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Black Adzuki Bean Extract

Also known as: Black adzuki bean, Black azuki bean, Adzuki bean extract, Vigna angularis

Overview

Black adzuki bean extract is derived from the seeds of Vigna angularis, a legume widely consumed in East Asian diets. This extract is recognized for its rich content of polyphenols and other bioactive compounds, which are believed to influence lipid metabolism and contribute to body weight regulation. Research into black adzuki bean extract primarily focuses on its potential applications in obesity management, improvement of lipid profiles, and overall metabolic health. While the body of evidence is still emerging, it includes promising in vitro, animal, and limited human clinical studies. The current quality of evidence is considered moderate, with human randomized controlled trial (RCT) data being limited, but animal and cellular studies provide valuable insights into its underlying mechanisms of action. It is typically used as a plant-based dietary supplement, often in the form of a polyphenol-rich botanical extract.

Benefits

Black adzuki bean extract shows promising benefits in several areas, primarily related to metabolic health: - **Body Weight Regulation:** Animal studies, specifically a controlled rat study, demonstrated that supplementation with 1-2% black adzuki bean extract significantly reduced body weight and epididymal fat compared to high-fat diet controls. This suggests a potential anti-obesity effect, though human data are needed to confirm this. - **Lipid Metabolism Improvement:** Human randomized controlled trial (RCT) data, from an 8-week double-blind, placebo-controlled study, indicated that adzuki bean extract significantly increased HDL cholesterol levels at 4 weeks compared to placebo. This suggests a positive impact on lipid profiles, with an approximate increase of 3.76 mg/dL in HDL-C relative to placebo. - **Adipocyte Modulation:** In vitro studies using 3T3-L1 cells have shown that black adzuki bean extract can inhibit adipocyte differentiation and lipid accumulation. This indicates a direct effect on fat cell metabolism, providing mechanistic support for its potential role in weight and lipid management. These effects have been observed over short to medium terms (4-8 weeks in human studies, 8 weeks in animal studies). While animal and in vitro data are robust, human evidence is still limited, particularly for weight loss, and further large-scale human RCTs are required to solidify these benefits.

How it works

Black adzuki bean extract exerts its effects through multiple mechanisms. It modulates hypothalamic neuropeptides involved in appetite regulation, specifically decreasing the expression of orexigenic (appetite-stimulating) AGRP mRNA while increasing anorexigenic (appetite-suppressing) POMC and CART mRNA expression. This leads to a suppression of food intake. The extract also appears to enhance leptin sensitivity by upregulating ObRb gene expression in the hypothalamus, potentially improving overall energy homeostasis. At a cellular level, it influences early transcription factors like C/EBPβ and C/EBPδ, which are crucial for adipocyte differentiation and lipid metabolism, thereby reducing lipid accumulation in fat cells. The polyphenols present in the extract are believed to contribute significantly to its antioxidant and lipid-modulating properties. Specifics regarding its absorption and bioavailability in the human body are not yet fully detailed in current research.

Side effects

Current research indicates that black adzuki bean extract has a favorable safety profile, particularly for short-term use. Human studies, including an 8-week randomized controlled trial, reported no adverse effects during supplementation with polyphenol-containing adzuki bean extract. No significant side effects or safety concerns have been documented in the reviewed clinical trials. Furthermore, there are no known drug interactions or contraindications reported in the available literature. However, it is crucial to note that data on its safety are still limited, especially concerning long-term use. Safety in special populations, such as pregnant or lactating individuals, and children, has not been established, and therefore, its use in these groups is not recommended without further research. As with any supplement, individuals with pre-existing medical conditions or those taking medications should consult a healthcare professional before use.

Dosage

Based on current research, specific human dosage guidelines for black adzuki bean extract are not yet definitively established. Animal studies have utilized dietary supplementation at 1-2% of freeze-dried ethanolic extract over an 8-week period. A human randomized controlled trial employed a polyphenol-containing adzuki bean extract dose that was sufficient to produce measurable increases in HDL cholesterol within 4 weeks and was found to be safe over 8 weeks. However, the exact milligram dosage used in this human study was not specified in the summary. Optimal dosing, maximum safe doses, and long-term efficacy in humans still require further investigation. Formulations are typically ethanolic extracts, often standardized for their polyphenol content. Benefits on lipid metabolism may be observed within 4 weeks of consistent use. Due to limited data, it is advisable to adhere to product-specific recommendations or consult a healthcare professional for personalized guidance.

FAQs

Is black adzuki bean extract safe?

Current evidence suggests it is safe for short-term use, with no adverse effects reported in human clinical trials. However, long-term safety and effects in special populations are not yet established.

How soon do benefits appear?

Improvements in lipid profiles, specifically HDL cholesterol, may be observed as early as 4 weeks. Effects on body weight in animal models were noted over an 8-week period.

Can it be used for weight loss?

Animal data support its potential for weight regulation by modulating appetite and fat metabolism. However, robust human data specifically on weight loss are currently lacking.

Are there known interactions?

No drug interactions or contraindications have been reported in the available research. Nevertheless, caution is advised, and consultation with a healthcare professional is recommended, especially if taking other medications.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/26493717/ – This animal study (Kim et al., 2015) investigated the effects of black adzuki bean extract on high-fat diet-fed rats. It found that supplementation significantly reduced body weight and fat mass, improved serum lipids, and modulated hypothalamic neuropeptide gene expression related to appetite, providing strong evidence for its anti-obesity potential in an animal model.
https://pubmed.ncbi.nlm.nih.gov/30782097/ – This human randomized, double-blind, placebo-controlled trial (2019) evaluated the effects of polyphenol-containing adzuki bean extract over 8 weeks. It reported a significant increase in HDL cholesterol levels at 4 weeks compared to placebo, with no adverse effects, suggesting a positive impact on human lipid profiles.
https://www.mdpi.com/2072-6643/7/1/277 – This in vitro study (2015) demonstrated that black adzuki bean extract inhibited adipocyte differentiation and lipid accumulation in 3T3-L1 cells. It provided mechanistic insights by showing modulation of key transcription factors and lipid metabolism genes, supporting the extract's direct effects on fat cell biology.