NEW YORK (Reuters Health) – Eating fish at least twice a week seems to reduce the incidence of kidney disease in patients with diabetes, according to findings from a large British study.

Although diabetics are advised to limit dietary protein to delay the progression of kidney disease, recent observations suggest that the benefit to the kidneys may have to do with “the protein source rather than quantity,” the investigators note in the American Journal of Kidney Diseases.

Despite research linking fish to improved outcomes in diabetics, they add, epidemiological evidence of this benefit is scarce.

Dr. Amanda I. Adler, at the Medical Research Council Epidemiology Unit in Cambridge, and fellow researchers therefore conducted a population-based cross-sectional analysis of 22,000 subjects.

Among the 517 subjects with diabetes, the prevalence of albumin (protein) in the urine (macroalbuminuria), an indication of kidney disease, was 8.3 percent.

According to food questionnaire responses, 18 percent of diabetics who ate fish less than once a week had macroalbuminuria, versus 4 percent of those who included fish in their diet more than twice a week.

After adjusting the data for clinical, social, demographic, lifestyle, and dietary factors, regular fish consumption remained a significant predictor of freedom from macroalbuminuria among diabetics.

Adler’s group suggests that “the unique nutrient composition of fish” may prevent kidney damage by enhancing blood sugar control or improving lipid profiles.

They suggest that these findings set the stage for nutritional intervention trials to determine the optimal types of fish, modes of preparation, and dietary frequency to best protect the kidneys of patients with diabetes.

SOURCE: American Journal of Kidney Diseases, November 2008.