The Linus Pauling Institute at Oregon State University provides a good review of research on fish oil (omega-3 fatty acids) and Type 2 diabetes (see excerpt below). Although there was some concern that fish oil supplements might interfere with glycemic control (= control of blood sugar levels) in diabetics, that does not seem to be the case. Moreover, fish oil supplementation can significantly lower triglycerides in people with diabetes, and there is good epidemiological evidence that over the long term higher omega-3 fatty acid intakes may also decrease the risk of cardiovascular disease in diabetics.
Cardiovascular diseases are the leading causes of death in individuals with diabetes mellitus (DM). Hypertriglyceridemia […] is a common lipid abnormality in individuals with type 2 DM, and a number of randomized controlled trials have found that fish oil supplementation significantly lowers serum triglyceride levels in diabetic individuals. Although early uncontrolled studies raised concerns that fish oil supplementation adversely affected blood glucose (glycemic) control, randomized controlled trials have not generally found adverse effects of fish oil supplementation on long-term glycemic control. A systematic review that pooled the results of 18 randomized controlled trials including more than 800 diabetic patients found that fish oil supplementation significantly lowered serum triglycerides, especially in those with hypertriglyceridemia. A more recent meta-analysis that combined the results of 18 randomized controlled trials in individuals with type 2 DM or metabolic syndrome found that fish oil supplementation decreased serum triglycerides by 31 mg/dl compared to placebo, but had no effect on serum cholesterol, fasting glucose or hemoglobin A1c concentrations. Although few controlled trials have examined the effect of fish oil supplementation on cardiovascular disease outcomes in diabetics, a prospective study that followed 5103 women diagnosed with type 2 DM, but free of cardiovascular disease or cancer at the start of the study, found that higher fish intakes were associated with significantly decreased risks of CHD over a 16-year follow up period. Thus, increasing EPA and DHA intakes may be beneficial to diabetic individuals, especially those with elevated serum triglycerides. Moreover, there is little evidence that daily EPA + DHA intakes of less than 3 g/day adversely affect long-term glycemic control in diabetics. The American Diabetes Association recommends that diabetic individuals increase omega-3 fatty acid consumption by consuming two to three 3-oz servings of fish weekly.
See also the NYBC entry on DHA Max, a DHA/EPA supplement from Jarrow.