Pinto bean consumption changes SCFA profiles in fecal fermentations, bacterial populations of the lower bowel, and lipid profiles in blood of humans

A review of the Hispanic paradox: time to spill the beans?

Past epidemiological observations and recent molecular studies suggest that chronic obstructive pulmonary disease (COPD) and lung cancer are closely related diseases, resulting from overlapping genetic susceptibility and exposure to aero-pollutants, primarily cigarette smoke. Statistics from the American Lung Association and American Cancer Society reveal that mortality from COPD and lung cancer are lowest in Hispanic subjects and generally highest in African American subjects, with mortality in non-Hispanic white subjects and Asian subjects in between. This observation, described as the “Hispanic paradox”, persists after adjusting for confounding variables, notably smoking exposure and sociodemographic factors. While differences in genetic predisposition might underlie this observation, differences in diet remain a possible explanation. Such a hypothesis is supported by the observation that a diet high in fruit and vegetables has been shown to confer a protective effect on both COPD and lung cancer. In this article, we hypothesise that a diet rich in legumes may explain, in part, the Hispanic paradox, given the traditionally high consumption of legumes (beans and lentils) by Hispanic subjects. Legumes are very high in fibre and have recently been shown to attenuate systemic inflammation significantly, which has previously been linked to susceptibility to COPD and lung cancer in large prospective studies. A similar protective effect could be attributed to the consumption of soy products (from soybeans) in Asian subjects, for whom a lower incidence of COPD and lung cancer has also been reported. This hypothesis requires confirmation in cohort studies and randomised control trials, where the effects of diet on outcomes can be carefully examined in a prospective study design.

Nutritional and health benefits of pulses

Pulses (beans, peas, and lentils) have been consumed for at least 10 000 years and are among the most extensively used foods in the world. A wide variety of pulses can be grown globally, making them important both economically as well as nutritionally. Pulses provide protein and fibre, as well as a significant source of vitamins and minerals, such as iron, zinc, folate, and magnesium, and consuming half a cup of beans or peas per day can enhance diet quality by increasing intakes of these nutrients. In addition, the phytochemicals, saponins, and tannins found in pulses possess antioxidant and anti-carcinogenic effects, indicating that pulses may have significant anti-cancer effects. Pulse consumption also improves serum lipid profiles and positively affects several other cardiovascular disease risk factors, such as blood pressure, platelet activity, and inflammation. Pulses are high in fibre and have a low glycemic index, making them particularly beneficial to people with diabetes by assisting in maintaining healthy blood glucose and insulin levels. Emerging research examining the effect of pulse components on HIV and consumption patterns with aging populations indicates that pulses may have further effects on health. In conclusion, including pulses in the diet is a healthy way to meet dietary recommendations and is associated with reduced risk of several chronic diseases. Long-term randomized controlled trials are needed to demonstrate the direct effects of pulses on these diseases.

Inverse association of legume consumption and dyslipidemia: Isfahan Healthy Heart Program

BACKGROUND

Dietary intervention for improving serum lipids emphasizes on dietary fiber, plant protein, and flavonoids. This study was performed to examine whether regular legume consumption could alter serum lipids level and prevalence of dyslipidemia.

MATERIALS AND METHODS

This cross-sectional study was performed among 9660 randomly selected Iranian adults in 3 districts in the central part of Iran, using data collected in the Isfahan Healthy Heart Program in 2007. Dietary behavior including frequency of legume consumption was assessed by 48-item food frequency questionnaire. Fasting serum lipids were measured by standard enzymatic methods. We applied analysis covariance test to compare adjusted mean of serum lipids across legume consumption quartile and logistic regression test was used to determine odds ratio 95% confidence interval of dyslipidemia based on legume consumption in unadjusted and 4-adjusted models.

RESULTS

Adjusted mean triglyceride significantly reduced and high-density lipoprotein cholesterol (HDL-C) enhanced by increasing legume consumption (P = .04). The frequency of legume consumption associated with occurrence of all kinds of dyslipidemia except for hypercholesterolemia, especially for those who had consumed legume more than 1 time per day in adjusted models (hypertriglyceridemia: 0.82 [0.68-0.98]; high low-density lipoprotein [LDL-C]: 0.76 [0.60-0.97], and low HDL-C: 0.81 [0.71-0.92]).

CONCLUSION

We found an inverse dose-response association between the frequency of legume consumption and the risk of hypertriglyceridemia, high LDL-C, and low HDL-C. Therefore it is suggested that increasing legume intake may be an important part of a dietary approach for primary prevention of cardiovascular disease.

