Garlic and onion for preventing upper respiratory tract infection Original paper

    In this randomized controlled trial, a supplement containing garlic powder and onion extract decreased the risk of upper respiratory tract infection in older adults.

    This Study Summary was published on August 16, 2023.

    Quick Summary

    In this randomized controlled trial, a supplement containing garlic powder and onion extract decreased the risk of upper respiratory tract infection in older adults.

    What was studied?

    The effect of a supplement containing garlic powder and onion extract on the risk of upper respiratory tract infection in older adults.

    The researchers also assessed 14 symptoms of an upper respiratory tract infection (e.g., cough, fever, nausea, and fatigue) and medication intake.

    Who was studied?

    66 older adults (average age of 84; 80% women, 20% men) living in a residential care facility in Spain.

    How was it studied?

    In this 36-week randomized controlled trial, the participants ingested a supplement containing garlic powder (14 mg) and onion extract (86 mg) or a placebo daily. The outcomes were assessed at baseline and every 4 weeks during the study.

    What were the results?

    The incidence of upper respiratory tract infection (i.e., the common cold and flu-like illness) was reduced in the supplement group. Additionally, the supplement group experienced a lower number of symptoms and a shorter duration of symptoms, compared with the placebo group. More specifically, the supplement group experienced a lower number of symptom events for cough, bone pain, fatigue, and difficulty breathing.

    Anything else I need to know?

    Because the participants were residents at a facility and this study took place during the months of October 2020 to July 2021, they had to follow certain COVID-19 protocols, which included mandatory use of masks and isolation. The participants were also vaccinated against flu and pneumonia and received two doses of the Pfizer vaccine for COVID-19.

    This Study Summary was published on August 16, 2023.