Preliminary evidence that regular vinegar ingestion favorably influences hemoglobin A1c values in individuals with type 2 diabetes mellitus

Harnessing and delivering microbial metabolites as therapeutics via advanced pharmaceutical approaches

Microbial metabolites have emerged as key players in the interplay between diet, the gut microbiome, and host health. Two major classes, short-chain fatty acids (SCFAs) and tryptophan (Trp) metabolites, are recognized to regulate inflammatory, immune, and metabolic responses within the host. Given that many human diseases are associated with dysbiosis of the gut microbiome and consequent reductions in microbial metabolite production, the administration of these metabolites represents a direct, multi-targeted treatment. While a multitude of preclinical studies showcase the therapeutic potential of both SCFAs and Trp metabolites, they often rely on high doses and frequent dosing regimens to achieve systemic effects, thereby constraining their clinical applicability. To address these limitations, a variety of pharmaceutical formulations approaches that enable targeted, delayed, and/or sustained microbial metabolite delivery have been developed. These approaches, including enteric encapsulations, esterification to dietary fiber, prodrugs, and nanoformulations, pave the way for the next generation of microbial metabolite-based therapeutics. In this review, we first provide an overview of the roles of microbial metabolites in maintaining host homeostasis and outline how compromised metabolite production contributes to the pathogenesis of inflammatory, metabolic, autoimmune, allergic, infectious, and cancerous diseases. Additionally, we explore the therapeutic potential of metabolites in these disease contexts. Then, we provide a comprehensive and up-to-date review of the pharmaceutical strategies that have been employed to enhance the therapeutic efficacy of microbial metabolites, with a focus on SCFAs and Trp metabolites.

Nutrition in the management of type 2 diabetes mellitus: review

Type 2 diabetes mellitus (T2DM) is the most prevalent disease and becoming a serious public health threat worldwide. In recent years, numerous effective T2DM intervention regimens have been developed, with promising results. However, these regimens are not usually economically available, and they are not well tolerated due to treatment-related toxicities. The focus nowadays is to identify new effective therapeutic agents, with relatively low cost and low toxicity, which can be used regularly to control a progression of T2DM in the prediabetic population. Accordingly, there has been growing attention in herbal remedies that can be presented into the general population with the tiniest side effects and the maximal preventive outcome. This article reviews recent publications in experimental models of T2DM not revised before, and supporting the potential use of nutraceuticals and phytochemicals through different mechanisms with promising results in the context of T2DM.

Daily Vinegar Ingestion Improves Depression Scores and Alters the Metabolome in Healthy Adults: A Randomized Controlled Trial

Daily vinegar ingestion has been linked to improved glycemic control, but recent data suggest a separate unexplored role for vinegar in mental health. Utilizing a placebo-controlled, parallel arm study design, this 4-week trial examined the impact of daily vinegar ingestion on mood states and urinary metabolites in healthy college students. Participants were randomized to the vinegar group (VIN: n = 14; 1.5 g acetic acid/day as liquid vinegar) or the control group (CON: n = 11; 0.015 g acetic acid/day as a pill) with no change to customary diet or physical activity. At baseline and at study week four, participants completed the Profile of Mood States (POMS) and the Center for Epidemiological Studies-Depression (CES-D) questionnaires and provided a first-morning urine sample for targeted metabolomics analyses. The change in both POMS depression scores and CES-D scores differed significantly between groups favoring improved affect in the VIN versus CON participants after four weeks. Metabolomics analyses pre and post-intervention suggested metabolite alterations associated with vinegar ingestion that are consistent for improved mood, including enzymatic dysfunction in the hexosamine pathway as well as significant increases in glycine, serine, and threonine metabolism. These data warrant continued investigation of vinegar as a possible agent to improve mood state.

Effects of Fermented Beverage in Subjects with Metabolic Syndrome

This study investigated the effects of fermented beverage, kale/apple juice containing 5% vinegar in subjects with metabolic syndrome. Subjects were randomly assigned to receive 250 mL fermented beverage or water containing fructose, glucose, and sucrose twice daily for 10 weeks. Consumption of the fermented beverage significantly decreased plasma triglyceride, thiobarbituric acid reactive substances (TBARS), tumor necrosis factor (TNF)-α, and high sensitivity C-reactive protein (hs-CRP) levels compared to baseline values (P<0.05). Furthermore, consumption of the fermented beverage significantly decreased homeostasis model assessment for insulin resistance (HOMA-IR) values and atherogenic indexes compared with baseline values (P<0.05). In the control group, plasma triglyceride, TBARS, TNF-α, and hs-CRP levels, atherogenic indexes, and HOMA-IR values did not significantly differ pre-and post-treatment. The fermented beverage inhibited the activities of α-glucosidase and pancreatic lipase in vitro, therefore could be helpful in alleviating metabolic syndrome in subjects with metabolic syndrome.

