In adults with diabetes, daily supplementation with omega-3 fatty acids (≥1000 mg/day of EPA/DHA) for at least 4 weeks is associated with a reduction in fasting blood glucose by approximately 16.1 mg/dL, a reduction in triglycerides by 44.9 mg/dL, and a decrease in HDL cholesterol by 2.3 mg/dL.

Omega-3 fats enter liver cells and stop the liver from making and releasing as many fat-carrying particles, which lowers blood triglycerides. They also change how immune cells behave, turning off long-term inflammation. This reduces signals that interfere with insulin's ability to lower blood sugar, but the same changes also cause the liver to release more glucose, raising fasting blood sugar. At the same time, the body breaks down less of the good cholesterol, causing it to drop slightly.