Old-fashioned cod liver oil supplements in infancy have already been associated with a decreased risk of type 1 diabetes among Norwegian children, who are apparently given the omega-3-rich, albeit nauseating, tonic on a regular basis.

Now researchers from the University of Colorado have discovered that among children at high risk of type 1 diabetes, those who ate a lot of omega-3s had a 55 percent lower risk of developing type 1. In another words, they were half as likely to develop type 1 as those who ate less omega-3.

The researchers examined 1,770 children who were at high risk of developing type 1, either because they had a family member with type 1 or because they had genetic markers indicating increased risk. The children were followed from the age of one year until they were slightly over six years old. During that time, 58 of the children developed pancreatic Islet Autoimmunity (IA).

IA is a precursor to type 1 diabetes; it's defined as being positive for three antibodies (insulin, glutamic acid decarboxylase, or insulinoma-associated antigen-2 antibodies) on two visits, and then still being autoantibody positive or having diabetes on a final visit.

In the study, total omega-3 intake (as reported by the children's parents) conferred a 55 percent reduced risk of developing IA. The link was even stronger if the end point included only those children positive for two, rather than all three, antibodies. In another group of children, whose blood was actually measured for biomarkers of omega-3 consumption, high levels of omega-2 reduced risk of type 1 by 37 percent.

The researchers hypothesize that the anti-inflammatory properties of omega-3 may underlie its protective effect. Although they warn that it's too soon to recommend that children be given omega-3s for the prevention of diabetes, any healthy diet can include them. Omega-3 is found in fish, walnuts, olive and canola oils, special supplement capsules, and, of course, the revolting cod liver oil.

Sources: Medline Plus, EurekAlert; Journal of the American Medical Association, September 2007