The role of n-6 polyunsaturated fat in stable asthmatics.

We investigated in a clinical setting whether increased intake of linoleic acid alters respiratory function in 26 mild asthmatics. Subjects completed a 16-week-dietary intervention comprising 8 weeks eating an enriched n-6 polyunsaturated fat diet (9.2% energy from linoleic acid) and consuming either a high monounsaturated or saturated fat diet in a random cross-over resign for 8 weeks. Neither FEV1 nor PC20 values changed significantly after increased linoleic acid consumption when compared with the other diets. Increased consumption of linoleic acid caused a 20% rise (p < or = 0.01) in plasma linoleic acid, a 38% decrease (p < or = 0.01) in plasma eicosapentaenoic acid, but no change in arachidonic acid. There were no changes in symptom scores or bronchodilator use.