Curcumin Confers Anti-Inflammatory Effects in Adults Who Recovered from COVID-19 and Were Subsequently Vaccinated: A Randomized Controlled Trial

COVID-19 infection and vaccination offer disparate levels of defense against reinfection and breakthrough infection. This study was designed to examine the effects of curcumin supplementation, specifically HydroCurc (CURC), versus placebo (CON) on circulating inflammatory biomarkers in adults who had previously been diagnosed with COVID-19 and subsequently received a primary series of monovalent vaccine doses. This study was conducted between June 2021 and May 2022. Participants were randomized to receive CURC (500 mg) or CON capsules twice daily for four weeks. Blood sampling was completed at baseline and week-4 and analyzed for biomarkers. Linear regression was utilized to examine the between-group differences in post-trial inflammatory biomarker levels, adjusting for baseline and covariates including age, sex, race/ethnicity, and interval between COVID-19 diagnosis and trial enrollment. The sample (n = 31) was 71% female (Age 27.6 ± 10.4 y). The CURC group exhibited significantly lower post-trial concentrations of proinflammatory IL-6 (β = −0.52, 95%CI: −1.03, −0.014, p = 0.046) and MCP-1 (β = −0.12, 95%CI: −0.23, −0.015, p = 0.027) compared to CON, adjusting for baseline and covariates. Curcumin intake confers anti-inflammatory activity and may be a promising prophylactic nutraceutical strategy for COVID-19. These results suggest that 4 weeks of curcumin supplementation resulted in significantly lower concentrations of proinflammatory cytokines in adults who recovered from COVID-19 infection and were subsequently vaccinated.