Commercial Vinegar Tablets Do Not Display the Same Physiological Benefits for Managing Postprandial Glucose Concentrations as Liquid Vinegar

Objective

Research evidence suggests that vinegar may effectively reduce postprandial glucose in both healthy adults and those with type 2 diabetes. There is heightened consumer interest in commercially available vinegar tablets; however, it is not known whether these products lower postprandial glycemia to the same extent as liquid vinegar. This crossover trial examined the impact of liquid vinegar versus commercial vinegar tablet ingestion at the start of a meal on the 60-minute glucose excursion postmeal in healthy adults.

Methods

Twelve young men and women (22.6 ± 0.6 y; 21.2 ± 1.2 kg/m²) completed this 4-arm Latin square crossover trial. Testing was separated by one week and consisted of a test meal (64 g carbohydrate) consumed immediately following one of the four oral treatments: CON, 60 g water (control treatment); VIN, 25 g liquid vinegar (5% acidity; 1.25 g acetic acid) diluted with 35 g water; PILL, four vinegar tablets (1.50 g acetic acid) swallowed whole with 60 g water; and PILL-c, four crushed vinegar tablets dissolved in 60 g water. Capillary blood glucose was tested in the fasted state and at 30 and 60 minutes postmeal.

Results

The 60-minute glucose excursion varied significantly by treatment (iAUC: 4.9 ± 0.6, 3.4 ± 0.4, 4.9 ± 0.6, and 4.1 ± 0.5 mmol˖h/l for CON, VIN, PILL, and PILL-c, respectively; F (3, 33) = 3.037, p = 0.043; repeated measures ANOVA). Post hoc analysis revealed a 31% reduction in the glucose postmeal excursion for VIN in comparison to CON and PILL (p = 0.040 and p = 0.049, respectively).

Conclusions

These data suggest that commercial vinegar tablets taken whole at mealtime are not as effective as liquid vinegar for reducing the postmeal glucose excursion in young, healthy adults.

Effect of Dietary Acetic Acid Supplementation on Plasma Glucose, Lipid Profiles, and Body Mass Index in Human Adults: A Systematic Review and Meta-analysis

BACKGROUND

Acetic acid is a short-chain fatty acid that has demonstrated biomedical potential as a dietary therapeutic agent for the management of chronic and metabolic illness comorbidities. In human beings, its consumption may improve glucose regulation and insulin sensitivity in individuals with cardiometabolic conditions and type 2 diabetes mellitus. Published clinical trial evidence evaluating its sustained supplementation effects on metabolic outcomes is inconsistent.

OBJECTIVE

This systematic review and meta-analysis summarized available evidence on potential therapeutic effects of dietary acetic acid supplementation via consumption of acetic acid-rich beverages and food sources on metabolic and anthropometric outcomes.

METHODS

A systematic search was conducted in Medline, Scopus, EMBASE, CINAHL Plus, and Web of Science from database inception until October 2020. Randomized controlled trials conducted in adults evaluating the effect of dietary acetic acid supplementation for a minimum of 1 week were included. Meta-analyses were performed using a random-effects model on fasting blood glucose (FBG), triacylglycerol (TAG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), glycated hemoglobin (HbA1c), body mass index (BMI), and body fat percentage. Statistical heterogeneity was assessed by calculation of Q and I² statistics, and publication bias was assessed by calculation of Egger's regression asymmetry and Begg's test.

