Conclusions
Findings indicate improvement in HbA1c and HOMA-IR in participants on no-carrageenan diets, but not in participants on carrageenan-containing diets. Significant differences between groups suggest that removing carrageenan may improve insulin signaling and glucose tolerance. Larger studies are needed to further consider the impact of carrageenan on development of diabetes.
Results
Subjects on no carrageenan had declines in HbA1c and HOMA-IR (p = 0.006, p = 0.026; paired t-test, two tailed). They had increases in C-peptide (p = 0.029) and Matsuda Index (2.1 ± 0.7 to 4.8 ± 2.3; p = 0.052) and declines in serum IL-8, serum galectin-3, and neutrophil phospho-(Ser307/312)-IRS1 (p = 0.049, p = 0.003, and p = 0.006; paired t-tests, two tailed). Subjects on the diet with carrageenan had no significant changes in these parameters. Significant differences between no-carrageenan and carrageenan-containing diet groups for changes from baseline to 12 weeks occurred in C-peptide, phospho-Ser-IRS1, phospho-AKT1, and mononuclear cell arylsulfatase B (p = 0.007, p = 0.038, p = 0.0012, and p = 0.0008; 2 × 2 ANOVA). Significant correlations were evident between several of the variables. Conclusions: Findings indicate improvement in HbA1c and HOMA-IR in participants on no-carrageenan diets, but not in participants on carrageenan-containing diets. Significant differences between groups suggest that removing carrageenan may improve insulin signaling and glucose tolerance. Larger studies are needed to further consider the impact of carrageenan on development of diabetes.