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A recent study from Northwestern University suggests that juice cleanses might not be as beneficial as many believe. The research, published in the journal Nutrients, found that a diet consisting solely of vegetable and fruit juices can disrupt gut and oral bacteria, potentially leading to inflammation and cognitive decline. These changes can occur in as little as three days.
The study involved three groups of healthy adults: one group consumed only juice, another had juice with whole foods, and a third ate only whole plant-based foods. Researchers collected saliva, cheek swabs, and stool samples to analyze bacterial changes using gene-sequencing techniques. The juice-only group experienced the most significant increase in bacteria associated with inflammation and gut permeability, while the plant-based whole food group saw more favorable microbial changes.
Dr. Melinda Ring, senior author and director of the Osher Center for Integrative Health at Northwestern University, explained that juicing removes much of the fiber in fruits and vegetables, which feeds beneficial bacteria. Without fiber, sugar-loving bacteria can multiply, disrupting the microbiome. The study also highlighted changes in the oral microbiome, with a reduction in beneficial Firmicutes bacteria and an increase in inflammation-associated Proteobacteria.
The findings emphasize the importance of fiber in maintaining a healthy microbiome. Dr. Ring suggests blending instead of juicing to retain fiber or pairing juices with whole foods.