Eating a diet rich in omega-3 fats may help keep high-risk children from developing type 1 diabetes, a recent study published in the Journal of the American Medical Association suggests.

Dietary intake of omega-3 fatty acids was associated with a lower incidence of auto-antibodies in the blood that signal the immune system to attack insulin-producing cells in the pancreas. Oily fish like salmon, sardines and mackerel are among the best food sources of omega-3s. Dark green vegetables and canola oil, sunflower oil and flaxseed oil are also good sources. Increasingly, eggs, breads, juices and other foods are being fortified with omega-3s.

Omega-3 fatty acids are known to have anti-inflammatory properties, and inflammation is believed to play a major role in the development of type 1 diabetes through destruction of the insulin-producing cells.

"The thinking is that omega-3 may increase the body's ability to fight the inflammation that leads to type 1 diabetes," researcher Jill M. Norris, MD, says.

The University of Colorado professor of preventive medicine adds that the findings, while intriguing, do not prove that omega-3-rich foods protect against type 1 diabetes.

The study included 1,770 children—from birth to age 3—with an increased risk of developing type 1 diabetes and followed them for an average of six years. These children either had a parent or a sibling with type 1 diabetes or had genetic tests that showed increased risk.

Omega-3 intake was determined through annual food-frequency questionnaires. Among other things, parents were asked how often their children ate canned tuna and oily fish like salmon or mackerel. They were also asked about the oil they used for home cooking.

Red blood cells from 244 children in the study were also tested for fatty acid composition to confirm the questionnaire findings.

The research confirmed that children who reportedly had higher intakes of omega-3 fatty acids also had less evidence of pancreatic Islet autoimmunity (IA), the auto-antibody associated with progression to type 1 diabetes.

An interventional trial funded by the National Institutes of Health should offer more clues about the link between diet and type 1 diabetes, especially the role of omega-3 fatty acids.

The trial is designed to explore whether babies with a genetic predisposition for developing type 1 diabetes show fewer signs of inflammation when given supplements of the omega-3 fatty acid docosahexaenoic acid (DHA) from infancy.

An expanded version of the trial is planned to determine whether DHA protects infants and children from the development of the auto-antibodies that lead to diabetes.

If researchers find a direct link between DHA supplementation and a reduction in the inflammatory activity that leads to diabetes, omega-3 supplementation could become a major strategy for preventing the disease.

Michael Clare-Salzler, MD, who will lead the study, says many questions must be answered before this happens.

"If supplementation does work, the timing may be critical," says Dr. Clare-Salzler. "That is what this trial is all about. We want to test this hypothesis that if we get to babies early with anti-inflammatory therapy, we can block the development of these auto-antibodies."