Anti-Oxidant Treatment of Alzheimer's Disease

Inclusion Criteria: * Men or women aged 60-85, inclusive * Diagnosis of probable Alzheimer's disease * English-speaking; Spanish-speaking if individual site allows * Study partner or caregiver to assure compliance * Mini-Mental State Examination score at screening visit greater than 14 * Female participants either surgically sterile or postmenopausal for over 1 year * Stable medical condition for 3 months prior to screening, with no significant abnormal liver, kidney, or blood studies * Stable medications for 4 weeks prior to screening * Able to take oral medications * Modified Hachinski Ischemic Index less than or equal to 4 * CT or MRI since onset of memory impairment demonstrating the absence of a clinically significant focal lesion * Physically acceptable for this study as confirmed by medical history, physical exam, neurological exam, and clinical tests Exclusion Criteria: * Significant neurologic disease such as Parkinson's disease, stroke, brain tumor, multiple sclerosis, or seizure disorder * Major depression in the past 12 months, major mental illness such as schizophrenia, or recent (in past 12 months) alcohol or substance abuse * History of invasive cancer within the past two years (excluding non-melanoma skin cancer) * Contra-indications to lumbar puncture * Use of any investigational agents within 30 days prior to screening * Major surgery within 8 weeks prior to the Baseline Visit * Uncontrolled cardiac conditions or severe unstable medical illnesses * Antiretroviral therapy for human immunodeficiency virus (HIV) * Conditions that will contribute to oxidative stress: current cigarette or cigar smokers (within past month), diabetics on insulin or poorly controlled on oral hypoglycemics * Residence in skilled nursing facility * Blindness, deafness, language difficulties or any other disability which may prevent the participant from participating or cooperating in the protocol Note: Exceptions to these criteria may be considered on a case-by-case basis, at the discretion of the Project Director. Excluded Medications: * Experimental drugs * Coumadin * Insulin * Immunosuppressive agents: prednisone and other corticosteroids (taken orally or by injection), methotrexate, cyclophosphamide, cyclosporin, tacrolimus, etc. * HIV protease inhibitors * Neuroleptics and lithium * Anti-cancer agents (exception: stable doses of hormonal therapy, e.g. Lupron, estrogen, are permitted)