Rubus idaeus (Red Raspberry)

Red raspberry (Rubus idaeus) is a polyphenol-rich superfruit whose primary bioactive compounds — ellagitannins, anthocyanins, and vitamin C — exert antioxidant and anti-inflammatory effects by scavenging free radicals and modulating NF-κB signaling. These compounds are metabolized into urolithins in the gut, which may contribute to downstream cellular protective effects.

Origin & History

Rubus idaeus, or red raspberry, is a perennial shrub from the Rosaceae family, native to Europe and North America. The supplement is primarily derived from its fruits, shoots, and leaves, which are processed using methods like solvent extraction to concentrate its rich polyphenol content. It is classified chemically as a polyphenol-rich fruit, containing high levels of anthocyanins and ellagitannins.

Historical & Cultural Context

The provided research dossier does not contain information regarding the historical or traditional medicinal uses of Rubus idaeus in systems like folk medicine or Ayurveda. Its primary context in the research is as a nutrient-dense food source.

Health Benefits

["\u2022 Provides a rich source of antioxidant compounds, including vitamin C and a wide range of polyphenols that may help neutralize oxidative stress. Evidence quality: Preliminary (based on chemical composition and in vitro analysis).", "\u2022 Contains a high concentration of ellagitannins, particularly sanguiin H-6 (139.2\u2013633.1 mg/100 g in shoots), a class of potent polyphenols. Evidence quality: Preliminary (based on compositional analysis).", "\u2022 Delivers a variety of flavonoids, such as quercetin (0.32\u20131.55 mg/100 g fw), catechin, and kaempferol, which contribute to its antioxidant profile. Evidence quality: Preliminary (based on compositional analysis).", "\u2022 Source of essential fatty acids, with its seed oil containing a beneficial ratio of linoleic acid to \u03b1-linolenic acid (<2:1). Evidence quality: Preliminary (based on compositional analysis).", "\u2022 Supplies key phenolic acids like ellagic acid (26.1\u2013106.8 mg/100 g), which is a well-studied antioxidant compound. Evidence quality: Preliminary (based on compositional analysis)."]

How It Works

Ellagitannins such as sanguiin H-6 are hydrolyzed in the gut to ellagic acid, which is further converted by intestinal microbiota into urolithins (notably urolithin A), compounds that activate Nrf2-mediated antioxidant response elements and inhibit pro-inflammatory NF-κB pathway signaling. Anthocyanins, particularly cyanidin-3-glucoside and cyanidin-3-sophoroside, directly scavenge reactive oxygen species (ROS) and chelate transition metals that catalyze oxidative chain reactions. Vitamin C (ascorbic acid) regenerates oxidized vitamin E and acts as a cofactor for collagen-synthesizing prolyl hydroxylase enzymes, reinforcing connective tissue integrity alongside the polyphenol fraction.

Scientific Research

The available research dossier lacks specific human clinical trials, randomized controlled trials (RCTs), or meta-analyses for Rubus idaeus. No PubMed PMIDs for human efficacy studies were provided, as the existing scientific literature focuses primarily on chemical composition and in vitro antioxidant activity rather than clinical outcomes.

Clinical Summary

Most human evidence for red raspberry is indirect, derived from freeze-dried whole-fruit or extract interventions in small pilot trials (n=10–40) examining biomarkers such as plasma antioxidant capacity (ORAC/FRAP), urinary ellagic acid excretion, and inflammatory cytokines (IL-6, CRP). A 2012 randomized crossover study in overweight adults found that a single serving of red raspberry (300 g) significantly increased plasma antioxidant capacity within 2 hours post-ingestion, though long-term cardiometabolic outcomes remain unestablished. Cell and animal studies consistently demonstrate anti-proliferative activity of ellagic acid against colon and breast cancer cell lines at micromolar concentrations, but no controlled human cancer prevention trials exist for this fruit specifically. Overall, evidence quality remains preliminary-to-moderate, with the strongest support for acute antioxidant bioavailability and the weakest for disease-endpoint claims.

Nutritional Profile

Red Raspberry (Rubus idaeus) per 100g fresh fruit: Macronutrients — Calories: ~52 kcal; Carbohydrates: 11.9g (of which sugars 4.4g); Dietary Fiber: 6.5g (one of the highest fiber densities among common fruits, predominantly insoluble cellulose and pectin); Protein: 1.2g; Fat: 0.7g (including omega-3 ALA in seeds). Micronutrients — Vitamin C: 26.2mg (29% DV; bioavailability moderate, enhanced by co-consumption with iron-containing foods); Vitamin K: 7.8mcg; Folate (B9): 21mcg; Vitamin E: 0.87mg; Manganese: 0.67mg (29% DV); Magnesium: 22mg; Potassium: 151mg; Calcium: 25mg; Iron: 0.69mg; Phosphorus: 29mg; Zinc: 0.42mg. Bioactive Compounds — Ellagitannins: 139.2–633.1mg/100g (shoots higher than fruit); sanguiin H-6 and lambertianin C are dominant forms; upon digestion, gut microbiota converts ellagitannins to urolithins (urolithin A, B), which are the primary bioavailable metabolites with estimated 15–50% conversion rate depending on individual microbiome composition. Anthocyanins: 20–60mg/100g fresh weight; cyanidin-3-sophoroside and cyanidin-3-glucoside are predominant forms; bioavailability approximately 1.5–5% from whole fruit. Quercetin: ~1.2mg/100g. Kaempferol: ~0.4mg/100g. Ellagic acid (free form): ~1.5mg/100g; glycosylated forms ~22mg/100g. Vitamin C bioavailability: approximately 80–90% from fresh fruit matrix. Raspberry ketone (rheosmin): trace amounts (~1–4mg/kg). Fiber note: The 6.5g fiber per 100g significantly supports polyphenol retention through the gastrointestinal tract, potentially enhancing colonic fermentation of ellagitannins to urolithins.

Preparation & Dosage

No clinically studied dosage ranges for red raspberry extracts, powders, or standardized forms have been established, as human trials are absent in the provided research. Compositional studies note standardization targets such as ellagic acid or sanguiin H-6, but these do not constitute a recommended dose. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Vitamin C, Vitamin E, Green Tea Extract (EGCG), Curcumin, Grape Seed Extract

Safety & Interactions

Red raspberry fruit and leaf are generally recognized as safe (GRAS) at culinary and moderate supplemental doses; adverse effects are rare but may include mild gastrointestinal upset (bloating, loose stools) at high polyphenol extract doses above 1,000 mg/day. Red raspberry leaf — distinct from the fruit — has uterotonic properties attributed to fragrine and tannins and is contraindicated in the first and second trimesters of pregnancy, though fruit consumption at normal dietary amounts is considered safe during pregnancy. The high vitamin C content (approximately 26 mg per 100 g fresh fruit) may interact additively with supplemental ascorbic acid and, at very high doses, could theoretically reduce the efficacy of certain chemotherapeutic agents that rely on oxidative mechanisms; individuals undergoing oncology treatment should consult a physician. Red raspberry polyphenols may mildly inhibit CYP3A4 activity in vitro, though clinically significant drug interactions from whole-fruit consumption have not been documented in humans.