Effect of an Olive Leaf Extract compared to a placebo on Cold and Flu Symptoms in an Adult Population – A double blind, randomised controlled trial

This is a double blind, randomised, clinical study with a maximum 4-month participant duration with 2 groups (1 active ingredient group and 1 inactive placebo group). Isenolic® is a commercial product standardised for Elenolic acid (ELA). ELA is derived from oleuropein extracted from olive oil and olive leaves. Each product will be consumed as per the following: One capsule containing 150 mg of olive leaf extract taken twice daily: one capsule in the morning and one capsule in the evening. Capsules are to be taken just prior to or with food. Once enrolled in the study, participants will be randomly allocated to either a placebo group or an active intervention group. Participants will receive a 2-week supply (28 capsules) of the study product per event. Participants will be asked to start consuming the allocated study product according to the dose prescribed (2 x 150 mg/day) immediately upon the onset of symptoms starting. During the study period, participants will be asked to only start the trial product once cold or flu symptoms start. Following the onset of symptoms, participants will then be required to record their daily symptoms (including the severity) using the WURSS-21 questionnaire. For participants presenting with flu-like symptoms, they will be asked to take a nasal swab on day 3. If nasal swab is positive for flu virus or if symptoms do not improve after 1 week, participants will be required to seek medical advice (consult a GP). Nasal swabs will be conducted by a certified commercial pathology laboratory. This will be tested for disease aetiology. Once symptoms have subsided, participants will stop taking the trial product. A participant may record more than 1 cold or flu episode. However, there must be a minimum 2-week symptom free period between events. Maximum treatment duration is up to 8 weeks with a two week symptom free period in between episodes.