The Study
Bilirubin reduces visceral obesity and insulin resistance by suppression of inflammatory cytokines
This study found that people with lower bilirubin tend to have more belly fat and worse insulin resistance, but it doesn't prove that low bilirubin causes those problems—it could be something else, like diet or genes. In mice, giving them a related chemical helped, but mice aren't people.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Your body makes a yellow stuff called bilirubin when it breaks down old blood cells. This study found that people with more belly fat tend to have less of it, and in mice, giving them a related compound made their fat cells smaller and less inflamed.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 545 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — if bilirubin helps reduce belly fat inflammation in humans like it did in mice, it could be a natural way to improve insulin resistance and type 2 diabetes.
- 2In humans: lower bilirubin linked to higher visceral fat (no link to under-skin fat).
- 3In mice: biliverdin (turns into bilirubin) reduced fat cell size and lowered TNF-α and Cd11c (inflammation markers) in fat tissue.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PLoS ONE
Year
2019
Authors
Ryoko Takei, T. Inoue, N. Sonoda, M. Kohjima, Misato Okamoto, R. Sakamoto, T. Inoguchi, Y. Ogawa
Related Content
Claims (6)
Inflammatory molecules released by visceral fat cause insulin resistance, leading to increased fat storage by reducing fat breakdown and increasing new fat production.
In obese mice fed a high-fat diet, biliverdin lowers the levels of TNF-α and Cd11c in fat tissue but does not change levels of M2 macrophage markers or adiponectin.
In Japanese adults with type 2 diabetes, levels of bilirubin in the blood show no link to the amount of fat under the skin, but are linked specifically to fat around internal organs.
In Japanese adults with type 2 diabetes, people with lower levels of bilirubin in their blood tend to have more fat around their internal organs, even after accounting for age, sex, and other metabolic differences.
In obese mice on a high-fat diet, daily oral biliverdin for two weeks reduces fat cell size and improves insulin resistance, while lowering levels of the inflammatory markers TNF-α and Cd11c in fat tissue.
In obese mice fed a high-fat diet, biliverdin lowers the levels of specific oxidative stress proteins in fat tissue and is linked to better metabolic health.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.