Can grape pomace be used as a cardiometabolic health-promoting ingredient?

By Bhavana KunkalikarReviewed by Lily Ramsey, LLMApr 25 2023

In a recent study published in the Antioxidants Journal, researchers explored the potential health benefits of using grape pomace to promote cardiometabolic health.

Study: Grape Pomace as a Cardiometabolic Health-Promoting Ingredient: Activity in the Intestinal Environment. Image Credit: PiotrVelixar/Shutterstock.com

Background

Grape pomace (GP) is a byproduct of winemaking primarily consisting of grape seeds and skins. GP is widely used in the production of fortified foods and dietary supplements.

The interest in estimating the impact of GP on regulating baseline hyperglycemia, an early indicator of type 2 diabetes and a primary anti-diabetic target, is increasing. GP-derived products have been found to lower plasma glucose levels.

Digestion and absorption of nutrients in the intestines

Physical impediments and digestion and absorption of nutrients

GP contains soluble as well as insoluble dietary fibers in abundance. Insoluble fiber can add bulk to stool and help food move across the digestive tract faster, which may reduce nutrient absorption time.

However, soluble fiber can cause a delay in nutrient absorption and slower gastric emptying by forming a gel-like element in the gut. GP's high dietary fiber composition can create a gel-like matrix that slows down glucose absorption within the small intestine.

The slower secretion of glucose in the bloodstream is caused by the hindrance of digestive enzymes' accessibility to glucose and carbohydrate diffusion. The mechanism helps improve glycemic control and decrease insulin spikes.

Soluble (poly)phenols and fiber found in GP can help reduce the reabsorption of bile salts in the intestine and improve their excretion. The liver uses more circulating cholesterol to create new bile salts, lowering serum cholesterol levels.

The mechanisms mentioned could have potential benefits for lowering the likelihood of cardiovascular diseases and enhancing lipid profiles.

GP and the release of enteroendocrine gut hormones and satiety

K-cells produce the hormone glucose-dependent insulinotropic polypeptide (GIP) in the proximal small intestine and act as an incretin. GIP is involved in promoting insulin secretion after consuming food, especially meals that are high in carbohydrates, and regulating lipid metabolism.

GP's dietary fiber content may affect GIP secretion by being fermented by gut microbiota, stimulating SCFAs like acetate, butyrate, and propionate. SCFAs play a role in controlling gut hormones, such as GIP. GP has bioactive (poly)phenols that can affect GIP release.

Impact of GP on gut morphology

Studies have shown that feeding GP-derived products to rodents, pigs, lambs, and broilers can improve villus length and height/crypt depth ratio and lowered crypt depth in the ileum, jejunum, and colon cells.

The fiber-bound (poly)phenols and dietary fiber of GP were more effective as compared to free (poly)phenols in lowering colonic lesions as well as colon shortening in rats exposed to stressful 2,4,6-trinitrobenzene sulfonic acid (TNBS) and dextran sodium sulfate (DSS) treatments.

Defective structural development of crypt villi can lead to intestinal disorders and dysfunctions like inflammatory bowel disease, celiac disease, brush border-related enteropathies, and colorectal cancer due to the decreased inner surface area.

The study also suggested that GP-derived products may be useful in managing certain pathologies. However, no human interventions with GP have been known specifically for these conditions.

Impact of GP on the gut microbiome

The gut microbiota can break down GP components, resulting in the production of SCFAs and phenolic metabolites. These can impact the content and functionality of gut communities.

GP supplementation has been found to have various benefits in animals, including promoting intestinal health, improving metabolic profiles, enhancing anti-inflammatory and antioxidant mechanisms, and increasing the presence of beneficial bacteria.

Clinical trials using GP-derived products have revealed differences in biomarkers among individuals, highlighting the significance of metabolic-associated bacterial communities rather than bacterial genera or families.

GP-based products show promise in regulating gut microbiota content and function for various health conditions, including reducing the likelihood of non-communicable diseases like cardiovascular disease. Additional research is required to investigate the potential therapeutic uses of GP-derived products for enhancing gut health.

Conclusion

The study findings highlighted the importance of intestinal function as the primary defense against various disorders, including those affecting cardiometabolic health, and how GP's overall effect supports this notion.

GP's systemic bioactivity starts in the gut, which may aid in the prevention and management of cardiovascular diseases. Future research on GP's health benefits should explore the relationship between the gut and other organs to confirm its role in improving cardiometabolic health.