Red wine and diabetes health: getting skin in the game

Moderate alcohol drinking with meals is related to lower incidence of type 2 diabetes

BACKGROUND

Previous studies on alcohol drinking and health largely have ignored the potential impact of the timing of drinking.

OBJECTIVES

We aimed to investigate the joint associations of the timing of alcohol intake with respect to meals (i.e., with meals or outside of meals) and the amount of alcohol consumed with the risk of type 2 diabetes (T2D).

METHODS

A total of 312,388 current drinkers from the UK Biobank without T2D at baseline were included. Cox proportional hazards models were used to examine the association between the timing of alcohol intake with respect to meals and the risk of T2D.

RESULTS

During a median of 10.9 y of follow-up, 8598 incident cases of T2D were documented. After adjustment for covariates and the amount of alcohol consumed, consuming alcohol with meals was significantly associated with a 12% lower risk of T2D (HR: 0.88; 95% CI: 0.83, 0.93) than was consuming alcohol outside of meals. In addition, we found that the timing of alcohol intake with respect to meals significantly modified the relations between the amount of alcohol consumed and risk of T2D (P-interaction = 0.017); the beneficial association of moderate drinking with T2D risk was only observed in participants who consumed alcohol with meals, but not in others. Further analyses on various types of alcoholic beverages indicated that the beneficial associations between alcohol drinking with meals and T2D were mainly driven by wine consumption. Moreover, we found that when consumed together with meals, drinking more wine, rather than other alcoholic beverages, was related to lower concentrations of C-reactive protein.

CONCLUSIONS

In current drinkers, moderate drinking of alcohol, especially wine, with meals is associated with a lower risk of T2D.

Procyanidine resists the fibril formation of human islet amyloid polypeptide

Human islet amyloid polypeptide (hIAPP) is widely studied due to its close correlation with the pathogenic mechanism of type II diabetes mellitus (T2DM). Bioflavonoids have been used in the neurodegeneration and diabetes studies. However, the structure-activity relationship remains unclear in many of these compounds. In this work, we performed diverse biophysical and biochemical methods to explore the inhibition of procyanidine on hIAPP and compared with that on amyloid-β (Aβ) protein which is linked to Alzheimer's disease (AD). The procyanidine effectively inhibited the aggregation of hIAPP and Aβ through hydrophobic and hydrogen bonding interactions, it dissolved the aged fibrils into nanoscale particles. The compound also ameliorated the cytotoxicity and the membrane leakage by reducing the peptide oligomerization. The procyanidine showed better binding affinity and inhibitory effects on peptide aggregation and upregulated the cell viability to hIAPP than to Aβ, which could be a prospective inhibitor against hIAPP. This work also offered a possible strategy for T2DM and AD treatments.

Glucokinase activation as antidiabetic therapy: effect of nutraceuticals and phytochemicals on glucokinase gene expression and enzymatic activity

Diabetes represents an important public health problem. Recently, new molecular targets have been identified and exploited to treat this disease. Due to its pivotal role in glucose homeostasis, glucokinase (GCK) is a promising target for the development of novel antidiabetic drugs; however, pharmacological agents that modulate GCK activity have been linked to undesirable side-effects, limiting its use. Interestingly, plants might be a valuable source of new therapeutic compounds with GCK-activating properties and presumably no adverse effects. In this review, we describe biochemical characteristics related to the physiological and pathological importance of GCK, as well as the mechanisms involved in its regulation at different molecular levels. Posteriorly, we present a compendium of findings supporting the potential use of nutraceuticals and phytochemicals in the management of diabetes through modulation of GCK expression and activity. Finally, we propose critical aspects to keep in mind when designing experiments to evaluate GCK modulation properly.

