Dietary modification of omega 6 fatty acid intake and its effect on urinary eicosanoid excretion.

A group of women were fed two separate diets in a crossover study and urinary eicosanoids were quantified. One diet contained 3.1% of total energy (en%) as polyunsaturated fatty acids (3.0 en% linoleic acid) and the other contained 8.4 en% polyunsaturated fatty acids (8.3 en% linoleic acid). Carbohydrate replaced fat in the low-polyunsaturated-fat diet. No changes were observed in the urinary excretion of 6-oxo-prostaglandin F1 alpha, its 2,3-dinor metabolite or thromboxane B2 by subjects on either of the diets. Urinary 2,3-dinor-thromboxane B2 excretion was lower (206.5 ng/24 h) when subjects were fed the high-omega 6 polyunsaturated fatty acid diet when compared with the lower-omega 6 polyunsaturated fatty acid diet (275.3 ng/24 h). Conversely, urinary prostaglandin E2 was higher (139.2 ng/g creatinine) during the higher-omega 6 polyunsaturated fatty acid diet when compared with the lower-omega 6 polyunsaturated fatty acid diet (94.4 ng/g creatinine).