In vitro fermentation of spent turmeric powder with a mixed culture of pig faecal bacteria

The fermentation potential of spent turmeric was studied in in vitro swine faecal batch cultures. The spent turmeric residue (the enzyme-resistant fraction from spent turmeric, EST) was obtained through the use of the digestive enzymes amyloglucosidase and pancreatin and compared to cellulose and high-amylose starch (HAS) as carbon sources. EST showed significant increases in total anaerobes, bifidobacteria, lactobacilli and lactic acid bacteria populations compared to cellulose at 12, 24 and 48 h, and the total anaerobic level in the HAS group was significantly higher than that in the cellulose group at 24 and 48 h. However, a significant decrease in the coliform population was only found in the HAS group compared to the cellulose group at 48 h. The total short-chain fatty acid (SCFA) concentrations in the EST and HAS groups were significantly higher than that in the cellulose group at 12 h and 48 h. However, there was no significant difference in the total SCFA concentration between the EST and HAS groups at 12 h and 48 h. Ammonia and pH levels in the EST and HAS groups were significantly lower than those in the cellulose group at 24 and 48 h, but there was no significant difference between the EST and HAS groups. These results indicate that the fermentation potential of the enzyme-resistant fraction from spent turmeric is comparable to that of commercially established resistant starch.

Nutritional and health perspectives of beans (Phaseolus vulgaris L.): an overview

Beans, the variants of Phaseolus vulagris, are nutritionally and economically important food crop in each part of the world. Besides providing nutrients such as multifaceted carbohydrates, elevated proteins, dietary fiber, minerals, and vitamins, these also contain rich variety of polyphenolic compounds with prospective health benefits. This review mainly focuses the important nutritional aspects of beans as well as their contribution in decreasing the risks of chronically degenerative diseases.

Effect of dietary pulse intake on established therapeutic lipid targets for cardiovascular risk reduction: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Evidence from controlled trials encourages the intake of dietary pulses (beans, chickpeas, lentils and peas) as a method of improving dyslipidemia, but heart health guidelines have stopped short of ascribing specific benefits to this type of intervention or have graded the beneficial evidence as low. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of dietary pulse intake on established therapeutic lipid targets for cardiovascular risk reduction.

METHODS

We searched electronic databases and bibliographies of selected trials for relevant articles published through Feb. 5, 2014. We included RCTs of at least 3 weeks' duration that compared a diet emphasizing dietary pulse intake with an isocaloric diet that did not include dietary pulses. The lipid targets investigated were low-density lipoprotein (LDL) cholesterol, apolipoprotein B and non-high-density lipoprotein (non-HDL) cholesterol. We pooled data using a random-effects model.

RESULTS

We identified 26 RCTs (n = 1037) that satisfied the inclusion criteria. Diets emphasizing dietary pulse intake at a median dose of 130 g/d (about 1 serving daily) significantly lowered LDL cholesterol levels compared with the control diets (mean difference -0.17 mmol/L, 95% confidence interval -0.25 to -0.09 mmol/L). Treatment effects on apolipoprotein B and non-HDL cholesterol were not observed.

INTERPRETATION

Our findings suggest that dietary pulse intake significantly reduces LDL cholesterol levels. Trials of longer duration and higher quality are needed to verify these results.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT01594567.

Cooked navy and black bean diets improve biomarkers of colon health and reduce inflammation during colitis

Common beans contain non-digestible fermentable components (SCFA precursors) and phenolic compounds (phenolic acids, flavonoids and anthocyanins) with demonstrated antioxidant and anti-inflammatory potential. The objective of the present study was to assess the in vivo effect of cooked whole-bean flours, with differing phenolic compound levels and profiles, in a mouse model of acute colitis. C57BL/6 mice were fed a 20 % navy bean or black bean flour-containing diet or an isoenergetic basal diet (BD) for 2 weeks before the induction of experimental colitis via 7 d dextran sodium sulphate (DSS, 2 % (w/v) in the drinking-water) exposure. Compared with the BD, both bean diets increased caecal SCFA and faecal phenolic compound concentrations (P< 0·05), which coincided with both beneficial and adverse effects on colonic and systemic inflammation. On the one hand, bean diets reduced mRNA expression of colonic inflammatory cytokines (IL-6, IL-9, IFN-γ and IL-17A) and increased anti-inflammatory IL-10 (P< 0·05), while systemically reduced circulating cytokines (IL-1β, TNFα, IFNγ, and IL-17A, P< 0·05) and DSS-induced oxidative stress. On the other hand, bean diets enhanced DSS-induced colonic damage as indicated by an increased histological injury score and apoptosis (cleaved caspase-3 and FasL mRNA expression) (P< 0·05). In conclusion, bean-containing diets exerted both beneficial and adverse effects during experimental colitis by reducing inflammatory biomarkers both locally and systemically while aggravating colonic mucosal damage. Further research is required to understand the mechanisms through which beans exert their effects on colonic inflammation and the impact on colitis severity in human subjects.