RESULTS

Sixteen studies were included, involving 910 participants who consumed between 750 and 3600 mg acetic acid daily in interventions lasting an average of 8 weeks. Dietary acetic acid supplementation resulted in significant reductions in TAG concentrations in overweight and obese but otherwise healthy individuals (mean difference [MD] = -20.51 mg/dL [95% confidence intervals = -32.98, -8.04], P = .001) and people with type 2 diabetes (MD = -7.37 mg/dL [-10.15, -4.59], P < .001). Additionally, acetic acid supplementation significantly reduced FBG levels (MD = -35.73 mg/dL [-63.79, -7.67], P = .01) in subjects with type 2 diabetes compared with placebo and low-dose comparators. No other changes were seen for other metabolic or anthropometric outcomes assessed. Five of the 16 studies did not specify the dose of acetic acid delivered, and no studies measured blood acetate concentrations. Only one study controlled for background acetic acid-rich food consumption during intervention periods. Most studies had an unclear or high risk of bias.

CONCLUSION

Supplementation with dietary acetic acid is well tolerated, has no adverse side effects, and has clinical potential to reduce plasma TAG and FBG concentrations in individuals with type 2 diabetes, and to reduce TAG levels in people who are overweight or obese. No significant effects of dietary acetic acid consumption were seen on HbA1c, HDL, or anthropometric markers. High-quality, longer-term studies in larger cohorts are required to confirm whether dietary acetic acid can act as an adjuvant therapeutic agent in metabolic comorbidities management.

The Effect of Vinegar Supplementation on High-Intensity Cycling Performance within Recreationally Trained Individuals

Background and objectives: To investigate the effects of vinegar ingestion upon high-intensity cycle performance in recreationally trained individuals. Materials and methods: Twenty-two participants consumed one of the following in a randomized order on four separate visits: (1) 29 mL of vinegar along with 451 mL of water, (2) 39 g of sucrose along with 441 mL of water, (3) 29 mL of vinegar and 39 g of sucrose along with 412 mL of water, or (4) 480 mL of water alone. For each of the experimental testing sessions, all participants completed in order: (1) high-intensity cycle test 1, (2) fatiguing cycle test, (3) high-intensity cycle test 2, (4) supplement consumption, (5) 90 min rest period, and (6) high-intensity cycle test 3. Total time to exhaustion (TTE) and average heart rate (HR) for each set of sprints was used in analysis. Results: There was no supplement by time interaction or significant main treatment effect observed (p > 0.05) for either TTE or HR. However, there was a main time effect observed, with TTE (p = 0.0001) being lower for cycle test 2 than both cycle test 1 and cycle test 3, and cycle test 3 being lower than cycle test 1. HR (p = 0.0001) was lower for cycle test 3 than both cycle test 1 and cycle test 2, but HR for cycle test 1 did not differ significantly from HR for cycle test 2. Conclusions: The addition of vinegar or sucrose alone, or in combination, was ineffective in improving cycle sprinting TTE when performing three cycle tests.

The Alcohol-High-Density Lipoprotein Athero-Protective Axis

Ingestion of alcohol is associated with numerous changes in human energy metabolism, especially that of plasma lipids and lipoproteins. Regular moderate alcohol consumption is associated with reduced atherosclerotic cardiovascular disease (ASCVD), an effect that has been attributed to the concurrent elevations of plasma high-density lipoprotein-cholesterol (HDL-C) concentrations. More recent evidence has accrued against the hypothesis that raising plasma HDL concentrations prevents ASCVD so that other metabolic processes associated with alcohol consumption have been considered. This review explored the roles of other metabolites induced by alcohol consumption-triglyceride-rich lipoproteins, non-esterified free fatty acids, and acetate, the terminal alcohol metabolite in athero-protection: Current evidence suggests that acetate has a key role in athero-protection but additional studies are needed.

Daily red wine vinegar ingestion for eight weeks improves glucose homeostasis and affects the metabolome but does not reduce adiposity in adults

This is the first study to investigate the effects of vinegar on adiposity and glycemia using both anthropometrics and metabolomics.

Diabetes Control: Is Vinegar a Promising Candidate to Help Achieve Targets?

BACKGROUND

Renewed interest in vinegar as a glucose-lowering agent led to several small trials in the recent past. However, none of the trials could independently provide sufficient evidence.

OBJECTIVES

Our review aimed to obtain reliable estimates of effects of vinegar on short-term and long-term blood glucose control.

METHODS

Large bibliographic databases were searched from inception to date of search without language and publication date restrictions. All clinical trials evaluating effect of vinegar on diabetes mellitus patients were eligible. Two authors independently extracted data on fasting and 2-hour postprandial blood glucose, insulin, and HbA1c levels at the various time points. MS Excel, SAS® v9.3, and RevMan v5.3 were used for data analysis.

