Muscadine Grape Seed and Skin Powder
Also known as: Muscadine grape, Muscadine grape seed and skin powder, Muscadine grape extract, MPX (for skin powder), Vitis rotundifolia
Overview
Muscadine grapes (*Vitis rotundifolia*) are native to the southeastern United States, known for their thick skins and seeds rich in polyphenols. The supplement, typically in powdered form, utilizes extracts from the seed and skin. It is primarily used to support cardiovascular health, provide antioxidant and anti-inflammatory effects, and as a potential adjunctive therapy in prostate cancer management. Key characteristics include a high concentration of antioxidants like ellagic acid, quercetin, resveratrol, and proanthocyanidins, which help reduce oxidative stress and inflammation. Research maturity is moderate, with several randomized controlled trials (RCTs) and meta-analyses available for grape seed extract broadly, but fewer high-quality RCTs specifically on muscadine grape seed and skin powder. Evidence is stronger for grape seed extract in general, with some RCTs on muscadine grape seed and skin powder showing promising but preliminary results.
Benefits
Muscadine grape seed and skin powder offers several evidence-based benefits. Grape seed extract supplementation (not exclusively muscadine) significantly reduces oxidative stress biomarkers such as malondialdehyde (SMD: -1.04, 95% CI: -1.65 to -0.42) and oxidized LDL (SMD: -0.44, 95% CI: -0.75 to -0.13). Furthermore, it improves endothelial function and vascular health markers in subjects with cardiovascular risk factors after 4 weeks of muscadine grape seed supplementation (1300 mg/day). Meta-analyses of grape seed extract studies have also shown modest blood pressure reduction. A phase I trial suggests a potential slowing of prostate cancer progression markers (non-significant increase in PSA doubling time) with muscadine grape skin extract. Anti-inflammatory effects are evidenced by reductions in high-sensitivity C-reactive protein (hs-CRP), and improvements in lipid profiles (total cholesterol, LDL) have been observed with grape products including seed extracts. Adults with cardiovascular disease or risk factors benefit from improved endothelial function and reduced oxidative stress, while men with biochemically recurrent prostate cancer showed good tolerability and some biological activity with muscadine grape skin extract.
How it works
Muscadine grape seed and skin powder exerts its effects through several primary biological pathways. Its antioxidant activity involves scavenging free radicals and inhibiting lipid peroxidation. Anti-inflammatory effects are achieved through the downregulation of inflammatory cytokines and hs-CRP. The improvement of endothelial function is likely mediated by enhanced nitric oxide bioavailability and reduced oxidative damage. In terms of interaction with body systems, it primarily affects the cardiovascular system by improving vascular endothelial function and reducing oxidative damage to lipids, and it modulates inflammatory responses within the immune system. In vitro evidence suggests potential anti-cancer effects through modulation of cell proliferation and apoptosis pathways. The polyphenols in muscadine grape seed and skin have variable bioavailability; ellagic acid and resveratrol are metabolized by gut microbiota, affecting systemic levels.
Side effects
Muscadine grape seed and skin powder is generally well-tolerated, with no serious adverse events reported in clinical trials. Common side effects (>5%) include mild gastrointestinal symptoms such as flatulence, soft stools, and eructation reported in some subjects. No significant uncommon (1-5%) or rare (<1%) side effects have been reported in controlled trials. While no major drug interactions have been reported, caution is advised with anticoagulants due to polyphenol effects on platelet function (inference from general grape seed extract data). There are no formally established contraindications; however, caution is advised in pregnancy and lactation due to a lack of data. Limited data are available for children, pregnant women, and individuals with severe comorbidities. Overall, the safety profile appears favorable, but further research is needed to fully characterize potential risks in specific populations and with long-term use.
Dosage
The minimum effective dose of muscadine grape seed powder is approximately 1300 mg/day, which has demonstrated vascular benefits. Optimal dosage ranges have been tested up to 4000 mg/day of muscadine grape skin extract safely in prostate cancer patients. The maximum safe dose observed in studies is 4000 mg/day, with no dose-limiting toxicities reported. For timing considerations, daily supplementation with consistent dosing is recommended, although the timing relative to meals has not been specifically studied. Powdered extracts standardized for polyphenol content are preferred for consistency. Bioavailability may be enhanced with food intake, and gut microbiota influence metabolism. While no specific cofactors are required, general antioxidant support (e.g., vitamin C) may be synergistic.
FAQs
Is muscadine grape seed and skin powder safe for long-term use?
Current evidence suggests good safety up to several months, but long-term data are limited. Consult with a healthcare provider for extended use.
How soon can benefits be expected?
Vascular benefits may appear within 4 weeks; antioxidant effects may be measurable sooner with consistent supplementation.
Can it replace conventional cardiovascular or cancer therapies?
No; it should be considered adjunctive and not a replacement for standard medical care. Always follow your doctor's recommendations.
Are there differences between muscadine grape extracts and other grape seed extracts?
Muscadine grapes have a unique polyphenol profile, but clinical effects are broadly similar to other grape seed extracts. Individual responses may vary.
Research Sources
- https://onlinelibrary.wiley.com/doi/abs/10.1111/ijcp.14469 – This systematic review and meta-analysis of 19 RCTs found that grape seed extract significantly reduced oxidative stress markers (MDA, oxLDL) and inflammation (hs-CRP) across various populations. The study highlights the potential of grape seed extract as a beneficial supplement for managing oxidative stress and inflammation. However, the authors noted heterogeneity in study designs and populations.
- https://www.tandfonline.com/doi/full/10.1080/10942912.2021.1901731 – This study investigated the effects of muscadine grape seed supplementation on adults with coronary disease or risk factors. The double-blind, placebo-controlled crossover RCT with 50 participants showed improved endothelial function (flow-mediated dilation) and reduced oxidative stress biomarkers after 4 weeks of intervention, suggesting a positive impact on cardiovascular health.
- https://www.mdpi.com/2077-0383/9/2/313 – This review provides a comprehensive overview of grape pomace extracts, focusing on their extraction, characterization, and applications. It highlights the potential of these extracts as a source of bioactive compounds with various health benefits. The review emphasizes the importance of optimizing extraction methods to maximize the yield and bioactivity of the extracts.
- https://pubmed.ncbi.nlm.nih.gov/21504973/ – This study investigated the effects of grape seed extract on blood pressure in hypertensive subjects. The results showed that grape seed extract supplementation led to a significant reduction in both systolic and diastolic blood pressure. The study suggests that grape seed extract may be a useful adjunct therapy for managing hypertension.
- https://pubmed.ncbi.nlm.nih.gov/26012728/ – This phase I clinical trial evaluated the safety and tolerability of muscadine grape skin extract in men with biochemically recurrent prostate cancer. The study found that the extract was safe up to 4000 mg/day and showed a non-significant increase in PSA doubling time. The results suggest potential biological activity, warranting further investigation in larger, controlled trials.