Combining functional features of whole-grain barley and legumes for dietary reduction of cardiometabolic risk: a randomised cross-over intervention in mature women

The usefulness of dietary strategies against cardiometabolic risk is increasingly being acknowledged. Legumes and whole grains can modulate risk markers associated with cardiometabolic diseases, but their possible additive/synergistic actions are unknown. The objective of the present study was to assess, in healthy subjects, the effect of a diet including specific whole-grain barley products and legumes with prior favourable outcomes on cardiometabolic risk parameters in semi-acute studies. A total of forty-six overweight women (50–72 years, BMI 25–33 kg/m2and normal fasting glycaemia) participated in a randomised cross-over intervention comparing a diet rich in kernel-based barley products, brown beans and chickpeas (D1, diet 1 (functional diet)) with a control diet (D2, diet 2 (control diet)) of similar macronutrient composition but lacking legumes and barley. D1 included 86 g (as eaten)/d brown beans, 82 g/d chickpeas, 58 g/d whole-grain barley kernels and 216 g/d barley kernel bread. Both diets followed the Nordic Nutrition Recommendations, providing similar amounts of dietary fibre (D1: 46·9 g/d; D2: 43·5 g/d), with wheat-based products as the main fibre supplier in D2. Each diet was consumed for 4 weeks under weight-maintenance conditions. Both diets decreased serum total cholesterol, LDL-cholesterol and HDL-cholesterol levels, but D1 had a greater effect on total cholesterol and LDL-cholesterol levels (P< 0·001 andP< 0·05, respectively). D1 also reduced apoB (P< 0·001) and γ-glutamyl transferase (P< 0·05) levels, diastolic blood pressure (P< 0·05) and the Framingham cardiovascular risk estimate (P< 0·05). D1 increased colonic fermentative activity, as judged from the higher (P< 0·001) breath hydrogen levels recorded. In conclusion, a specific barley/legume diet improves cardiometabolic risk-associated biomarkers in a healthy cohort, showing potential preventive value beyond that of a nutritionally well-designed regimen.

Increased consumption of fruit and vegetables for the primary prevention of cardiovascular diseases

EDITORIAL NOTE

This Cochrane Review has been superseded by a review entitled Vegan dietary pattern for the primary and secondary prevention of cardiovascular diseases (https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD013501.pub2/full) https://pubmed.ncbi.nlm.nih.gov/33629376/

BACKGROUND

There is increasing evidence that high consumption of fruit and vegetables is beneficial for cardiovascular disease (CVD) prevention.

OBJECTIVES

The primary objective is to determine the effectiveness of i) advice to increase fruit and vegetable consumption ii) the provision of fruit and vegetables to increase consumption, for the primary prevention of CVD.

SEARCH METHODS

We searched the following electronic databases: The Cochrane Library (2012, issue 9-CENTRAL, HTA, DARE, NEED), MEDLINE (1946 to week 3 September 2012); EMBASE (1980 to 2012 week 39) and the Conference Proceedings Citation Index - Science on ISI Web of Science (5 October 2012). We searched trial registers, screened reference lists and contacted authors for additional information where necessary. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials with at least three months follow-up (follow-up was considered to be the time elapsed since the start of the intervention) involving healthy adults or those at high risk of CVD. Trials investigated either advice to increase fruit and vegetable intake (via any source or modality) or the provision of fruit and vegetables to increase intake. The comparison group was no intervention or minimal intervention. Outcomes of interest were CVD clinical events (mortality (CVD and all-cause), myocardial infarction (MI), coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA), angiographically-defined angina pectoris, stroke, carotid endarterectomy, peripheral arterial disease (PAD)) and major CVD risk factors (blood pressure, blood lipids, type 2 diabetes). Trials involving multifactorial lifestyle interventions (including different dietary patterns, exercise) or where the focus was weight loss were excluded to avoid confounding.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias. Trials of provision of fruit and vegetables were analysed separately from trials of dietary advice.