RESULTS

Small significant reduction in mean HbA1c was observed after 8 to 12 weeks of vinegar administration: -0.39% (95% confidence interval = -0.59, -0.18; I² = 0%). Other long-term outcomes favored vinegar but were not significant. Short-term outcomes showed significantly lower pooled mean difference in glucose levels at 30 minutes in the vinegar group. Readings at 60, 90, and 120 minutes were lower in the vinegar group but not statistically significant. Adverse effects profile also favored the vinegar group.

CONCLUSIONS

It is worthwhile to carry out carefully planned large trails to determine the efficacy and effectiveness of vinegar as an adjunct treatment modality.

Weight Loss Associated With Consumption of Apples: A Review

Apples are known as a major source of polyphenols, dietary fiber, carotenoids, and other nutrients. There are many documents and studies that show fruit polyphenols likely promote anti-obesity effects and exert their beneficial effects via scavenging free radicals, regulating gene expression, and altering signal transduction in target cells and tissues, especially fat tissues.The goal of this review is to presenti the major components of apple and the evidence that indicates its potential to diminution weight gain risk from in vitro, animal, and epidemiological and clinical studies. This review summarizes data about the apple and apple products that been have reported to reduce weight gain by various mechanisms, including antioxidant, antiproliferative, and cell signaling pathways. An extensive search was performed in PubMed, Science Direct, Scopus, and Google Scholar to identify human, animal, and cell culture studies on the association between weight loss and apple consumption, published from inception up to journey 15, 2017. The feeding of apples rats (7-10 mg/kg/d) in different forms in 8 experiments have shown that this caused weight loss during 3 to 28 weeks. In agreement with this, the obtained results from 5 experiments on humans have revealed that consumption of the whole apple or apple juice (240-720 mg/d) in 4-12 weeks by fat people can cause weight loss. Experiments on animals and humans have shown that the consumption of apples in different forms can cause weight loss in overweight ones. However, the main questions are which kind of apple, which part of it, how much, and how long overweight persons should consume them to reduce their body fat and body mass index (BMI). Then, it is necessary to do a meta-analysis to show how these factors affect the body fat percentage and whether this weight-lowering effect is statistically significant or not.

Vinegar consumption can attenuate postprandial glucose and insulin responses; a systematic review and meta-analysis of clinical trials

OBJECTIVE

Postprandial hyperglycemia plays a decisive role in the development of chronic metabolic disorders. The effect of vinegar intake with a meal on postprandial glucose has been studied in several trials with conflicting results.

RESEARCH METHODS AND PROCEDURES

The purpose of the current study was to systematically review control trials that report on the effect of vinegar intake on postprandial glucose response. Postprandial insulin response was considered as secondary outcome.

RESULTS

The pooled analysis of studies revealed a significant mean glucose and insulin area under the curve (AUC) reduction in participants who consumed vinegar compared with the control group (standard mean difference=-0.60, 95%CI -1.08 to -0.11, p=0.01 and -1.30, 95%CI -1.98 to -0.62, p<0.001, respectively).

CONCLUSIONS

The findings suggest that vinegar can be effective in reducing postprandial glucose and insulin levels, indicating it could be considered as an adjunctive tool for improving glycemic control.

Vinegar Functions on Health: Constituents, Sources, and Formation Mechanisms

Vinegars are one of only a few acidic condiments throughout the world. Vinegars can mainly be considered grain vinegars and fruit vinegars, according to the raw materials used. Both grain vinegars and fruit vinegars, which are fermented by traditional methods, possess a variety of physiological functions, such as antibacteria, anti-infection, antioxidation, blood glucose control, lipid metabolism regulation, weight loss, and anticancer activities. The antibacteria and anti-infection abilities of vinegars are mainly due to the presence of organic acids, polyphenols, and melanoidins. The polyphenols and melanoidins also provide the antioxidant abilities of vinegars, which are produced from the raw materials and fermentation processes, respectively. The blood glucose control, lipid metabolism regulation, and weight loss capabilities from vinegars are mainly due to acetic acid. Besides caffeoylsophorose (inhibits disaccharidase) and ligustrazine (improves blood circulation), other functional ingredients present in vinegars provide certain health benefits as well. Regarding anticancer activities, several grain vinegars strongly inhibit the growth of some cancer cells in vivo or in vitro, but related functional ingredients remain largely unknown, except tryptophol in Japanese black soybean vinegar. Considering the discovering of various functional ingredients and clarifying their mechanisms, some vinegars could be functional foods or even medicines, depending on a number of proofs that demonstrate these constituents can cure chronic diseases such as diabetes or cardiovascular problems.

