Type 1 diabetes (T1D) is a common childhood disease caused by islet cell autoimmunity. Reports suggest omega-3 fatty acids may decrease the risk of T1D by suppressing the inflammatory immune responses that initiate the process of islet autoimmunity. Various epidemiological studies and observations have concluded that the intake of omega-3 fatty acids is associated with a decreased risk of the development of T1D in children with an increased genetic risk for the disease.

The TrialNet 06 study hypothesized that islet autoimmunity could be prevented in infants, with an increased risk for T1D, through the consumption of DHA, an omega-3 fatty acid. Participants were enrolled during pregnancy or after birth, and randomized into the treatment or control group. During the study, subjects in the treatment group received a vegetarian DHA substance while those in the control group received a placebo. Treatments were administered daily for at least 36 months from the date of birth or the date of randomization. Participants were regularly tested for DHA and inflammatory cytokine levels. Additionally, TrialNet 06 was used as a pilot trial in order to determine the feasibility of a full-scale DHA supplementation study.

The objective of the TrialNet 06 study was to determine whether the risk of T1D, in high-risk infants, could be reduced through the nutritional intervention of DHA. Additionally, this study was used as a pilot trial in order to determine the feasibility of a full-scale DHA supplementation study.

Primary Outcome Measures:

• Participants were tested for DHA and inflammation levels, every three months for two years and every six months until age three, and the results were compared between the two groups. The objective was for the whole blood phospholipid DHA level of the treatment group to be at least 20% higher than the control group. Additionally, the objective for the major inflammatory cytokine level was at least a 20% lower level in the treatment group when compared to the control group.

Secondary Outcome Measures:

• Visit compliance was attained if at least 95% of the families continued to attend the scheduled follow-up visits.

Inclusion:

• Pregnant mothers were eligible for trial enrollment if they were age 18 or older; were in the third trimester of pregnancy; and if they, the child’s father, or the child’s full or half-sibling had T1D.

• Infants were eligible for enrollment if they were age 6 months or younger at the time of randomization; their mother, father, or full or half-sibling had T1D; and they had a DR3 or DR4 allele, or they had another relative with T1D.

Exclusion:

• Pregnant mothers were excluded from the study if they planned on taking DHA supplementation during the study period; had previous multiple pre-term births; they had a condition or pregnancy complication that would put her or the fetus at an increased or unacceptable medical risk; or if they had diabetes and a HbA1c value greater than 9% during the pregnancy.

• Infants were excluded from the study if they were born prior to 36 weeks’ gestation and required pre-term infant formula; had a protective allele; would be directly or indirectly given DHA supplementation; or they had a condition that would put them at an unacceptable medical risk.

This study has been completed, but the official results have not been released. Preliminary results suggested that a full-scale nutritional intervention trial could be feasible, as long as the appropriate safety precautions are taken.