Improving quercetin bioavailability: A systematic review and meta-analysis of human intervention studies.

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Quercetin is a flavonoid abundant in onions, apples, and tea, known for its antioxidant and anti-inflammatory properties. However, its poor solubility, pH sensitivity, and hydrophobic nature limit its absorption. This study systematically reviewed methods used to enhance quercetin bioavailability. This research was a systematic review of thirty-one human intervention studies. It found that modified forms of quercetin such as quercetin nanoparticles, liposomal quercetin, and quercetin phospholipid complexes all improve absorption. Quercetin absorption can also be improved when consumed with fats and fibre. Quercetin absorption depended on its source with quercetin in onions being better absorbed than that found in apples and tea. Consuming quercetin with a high-fat meal increases its absorption compared to intake on an empty stomach. Multiple smaller doses throughout the day enhance plasma quercetin levels better than a single large dose. Factors like gut microbiota composition, genetics, and health status influence quercetin absorption and metabolism. The authors concluded that high bioavailability is a prerequisite for achieving the potential beneficial effects of quercetin. Further research is needed to determine the most effective formulations and dosing strategies.