Type 1 diabetes is often viewed as a disease that develops during childhood — and it is, in fact, usually diagnosed in younger people. But adults are increasingly at risk for developing type 1, which happens when your pancreas stops producing enough insulin due to an attack from your own immune system on pancreatic beta cells.
In recent years, research has made clear that in most people, the autoimmune attack on pancreatic beta cells begins years before a person develops any symptoms of diabetes or measurable deficiency of insulin. The telltale sign of this attack is specific antibodies, or proteins that your immune system produces to address a particular threat. When your body’s own cells or tissues are the target, these antibodies are known as autoantibodies.
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Until recently, little could be done to help delay the onset of diabetes in children or adults found to have autoantibodies typical of type 1. There are now treatments being developed that, preliminary research shows, may help delay the onset of diabetes by years in children. But a new study suggests that your diet may have an effect on diabetes development when you have autoantibodies — specifically, how much fish you eat.
High fish consumption may be protective
The new study, published in the journal Diabetes Care, looked at fish consumption in adults with autoantibodies known as GAD65 antibodies, which are known to be associated with an attack on pancreatic beta cells and diabetes development. The data was from adults in eight European countries, and included 11,247 people who developed diabetes as adults and 14,288 adults who didn’t have diabetes.
Blood samples from all participants were tested for GAD65 antibodies, as well as levels of omega-3 fatty acids — healthy fats that can be obtained from several different dietary sources, including fatty fish (like salmon, mackerel and herring). Fish consumption was also assessed based on a questionnaire.
The researchers found that participants with GAD65 antibodies and a low intake of fish in their diet were 2.52 times as likely to have diabetes as those without GAD65 antibodies and a high intake of fish. The combined effect of GAD65 antibody status and blood levels of omega-3 fatty acids was even more dramatic: Participants with high levels of GAD65 antibodies, as well as low omega-3 levels in their blood, were more than four times as likely to have diabetes as those without GAD65 antibodies and high omega-3 levels in their blood.
When the analysis was restricted to look at fish intake only in adults with GAD65 antibodies, the researchers found a lower risk of diabetes among those with a high reported consumption of fatty fish, but this analysis was limited by small numbers of participants in the relevant groups, as noted in a Healio article on the study.
Lessons for people with diabetes autoantibodies
Based on their overall findings, the researchers write that high fish intake or high blood levels of omega-3 fatty acids “may partially counteract the increased diabetes risk conferred by GAD65 antibody positivity.” It’s not known why, exactly, this protective effect from fish consumption — especially of fatty fish — may exist. But many different factors can affect how the immune system functions, and in this case, it appears that blood levels of omega-3 fatty acids may be one of them.
Right now, general dietary guidelines from the U.S. Food and Drug Administration (FDA) recommend eating at least 8 ounces of fish each week for most people, with young children eating somewhat less. The FDA also gives guidance on which types of fish are fairly safe when it comes to mercury levels (a toxic contaminant found in many types of fish), which types should be limited to one serving per week, and which types should be avoided.
If you or your child has tested positive for autoantibodies associated with diabetes, and you’re interested in increasing your fish intake, talk to your healthcare provider about how much fish is safe or reasonable to consume.
Want to learn more about type 1 diabetes? Read “Type 1 Diabetes Questions and Answers,” “Six Type 1 Diabetes Symptoms You Need to Know” and “Living With Type 1 Diabetes: Four Tips to Get You Started.”