Ten patients with steady-state cystic fibrosis (CF) - not hospitalized, not on intravenous antibiotics, with stable FEV1 40-100% predicted were enrolled in a four week long pilot study where-in each patient consumed 40 grams of flaxseed each day, in the form of finely ground flaxseed, however they wished. Prior to starting flaxseed, each week, and then four weeks after each patient had finished taking flaxseed, markers of inflammation and oxidative stress, as well as measurements of flaxseed metabolism were collected. F2-isoprostanes, 8-oxo-dGuo, as well as cytokines including IL-6, TNF-a, IFN-g among others were measured to trend flaxseed effects. Enterolignans - enterodiol and enterolactone (products of flaxseed metabolism) were measured each week as well.