Sudden death due to forced ingestion of vinegar

Vinegar is a clear colorless liquid that commercially consists of 5% acetic acid. It has numerous benefits in everyday use, including culinary, medical, and cleaning. The ingestion of concentrated acetic acid is strongly discouraged and may have detrimental consequences, such as acute pancreatitis, disseminated intravascular coagulopathy, gastric and hepatic complications, upper airway obstruction, or death. We report the first case in the literature of a 5-year-old boy who experienced a sudden death due to ingestion of distilled white vinegar. The manner was homicide. There was evidence of nonfatal blunt force impacts of the head, trunk, and extremities. A pungent aromatic odor of the viscera, gastric/small bowel contents, and cranial cavity was noted at autopsy. A dusky gray discoloration of the gastric mucosa, small bowel, and pancreas was observed. Forensic pathologists should consider ingestion of vinegar when confronted with a compelling history as well as an aromatic odor suggesting vinegar and dusky gray discoloration of the gastric mucosa and small bowel. While vinegar is a common household item and has several advantages, it may prove fatal if ingested in large quantities.

Vinegar as a functional ingredient to improve postprandial glycemic control-human intervention findings and molecular mechanisms

Type 2 diabetes prevalence worldwide is increasing and the burden is particularly high in Asian countries. Identification of functional food ingredients to curb the rise of diabetes among various Asian population groups is warranted. Vinegar is widely consumed throughout Asia, where the principle bioactive component is acetic acid. This review has collated data from human intervention trials to show that vinegar consumption seems more effective in modulating glycemic control in normal glucose-tolerant individuals than in either type 2 diabetics or in those with impaired glucose tolerance. The molecular mechanisms by which vinegar can improve glycemic control have been presented using human, animal and cell culture data. These mechanisms include (i) activation of the free fatty acid receptor 2 (FFAR2) receptors localized in the enteroendocrine L-cells of the intestinal lumen, leading to increased glucagon like peptide 1 (GLP-1) secretion, (ii) increased 5'adenosine monophosphate-activated protein kinase (AMPK) activation, leading to increased fatty acid oxidation and decreased hepatic gluconeogenesis, (iii) lowering of free fatty acid in circulation, potentially leading to improved insulin sensitivity, (iv) increased blood flow to the peripheral tissues and (v) increased satiety, leading to lower food intake. The review also discusses why these mechanisms appear more effective in nondiabetics than in diabetics.

Vinegar decreases blood pressure by down-regulating AT1R expression via the AMPK/PGC-1α/PPARγ pathway in spontaneously hypertensive rats

PURPOSE

Vinegar has been reported to lower blood pressure, but its mechanism is unclear. This study explored whether vinegar plays antihypertensive effect by activating AMP-activated protein kinase (AMPK) pathway.

METHODS

Male spontaneously hypertensive rats (SHRs) were assigned to vinegar, acetic acid, nifedipine, nifedipine + vinegar, or distilled water by oral gavage for 8 weeks. Blood and aortas were analyzed for biochemical indices and protein expression levels. Sv40-transformed aortic rat endothelia cell line (SVAREC) cells were treated with acetate at different doses for 24 h; protein expression levels were assessed.

RESULTS

Vinegar and acetic acid decreased blood pressure in SHRs on weeks 6 and 8, and nifedipine + vinegar had a better effect on blood pressure control than vinegar or nifedipine alone. Vinegar and acetic acid could decrease serum renin and angiotensin-converting enzyme (ACE) activities, angiotensin II and aldosterone concentrations in SHRs. Vinegar and acetic acid also increased AMP/ATP ratios and expression levels of pAMPK, PPARγ coactivator-1α (PGC-1α), and PPARγ while inhibited angiotensin II type 1 receptor (AT1R) expression in SHRs. The changes in these protein expressions were also found in SVAREC cells treated with 200 or 400 μmol/L acetate. In the presence of AMPK inhibitor or PGC-1α small interfering RNA, the effects of acetate on their downstream protein expression in SVAREC cells were abolished, respectively.

