Children who are at increased risk for type 1 diabetes may be able to reduce their chance of developing the disease by eating a diet rich in omega-3 fatty acids, researchers report in the Journal of the American Medical Association.

The research is still preliminary but it may offer hope to those who have been told they are at a high genetic risk of developing insulin-dependent diabetes.

The researchers, led by Jill Norris of the University of Colorado at Denver and Health Sciences Center, looked at how diet affected pancreatic islet autoimmunity, a condition in which the body develops antibodies against the cells in the pancreas that produce insulin. These antibodies are considered a strong predictor of type 1 diabetes.

The study included 1,770 children who were at increased risk for type 1 diabetes because they had a sibling or parent with the condition or they carried genes that put them at higher risk of developing diabetes.

The researchers wanted to know if children who ate a diet high in omega-3 fatty acids from the time they were one year of age would later develop islet autoimmunity. The children's parents were asked to report on their children's omega-3 intake at 3, 5, 7 and 9 years of age.

Fifty-eight children in the study developed these antibodies. But the children who ate a diet high in omega-3s reduced their risk of developing islet autoimmunity by 55 per cent.

To make sure parents in the study were accurately reporting the children's food intake, Norris' team tested for the presence of omega-3 fatty acids in blood cell membranes of 244 of the children. In that group, children with omega-3s in their blood cell membranes had a 37 per cent decreased risk of developing islet autoimmunity.

Type 1 diabetes, is usually diagnosed in childhood and is a life-long condition that requires daily insulin injections, since patients' pancreases can make little or no insulin. Scientists speculate that both genetic background and environmental factors - including diet - play a role in the autoimmune process that leads to diabetes.

Studies suggest that inflammation is involved in the development of type 1 diabetes. Since omega-3 fats have strong anti-inflammatory properties, it's thought they might help reduce the risk of the disorder.

"The thought is that the omega-3s reduce the amount of inflammatory cells -- chemicals called cytokines -- that destroy immune cells," pediatric endocrinologist Diane Wherrett explained to CTV News.

"If there are fewer of those destructive cytokines around, hopefully there's less damage going on inside the cells that make insulin."

Study author Jill Norris says the study is exciting, "because in the long run, with more research, it suggests we might be able to prevent diabetes with a nutritional intervention."

Omega-3 fatty acids are found in darker, oily fish including salmon, sardines and mackerel. They are also plentiful in canola oil, some nuts and flax seeds. Studies have suggested omega-3 fatty acids can help prevent heart disease by improving heart and blood vessel function and lowering triglyceride levels.

The ideal amount of omega-3s to take isn't clear and few organizations have released recommendations on them. The American Heart Association recommends eating fish (preferably fatty) at least twice a week, but also advised against taking more than 3,000 millgrams of omega-3 fatty acids from capsules a day.