Objective: To investigate the association between dietary n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) and the degree and development of albuminuria in type 1 diabetes.

Methods: We analyzed longitudinal data from 1,436 participants in the Diabetes Control and Complications Trial. We defined average intake of eicosapentaenoic- and docosahexaenoic acid from diet histories. Urinary albumin excretion rates (UAER) were measured over 24 hours; incident albuminuria was considered the first occurrence of an UAER >40 mg/24 hr sustained for >/=1 year in normo-albuminuric individuals.

Results: In a mean follow-up of 6.5 years, we observed a lower mean UAER [difference 22.7 mg/24 hr (95% CI 1.6, 43.8)] in the top vs. bottom third of dietary n-3 LC-PUFAs, but found no association with incident albuminuria.

Conclusions: Dietary n-3 LC-PUFAs appear inversely associated with the degree, but not with the incidence of albuminuria in type 1 diabetes. These findings require further investigation in prospective studies.