The research, published in Diabetes Care, investigated the associations between serum omega-3 polyunsaturated fatty acids (PUFAs) including eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), alpha-linolenic acid (ALA) and the later risk of developing type 2 diabetes in middle-aged and older Finnish men.
Led by Dr Jyrki Virtanen from the University of Eastern Finland, the research team analysed data from more than 2,000 men - finding that the risk of developing diabetes was 33% lower for the of quarter of men with the highest serum concentrations of EPA, DPA and DHA when compared to the quarter with the lowest serum concentrations.
"No statistically significant associations were observed with serum or dietary ALA, dietary fish or EPA + DHA, or hair mercury," wrote Virtanen and his colleagues.
The team noted that previous research investigating whether fish consumption - or indeed omega-3 status - has any effect on the risk of developing type 2 diabetes has been 'highly contradictory'.
Indeed, a protective link has mainly been observed in Asian populations, whereas a similar associations have not been observed in studies conducted in Europe or the US - with some studies even linking high consumption of fish to increased diabetes risk.
Virtanen and his colleagues used data from the ongoing Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) analyse the associations between serum omega-3 fatty acid concentrations and onset of diabetes after approximately 20 years follow up in 2,212 men.
During an average follow-up of 19.3 years the team identified 422 men who had been diagnosed with type 2 diabetes. Serum long-chain omega-3 fatty acid concentrations of all 2,212 men were divided in to quartiles, and then analysed for any differences in rate of onset.
Men with the highest serum concentrations of EPA, DPA and DHA, were found to have 33% lower risk of developing type 2 diabetes than those with the lowest concentrations. However, no statistically significant associations were observed with serum or dietary ALA, dietary fish, or measure of EPA plus DHA.
"Serum long-chain omega-3 PUFA concentration, an objective biomarker for fish intake, was associated with long-term lower risk of type 2 diabetes," the team concluded.
Source: Diabetes Care
Volume 37, Number 1, Pages 189-196, doi: 10.2337/dc13-1504
"Serum Omega-3 Polyunsaturated Fatty Acids and Risk of Incident Type 2 Diabetes in Men: The Kuopio Ischaemic Heart Disease Risk Factor Study"
Authors: Jyrki K. Virtanen, Jaakko Mursu, et al