From:  The impact of polyphenol-rich dark fruits on pain and inflammation in osteoarthritis: a systematic review and meta-analysis

 Intervention and comparator details, blinding/compliance, and adverse events.

AuthorIntervention (dose, formulation)Polyphenol/Anthocyanin contentComparatorBlinding & complianceAdverse events
Du et al. [66]40 g freeze-dried whole blueberry powder daily (two 20 g packets/day), reconstituted in waterNot reported40 g placebo powder daily, maltodextrin-based and matched for appearance and energy/carbohydrate contentDouble-blind; compliance tracked with daily calendars and follow-up calls, but no numeric adherence reportedNot reported
Basu et al. [67]50 g/day freeze-dried strawberry powder, reconstituted in water1,585 mg total polyphenols; 66 mg anthocyanins; 220 mg ellagic acid50 g/day matched control powder (75 mg polyphenols; 172 kcal; 38 g carbohydrate; 5 g fibre)Double-blind cross-over; 2-week washout; compliance 100% for strawberry phase and 97% for control phase; plasma ellagic acid used as an objective compliance markerNone reported
Schell et al. [68]50 g/day freeze-dried strawberry powder, reconstituted in water1,585 mg total polyphenols; 66 mg anthocyanins; 220 mg ellagic acid50 g/day matched control powder (75 mg polyphenols; 172 kcal; 38 g carbohydrate; 5 g fibre)Double-blind cross-over; 2-week washout; compliance 100% for strawberry phase and 97% for control phase; plasma ellagic acid used as an objective compliance markerNone reported
Schumacher et al. [69]2 × 8 oz/day tart cherry juice blend (> 90% cherry juice mixed with apple juice)At least 450 mg phenolics and ≥ 30 mg anthocyanins per 8 oz bottle (≥ 900 mg phenolics and ≥ 60 mg anthocyanins/day)Matched cherry-flavoured placebo beverage (Kool-Aid base; 13° Brix; 31 g sugar/serving)Double-blind cross-over; 1-week washout; compliance 92% ± 16% for cherry juice and 89% ± 17% for placebo; blinding judged adequateCherry phase: 4 AEs (possible cherry allergy, GI symptoms, low back injury, elevated blood glucose); placebo phase: 3 AEs
Kuehl et al. [70]2 × 10.5 oz/day tart cherry juice (Montmorency), morning and eveningAt least 600 mg phenolics and ≥ 40 mg anthocyanins per 10.5 oz bottleMatched placebo cherry drink (13° Brix), matched for calorie content, flavour, and consistencyDouble-blind; treatment assignments concealed until study completion; no numeric compliance data reported1 withdrawal during placebo phase due to nausea and diarrhea; no tart cherry-specific adverse event reported
Ghoochani et al. [71]200 mL/day sugar- and additive-free pomegranate juiceNot reportedControl group maintained usual lifestyle/diet; no placebo beverageNo placebo; no blinding; compliance not reportedNot reported

Note. For cross-over trials, comparator, compliance, and adverse-event information is summarized across both phases where the publication reported phase-specific data.