Resistance of nepetin and its analogs on the fibril formation of human islet amyloid polypeptide

The self-aggregation of human islet amyloid polypeptide (hIAPP) into toxic oligomers and fibrils is closely linked to the pathogenesis of type II diabetes mellitus. Inhibitors can resist hIAPP misfolding, and the resistance can be considered an alternative therapeutic strategy for this disease. Flavones have been applied in the field of diabetes research, however, the inhibition mechanism of many compounds on the fibril formation of related pathogenic peptides remains unclear. In this work, four flavones, namely, nepetin (1), genkwanin (2), luteolin (3), and apigenin (4), were used to impede the peptide aggregation of hIAPP and compared with that on Aβ protein, which is correlated with Alzheimer's disease. Results indicated that the four flavones effectively inhibited the aggregation of the two peptides and mostly dispersed the mature fibrils to monomers. The interactions of flavones with the two peptides demonstrated a spontaneous and exothermic reaction through predominant hydrophobic and hydrogen bonding interactions. The binding affinities of 1 and 3 were stronger than those of 2 and 4 possibly because of the difference in the substituent groups of these molecules. These flavones could also decrease membrane leakage and upregulate cell viability by reducing the formation of toxic oligomers. Moreover, the performance of these flavones in terms of binding affinity, cellular viability, and decreased oligomerization was better on hIAPP than on Aβ. This work offered valuable data about these flavones as prospective therapeutic agents against relevant diseases.

Why the endothelium? The endothelium as a target to reduce diabetes-associated vascular disease

Over the past 66 years, our knowledge of the role of the endothelium in the regulation of cardiovascular function and dysfunction has advanced from the assumption that it is a single layer of cells that serves as a barrier between the blood stream and vascular smooth muscle to an understanding of its role as an essential endocrine-like organ. In terms of historical contributions, we pay particular credit to (1) the Canadian scientist Dr. Rudolf Altschul who, based on pathological changes in the appearance of the endothelium, advanced the argument in 1954 that "one is only as old as one's endothelium" and (2) the American scientist Dr. Robert Furchgott, a 1998 Nobel Prize winner in Physiology or Medicine, who identified the importance of the endothelium in the regulation of blood flow. This review provides a brief history of how our knowledge of endothelial function has advanced and now recognize that the endothelium produces a plethora of signaling molecules possessing paracrine, autocrine, and, arguably, systemic hormone functions. In addition, the endothelium is a therapeutic target for the anti-diabetic drugs metformin, glucagon-like peptide I (GLP-1) receptor agonists, and inhibitors of the sodium-glucose cotransporter 2 (SGLT2) that offset the vascular disease associated with diabetes.

Stability of Anthocyanins and Their Degradation Products from Cabernet Sauvignon Red Wine under Gastrointestinal pH and Temperature Conditions

This study investigated the stability of wine anthocyanins under simulated gastrointestinal pH and temperature conditions, and further studied the evolution of anthocyanin degradation products through simulated digestive conditions. The aim of this study was to investigate the relation between anthocyanins' structure and their digestive stability. Results showed that a total of 22 anthocyanins were identified in wine and most of these anthocyanins remained stable under simulated gastric digestion process. However, a dramatic concentration decrease happened to these anthocyanins during simulated intestinal digestion. The stability of anthocyanins in digestive process appeared to be related to their structure. The methoxy group in the B-ring enhanced the stability of anthocyanins, whereas hydroxyl group resulted in a reduction of their stability. Acylation decreased the stability of malvidin 3-O-glucoside. Pyruvic acid conjugation enhanced the structural stability of pyranoanthocyanins, whereas acetaldehyde attachment weakened their stability. A commercial malvidin 3-O-glucoside standard was used to investigate anthocyanin degradation products under simulated digestion process, and syringic acid, protocatechuic acid and vanillic acid were confirmed to be the degradation products via anthocyanin chalcone conversion path. Gallic acid, protocatechuic acid, vanillic acid, syringic acid, and p-coumaric acid in wine experienced a significant concentration decrease during digestion process. However, wine model solution revealed that phenolic acids remained stable under gastrointestinal conditions, except gallic acid.

