Dietary advice is the basis of treatment of diabetes, but there’s uncertainty about the effects of polyunsaturated fatty acids.

Researchers at Uppsala University, in Sweden, compared the effects of diets rich in omega-3 or omega-6 fatty acids on glucose and lipoprotein metabolism in these patients.

First, the details.

  • During 2 consecutive 3.5-week periods, participants were provided diets with identical nutrient compositions containing either a high proportion of omega-3 fatty acids (fatty fish) or omega-6 fatty acids lean fish and fat containing linoleic acid).
  • All patients followed each diet in different order — crossover design.

And, the results.

  • Blood sugar concentrations at fasting and during the day were significantly lower with omega-6 than with omega-3.
  • The area under the insulin curve (measure of the glycemic index: effects of carbohydrates and blood sugar levels) during the day was significantly higher with the omega-6 diet.
  • Both diets showed similar effects on insulin sensitivity and plasminogen activator inhibitor 1 concentrations.
  • The reductions in VLDLs and serum apolipoprotein B concentrations were more pronounced after the omega-3 diet.
    • Elevated plasminogen activator inhibitor-1 concentrations are associated with cardiovascular diseases.
    • VLDL (very-low-density lipoprotein) is one of the 5 major groups of cholesterol.
    • Apolipoprotein B is part of the LDL (bad) cholesterol molecule that carries cholesterol to tissue.

The bottom line?

The authors concluded, “The risk related to the moderately higher blood glucose concentrations with the omega-3-enriched diet may be counteracted by positive effects with regard to lipoprotein concentrations.”

They also concluded, “An increase in long-chain omega-3 fatty acids from fatty fish, and of omega-6 fatty acids from linoleic acid, may be recommended for patients with type 2 diabetes.

Overall, there are benefits to people with diabetes who eat fish.

8/25/11 20:19 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.