CONCLUSION

Vinegar activates AMPK by increasing AMP/ATP ratios, thereby increases PGC-1α and PPARγ expressions, and inhibits AT1R expression in SHRs. Acetic acid is responsible for the antihypertensive effects of vinegar. There is a joint effect between vinegar and nifedipine in blood pressure control.

Effect of co-ingestion of amino acids with rice on glycaemic and insulinaemic response

Consumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.

The role of acetic acid on glucose uptake and blood flow rates in the skeletal muscle in humans with impaired glucose tolerance

BACKGROUND/OBJECTIVES

Previous studies support the glucose-lowering effect of vinegar. However, the effect of vinegar on muscle glucose metabolism and endothelial function has not been studied in humans. This open, randomized, crossover, placebo-controlled study aims to investigate the effects of vinegar on muscle glucose metabolism, endothelial function and circulating lipid levels in subjects with impaired glucose tolerance (IGT) using the arteriovenous difference technique.

SUBJECTS/METHODS

Eight subjects with IGT (4 males, age 46±10 years, body mass index 30±5) were randomised to consume 0.50 mmol vinegar (6% acetic acid) or placebo before a mixed meal. Plasma samples were taken for 300 min from the radial artery and the forearm vein for measurements of glucose, insulin, triglycerides, non-esterified fatty acids (NEFAs) and glycerol. Muscle blood flow was measured with strain gauge plethysmography. Glucose flux was calculated as the arteriovenous difference of glucose multiplied by the blood flow rates.

RESULTS

Vinegar compared with placebo: (1) decreased arterial plasma insulin (Poverall<0.001; P75 min=0.014, β=-42), (2) increased forearm blood flow (Poverall<0.001; P240 min=0.011, β=1.53; P300 min=0.023, β=1.37), (3) increased muscle glucose uptake (Poverall<0.001; P60 min=0.029, β=2.78) and (4) decreased arterial plasma triglycerides (Poverall=0.005; P240 min<0.001, β=-344; P300 min<0.001, β=-373), without changing NEFA and glycerol.

CONCLUSIONS

In individuals with IGT, vinegar ingestion before a mixed meal results in an enhancement of muscle blood flow, an improvement of glucose uptake by the forearm muscle and a reduction of postprandial hyperinsulinaemia and hypertriglyceridaemia. From this point of view, vinegar may be considered beneficial for improving insulin resistance and metabolic abnormalities in the atherogenic prediabetic state.

Vinegar Consumption Increases Insulin-Stimulated Glucose Uptake by the Forearm Muscle in Humans with Type 2 Diabetes

BACKGROUND AND AIMS

Vinegar has been shown to have a glucose-lowering effect in patients with glucose abnormalities. However, the mechanisms of this effect are still obscure. The aim of this randomised, crossover study was to investigate the effect of vinegar on glucose metabolism in muscle which is the most important tissue for insulin-stimulated glucose disposal.

MATERIALS AND METHODS

Eleven subjects with DM2 consumed vinegar or placebo (at random order on two separate days, a week apart), before a mixed meal. Plasma glucose, insulin, triglycerides, nonesterified fatty acids (NEFA), and glycerol were measured preprandially and at 30-60 min for 300 min postprandially from the radial artery and from a forearm vein. Muscle blood flow was measured with strain-gauge plethysmography. Glucose uptake was calculated as the arteriovenous difference of glucose multiplied by blood flow.

RESULTS

Vinegar compared to placebo (1) increased forearm glucose uptake (p = 0.0357), (2) decreased plasma glucose (p = 0.0279), insulin (p = 0.0457), and triglycerides (p = 0.0439), and (3) did not change NEFA and glycerol.

CONCLUSIONS

In DM2 vinegar reduces postprandial hyperglycaemia, hyperinsulinaemia, and hypertriglyceridaemia without affecting lipolysis. Vinegar's effect on carbohydrate metabolism may be partly accounted for by an increase in glucose uptake, demonstrating an improvement in insulin action in skeletal muscle. This trial is registered with Clinicaltrials.gov NCT02309424.

Effect and mechanisms of action of vinegar on glucose metabolism, lipid profile, and body weight

The aim of this review is to summarize the effects of vinegar on glucose and lipid metabolism. Several studies have demonstrated that vinegar can help reduce hyperglycemia, hyperinsulinemia, hyperlipidemia, and obesity. Other studies, however, have shown no beneficial effect on metabolism. Several mechanisms have been proposed to explain these metabolic effects, including delayed gastric emptying and enteral absorption, suppression of hepatic glucose production, increased glucose utilization, upregulation of flow-mediated vasodilation, facilitation of insulin secretion, reduction in lipogenesis, increase in lipolysis, stimulation of fecal bile acid excretion, increased satiety, and enhanced energy expenditure. Although some evidence supports the use of vinegar as a complementary treatment in patients with glucose and lipid abnormalities, further large-scale long-term trials with impeccable methodology are warranted before definitive health claims can be made.

