LONDON—Daily oral curcumin may improve memory and attention in cognitively normal middle-aged and older adults, according to a study presented at the 2017 Alzheimer’s Association International Conference.
“The FDDNP-PET findings raise the possibility that decreases in plaque and tangle accumulation in brain regions modulating mood and memory are associated with curcumin supplementation,” said Gary W. Small, MD, Professor of Psychiatry and Biobehavioral Sciences and Parlow-Solomon Professor on Aging at the David Geffen School of Medicine at the University of California, Los Angeles, and colleagues.
Previous studies suggested that curcumin’s anti-inflammatory, antioxidant, antiamyloid, and possible antitau properties may provide neuroprotective benefits. Prior human trials of the effects of curcumin on cognition were inconclusive, however.
To examine the effects of curcumin on memory performance in nondemented adults and explore its potential impact on brain amyloid plaques and tau tangles using FDDNP-PET, Dr. Small and colleagues conducted a randomized, double-blind, placebo-controlled trial. Forty participants ranging in age from 51 to 84 were randomized to a bioavailable formulation of curcumin (90 mg twice daily) or placebo for 18 months. To confirm subject compliance, investigators obtained curcumin blood levels at baseline and at 18 months.
The primary outcomes were verbal (Buschke Selective Reminding Test [SRT]) and visual (Brief Visual Memory Test-Revised) memory. Change in attention (Trail Making Test, Part A) was a secondary outcome. Researchers also assessed mood using the Beck Depression Inventory.
Among the 40 participants, 30 underwent baseline and post-treatment FDDNP-PET scans. Regions of interest included the amygdala, hypothalamus, medial and lateral temporal lobe, posterior cingulate cortex, parietal lobe, frontal lobe, and motor cortex. Data analyses included mixed-effects general linear models with age and education as covariates, and effect-size estimates.
The study population’s mean age was about 63, and 22 participants were women. SRT Consistent Long-Term Retrieval scores improved in the curcumin group, but not in the placebo group. Other memory scores, including the SRT Total and Long-Term Storage, as well as visual memory, also improved in the curcumin group. None of the memory measures changed significantly in the placebo group, said the researchers.
Daily curcumin also improved attention and mood. Researchers observed a significant difference between curcumin and placebo in Trail Making Test, Part A scores.
After 18 months, FDDNP binding was lower in the curcumin group than in the placebo group in the amygdala and the hypothalamus. In addition, the placebo group showed a significant increase in amyloid plaques and tau tangles in the hypothalamus, compared with baseline.
Four patients in the curcumin group and two patients in the placebo group experienced gastrointestinal side effects (primarily transient abdominal pain, gastritis, and nausea). “This relatively inexpensive and nontoxic treatment may have a potential for not only improving age-related memory decline, but also as a prevention therapy, possibly staving off progression, and eventually future symptoms of Alzheimer’s disease,” said Dr. Small and colleagues.