Reflux Relief, Antioxidant Phenolics, and Traditional Uses

Evidence Review

Pediatric GERD Trial: Quince Syrup vs. Omeprazole (Zohalinezhad et al., 2015)

This double-blind randomized controlled trial enrolled 80 children aged 2–18 with diagnosed gastroesophageal reflux disease and randomized them to receive either quince syrup (0.6 mL/kg/day, in two divided doses) or omeprazole syrup (1 mL/kg/day) for four weeks [1]. Symptom severity was assessed at baseline, two weeks, and four weeks using a validated GERD symptom questionnaire covering heartburn, regurgitation, epigastric pain, vomiting, dysphagia, and feeding difficulties.

Both groups showed statistically significant within-group improvement on every symptom domain by week 4. When the two groups were compared head-to-head, no significant difference emerged between quince and omeprazole on the primary symptom score — the quince group was non-inferior across the board. Quince showed a slight numerical advantage on feeding difficulty and vomiting, while omeprazole had a slight numerical advantage on heartburn, but neither reached statistical significance. No adverse events were reported in either arm.

The clinical significance is meaningful in this population: long-term proton pump inhibitor use in children has been associated with increased risk of respiratory infections, gastrointestinal infections, micronutrient malabsorption, and altered gut microbiome composition. A locally acting, food-based alternative that performs comparably is a useful option for clinicians and families. Limitations: single-center trial, four-week duration (no data on durability of effect after discontinuation), and the population included a wide age range that limits subgroup analysis.

Pregnancy GERD Trial: Quince Sauce vs. Ranitidine (Shakeri et al., 2018)

This randomized open-label active-controlled trial enrolled 137 pregnant women experiencing symptomatic GERD and assigned them to receive either quince sauce (10 g after each main meal, three times daily) or ranitidine (150 mg twice daily) for four weeks [2]. The primary outcome was the GERD symptom score; outcomes were assessed at baseline, week 2, and week 4.

Both groups improved substantially from baseline. At the week 2 assessment, the quince group had a significantly lower mean symptom score than the ranitidine group (p = 0.036) — quince was actually performing better at the interim point. By week 4, both treatments produced similar overall symptom relief, with no significant between-group difference. Side effects were rare in both groups, with no serious adverse events.

The pregnancy context is particularly important. Roughly 40–80% of pregnant women experience GERD, and pharmacological options are constrained by safety concerns. Ranitidine has since been withdrawn in many markets due to NDMA contamination concerns, and PPIs in pregnancy have been associated with mixed signals on neonatal outcomes. A food-based intervention with millennia of safe culinary use during pregnancy fills a real clinical gap.

Limitations: open-label design (no placebo blinding), single-center, and the specific quince preparation (boiled with sugar to a sauce consistency) is not fully standardized between batches in real-world use. Nonetheless, the demonstration of non-inferiority to a standard pharmaceutical agent in this difficult-to-treat population is clinically meaningful.

Phytochemistry and Pharmacology Review (Ashraf et al., 2016)

This Frontiers in Pharmacology comprehensive review catalogued the chemistry and pharmacology of Cydonia oblonga based on the published literature through 2015 [3]. The review identified the major active compound classes — phenolic acids (chlorogenic acids, caffeic acid derivatives), flavonoids (quercetin, kaempferol, isorhamnetin glycosides), procyanidins, organic acids (malic, quinic, citric, shikimic), pectin, and the seed-specific glucuronoxylan mucilage — and their distribution across pulp, peel, leaves, and seeds.

Documented pharmacological activities reviewed included antioxidant (consistent across multiple in vitro and animal studies), anti-inflammatory (NF-kB suppression and reduced pro-inflammatory cytokine expression), antimicrobial (notable activity against Staphylococcus aureus and Escherichia coli at moderate concentrations), antiulcer and gastroprotective (mucosal coating and acid neutralization mechanisms), antihypertensive (consistent in spontaneously hypertensive rat models), antidiabetic (alpha-glucosidase inhibition and improved insulin sensitivity in animal models), and antitussive/expectorant (the historical basis for quince's use in cough preparations).

The review noted that the leaves and the seed mucilage have distinct activity profiles from the fruit, with leaves rich in additional flavonoids and the seeds providing the unique glucuronoxylan polysaccharide. The authors explicitly identified the gap between robust traditional and preclinical evidence and the limited number of human clinical trials, recommending GERD, hyperlipidemia, and wound healing as the highest-priority targets for clinical research.

Phenolic Profile and Anti-Inflammatory Activity (Herrera-Rocha et al., 2022)

This Molecules study used HPLC-DAD-ESI-MS quantitative analysis to characterize the phenolic profile of quince acetonic extracts and tested their antioxidant and anti-inflammatory activity in vitro [4]. The total phenolic content of the peel was significantly higher than the pulp (peel approximately 3–4 times more concentrated), with chlorogenic acid (3-O-caffeoylquinic acid) as the most abundant single phenolic compound, followed by 5-O-caffeoylquinic acid and quercetin-3-O-rutinoside.

