Muscadine Grape Pomace Extract
Also known as: Muscadine grape pomace extract, MGPE, grape pomace extract, Vitis rotundifolia pomace extract
Overview
Muscadine grape pomace extract (MGPE) is a polyphenol-rich botanical extract derived from the byproduct of muscadine grape (*Vitis rotundifolia*) winemaking, specifically the skins, seeds, and stems. This extract is characterized by its high total phenolic content (TPC), significant antioxidant activity (AA), and considerable dietary fiber content. It is primarily utilized as a dietary antioxidant supplement and a functional food ingredient, with emerging applications for its potential cardiometabolic health benefits. MGPE is also employed in food fortification to enhance the nutritional profile of various products by increasing their fiber and polyphenol content. While research on MGPE is growing, much of the current evidence on its health benefits is extrapolated from broader studies on grape polyphenol products, rather than specific high-quality randomized controlled trials exclusively on muscadine pomace extract. The quality of available evidence is moderate, with systematic reviews and meta-analyses often grouping various grape products.
Benefits
Muscadine grape pomace extract, primarily through its rich polyphenol content, offers several potential health benefits. Products containing grape polyphenols, including pomace extracts, have been shown to reduce markers of oxidative stress. A meta-analysis indicated that longer supplementation duration was significantly associated with improvements in malondialdehyde (MDA) levels, a marker of oxidative stress. While the effect sizes can be modest and sometimes not statistically significant, the trend suggests an antioxidant effect. Furthermore, supplementation with grape products has significantly reduced insulin resistance, as measured by HOMA-IR, in a meta-analysis of randomized controlled trials. This suggests a potential role in metabolic health. Beyond direct health effects, grape pomace fortification significantly increases the total dietary fiber and polyphenol content in foods, enhancing their nutritional quality. The evidence for these benefits is moderate, often derived from studies on general grape products rather than exclusively muscadine pomace, and further specific research is needed to confirm the magnitude and clinical significance of these effects for MGPE.
How it works
Muscadine grape pomace extract exerts its effects primarily through its rich content of polyphenols. These polyphenols act as powerful antioxidants by scavenging free radicals and reducing lipid peroxidation, thereby mitigating oxidative stress within the body. This involves modulating various oxidative stress pathways. The extract's interaction with body systems includes enhancing the body's natural antioxidant defense mechanisms and potentially improving metabolic parameters, such as insulin sensitivity. At a molecular level, the polyphenols interact directly with reactive oxygen species and may modulate the activity of enzymes involved in oxidative stress and inflammation. The bioavailability of polyphenols from pomace extracts can vary, with processing methods like drying significantly influencing their phenolic content and antioxidant activity, which in turn affects their biological efficacy.
Side effects
Muscadine grape pomace extract is generally regarded as safe, with grape polyphenols having low reported toxicity. High-quality clinical trials have not reported any significant common adverse effects (occurring in >5% of users). Data on uncommon (1-5%) or rare (<1%) side effects are not well documented. However, due to its polyphenol content, there is a potential for interaction with anticoagulant medications, and caution is advised for individuals taking such drugs. No specific contraindications have been established for muscadine grape pomace extract. Special population considerations include limited data for pregnant or nursing women, and individuals on medications that may interact with polyphenols. Therefore, these groups should exercise caution and consult a healthcare professional before use. Overall, while generally safe, comprehensive safety data specifically for muscadine grape pomace extract is still developing.
Dosage
The minimum effective dose and optimal dosage ranges for muscadine grape pomace extract are not well established due to limited specific research. Meta-analyses on grape polyphenol products include a wide range of doses without identifying a clear dose-response effect. A maximum safe dose has not been defined, but doses used in existing trials are generally considered safe. Regarding timing, longer durations of supplementation, typically several weeks or more, may be required to observe beneficial effects, particularly on oxidative stress markers. For optimal efficacy, extracts standardized for their polyphenol content are preferred. It's important to note that the processing method, such as drying, significantly impacts the phenolic content and antioxidant activity of the extract; vacuum belt drying and freeze drying are known to preserve bioactivity better than hot air drying, which is a crucial factor for supplement manufacturing quality. No specific cofactors are identified as necessary for its absorption or efficacy.
FAQs
Is muscadine grape pomace extract effective as an antioxidant supplement?
Evidence suggests it may modestly improve oxidative stress markers, especially with longer use. However, results are not conclusive, and more specific research is needed to confirm its efficacy as a standalone antioxidant supplement.
Can it improve insulin resistance?
Meta-analyses of grape polyphenol products show a significant reduction in insulin resistance markers. While promising, specific data on muscadine pomace extract's direct impact on insulin resistance is limited.
Is muscadine grape pomace extract safe to use?
It is generally considered safe, with no major adverse effects reported in studies. However, caution is advised for individuals on anticoagulant medications due to potential interactions with polyphenols.
How should muscadine grape pomace extract be taken?
There is no standardized dosing, and longer supplementation durations (several weeks) are likely more beneficial for observing effects. Extracts standardized for polyphenol content are recommended.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7971097/ – This systematic review and meta-analysis of 7 RCTs found that grape polyphenol products may reduce oxidative stress markers, with duration of supplementation significantly correlating with improvements in malondialdehyde (MDA) levels. The study highlighted heterogeneity and the need for more specific research on muscadine pomace.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7695143/ – This systematic review and meta-analysis focused on food fortification, concluding that grape pomace significantly increases dietary fiber and polyphenol content in fortified foods. While not directly clinical, it supports the nutritional enhancement potential of grape pomace.
- https://openscholar.uga.edu/record/14373/files/vashisth_tripti_200905_ms.pdf – This study evaluated different drying methods for muscadine pomace, finding that vacuum belt drying and freeze drying effectively preserve phenolic content and antioxidant activity, comparable to each other, which is crucial for maintaining the quality and bioactivity of the extract in supplement manufacturing.
- https://onlinelibrary.wiley.com/doi/10.1002/ptr.7135 – This systematic review and meta-analysis of RCTs demonstrated that grape products significantly reduce insulin resistance (HOMA-IR) in adults with metabolic risk. The study included various grape products, indicating a broader benefit of grape polyphenols on metabolic health.