MAIN RESULTS

We identified 10 trials with a total of 1730 participants randomised, and one ongoing trial. Six trials investigated the provision of fruit and vegetables, and four trials examined advice to increase fruit and vegetable consumption.The ongoing trial is examining the provision of an avocado-rich diet.The number and type of intervention components for provision, and the dietary advice provided differed between trials.None of the trials reported clinical events as they were all relatively short term. There was no strong evidence for effects of individual trials of provision of fruit and vegetables on cardiovascular risk factors, but trials were heterogeneous and short term. Furthermore, five of the six trials only provided one fruit or vegetable. Dietary advice showed some favourable effects on blood pressure (systolic blood pressure (SBP): mean difference (MD) -3.0 mmHg (95% confidence interval (CI) -4.92 to -1.09), diastolic blood pressure (DBP): MD -0.90 mmHg (95% CI -2.03 to 0.24)) and low-density lipoprotein (LDL) cholesterol but analyses were based on only two trials. Three of the 10 included trials examined adverse effects, which included increased bowel movements, bad breath and body odour.

AUTHORS' CONCLUSIONS

There are very few studies to date examining provision of, or advice to increase the consumption of, fruit and vegetables in the absence of additional dietary interventions or other lifestyle interventions for the primary prevention of CVD. The limited evidence suggests advice to increase fruit and vegetables as a single intervention has favourable effects on CVD risk factors but more trials are needed to confirm this.

Composition of two Spanish common dry beans (Phaseolus vulgaris), 'Almonga' and 'Curruquilla', and their postprandial effect in type 2 diabetics

BACKGROUND

Legume consumption has been associated with a lower risk of developing type 2 diabetes. However, the type of legume is a modifier of its effect. Two Spanish dry bean varieties-white ('Almonga') and cream ('Curruquilla')-were analyzed and used in a postprandial study in type 2 diabetics to assess glucose, insulin and triacylglycerol in blood.

RESULTS

'Curruquilla' variety had higher total galactoside (stachyose, mainly), trypsin inhibitors and lectin content than 'Almonga'. The canning liquid was discarded prior to the analysis and the bean consumption by the subjects. The canning process reduced the total α-galactoside content (>50%), practically eliminated trypsin inhibitors, and no lectin content was found. After bean consumption, maximum glucose was obtained at 60 min and was three times lower than that in bread. After bean intake, maximum insulin was produced 60 min with 'Almonga' and occurred later (90 min) with 'Curruquilla' and bread. After 'Almonga' intake, the area under the curve response of triglycerides was 14% lower compared to bread (P = 0.013).

CONCLUSIONS

'Almonga' and 'Curruquilla' are similar in the content of the nutritional but not in that of the antinutritional components. Both beans showed similar effects on blood glucose and insulin in type 2 diabetics and marked differences compared to those of bread in terms of magnitude and time course, but only 'Almonga' rendered a significant reduction in the triglyceridemic response.

Inter-individual differences in response to dietary intervention: integrating omics platforms towards personalised dietary recommendations

Technologic advances now make it possible to collect large amounts of genetic, epigenetic, metabolomic and gut microbiome data. These data have the potential to transform approaches towards nutrition counselling by allowing us to recognise and embrace the metabolic, physiologic and genetic differences among individuals. The ultimate goal is to be able to integrate these multi-dimensional data so as to characterise the health status and disease risk of an individual and to provide personalised recommendations to maximise health. To this end, accurate and predictive systems-based measures of health are needed that incorporate molecular signatures of genes, transcripts, proteins, metabolites and microbes. Although we are making progress within each of these omics arenas, we have yet to integrate effectively multiple sources of biologic data so as to provide comprehensive phenotypic profiles. Observational studies have provided some insights into associative interactions between genetic or phenotypic variation and diet and their impact on health; however, very few human experimental studies have addressed these relationships. Dietary interventions that test prescribed diets in well-characterised study populations and that monitor system-wide responses (ideally using several omics platforms) are needed to make correlation-causation connections and to characterise phenotypes under controlled conditions. Given the growth in our knowledge, there is the potential to develop personalised dietary recommendations. However, developing these recommendations assumes that an improved understanding of the phenotypic complexities of individuals and their responses to the complexities of their diets will lead to a sustainable, effective approach to promote health and prevent disease - therein lies our challenge.

