A diet rich in fish and other sources of omega-3 fatty acids helped
cut the risk that children with a family history of diabetes would
develop the disease,
“It is a relatively large effect,” said Jill Norris, whose
study appears in the Journal of the American Medical Association.
“It is exciting because it suggests we might be able to develop
nutritional interventions to prevent diabetes.”
Type 1 diabetes, formerly called juvenile diabetes, is the most common
form of diabetes in children. It occurs when the immune system goes
haywire and starts attacking insulin-producing cells in the pancreas.
No one knows exactly what triggers this process, but heredity and
environmental factors such as diet are thought to play a role.
Several studies in animals have suggested that omega-3 fatty acids
— which are found in fish, flaxseed oil, walnuts, soybeans and
other foods — may help.
To test whether omega-3 fatty acids offer a potential protective effect,
Norris and colleagues at the University of Colorado at Denver studied
1,770 children between 1994 and 2006 who were deemed at high risk
for diabetes because of genetic tests or because they had a sibling
or parent with type 1 diabetes.
Data about their dietary intake were collected in food frequency surveys.
Their blood was tested at least once a year for what is known as islet
autoimmunity — the development of antibodies made by the immune
system that attack insulin-producing cells in the pancreas. These
antibodies are considered a strong predictor of type 1 diabetes.
Fifty-eight children in the study developed these antibodies.
Overall, the researchers found at-risk children who ate a lot of foods
rich in omega-3 were 55 percent less likely to have pancreatic islet
autoimmunity.
“This is the first study to show this,” Norris said in
a telephone interview. “This is all omega-3 fatty acids, not
just the kind that are found in fish.”
To make sure parents in the study were accurately reporting the children’s
food intake, Norris and colleagues tested for the presence of omega-3
fatty acids in blood cell membranes of 244 of the children.
In that group, children with omega-3 fatty acids in their blood cell
membranes had a 37 percent decreased risk of having islet autoimmunity.
“It is certainly not time to make any recommendations until
we can see this in other populations,” Norris said, but added
that it is a very promising result.
Omega-3 fatty acids interfere with enzymes that play a role in inflammation,
a potential trigger for type 1 diabetes.
At least 194 million people in the world have diabetes, and the World
Health Organization expects that number to rise to more than 300 million
by 2025. Most of these people have type 2 diabetes, which is linked
with poor diet and lack of exercise.
People with type 1 diabetes often must take insulin injections to
control blood sugar levels.
