Blood pressure lowering in elderly subjects: a double-blind crossover study of omega-3 and omega-6 fatty acids. In 46 elderly (aged greater than or equal to 60 y) hypertensive subjects with entry systolic blood pressure (SBP) greater than or equal to 160 or diastolic blood pressure (DBP) greater than or equal to 90 mm Hg, our specific aim in a randomized, double-blind, crossover study (two 8-wk treatment periods separated by a 3-wk washout) was to compare blood pressure-lowering effects of 9 g fish oil/d [omega-3 (n-3) fatty acid] vs 9 g corn oil/d [omega-6 (n-6) fatty acid]. After a 4-wk baseline period, 22 subjects were randomly assigned to receive fish oil and 24 to receive corn oil. For both 8-wk treatments there were no between-group differences in the change in blood pressure. There was a treatment difference for standing DBP when baseline values were compared with those after treatment 2; DBP decreased by 5.1 mm Hg in the fish-oil group vs 0.72 mm Hg in the corn-oil group (P = 0.024). Within groups during the first treatment, both fish oil and corn oil lowered all four blood pressure measures (P less than 0.05); blood pressures were not further lowered during the second treatment compared with the washout period. There were no significant between-group differences in laboratory safety tests or categorical side effects. Fish oil lowered triglycerides by 0.47 mmol/L (P less than 0.001). In elderly subjects, diet plus both omega-3 and omega-6 supplements (9 g/d) safely and effectively lower SBP and DBP. 