Dietary dry bean effects on hepatic expression of stress and toxicity-related genes in rats

Dry bean (Phaseolus vulgaris L.) consumption is associated with reduced risk for a number of chronic diseases. In westernised societies, dry bean consumption is particularly low (approximately 2-4 kg/capita per year) and little information is available about the safety of increasing dietary intake in humans to achieve levels that prevent and control chronic diseases. In anticipation of a human intervention study to address the safety and efficacy of increasing bean consumption, a dose-response study with dietary beans was conducted to establish whether increased bean consumption in rats exhibits changes indicative of hepatic stress or toxicity. Transcript levels from a panel of stress and toxicity-related genes were analysed in female Sprague-Dawley rats fed a dose range of dietary beans that bracketed amounts relevant to human consumption globally. Cooked red bean was incorporated into a purified diet formulation at 0, 7·5, 15, 30 or 60 % w/w for the assessment of adaptive patterns of gene expression using quantitative PCR array. Of the eighty-four genes evaluated, the expressions of Cyp3a11, Cyp7a1, Fmo1, Gstm1, Mif and Ugt1a6 were elevated, whereas the expression of Hspa8 was down-regulated. Liver gene expression was not modulated in a manner indicative of an adverse response. Only the expression of the cholesterol 7α hydoxylase and UDP-glucuronosyltransferase genes increased in a dose-dependent manner at nutritionally relevant dietary bean concentrations. These candidate genes may contribute to the health benefits attributed to increased bean consumption.

Dietary agents that target gastrointestinal and hepatic handling of bile acids and cholesterol

Several food components have been demonstrated to exhibit cholesterol-lowering properties by interfering with cholesterol absorption and bile-acid trafficking. Such components include stearic acid, plant sterols, soluble fiber, and soy protein. Among saturated fatty acids, stearic acid is unique in its ability to reduce circulatory low-density lipoprotein cholesterol levels. This action is accompanied by an observed suppression in cholesterol absorption, an effect seen repeatedly in animal and human studies. Proposed mechanisms include micellar exclusion of cholesterol by this high melting point fatty acid, as well as the ability of stearate to alter the biliary ratios of primary to secondary bile acids, leading to a reduction in hydrophobicity index and lower overall solubility of sterols in micelles. Another dietary ingredient that interferes with absorption of sterols is soy protein, in which studies in animals and humans have identified that compared to casein, consumption of soy protein reduces intestinal absorption of cholesterol while enhancing fecal cholesterol excretion. Considerable investigation using free amino acid mixtures mirroring the composition of soy versus animal proteins has determined that co-existing agents other than soy's amino acid pattern are likely responsible for the inhibitory action of soy protein on sterol uptake. Recently, it has been shown that hydrolysates of soy protein appear to be effective in reducing sterol absorption; these are now being targeted as the possible factor responsible for the overall effect of this dietary ingredient. Plant sterols appear to impact absorption of sterols through several mechanisms, including competition with cholesterol for incorporation into micelles, co-crystallization with cholesterol to form insoluble crystals, interaction with digestive enzymes, and inhibition of cholesterol transporter proteins. Clinical trials attest to plant sterols lowering cholesterol absorption by 20% to 40%, an extent beyond which cholesterogenesis can compensate to restore normal circulatory cholesterol levels. As such, 2 g/day of plant sterols effectively lowers low-density lipoprotein cholesterol by 8% to 12%. Dietary soluble fiber represents another means of reducing intestinal cholesterol uptake, in part through enhanced bile-acid clearance through the gut. Pectin, β-glucans, fructans, and gums have been identified as agents that can work through the production of a viscous matrix that hinders movement of cholesterol and bile acids into micelles as well as the subsequent uptake of micelles into the enterocyte. Additional work on design of novel fibers that impede sterol absorption is warranted. In summary, a number of novel dietary factors exist that contribute to heart disease risk reduction via mechanisms that involve cholesterol absorption inhibition and/or biliary pathway perturbation.

Regular consumption of pulses for 8 weeks reduces metabolic syndrome risk factors in overweight and obese adults

Pulses are low in energy density, supporting their inclusion in the diet for the management of risk factors of the metabolic syndrome (MetSyn). The aim of the present study was to describe the effects of frequent consumption (five cups/week over 8 weeks) of pulses (yellow peas, chickpeas, navy beans and lentils), compared with counselling to reduce energy intake by 2093 kJ/d (500 kcal/d), on risk factors of the MetSyn in two groups (nineteen and twenty-one subjects, respectively) of overweight or obese (mean BMI 32·8 kg/m2) adults. Body weight, waist circumference, blood pressure, fasting blood parameters and 24 h food intakes were measured at weeks 1, 4 and 8. Blood glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and ghrelin were measured after a 75 g oral glucose load at weeks 1 and 8. At week 8, both groups reported reductions in energy intake, waist circumference, systolic blood pressure, glycosylated Hb (HbA1c) and glucose AUC and homeostasis model of insulin resistance (HOMA-IR) following the glucose load (P < 0·05). However, HDL, fasting C-peptide and insulin AUC responses were dependent on diet (P < 0·05). HDL and C-peptide increased by 4·5 and 12·3 %, respectively, in the pulse group, but decreased by 0·8 and 7·6 %, respectively, in the energy-restricted group. Insulin AUC decreased in both females and males on the energy-restricted diet by 24·2 and 4·8 %, respectively, but on the pulse diet it decreased by 13·9 % in females and increased by 27·3 % in males (P < 0·05). In conclusion, frequent consumption of pulses in an ad libitum diet reduced risk factors of the MetSyn and these effects were equivalent, and in some instances stronger, than counselling for dietary energy reduction.

