18-Month Study of Memory Effects of Curcumin — Curcumin  

Mild Cognitive Impairment (MCI) Clinical Trial

Official title: 18-Month Double-Blind, Placebo-Controlled Study of Curcumin

Status Completed

Clinical Trial Summary

This project is designed to study the effects of the dietary supplement curcumin on age-related cognitive impairment. In particular, the study seeks to determine the effects of curcumin on cognitive decline and the amount of abnormal amyloid protein in the brain. Genetic risk will also be studied as a potential predictor of cognitive decline.

Subjects will be randomly assigned to one of two treatment groups: either a placebo twice daily or the curcumin supplement (Theracurmin®, containing 90 mg of curcumin). The investigators expect that the volunteers receiving the curcumin supplement will show less evidence of decline after 18 months than those receiving the placebo. The investigators predict that cognitive decline and treatment response will vary according to genetic risk for Alzheimer's.

The investigators will study subjects with memory complaints aged 50-90 years. Initially, subjects will undergo a clinical assessment, an MRI and a blood draw to determine genetic risk and to rule out other neurodegenerative disorders linked to memory complaints. Subsequently, subjects will undergo an -(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile (FDDNP) PET scan and a baseline neuropsychological assessment to confirm a diagnosis of MCI or normal aging. Once enrolled, subjects will begin taking the supplement (either curcumin or a placebo). Some of the initial subjects will be asked to return every three months for regular MRIs. Every 6 months, subjects will also receive neuropsychological assessments. At the conclusion of the study, subjects will be asked to complete a final neuropsychological assessment, MRI scan, PET scan and blood draw. Additional blood will be drawn at baseline and at 18 months and frozen to assess inflammatory markers if cognitive outcomes are positive.

FDDNP-PET scans will be used to measure the amount of abnormal amyloid plaque- and tau tangle-proteins in the brain; the MRIs will be used to monitor supplement side effects and measure brain structure; the neuropsychological assessments will monitor rates of cognitive decline; the blood draws will be used to determine genetic risk and to test levels of inflammatory markers.

Clinical Trial Description

Several lines of evidence suggest that the neuropathological and clinical decline leading to Alzheimer disease (AD) begins years before patients develop the full AD clinical syndrome (NINCDS-ADRDA diagnostic criteria; McKhann et al, 1984). Mild memory complaints build gradually years before patients develop dementia. The neuropathological hallmarks of AD, "preclinical" neuritic plaques (Braak & Braak, 1991) and neurofibrillary tangles (Price & Morris, 1999), are also present years prior to clinical diagnosis. These abnormal protein deposits correlate strongly with cognitive decline.

Preclinical amyloid deposits may begin decades prior to dementia onset. In fact, diffuse plaques in non-demented elderly persons are associated with an accelerated age-related cortical cholinergic deficit, consistent with preclinical AD (Beach et al, 1997; Arai et al, 1999). Also consistent with a prolonged preclinical disease stage is our own work showing that position emission tomography (PET) measures of cerebral glucose metabolism vary according to AD genetic risk (apolipoprotein E-4 [APOE-4]) and predict cerebral metabolic and cognitive decline in people with mild cognitive complaints (age-associated memory impairment [AAMI]; Small et al, 2000). Such observations have stimulated interest in preclinical AD markers or biomarkers of brain aging that may assist in tracking treatments of AAMI and related conditions. New PET imaging methods now make it possible to provide in vivo measures of cerebral amyloid neuritic plaques (e.g., florbetapir-PET; Clarke et al, 2011) and tau neurofibrillary tangles (e.g. FDDNP-PET; Small et al, 2006, 2009).

Despite these previous research findings, clinical trials (including those using biomarkers as response measures) and subsequent treatment recommendations have been limited to patients with the full clinical dementia syndrome or mild cognitive impairment (MCI), a condition that increases the risk for developing dementia (Petersen et al, 2001). Cholinesterase inhibitors are currently the only drugs that have FDA clearance for treatment of AD, but previous studies (e.g., Ringman et al, 2005) suggest that other interventions, such as dietary or herbal supplements, may benefit cognition, and possibly interrupt the accumulation of abnormal amyloid protein deposits in the brain. For example, curcumin (diferulomethane), a low molecular weight molecule with antioxidant and anti-inflammatory activities that is derived from dietary spice, may have both cognitive-enhancing and anti-amyloid properties (Ringman et al, 2005; Yang et al, 2005).

To address such issues, the investigators propose to build upon our group's previous longitudinal brain imaging and genetic risk studies in people with age-related memory decline. Because previous studies suggest that curcumin may improve cognitive ability and prevent the build-up of age-associated plaques and tangles in the brain, the investigators will perform a double-blind, placebo-controlled trial of curcumin to test the following hypotheses:

1. People with age-related cognitive decline (i.e., MCI, AAMI or normal aging),, who receive curcumin 90 mg twice each day will show less evidence of cognitive decline (as measured with neuropsychological assessments) than those receiving placebo after 18 months.

2. People with age-related cognitive decline who receive an oral dose of curcumin 90 mg twice each day will show less build-up of plaques and tangles (as measured with FDDNP-PET imaging) than those receiving placebo after 18 months.

3. People with age-related cognitive decline, who receive curcumin 90 mg twice each day, will show decreased measures of inflammation in the blood compared with those receiving placebo after 18 months.

4. Cognitive change, FDDNP-PET measures, and treatment response will vary according to genotypes found to influence age at dementia onset (e.g., apolipoprotein E [APOE] TOMM40).

Because curcumin may alter inflammatory markers in the blood, the investigators will draw blood samples at baseline and at 18 months and freeze them for later analyses.

To test theses hypotheses, subjects with age-related cognitive decline will be enrolled (Crook et al, 1986; Petersen et al, 2001). Subjects will be randomized, using a double-blind design, to one of two treatment groups: curcumin (three 30 mg capsules twice each day) or placebo, and followed for 18 months. FDDNP-PET scanning will be performed at baseline and at 18 months. Magnetic resonance imaging (MRI) scans also will be performed for co-registration of PET and assistance in identifying regions of interest. Neuropsychological assessments will be performed at baseline, 6 months, 12 months and at the conclusion of the clinical trial (18 months). Blood will be drawn at baseline to perform genotyping. ;

Related Conditions & MeSH terms

• Age-associated Cognitive Impairment
• Cognitive Dysfunction
• Mild Cognitive Impairment (MCI)

• NCT number: NCT01383161
• Study type: Interventional
• Source: University of California, Los Angeles
• Status: Completed
• Phase: Phase 2
• Start date: March 2012
• Completion date: April 2017