# Caper (Capparis spinosa)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/caper
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-19
**Evidence Score:** 4 / 10
**Category:** European
**Also Known As:** Capparis spinosa, Caper bush, Flinders rose, Spiny caper, Mediterranean caper, Kabbar, Lasaf, Tapenade berry

## Overview

Caper (Capparis spinosa) contains quercetin and rutin as primary bioactive compounds that provide [antioxidant](/ingredients/condition/antioxidant) and anti-inflammatory effects. These flavonoids help regulate [blood glucose](/ingredients/condition/weight-management) levels and reduce inflammatory markers through inhibition of [pro-inflammatory cytokine](/ingredients/condition/inflammation)s.

## Health Benefits

• Blood sugar control: Significantly reduced fasting [blood glucose](/ingredients/condition/weight-management) and HbA1c in type 2 diabetic patients (Strong evidence - RCT, PMID: 24050578)
• [Anti-inflammatory](/ingredients/condition/inflammation) effects: Reduced inflammatory markers in preclinical colitis models through decreased cytokine levels (Preliminary evidence - animal studies)
• [Antioxidant protection](/ingredients/condition/antioxidant): Increased superoxide dismutase, catalase, and [glutathione](/ingredients/condition/detox) while reducing oxidative stress markers (Preliminary evidence - animal studies)
• Metabolic support: Meta-analysis found overall benefits for glycemic, lipid, and liver enzyme modulation (Moderate evidence - PMID: 37806093)
• Anti-cancer potential: Quercetin content showed tumor cell proliferation inhibition in vitro (Preliminary evidence - cell studies)

## Mechanism of Action

Caper's quercetin and rutin compounds inhibit alpha-glucosidase enzyme activity, slowing carbohydrate absorption and reducing postprandial glucose spikes. These flavonoids also suppress NF-κB signaling pathway, decreasing production of [inflammatory](/ingredients/condition/inflammation) cytokines like TNF-α and IL-1β. Additionally, the antioxidant properties help neutralize [reactive oxygen species](/ingredients/condition/antioxidant) and reduce oxidative stress markers.

## Clinical Summary

A randomized controlled trial demonstrated significant reductions in fasting [blood glucose](/ingredients/condition/weight-management) and HbA1c levels in type 2 diabetic patients taking caper extract. Animal studies show promising [anti-inflammatory](/ingredients/condition/inflammation) effects in colitis models with decreased inflammatory cytokine levels. However, human clinical data remains limited, with most evidence coming from preclinical research. Larger, longer-term human studies are needed to confirm therapeutic potential.

## Nutritional Profile

Per 100g of drained canned capers: Energy ~23 kcal; Protein ~2.4g; Fat ~0.9g; Carbohydrates ~1.7g; Dietary fiber ~3.2g. Exceptionally high in sodium (~2,348mg, due to brining/salt-packing). Key micronutrients: Vitamin K ~24.6µg (31% DV), Vitamin C ~4.3mg, Riboflavin (B2) ~0.14mg, Niacin (B3) ~0.65mg, Iron ~1.67mg (9% DV), Copper ~0.37mg (41% DV), Magnesium ~33mg, Calcium ~40mg, Manganese ~0.08mg. Bioactive compounds: Exceptionally rich in quercetin (~180mg/100g dry weight, among the highest of any plant food) and its glycosides including quercetin-3-rutinoside (rutin, ~332mg/100g dry weight) and quercetin-3-rhamnoside; Kaempferol and kaempferol glycosides (~131mg/100g dry weight); Glucocapparin (a glucosinolate unique to Capparis, ~50–90mg/100g dry weight); Stachydrine (a proline betaine, ~0.2–0.8% dry weight, linked to anti-diabetic activity); Capparisine and other spermidine alkaloids; p-Methoxy benzoic acid; Tocopherols (primarily α-tocopherol, ~3–5mg/100g in buds); Indole-3-carbinol (trace amounts); Beta-carotene and lutein (small amounts contributing to [antioxidant](/ingredients/condition/antioxidant) capacity). The seed oil (if consumed) contains oleic acid (~40%), linoleic acid (~30%), and minor amounts of stearic and palmitic acids. Bioavailability notes: Quercetin glycosides in capers have relatively high bioavailability compared to quercetin aglycone, as rutinoside forms are cleaved by gut microbiota to release quercetin for colonic absorption; however, brining and pickling may reduce total flavonoid content by 30–50% compared to fresh buds. Sodium content is significantly modifiable by rinsing before consumption. The glucosinolate glucocapparin undergoes hydrolysis by myrosinase upon tissue disruption, yielding methyl isothiocyanate, which may have bioactive properties but is partly lost during cooking.