DPPH and ABTS antioxidant assays showed the peel extract exhibited approximately 70% radical-scavenging activity at concentrations equivalent to 100 μg/mL, comparable to ascorbic acid as a positive control. In a RAW 264.7 macrophage anti-inflammatory model, the quince peel extract significantly reduced lipopolysaccharide-induced production of tumor necrosis factor-alpha and interleukin-6 in a dose-dependent manner, with the chlorogenic acid and rutin fractions showing the strongest individual effects.

The practical implication is that conventional preparation methods that discard the peel — peeling quinces before cooking, juicing — significantly reduce the polyphenol content of the final product. Traditional whole-fruit preparations (poaching with the peel on, then removing skins after cooking when phenolics have leached into the syrup) capture more of the antioxidant load.

Antioxidant Phytoconstituents for Functional Foods (Sut et al., 2019)

This Italian study comprehensively profiled the antioxidant phytoconstituents of three quince cultivars grown in northern Italy and evaluated extraction efficiency for nutraceutical applications [5]. Total polyphenol content ranged from 80 to 250 mg gallic acid equivalents per 100 g fresh weight depending on cultivar and tissue, with the peel consistently 2–3 times higher than pulp.

The dominant phenolics identified by LC-DAD-MSn analysis were 3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, and quercetin-3-O-rutinoside, with smaller amounts of kaempferol-3-O-rutinoside and various hydroxycinnamic acid derivatives. ORAC and FRAP antioxidant capacity values placed quince in the upper range of cultivated Rosaceae fruits, comparable to apple and pear cultivars rich in chlorogenic acid.

The authors evaluated several extraction methods (water, ethanol, acetone, supercritical CO2) and found ethanol-water mixtures gave the best balance of extraction efficiency and food-safe processing for nutraceutical applications. The study supports the case for quince — particularly the peel — as a meaningful dietary source of bioavailable antioxidants and for its development as a functional food ingredient.

Wound Healing in Rabbit Full-Thickness Wounds (Tamri et al., 2014)

This in vivo study used the well-validated rabbit full-thickness excisional wound model to test the wound-healing properties of quince seed mucilage at 10% and 20% topical concentrations against a 1% phenytoin cream positive control and an untreated negative control [6]. Wounds were monitored macroscopically (planimetric wound area measurement) and histologically (collagen deposition, epithelialization, inflammatory infiltrate) over 14 days.

The 20% quince seed mucilage group showed the fastest wound contraction and epithelialization, with statistically significant differences from both the untreated control and the phenytoin reference at days 7 and 14. Mean wound closure at day 14 was approximately 95% for the 20% mucilage group versus 78% for phenytoin and 62% for untreated controls. Histological analysis showed greater fibroblast density, more organized collagen deposition, and reduced inflammatory infiltrate in the mucilage groups.

The mechanism was attributed to a combination of moist wound environment maintenance (the mucilage gel retains water and prevents desiccation, which is now recognized as a key principle of modern wound care), direct fibroblast stimulation by the polysaccharide, and possibly mild antimicrobial activity from associated phenolic compounds. The performance against phenytoin — a recognized topical wound-healing accelerant — establishes meaningful biological activity rather than simple barrier protection.

Fibroblast Proliferation Mechanism (Ghafourian et al., 2015)

This in vitro study isolated quince seed mucilage and tested it on human skin fibroblast cell cultures at concentrations of 10, 50, 100, and 200 μg/mL using the MTT proliferation assay [7]. After 24, 48, and 72 hours of treatment, fibroblast proliferation increased significantly in a dose-dependent manner up to 100 μg/mL, with the highest response at 72 hours showing approximately 165% of control proliferation.

At 200 μg/mL the effect plateaued — a typical biological dose-response curve — without crossing into cytotoxicity, suggesting a wide therapeutic window. The fibroblast proliferation mechanism is the cellular foundation of dermal wound healing: fibroblasts produce the collagen, elastin, and ground substance that rebuild damaged tissue. This in vitro confirmation of a direct mitogenic effect on the relevant cell type complements the in vivo wound healing data and provides a plausible mechanism beyond simple physical barrier effects.

The study supports the rational use of quince seed mucilage in topical preparations for wound care, dry skin, post-procedural skin recovery, and similar dermatological applications. Combined with the favorable safety profile (the mucilage is essentially food-grade and used in beverages and confections worldwide), it is a reasonable adjunct in natural skin care.

Evidence Strength Summary

The clinical evidence for quince syrup in GERD is the strongest part of the quince literature: two randomized controlled trials in difficult-to-treat populations (children and pregnant women) demonstrate non-inferiority to standard pharmaceutical acid suppressors, with an excellent safety profile. The antioxidant and anti-inflammatory data is robust at the in vitro and animal level, with consistent identification of chlorogenic acid and quercetin glycosides as the active polyphenols and the peel as the highest-yielding tissue. The wound-healing evidence for seed mucilage is supported by both rabbit in vivo data and human fibroblast in vitro data, with a more recent randomized trial in post-episiotomy healing extending the evidence to a clinical setting. The cardiovascular and antidiabetic claims rest mostly on animal data and one observational human study of a multi-component supplement — encouraging but not yet ready for treatment recommendations. Overall, quince is a useful traditional food with one well-validated clinical application (GERD), one well-validated topical application (wound healing), and a strong preclinical foundation for additional health benefits that warrant continued investigation.