Edible dry bean consumption (Phaseolus vulgaris L.) modulates cardiovascular risk factors and diet-induced obesity in rats and mice

Pulses are grain legumes that have sustained the civilisations of the world throughout their development; yet this staple food crop has fallen into disuse, particularly in Westernised societies, and decreased consumption parallels increased prevalence of CVD. The objective of the present study was to identify mechanisms that account for the cardioprotective activity of dry bean (Phaseolus vulgaris L.), one of the four primary pulse crops, which is widely produced and consumed globally. Laboratory assays that can be used for in vivo screening of dry beans and other pulses to identify those with the greatest potential to benefit human health are also reported. Sprague–Dawley rats and a diet-induced obesity model in C57Bl/6 mice were used to assess the effect of cooked dry bean incorporated into a purified diet formulation on plasma lipids and hepatic proteins involved in the regulation of lipid biosynthesis. In both animal species, short-term feeding of a bean-containing diet reduced plasma total cholesterol and LDL-cholesterol without affecting HDL-cholesterol or total TAG. Mechanisms associated with cholesterol catabolism and excretion are the likely targets of the bean effect. Unexpectedly, bean-fed obese mice experienced weight loss as well as an improved plasma lipid profile within a 12 d time frame. These findings support the use of short-term (7–14 d) assays to investigate mechanisms that account for the cardioprotective and weight regulatory effects of dry bean and to screen dry bean germplasm resources for types of bean with high protective activity. These same assays can be used to identify the bioactive components of bean that account for the observed effects.

Perceptions of flatulence from bean consumption among adults in 3 feeding studies

Background

Many consumers avoid eating beans because they believe legume consumption will cause excessive intestinal gas or flatulence. An increasing body of research and the 2010 Dietary Guidelines for Americans supports the benefits of a plant-based diet, and legumes specifically, in the reduction of chronic disease risks. The purpose of the current research was to investigate the perception of increased flatulence and gastrointestinal discomfort among participants who consumed a ½ cup of beans daily for 8 or 12 weeks.

Methods

Participants in three studies to test the effects of beans on heart disease biomarkers completed the same weekly questionnaire to assess gastrointestinal discomfort issues such as increased flatulence, stool changes, and bloating. Studies 1 and 2 were randomized crossover trials. Participants consumed ½ cup of pinto beans, black-eyed peas, and canned carrots as control (n = 17) in Study 1 for three randomized 8-week phases. For Study 2, participants ate ½ cup baked beans or canned carrots as control (n = 29) for two randomized 8-week phases. Study 3 was a parallel arm trial with 40 subjects receiving ½ cup pinto beans and 40 consuming a control soup for 12 weeks. Changes in the frequency of perceived flatulence, stool characteristics, and bloating were the primary outcome measures. Chi-square distributions were examined for the presence or absence of symptoms and demographic characteristics to determine differences by gender, age, body mass index (BMI), and bean type.

Results

Less than 50% reported increased flatulence from eating pinto or baked beans during the first week of each trial, but only 19% had a flatulence increase with black-eyed peas. A small percentage (3-11%) reported increased flatulence across the three studies even on control diets without flatulence-producing components.

Conclusions

People's concerns about excessive flatulence from eating beans may be exaggerated. Public health nutritionists should address the potential for gastrointestinal discomfort when increasing fiber intake from beans with clients. It is important to recognize there is individual variation in response to different bean types.

Urinary collagen fragments are significantly altered in diabetes: a link to pathophysiology

Background

The pathogenesis of diabetes mellitus (DM) is variable, comprising different inflammatory and immune responses. Proteome analysis holds the promise of delivering insight into the pathophysiological changes associated with diabetes. Recently, we identified and validated urinary proteomics biomarkers for diabetes. Based on these initial findings, we aimed to further validate urinary proteomics biomarkers specific for diabetes in general, and particularity associated with either type 1 (T1D) or type 2 diabetes (T2D).

