ABSTRACT
OBJECTIVE: COVID-19 is a disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged as a global pandemic in 2019. Its main symptoms include fever, cough, fatigue, and, in severe cases, pneumonia, acute respiratory distress syndrome, and organ failure, which can be life-threatening. Various therapies have been proposed for treating COVID-19, among which antiviral drugs and monoclonal antibodies, but natural molecules have gained attention for their potential antiviral properties against various viral infections, including COVID-19. The use of hydroxytyrosol (HT), a polyphenol from the olive tree possessing antioxidant, anti-inflammatory, and anti-viral properties, has been proposed to reduce COVID-19 infection. SUBJECTS AND METHODS: A total of 443 subjects were recruited from four centers, located in Albania, Germany, and Italy (Milan and Trento provinces). The participants were randomly assigned to receive either the dietary supplement containing HT or a placebo for a duration of one month. RESULTS: Analysis of the study data revealed that, among the subjects who tested positive for COVID-19 during the study, 36% belonged to the group that received the dietary supplement containing HT, while 64% belonged to the placebo group. The difference was statistically significant. These findings suggest that the use of a dietary supplement containing HT may have a possible preventive effect against COVID-19 infection. CONCLUSIONS: The study's results indicate that the dietary supplement containing HT shows promise as a possible preventive measure against COVID-19 infection. Large-scale, randomized clinical trials and animal studies could be useful to provide more definitive conclusions on HT's possible potential preventive effects against COVID-19, which could potentially supplement existing therapies and contribute to fighting COVID-19 infection.