Key Findings:
ALA from flaxseed oil was compared to EPA plus DHA on anthropometric measures, glucose homeostasis, cardiovascular risk factors, and androgen levels in women with polycystic ovary syndrome (PCOS). Soybean oil was used as the control. Fish and soybean had similar effects on glucose homeostasis, which differed from the effects of flaxseed oil. Fish and flaxseed oils had similar effects on the lipid metabolism, which differed from the effects of soybean oil. Fish oil elevated peripheral insulin resistance and reduced early insulin secretion. Flaxseed oil did not change glucose homeostasis significantly, except for the increase in 30-minute OGTT glucose. Both fish and flaxseed oils decreased triglyceride and tended to increase LDL-C. None of the oils affected the hs-CRP levels. In these patents, fish and soybean oils decreased early insulin secretion, impaired glucose tolerance, and increased hyperinsulinemia. In contrast, flaxseed oil did not have any adverse effects.
ABSTRACT:
The objective of the study was to compare the effects of essential vs long-chain omega (n)-3 polyunsaturated fatty acids (PUFAs) in polycystic ovary syndrome. In this 6-week, prospective, double-blinded, placebo (soybean oil)-controlled study, 51 completers received 3.5 g n-3 PUFA per day (essential PUFA from flaxseed oil or long-chain PUFA from fish oil). Anthropometric variables, cardiovascular risk factors, and androgens were measured; oral glucose tolerance test (OGTT) and frequently sampled intravenous GTT (IVGTT) were conducted at baseline and 6 weeks. Between-group comparisons showed significant differences in serum triglyceride response (P = .0368), whereas the changes in disposition index also tended to differ (P = .0621). When within-group changes (after vs before intervention) were considered, fish oil and flaxseed oil lowered serum triglyceride (P = .0154 and P = .0176, respectively). Fish oil increased glucose at 120 minutes of OGTT (P = .0355), decreased the Matsuda index (P = .0378), and tended to decrease acute insulin response during IVGTT (P = .0871). Soybean oil increased glucose at 30 (P = .0030) and 60 minutes (P = .0121) and AUC for glucose (P = .0122) during OGTT, tended to decrease acute insulin response during IVGTT (P = .0848), reduced testosterone (P = .0216), and tended to reduce sex hormone–binding globulin (P = .0858). Fasting glucose, insulin, adiponectin, leptin, or high-sensitivity C-reactive protein did not change with any intervention. Long chain vs essential n-3 PUFA–rich oils have distinct metabolic and endocrine effects in polycystic ovary syndrome; and therefore, they should not be used interchangeably. (Author’s abstract)