Kidney function was improved in type-1 diabetics with the highest average intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), compared with people with the lower intakes of the fatty acids, according to findings published in Diabetes Care.
The results are based on data from 1,436 participants in the Diabetes Control and Complications Trial – a trial including people aged between 13 and 39 and funded by the National Institute of Diabetes and Digestive and Kidney Diseases.
Type-1 diabetes occurs when people are not able to produce any insulin after the cells in the pancreas have been damaged, thought to be an autoimmune response. The disease is most common among people of European descent, with around two million Europeans and North Americans affected.
In addition, the incidence of the disease is reportedly on the rise at about three per cent per year. The number of new cases is estimated to rise 40 per cent between 2000 and 2010.
Diabetics are known to be at increased risk of kidney disease.
The researchers, led by Dr Amanda Adler from the MRC Epidemiology Unit at the Institute of Metabolic Science in Cambridge (UK), measured the excretion of the protein albumin in urine. Albumin is the most abundant protein in human serum and in people with kidney problems the protein leaks from the kidney into the urine. A level of 30 mg per 24 hours is reportedly representative of sufficient function.
According to the results, people with a higher average intake of omega-3s had albumin excretion levels 22.7 mg per 24 hours lower than people with the lowest average intakes of omega-3.
However, no link was observed with the incidence of kidney damage or raised albumin levels, said the researchers.
“Dietary omege-3 long-chain polyunsaturated fatty acids appear inversely associated with the degree, but not with the incidence of albuminuria in type-1 diabetes,” wrote Dr Adler and her co-workers. “These findings require further investigation in prospective studies.”
Omega-3 and type-2 diabetes
Results of a double-blind placebo-controlled trial from Hong Kong published earlier this year suggested that supplements of omega-3 fatty acids may improve the kidney health of diabetics. In this study, the researchers evaluated kidney function by measuring creatine levels, with high levels indicative of damage to the functioning of nephrons in the kidney.
“Our results showed a significant decrease in serum creatinine level after fish-oil supplement in Type 2 diabetes mellitus patients,” stated the researchers in Diabetic Medicine (Vol. 27, pp. 54-60). “Prior studies have [also] suggested that fish-oil supplement has renoprotective effects in diabetes mellitus,” they added.
Fish oils may reduce the risk of type-1 diabetes
A study published in the Journal of the American Medical Association (2007, Vol. 298, pp. 1420-1428) reported that higher intakes of omega-3 may actually reduce the rosk of type-1 diabetes by 55 per cent. The study analysed data from 1,770 children at high risk of developing type-1 diabetes.
Source: Diabetes Care
Published online ahead of print, doi:10.2337/dc09-2245
“Dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and diabetic nephropathy – cohort analysis of the Diabetes Control and Complications Trial (DCCT) Diabetes Care”
Authors: C.C. Lee, S.J. Sharp, D.J. Wexler, A.I. Adler