A comparison of the effects of n-3 fatty acids from linseed oil and fish oil in well-controlled type II diabetes.

OBJECTIVE

Supplementation of type II diabetic diets with n-3 fatty acids (FAs) from fish oil (FO) has been associated with lowered triglyceride and VLDL levels, although reports of impaired glycemic control have limited their use. Effects of n-3FAs from nonmarine sources are less well documented. Therefore, an investigation comparing the effects of linseed oil (LO) with FO supplementation was undertaken in subjects with type II diabetes.

RESEARCH DESIGN AND METHODS

Eleven subjects with type II diabetes were given supplements with LO and FO for 3 months each in a randomized double-blind crossover fashion after 3 months of olive oil placebo. Oils were given as 35 mg FA.kg body wt-1.day-1. After each 3-month period, fasting glucose and insulin levels, HbA1c, lipid profiles, insulin sensitivity (SI), glucose effectiveness (SG), and acute insulin response to glucose (AIRG) were evaluated.

RESULTS

HbA1c and lipid values were within the normal range at randomization. Repeated measures analysis of variance testing found no significant differences in weight; fasting glucose and insulin levels; HbA1c; total, LDL, and HDL cholesterol levels; SI; SG; or AIRG with either active oil. FO was associated with significant reductions in triglycerides and a trend toward decreased SI.

CONCLUSIONS

In a population with well-controlled type II diabetes, 3 months of FO but not LO resulted in lowered triglyceride levels. Neither LO nor FO significantly affected glycemic control, cholesterol values, SG, or insulin secretion, while a nonsignificant trend toward decreased insulin sensitivity was found with FO.