In experiments with mice, dietary supplementation of omega-3 polyunsaturated fatty acids (PUFAs) led to long-term improvements in glucose and insulin levels.
Additionally, the team observed signs of β-cell regeneration in these mice.
“The findings suggest that omega-3 PUFAs could potentially serve as a therapeutic modality for type 1 diabetes (T1D),” the study said.
“Our observations may also offer clinical guidance, in that those patients who are either at the early-onset stage of T1D or have consistently had good management of their blood glucose levels may benefit the most from these interventions.”
Given the very different metabolic profiles of mice and humans, the findings may prove difficult in translating into a dose for humans in order to achieve the same results.
The DAISY study showed that daily supplementation of a 150 milligram (mg) dose of EPA/DHA in infants had a strong preventative effect in children.
More research from Norway suggested that 1-year old infants may benefit from daily supplementation of 1.0 g eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in reducing their risk of developing T1D.
Study details
Writing in the latest issue of Journal of Clinical Investigation (JCI), the researchers began by feeding female non-obese diabetic (NOD) mice with a control diet or the same control diet supplemented with either 10% arachidonic acid (AA, an omega-6 PUFA) or 10% EPA/DHA.
These mice were subject to this regimen for 35 weeks, starting at five weeks of age. Glucose tolerance tests were carried out as were procedures to test insulin tolerance.
The team based at Guangdong University of Technology recorded significant changes in fatty acid composition in serum and tissue samples.
The EPA/DHA-enriched diet resulted in a substantial increase in omega-3 PUFAs that were accompanied by a significant decrease in omega-6 PUFAs.
Interestingly, 80% of female NOD mice on a regular diet developed diabetes by the age of 40 weeks, while only 33% of the mice fed an EPA/DHA-enriched diet were considered diabetic.
93% of NOD mice on the diet containing comparable levels of AA developed diabetes at the same age, although there was no significant difference between the AA intervention group and the control diet group.
“Long-term supplementation of dietary EPA/DHA reduced the incidence of T1D and delayed its onset in female NOD mice,” the team observed.
“Most of the preventative and therapeutic modalities developed in NOD mice have not been successfully realized in humans with T1D. Part of this failure may reside in the complexity of the pathogenesis of T1D.”
Human parallels
The researchers then began looking into the same effects of EPA/DHA on human CD4+ T cells, a type of cell that play an important role in the immune system, particularly in the adaptive immune system.
“In further extending this concept to application in humans, we found that DHA and EPA had the same effects on the differentiation of CD4+ T cells isolated from T1D donors as those observed in NOD mice.
“Thus, omega-3 PUFA–initiated changes in CD4+ T cells are likely the primary cellular mechanisms underlying the blockade of autoimmune development.”
The team pointed out that these results were entirely consistent with the conclusions derived from the DAISY and Norwegian clinical studies.
Source: Journal of Clinical Investigation
Published online ahead of print: doi.org/10.1172/JCI87388
“ω-3 polyunsaturated fatty acids ameliorate type 1 diabetes and autoimmunity.”
Authors: Allan Zhao et al.