A Meta-Analysis of Curcumin in Neurodegenerative Disease Treatment and Prevention: Achieving Neuroprotection through a Medicinal Meal

Abstract

Curcumin, a potent antioxidant and anti-inflammatory compound found in the curry ingredient turmeric, has been shown in vitro and in animal models of Alzheimer’s disease (AD) to reverse neurodegeneration and cognitive decline. However, the low bioavailability of curcumin poses a challenge to its potential neuroprotection in humans. Clinical trials have recently been published to test whether curcumin reliably alleviates or prevents AD-associated cognitive decline, providing a valuable opportunity to investigate emerging patterns from the current literature. Hence, this thesis presents a meta-analysis of these five studies meeting inclusion criteria and tests for curcumin’s overall and differential effects on subgroups based on participant characteristics, curcumin dosage, and intervention duration. Using cognitive task performance as the primary outcome of interest, meta-analyses did not show a statistically significant effect of curcumin overall or in any of the subgroups assessed. However, there was a trend toward a positive effect favoring curcumin’s neuroprotective effects on non-demented adults. Additional studies with larger sample sizes and consistent measurement of plasma curcumin can provide more statistical power to determine whether bioavailable curcumin serves a robust neuroprotective role in humans. Nevertheless, regular consumption of turmeric along with ingredients such as black pepper and cumin seeds, which enhance curcumin’s bioavailability and additionally serve gastroprotective roles, may produce synergistic neuroprotective effects that optimally outweigh those of curcumin in isolation. In collaboration with Princeton University Campus Dining, tentative recipes incorporating these ingredients were thus created as part of an evidence-based, holistic approach toward a neuroprotective diet.