Three months of daily supplementation with docosahexaenoic acid (DHA) produced a "clinically significant" improvement in insulin sensitivity in overweight study participants, according to Dr. Yvonne Denkins, a nutrition researcher at the Pennington Biomedical Research Institute.

More than 9 out of 10 diabetics have the type 2 form of the disease, where the body's gradual failure to respond to insulin can cause blood sugar levels to rise to dangerous levels.

Previous population studies have suggested that fish oil might help protect against diabetes. "There were epidemiological studies on the Greenland Eskimos, a population of people that eat mainly whale blubber.

These are people that are overweight, that should be diabetic and have heart disease, but they do not. The scientists that studied them thought it was probably because of what they eat, and they found that it was the omega-3s."

In the study, researchers had 12 overweight men and women, aged 40 to 70, consume 1.8 grams of DHA at breakfast for 12 weeks. While none of the study participants had full-blown diabetes, they all suffered from insulin resistance -- a pre-diabetic condition in which the body fails to efficiently respond to insulin.

Using blood tests taken at the start and end of the study, the researchers assessed changes in each person's insulin resistance.

They saw a change in insulin sensitivity after 12 weeks of DHA supplementation. A full 70% of the study participants showed an improvement in insulin-related function, and in 50% it was a clinically significant change.