Plants of the Vaccinium genus are low-branched, deciduous shrubs that belong to the Ericaceae family. They produce berries rich in various phenolic compounds, including quercetin, myricetin, isorhamnetin, tannins, ellagitannins, phenolic acids, and anthocyanins. The most abundant bioactive compounds in these berries are anthocyanins, which give the fruits their distinctive dark blue color. These metabolites comprise anthocyanin aglycones, sugar moieties, and acyl groups.

This study aimed to systematically review clinical research on the effects of berry fruits on drug-metabolizing enzyme activity.

This review followed the PRISMA guidelines. We conducted electronic searches in academic databases such as Cochrane, Ebsco, PubMed, Embase, Scopus, and Web of Science. The primary inclusion criteria for all databases included the following: 1. keywords (Vaccinium, blueberry, bilberry, cranberry) and (“drug interactions” or “medicines interactions”), 2. publication years (1993–2022), 3. language (English), 4. publication type (article). Three reviewers independently conducted the search and selection process. Initial searches yielded 249 results. Two independent researchers then reviewed titles, abstracts, and full papers, excluding those not meeting the inclusion criteria through discussion. A total of 31 original studies were selected for review.

The positive health benefits of berry fruits have increased the production and consumption of dietary supplements rich in blueberry extract. However, high doses of berry extracts from the Vaccinium genus may cause adverse effects, including potential interactions with other drugs. Blueberry extracts can influence drug behavior and efficacy by altering the activity of drug-metabolizing enzymes, which convert lipophilic drugs and other xenobiotic compounds into polar products for more straightforward elimination from the body. Such interactions between berry fruit compounds and medications can pose risks to patients.