Blueberry fiber has been studied for its potential benefits in metabolic syndrome, a cluster of conditions including insulin resistance, obesity, dyslipidemia, and hypertension. The justification for its use is primarily scientific, though the evidence is still emerging and not robust. Animal studies have shown that blueberry supplementation, including fiber components, may improve insulin sensitivity, reduce inflammation, and positively modulate gut microbiota—factors relevant to metabolic syndrome. Some small human clinical studies have observed modest improvements in markers such as blood pressure, lipid profiles, and oxidative stress after blueberry or blueberry extract supplementation; however, these studies often use whole blueberries or extracts rather than isolated fiber, making it difficult to attribute effects specifically to the fiber content.

The mechanisms proposed include the prebiotic effects of blueberry fiber, leading to beneficial changes in gut bacteria and short-chain fatty acid production, which may influence metabolic regulation. However, direct evidence linking blueberry fiber alone—separate from polyphenols and other constituents—to significant improvements in metabolic syndrome is limited. Larger, well-controlled human trials are needed to confirm these findings and to establish effective dosages and forms. In summary, scientific evidence exists suggesting potential benefits, but it is currently weak to moderate (rated 2/5), and should be interpreted cautiously.