Omega-Cold Supplementation With Free Fatty Acids for the Prevention of Respiratory Infections in Adults.

The purpose of this study is to investigate whether fish oil containing free fatty acids affects people\'s susceptibility to viral infections such as colds, influenza, and COVID-19, as well as the course of these illnesses. Omega Cold is purified fish oil with 2% added free fatty acids, making it similar in that respect to less-purified fish oils. Participants aged 18-80 in generally good health will be recruited through Matís\' consumer mailing list and social media advertisements. A total of 400 participants are planned: 100 in the winter of 2025-2026 and 300 in the winter of 2026-2027. Participants will be randomly assigned to two equal groups. One group will take Omega Cold orally twice a day for four months, while the other receives a placebo (vegetable oil) taken in the same way. They will not be asked to change any other habits. All participants will report weekly on their health and any cold or flu symptoms during the time they take the oil, using short questionnaires. The study is scheduled to begin in December 2025, when the oil will be sent to participants.