From Our 2007 Archives

Omega-3 May Lower Type 1 Diabetes Risk

Diet Rich in Omega-3 Fatty Acids May Help Body Fight Inflammation That Leads to Diabetes

By Salynn Boyles
WebMD Health News

Reviewed By Louise Chang, MD

Sept. 25, 2007 -- Eating a diet rich in omega-3 fats may help keep high-risk children from developing type 1 diabetes, early research suggests.

Dietary intake of omega-3 fatty acids was associated with a lower incidence of autoantibodies in the blood that signal the immune system toattack insulin-producing cells in the pancreas.

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 these 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, MPH, PHD, tells WebMD.

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

The study appears in the Sept. 27 issue of TheJournal of the American Medical Association.

"This is a preliminary study," she says. "We really can't make dietary recommendations based on these findings."

Omega-3, Diabetes Research

In adults, omega-3 rich diets are believed to lower cardiovascular risk, and in babies the fatty acid is believed to boost brain development.

A 2003 study from Norway was one of the first human trials to suggest a protective role for omega-3 fatty acids in type 1 diabetes. Researchers reported a lower incidence of omega-3-rich cod liver oil supplementation during infancy in children with diabetes, compared to children without the disease.

The newly published study included 1,770 children -- from birth to age 3 -- at increased risk for developing type 1 diabetes, followed for an average of six years. These children either had a parent or 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.

Oily fish like salmon, sardines, and mackerel are among the best food sources of omega-3s, but 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.

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 the autoantibodies associated with progression to type 1 diabetes.

Plans for More Omega-3 Research

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 autoantibodies 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, tells WebMD that many questions must be answered before this happens.

"If supplementation does work, the timing may be critical," he says. "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 autoantibodies."

SOURCES: Norris, J.M. The Journal of the American Medical Association, Sept. 26, 2007; vol 298: pp 1420-1428. Jill M. Norris, MPH, PhD, professor of preventive medicine and biometrics, University of Colorado, Health Sciences Center, Denver. Michael Clare-Salzler, MD, professor of pathology, immunology, and laboratory medicine, University of Florida College of Medicine at Gainesville.

© 2007 WebMD Inc. All rights reserved.