TY - JOUR
T1 - Carrageenan and insulin resistance in humans
T2 - a randomised double-blind cross-over trial
AU - Wagner, Robert
AU - Buettner, Janine
AU - Heni, Martin
AU - Fritsche, Louise
AU - Kullmann, Stephanie
AU - Wagmüller, Moritz
AU - Peter, Andreas
AU - Preissl, Hubert
AU - Machann, Jürgen
AU - Jumpertz von Schwartzenberg, Reiner
AU - Birkenfeld, Andreas L.
AU - Pape, Ulrich Frank
AU - van Hall, Gerrit
AU - Plomgaard, Peter
AU - Häring, Hans Ulrich
AU - Fritsche, Andreas
AU - Thompson, Kelsey N.
AU - Klein, Reinhild
AU - Stefan, Norbert
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024
Y1 - 2024
N2 - Background: The potential impact of specific food additives, common in Western diets, on the risk of developing type 2 diabetes is not well understood. This study focuses on carrageenan, a widely used food additive known to induce insulin resistance and gut inflammation in animal models, and its effects on human health. Methods: In a randomised, double-blind, placebo-controlled, cross-over trial conducted at a university hospital metabolic study centre, 20 males (age 27.4 ± 4.3 years, BMI 24.5 ± 2.5 kg/m2) participated. The intervention involved oral intake of carrageenan (250 mg) or placebo in the morning and in the evening and each intervention lasted 2 weeks. The primary outcome measured was insulin sensitivity (using oral glucose tolerance test [OGTT] and hyperinsulinaemic-euglycaemic clamp). Additional end-points included whole body and hepatic insulin sensitivity, MRI-measured brain inflammation and insulin resistance, intestinal permeability (via lactulose-mannitol test and plasma zonulin levels), and gut microbiome composition. Immune-cell activation and pro-inflammatory cytokine release from peripheral blood mononuclear cells were measured. Results: Overall insulin sensitivity did not show significant differences between the treatments. However, interactions between BMI and treatment were observed (OGTT-based insulin sensitivity index: p=0.04, fasting insulin resistance:p=0.01, hepatic insulin sensitivity index: p=0.04). In overweight participants, carrageenan exposure resulted in lower whole body and hepatic insulin sensitivity, a trend towards increased brain inflammation, and elevated C-reactive protein (CRP) and IL-6 levels compared to placebo. Additionally, carrageenan was associated with increased intestinal permeability. In vitro natural killer (NK-)cell activation and increased pro-inflammatory cytokine release were found after carrageenan exposure in the participant’s peripheral blood mononuclear cells. Conclusions: These findings suggest that carrageenan, a common food additive, may contribute to insulin resistance and subclinical inflammation in overweight individuals through pro-inflammatory mechanisms in the gut. Further investigation into the long-term health impacts of carrageenan and other food additives is warranted. Trial registration: NCT02629705.
AB - Background: The potential impact of specific food additives, common in Western diets, on the risk of developing type 2 diabetes is not well understood. This study focuses on carrageenan, a widely used food additive known to induce insulin resistance and gut inflammation in animal models, and its effects on human health. Methods: In a randomised, double-blind, placebo-controlled, cross-over trial conducted at a university hospital metabolic study centre, 20 males (age 27.4 ± 4.3 years, BMI 24.5 ± 2.5 kg/m2) participated. The intervention involved oral intake of carrageenan (250 mg) or placebo in the morning and in the evening and each intervention lasted 2 weeks. The primary outcome measured was insulin sensitivity (using oral glucose tolerance test [OGTT] and hyperinsulinaemic-euglycaemic clamp). Additional end-points included whole body and hepatic insulin sensitivity, MRI-measured brain inflammation and insulin resistance, intestinal permeability (via lactulose-mannitol test and plasma zonulin levels), and gut microbiome composition. Immune-cell activation and pro-inflammatory cytokine release from peripheral blood mononuclear cells were measured. Results: Overall insulin sensitivity did not show significant differences between the treatments. However, interactions between BMI and treatment were observed (OGTT-based insulin sensitivity index: p=0.04, fasting insulin resistance:p=0.01, hepatic insulin sensitivity index: p=0.04). In overweight participants, carrageenan exposure resulted in lower whole body and hepatic insulin sensitivity, a trend towards increased brain inflammation, and elevated C-reactive protein (CRP) and IL-6 levels compared to placebo. Additionally, carrageenan was associated with increased intestinal permeability. In vitro natural killer (NK-)cell activation and increased pro-inflammatory cytokine release were found after carrageenan exposure in the participant’s peripheral blood mononuclear cells. Conclusions: These findings suggest that carrageenan, a common food additive, may contribute to insulin resistance and subclinical inflammation in overweight individuals through pro-inflammatory mechanisms in the gut. Further investigation into the long-term health impacts of carrageenan and other food additives is warranted. Trial registration: NCT02629705.
KW - Carrageenan
KW - Emulsifiers
KW - Gut microbiome
KW - Insulin sensitivity
KW - Intestinal permeability
KW - Type 2 diabetes
U2 - 10.1186/s12916-024-03771-8
DO - 10.1186/s12916-024-03771-8
M3 - Journal article
C2 - 39593091
AN - SCOPUS:85210227235
VL - 22
JO - BMC Medicine
JF - BMC Medicine
SN - 1741-7015
IS - 1
M1 - 558
ER -