Targeting cognitive aging with curcumin supplementation: A systematic review and meta-analysis.

Background: Cognitive aging is a growing public health concern, and curcumin, a bioactive compound derived from turmeric, has been proposed as a potential intervention to support cognitive function due to its anti-inflammatory and antioxidant properties.

Objectives: This systematic review and meta-analysis aimed to evaluate the effects of curcumin on cognitive outcomes related to aging.

Methods: A comprehensive search of PubMed, Embase, Cochrane Library, Web of Science, and Scopus was conducted to identify studies published up to June 18, 2024, including both in vivo preclinical animal studies and randomized controlled trials (RCTs) assessing curcumin's effects on cognitive function. In vivo animal studies using Alzheimer's disease (AD) models and RCTs in human participants were included. Data were extracted and analyzed using meta-analytic techniques.

Results: In preclinical in vivo murine studies (n = 25; total animals = 572), curcumin consistently improved both acquisition memory (SMD = -1.78, 95 % CI: -2.12 to -1.43) and retention memory (SMD = 2.36, 95 % CI: 1.72 to 3.00) in rodent models of AD. Ten human studies include 531 participants. Overall, curcumin showed no significant effect on global cognitive outcomes compared to placebo (SMD = 0.14, 95 % CI: -0.78 to 1.07). Subgroup analyses revealed significant improvements in working memory (SMD = 1.01, 95 % CI: 0.15 to 1.87) and processing speed (SMD = 0.37, 95 % CI: 0.07 to 0.67). The incidence of adverse events was higher in the curcumin group than in the control group.

Conclusions: Preclinical in vivo evidence suggests curcumin enhances cognitive function in AD models. However, human studies show inconsistent findings with benefits limited to specific cognitive domains. Larger, well-designed randomized controlled trials are needed to establish curcumin's efficacy and safety in cognitive aging.