AMPK activation--protean potential for boosting healthspan

AMP-activated kinase (AMPK) is activated when the cellular (AMP+ADP)/ATP ratio rises; it therefore serves as a detector of cellular "fuel deficiency." AMPK activation is suspected to mediate some of the health-protective effects of long-term calorie restriction. Several drugs and nutraceuticals which slightly and safely impede the efficiency of mitochondrial ATP generation-most notably metformin and berberine-can be employed as clinical AMPK activators and, hence, may have potential as calorie restriction mimetics for extending healthspan. Indeed, current evidence indicates that AMPK activators may reduce risk for atherosclerosis, heart attack, and stroke; help to prevent ventricular hypertrophy and manage congestive failure; ameliorate metabolic syndrome, reduce risk for type 2 diabetes, and aid glycemic control in diabetics; reduce risk for weight gain; decrease risk for a number of common cancers while improving prognosis in cancer therapy; decrease risk for dementia and possibly other neurodegenerative disorders; help to preserve the proper structure of bone and cartilage; and possibly aid in the prevention and control of autoimmunity. While metformin and berberine appear to have the greatest utility as clinical AMPK activators-as reflected by their efficacy in diabetes management-regular ingestion of vinegar, as well as moderate alcohol consumption, may also achieve a modest degree of health-protective AMPK activation. The activation of AMPK achievable with any of these measures may be potentiated by clinical doses of the drug salicylate, which can bind to AMPK and activate it allosterically.

White rice vinegar improves pancreatic beta-cell function and fatty liver in streptozotocin-induced diabetic rats

Vinegar is a traditional remedy for ailments including diabetes. This study was conducted to investigate the beneficial effects of vinegar in streptozotocin (STZ)-induced diabetic rats. STZ-induced diabetic rats were orally administered with white rice vinegar (WRV, 2 ml/kg body weight per day, n = 6) or with an equal volume of drinking water (n = 6) for 1 month. Fasting and random blood glucose was measured from tail vein samples. Body weight, 24-h food and water intake were monitored 1 week and 1 month after STZ injection. Fasting serum insulin concentrations were assayed using ELISA. Pancreatic beta- and alpha-cell proportions were measured using immunofluorescence microscopy. Periodic acid Schiff staining was performed to access glycogen contents and histological changes in liver tissues. Compared with control animals, the WRV-treated rats had less weight loss, lower fasting and random blood glucose, higher fasting serum insulin and higher beta-cell proportion. The WRV treatment also improved fatty changes and glycogen storages in the liver of STZ rats. Oral intake of WRV improved fasting hyperglycemia and body weight loss through attenuating insulin deficiency, pancreatic beta-cell deficit, and hepatic glycogen depletion and fatty changes in STZ-induced diabetic rats.

Apple cider vinegar attenuates lipid profile in normal and diabetic rats

In this study, the effect of apple cider vinegar on Fasting Blood Glucose (FBG), glycated haemoglobin (HbA1c) and lipid profile in normal and diabetic rats was investigated. Diabetes was induced in male Wistar rats (300+/-30 g) by the intraperitoneal injection of streptozotocin (60 mg kg(-1) of body weight). Both normal and diabetic animals were fed with standard animal food containing apple cider vinegar (6% w/w) for 4 weeks. Fasting blood glucose did not change, while HbA1c significantly decreased by apple cider vinegar in diabetic group (p<0.05). In normal rats fed with vinegar, significant reduction of low density lipoprotein-cholesterol (LDL-c) (p<0.005) and significant increase of high density lipoprotein-cholesterol (HDL-c) levels (p<0.005) were observed. Apple cider vinegar also reduced serum triglyceride (TG) levels (p<0.005) and increased HDL-c (p<0.005) in diabetic animals. These results indicate that apple cider vinegar improved the serum lipid profile in normal and diabetic rats by decreasing serum TG, LDL-c and increasing serum HDL-c and may be of great value in managing the diabetic complications.