Clinical Evidence on the Health Effects of Aristotelia chilensis (Maqui Berry) Supplementation: A Systematic Review of Human Trials

Aristotelia chilensis (maqui berry) is a Chilean native fruit rich in anthocyanins with potential antioxidant, glycemic, cardiometabolic, and ocular benefits, but its clinical efficacy remains unclear. This systematic review synthesized and critically appraised human trials evaluating oral maqui supplementation in adults. Following PRISMA 2020 and a PROSPERO-registered protocol, five databases were searched, and risk of bias and certainty of evidence were assessed using RoB 2/ROBINS-I and GRADE. Twelve clinical trials published between 2014 and 2023 were included. Acute studies consistently showed reduced postprandial glucose and modulation of insulin response, whereas chronic interventions showed modest and inconsistent effects on HbA1c, lipid profile, and other cardiometabolic markers. Favorable changes were also reported for oxidative stress biomarkers and autonomic parameters, although these findings were mainly based on surrogate endpoints. The most consistent evidence was observed in the ocular domain, where maqui supplementation improved tear production, dry eye symptoms, and tear inflammatory markers. The overall certainty of evidence ranged from moderate to very low because of methodological heterogeneity, small sample sizes, and short intervention duration. Maqui berry supplementation shows promise, particularly for acute glycemic control and ocular surface health, but larger long-term randomized trials using standardized formulations are needed before definitive clinical recommendations can be made.