Protective effects of tea, red wine and cocoa in diabetes. Evidences from human studies

Prevention of diabetes through the diet has recently received an increasing interest, and polyphenolic compounds, such as flavanols, have become important potential chemopreventive natural agents due to their proved benefits on health, with low toxicity and cost. Tea, red wine and cocoa are good sources of flavanols and these highly consumed foods might contribute to prevent diabetes. In this regard, there is increasing evidence for a protective effect of tea, red wine and cocoa consumption against this disorder. This review summarizes the available epidemiological and interventional human studies providing evidence for and against this effect. Overall observational data suggest a benefit, but results are still equivocal and likely confounded by lifestyle and background dietary factors. The weight of data indicate favourable effects on diabetes risk factors for tea, red wine and cocoa intake, and a number of plausible mechanisms have been elucidated in human studies. However, despite the growing evidence it remains uncertain whether tea, red wine and cocoa consumption should be recommended to the general population or to patients as a strategy to reduce the risk of diabetes.

Specific types of alcoholic beverage consumption and risk of type 2 diabetes: A systematic review and meta-analysis

Aims/Introduction

Previous meta‐analyses identified an inverse association of total alcohol consumption with the risk of type 2 diabetes. The current study further explored the relationship between specific types of alcoholic beverage and the incidence of type 2 diabetes.

Materials and Methods

A search of PubMed, Embase and Cochrane Library databases from January 1966 to February 2016 was carried out for prospective cohort studies that assessed the effects of specific types of alcoholic beverage on the risk of type 2 diabetes. The pooled relative risks with 95% confidence interval were calculated using random‐ or fixed‐effect models when appropriate.

Results

A total of 13 prospective studies were included in this meta‐analysis, with 397,296 study participants and 20,641 cases of type 2 diabetes. Relative to no or rare alcohol consumption, wine consumption was associated with a significant reduction of the risk of type 2 diabetes, with the pooled relative risks of 0.85, whereas beer or spirits consumption led to a slight trend of decreasing risk of type 2 diabetes (relative risk 0.96, 0.95, respectively). Further dose–response analysis showed a U‐shaped relationship between all three alcohol types and type 2 diabetes. Additionally, the peak risk reduction emerged at 20–30 g/day for wine and beer, and at 7–15 g/day for spirits, with a decrease of 20, 9 and 5%, respectively.

Conclusions

Compared with beer or spirits, wine was associated with a more significant decreased risk of type 2 diabetes. The present study showed that wine might be more helpful for protection against type 2 diabetes than beer or spirits.

Clinical implications of oxidative stress and potential role of natural antioxidants in diabetic vascular complications

AIMS

The possible link between hyperglycaemia-induced oxidative stress (OxS) and diabetic complications is suggested by many in vitro studies. However, not much attention has been paid to the clinical evidence supporting this hypothesis, as well as to their possible therapeutic implications.

DATA SYNTHESIS

Some prospective studies show a direct correlation between an increase in OxS biomarkers and the appearance of diabetes complications. This is consistent with the evidence that any acute increase of glycaemia, particularly post-prandial, and hypoglycaemia causes endothelial dysfunction and inflammation, through the generation of an OxS. However, the detection of free radicals is difficult as they are highly reactive molecules with a short half-life. Instead, the metabolites of OxS are measured. Interventional trials with supplemented antioxidants have failed to show any beneficial effects. Conversely, natural foods show very promising results.

CONCLUSIONS

The "new antioxidant" approach includes the possibility of controlling free radical production and increasing intracellular antioxidant defence, a concept different from the old one, when antioxidant activities implied scavenging the free radicals already produced. A synergistic action in this respect could convincingly be obtained with a balanced 'Mediterranean Diet' (MedD) type. Early intensive glucose control is still the best strategy to avoid OxS and its associated diabetes complications.

Hypoglycemic and hypolipidemic effects of neohesperidin derived from Citrus aurantium L. in diabetic KK-Aymice

The present study is to investigate the possible hypoglycemic and hypolipidemic effects of neohesperidin (NHP) derived fromCitrus aurantiumL.in vivo.