## Dosage & Preparation

Clinical studies used caper fruit extract at 400 mg three times daily (total 1,200 mg/day) for blood sugar management. Preclinical studies suggest 1-5 g/day equivalents, but these doses lack human validation. No standardized extract specifications were detailed in trials. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Caper supplements are generally well-tolerated with minimal reported side effects in clinical studies. Individuals taking diabetes medications should monitor [blood glucose](/ingredients/condition/weight-management) closely due to potential additive glucose-lowering effects. No significant drug interactions have been documented, though caution is advised with anticoagulant medications due to flavonoid content. Safety during pregnancy and lactation has not been established through clinical research.

## Scientific Research

A randomized double-blind placebo-controlled trial (PMID: 24050578) in 54 type 2 diabetic patients found that 400 mg caper fruit extract three times daily for 2 months significantly reduced [blood glucose](/ingredients/condition/weight-management) and HbA1c. A systematic review and meta-analysis (PMID: 37806093) evaluated caper fruit's effects on metabolic markers, finding overall benefits, though human evidence remains limited to one key diabetes RCT.

## Historical & Cultural Context

Caper has been used for centuries in Mediterranean, Middle Eastern, and North African traditional medicine to treat [inflammation](/ingredients/condition/inflammation), gastrointestinal issues, liver dysfunction, rheumatism, and as a diuretic. Historical records span ancient times, with ongoing folk use in regions like Iran, Italy, and Turkey.

## Synergistic Combinations

Chromium, Alpha-lipoic acid, Berberine, Green tea extract, Milk thistle

## Frequently Asked Questions

### How much caper extract should I take for blood sugar control?

Clinical studies used doses ranging from 400-800mg of standardized caper extract daily. The effective dose in the diabetes trial was 400mg twice daily with meals for 8 weeks.

### What compounds in capers provide the health benefits?

Quercetin and rutin are the primary bioactive flavonoids in capers responsible for antioxidant and anti-inflammatory effects. Caper buds contain the highest concentrations of these beneficial compounds.

### Can capers interact with diabetes medications?

Caper supplements may enhance blood glucose-lowering effects of diabetes medications like metformin or insulin. Monitor blood sugar closely and consult your healthcare provider before combining with diabetes drugs.

### Are caper supplements safe for long-term use?

Limited long-term safety data exists for caper supplements. The longest human study was 8 weeks with no adverse effects reported, but extended use safety requires further research.

### Do pickled capers provide the same benefits as supplements?

Pickled capers contain beneficial flavonoids but in lower concentrations than standardized extracts. The high sodium content in pickled capers may offset cardiovascular benefits compared to supplement forms.

### What is the difference between caper berry and caper bud supplements?

Caper buds (the immature flower buds of Capparis spinosa) are the most commonly used form and contain the highest concentration of bioactive compounds like flavonoids and glucosinolates. Caper berries are the mature fruit and have a different nutritional profile with potentially lower active compound levels, though both forms offer antioxidant benefits. For standardized dosing and maximum efficacy, caper bud extracts are generally preferred in clinical research.

### Is caper supplementation safe for people with kidney disease?

Capers are naturally high in sodium, especially in pickled forms, which may be problematic for individuals with kidney disease or those on sodium-restricted diets. Fresh or desalted caper extracts may be safer alternatives for this population, though consultation with a healthcare provider is essential. People with compromised kidney function should avoid high-sodium pickled capers and opt for standardized supplements with controlled sodium content.

### What clinical evidence supports caper use for inflammatory conditions beyond blood sugar control?

Preliminary animal studies demonstrate that caper compounds reduce inflammatory markers and cytokine levels in colitis models, suggesting potential benefits for inflammatory bowel conditions. However, human clinical trials specifically investigating caper's anti-inflammatory effects in conditions like rheumatoid arthritis or inflammatory bowel disease remain limited. Most robust clinical evidence currently exists for blood sugar management in type 2 diabetes, while inflammatory benefits remain in early research stages.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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