Consumption of long-chain n-3 PUFA, α-linolenic acid and fish is associated with the prevalence of chronic kidney disease

Due to the anti-inflammatory properties of PUFA, it has been suggested that they may protect against kidney damage in adults. However, relatively few epidemiological studies have examined this hypothesis in human subjects. We investigated the association between dietary intakes of PUFA (n-3, n-6 and α-linolenic acid), fish and the prevalence of chronic kidney disease (CKD). A total of 2600 Blue Mountains Eye Study (1997–9) participants aged ≥ 50 years were analysed. Dietary data were collected using a semi-quantitative FFQ, and PUFA and fish intakes were calculated. Baseline biochemistry including serum creatinine was measured. Moderate CKD was defined as an estimated glomerular filtration rate of < 60 ml/min per 1·73 m2. Participants in the highest quartile of long-chain n-3 PUFA intake had a significantly reduced likelihood of having CKD compared with those in the lowest quartile of intake (multivariable-adjusted OR 0·69, 95 % CI 0·49, 0·99). α-Linolenic acid intake was positively associated with CKD (OR, per standard deviation increase in α-linolenic acid, 1·18, 95 % CI 1·05, 1·32). Total n-3 PUFA or total n-6 PUFA were not significantly associated with CKD. The highest compared with the lowest quartile of fish consumption was associated with a reduced likelihood of CKD (OR 0·68, 95 % CI 0·48, 0·97; P for trend = 0·02). The present study shows that an increased dietary intake of long-chain n-3 PUFA and fish reduces the prevalence of CKD. Hence, a diet rich in n-3 PUFA and fish could have a role in maintaining healthy kidney function, in addition to roles of these nutrients in the prevention and modulation of other diseases.