This study investigates the effect of a bioavailable form of curcumin on cognitive performance and the deposition of beta-amyloid and tau proteins in the brain. In an 18-month, double-blind, placebo-controlled study of 40 non-demented adults (aged 51-84 years), participants received either 90 mg curcumin twice daily or a placebo.
The results show that curcumin produced significant improvements in verbal and visual memory performance. Participants in the curcumin group achieved higher scores in the Selective Reminding Test (SRT) and the Brief Visual Memory Test-Revised (BVMT-R ). In addition, attention improved in Trail Making Test A. PET scans revealed a reduction in beta-amyloid and tau deposits in the amygdala and hypothalamus – brain regions that are important for memory and emotions.
Conclusion: Daily intake of bioavailable curcumin could not only improve cognitive performance but also slow down neurodegenerative processes. This suggests that curcumin could play a potential role in the prevention of Alzheimer’s disease.
Background:
Curcumin is a polyphenol with strong antioxidant and anti-inflammatory properties. It is thought to have neuroprotective effects, particularly by inhibiting the deposition of beta-amyloid plaques and neurofibrillary tau tangles – two of the main hallmarks of Alzheimer’s disease. While epidemiologic studies suggest that curcumin may reduce the risk of cognitive decline, clinical evidence for these effects is limited. This study therefore investigates the effects of a bioavailable form of curcumin on memory performance and neurodegenerative processes in non-demented adults.
Methodology:
- Participants: 40 healthy, non-demented adults (age 51-84 years).
- Study design: Randomized, double-blind, placebo-controlled study over 18 months.
- Intervention: 90 mg curcumin (Theracurmin®) twice daily or placebo.
Measurement methods:
- Verbal and visual memory were assessed using the Selective Reminding Test (SRT) and the Brief Visual Memory Test-Revised (BVMT-R).
- Attention was drawn to the Trail Making Test A evaluated.
- PET scans with FDDNP tracers to analyze beta-amyloid and tau deposits in brain regions such as the amygdala and hypothalamus.
Results:
Improvement of memory performance:
- The participants in the curcumin group showed significant improvements in SRT Consistent Long-Term Retrieval(effect size: 0.63, p = 0.002) and SRT Total Recall (effect size: 0.53, p = 0.002).
- Visual memory(BVMT-R Recall and BVMT-R Delay) improved significantly compared to the placebo group.
- Attention, measured with the Trail Making Test A, was also improved (effect size: 0.96, p < 0.0001).
Reduction of beta-amyloid and tau deposits:
- PET scans showed a significant reduction in FDDNP binding (an indicator of beta-amyloid and tau deposits) in the amygdala in participants in the curcumin group (effect size: -0.41, p = 0.04).
- In the hypothalamus, FDDNP binding remained stable in the curcumin group, while it increased in the placebo group (effect size: 0.55, p = 0.02).
Additional effects:
- The curcumin group showed a significant improvement in depression scores on the Beck Depression Inventory (p = 0.04), indicating a possible mood-lifting effect.
- Side effects were minimal, with occasional mild gastrointestinal discomfort.
Discussion:
The results show that curcumin provides significant cognitive benefits while reducing neurodegenerative markers such as beta-amyloid and tau deposits. Particularly noteworthy is the improvement in memory and attention.
The observed reduction in amyloid and tau deposits could be explained by several mechanisms:
- Inhibition of inflammation: Curcumin inhibits NF-κB and reduces neuroinflammatory processes.
- Antioxidant effect: It neutralizes free radicals and protects neuronal structures from oxidative stress.
- Influencing the amyloid cascade: Curcumin could prevent the aggregation of beta-amyloid or promote its degradation by microglia.
- Modulation of the limbic system: The amygdala is involved in emotional processing and memory formation. The reduction of amyloid deposits in this region could contribute to cognitive improvements.
Conclusion:
The results suggest that a long-term intake of bioavailable curcumin could improve cognitive functions and slow down neurodegenerative processes. The positive effects on memory performance and the reduction of beta-amyloid and tau deposits suggest that curcumin is a promising candidate for the prevention of Alzheimer’s disease.
Future studies should include larger samples and longer observation periods to further investigate the long-term effects and optimal dosages.