Methodology/Principal Findings

Therefore, the low-molecular-weight urinary proteome of 902 subjects from 10 different centers, 315 controls and 587 patients with T1D (n = 299) or T2D (n = 288), was analyzed using capillary-electrophoresis mass-spectrometry. The 261 urinary biomarkers (100 were sequenced) previously discovered in 205 subjects were validated in an additional 697 subjects to distinguish DM subjects (n = 382) from control subjects (n = 315) with 94% (95% CI: 92–95) accuracy in this study. To identify biomarkers that differentiate T1D from T2D, a subset of normoalbuminuric patients with T1D (n = 68) and T2D (n = 42) was employed, enabling identification of 131 biomarker candidates (40 were sequenced) differentially regulated between T1D and T2D. These biomarkers distinguished T1D from T2D in an independent validation set of normoalbuminuric patients (n = 108) with 88% (95% CI: 81–94%) accuracy, and in patients with impaired renal function (n = 369) with 85% (95% CI: 81–88%) accuracy. Specific collagen fragments were associated with diabetes and type of diabetes indicating changes in collagen turnover and extracellular matrix as one hallmark of the molecular pathophysiology of diabetes. Additional biomarkers including inflammatory processes and pro-thrombotic alterations were observed.

Conclusions/Significance

These findings, based on the largest proteomic study performed to date on subjects with DM, validate the previously described biomarkers for DM, and pinpoint differences in the urinary proteome of T1D and T2D, indicating significant differences in extracellular matrix remodeling.

A high legume low glycemic index diet improves serum lipid profiles in men

Clinical studies have shown that fiber consumption facilitates weight loss and improves lipid profiles; however, the beneficial effects of high fermentable fiber low glycemic index (GI) diets under conditions of weight maintenance are unclear. In the Legume Inflammation Feeding Experiment, a randomized controlled cross-over feeding study, 64 middle-aged men who had undergone colonoscopies within the previous 2 years received both a healthy American (HA) diet (no legume consumption, fiber consumption = 9 g/1,000 kcal, and GI = 69) and a legume enriched (1.5 servings/1,000 kcal), high fiber (21 g/1,000 kcal), low GI (GI = 38) diet (LG) in random order. Diets were isocaloric and controlled for macronutrients including saturated fat; they were consumed each for 4 weeks with a 2-4 week break separating dietary treatments. Compared to the HA diet, the LG diet led to greater declines in both fasting serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) (P < 0.001 and P < 0.01, respectively). Insulin-resistant (IR) subjects had greater reductions in high density lipoprotein cholesterol (HDL-C; P < 0.01), and triglycerides (TAG)/HDL-C (P = 0.02) after the LG diet, compared to the HA diet. Insulin-sensitive (IS) subjects had greater reductions in TC (P < 0.001), LDL-C (P < 0.01), TC/HDL-C (P < 0.01), and LDL-C/HDL-C (P = 0.02) after the LG diet, compared to the HA diet. In conclusion, a high legume, high fiber, low GI diet improves serum lipid profiles in men, compared to a healthy American diet. However, IR individuals do not achieve the full benefits of the same diet on cardiovascular disease (CVD) lipid risk factors.

The potential health benefits of legumes as a good source of dietary fibre

Dietary fibre has been shown to have important health implications in the prevention of risks of chronic diseases. The objective of the present study was to determine the potential health benefits of legumes as a good source of dietary fibre. Six to ten local legumes were studied as follows: cowpeas, mung beans, pole sitao, chickpeas, green peas, groundnuts, pigeon peas, kidney beans, lima beans and soyabeans. The following studies were conducted: (a) mineral availability, in vitro; (b) glycaemic index (GI) in non-diabetic and diabetic human subjects; (c) the cholesterol-lowering effect in human subjects with moderately raised serum cholesterol levels. The highest Fe availability among legumes was for lima beans (9·5 (sem 0·1)) while for Zn and Ca, the highest availability was for kidney beans (49·3 (sem 4·5)) and pigeon peas (75·1 (sem 7·1)), respectively. Groundnuts have the lowest Fe (1·3 (sem 1·1)), Zn (7·9 (sem 1·3)) and Ca (14·6 (sem 2·8)) availability. Legumes are low-GI foods ( < 55), ranging from 6 (chickpeas) to 13 (mung beans). Kidney beans showed significant reductions for both total (6 %) and LDL-cholesterol (9 %), and groundnuts for total cholesterol (7 %; P < 0·05). We conclude that mineral availability from legumes differs and may be attributed to their mineral content, mineral–mineral interaction and from their phytic and tannic acid content; legumes are considered low-GI foods and have shown potential hypocholesterolaemic effects. The above studies can be a scientific basis for considering legumes as functional foods.

