcers and Chron's disease, kidney, or blood problems. Any other clinically significant abnormalities in physical examination, vital signs, laboratory tests, or ECG at Screening or Baseline. Any other medical conditions (e.g., cardiac, respiratory, GI, renal disease) which are not adequately controlled, or which in the opinion of the investigator(s) could affect the subject's safety or interfere with the study assessments and are below grade 3 criteria as outlined in table 2. * Enrolled as an active participant in another clinical study * Anti-coagulant medications, including Coumadin, heparin, enoxaparin, fondaparinux etc. * Any immunological disease which is not adequately controlled, or which requires treatment with immunoglobulins, systemic monoclonal antibodies (or derivatives of monoclonal antibodies), systemic immunosuppressant's, or plasmapheresis during the * Geriatric Depression Scale (GDS) score greater than or equal to 8 at Screening. * Answer "yes" to C-SSRS suicidal ideation Type 4 or 5, or any suicidal behavior assessment within 6 months before Screening, at Screening, or at the Baseline Visit, or has been hospitalized or treated for suicidal behavior in the past 5 years before Screening. * Planned surgery which requires general anesthesia that would take place during the study. * Severe visual or hearing impairment that would prevent the subject from performing psychometric tests accurately. * Women of Childbearing Potential (WCBP) or lactating. * Must not be on any nutritional or medicinal supplements at least 6 weeks prior to enrollment.