Probiotic therapy to men with incipient arteriosclerosis initiates increased bacterial diversity in colon: a randomized controlled trial

OBJECTIVE

This study aimed to clarify the microbial change in the intestinal microbiota in patients, with cardiovascular disease, consuming a drink with high numbers of live Lactobacillus plantarum.

METHODS

Sixteen males, with atherosclerotic plaque on the carotid wall, were randomly selected from a larger cohort and included in this double blind, placebo controlled study. Colonic biopsies, taken before and after four weeks of probiotic treatment, were analysed with Terminal Restriction Fragment Length Polymorphism, including digestion with MspI and HaeIII. Microbial diversity was calculated, short-chain fatty acids in faeces, and blood markers were analysed.

RESULTS

Consumption of one probiotic strain of L. plantarum (DSM 9843) increased intestinal microbial diversity. The probiotic group had an increased diversity after consumption of the probiotic drink compared to the change in the placebo group when Shannon and Weaner diversity index (MspI and HaeIII, p=0.026) and Simpson index of diversity (MspI, p=0.044 and HaeIII, p=0.026) were calculated. The fermentation pattern of short-chain fatty acids in faeces were unaffected for most acids, but the probiotic group had decreased concentration of isovaleric acid (p=0.006) and valeric acid (p=0.029). Viable count of lactobacilli increased in the probiotic group (p=0.001), but no significant changes in blood markers were observed.

CONCLUSION

Administration of a single-strain probiotic increases the bacterial diversity in the gut, and affects the concentration of some short-chain fatty acids. Consumption of the single strain L. plantarum DSM 9843 might be a strategy to favour a diverse intestinal microbiota, which is beneficial for the host.

Inflammation-associated serum and colon markers as indicators of dietary attenuation of colon carcinogenesis in ob/ob mice

Although inflammatory cytokines and obesity-associated serum proteins have been reported as biomarkers of colorectal adenoma risk in humans, little is known of biomarkers of response to interventions that attenuate tumorigenesis. Dietary navy beans and their fractions attenuate colon carcinogenesis in carcinogen-induced genetically obese mice. We hypothesized that this attenuation would be associated with changes in inflammatory cytokines and obesity-related serum proteins that may serve as measures of efficacy. ob/ob mice (n = 160) were injected with the carcinogen azoxymethane (AOM) to induce colon cancer and randomly placed on one of four diets (control, whole navy bean, bean residue fraction, or bean extract fraction) for 26 to 28 wk. Serum was analyzed for 14 inflammation- or obesity-related proteins, and colon RNA was analyzed for expression of 84 inflammation-associated genes. Six of 14 serum proteins were increased [i.e., interleukin (IL)-4, IL-5, IL-6, IL-10, IFN gamma, granulocyte macrophage colony-stimulating factor] in hyperplastic/dysplastic stages of colon carcinogenesis. Bean-fed mice had significantly higher monocyte chemoattractant protein-1 and lower IL-6 levels in serum. In colon mucosa, 55 of 84 inflammation-associated genes differed between AOM-induced and noninduced mice. Of the 55 AOM-induced genes, 5 were counteracted by bean diets, including IL-6 whose increase in expression levels was attenuated by bean diets in AOM-induced mice. In summary, IL-6 emerged as a serum protein that was increased in hyperplastic/dysplastic stages of colon carcinogenesis, but attenuated with bean-based diet in serum and colon mucosa. Changes in a subset of inflammation-associated serum proteins and colon gene expression may serve as response indicators of dietary attenuation of colon carcinogenesis.

Effects of soluble dietary fiber on low-density lipoprotein cholesterol and coronary heart disease risk

Strong epidemiologic and experimental data suggest that increasing dietary fiber may help to lower low-density lipoprotein cholesterol (LDL-C) and decrease the risk of coronary heart disease. Recent studies have highlighted the role of dietary fiber, particularly water-soluble varieties, in decreasing the risk of cardiovascular disease. Several types of soluble fiber, including psyllium, beta-glucan, pectin, and guar gum, have been shown to decrease LDL-C in well-controlled intervention studies, whereas the soluble fiber content of legumes and vegetables has also been shown to decrease LDL-C. Current investigations continue to explore this area in depth and examine potential synergies between dietary fiber and other phytochemicals that may lower cholesterol. These studies, along with recent analyses of ongoing prospective cohort studies, have provided new insights into the probable protective role of dietary fiber in the development of coronary heart disease and other cardiovascular diseases.