Effect of chronic consumption of pistachios (Pistacia vera L.) on glucose metabolism in pre-diabetics and type 2 diabetics: A systematic review.

Pistachio is a nut with high polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), polyphenols and carotenoids content, and the synergism between these compounds appears to affect glucose metabolism. In this systematic review we analyzed studies in which the effect of chronic consumption of pistachio on markers of glucose metabolism was evaluated in pre-diabetic and type 2 diabetics. We used the PubMed, Scopus, Cochrane and Lilacs databases. The research terms used were pistachio, pre-diabetes, type 2 diabetes mellitus, insulin resistance, blood glucose, hyperglycemia and glycated hemoglobin (HbA1c). Four articles were selected, of which three tested the intake of 50 to 57 g of pistachio/day and one 20% of the daily caloric intake, for a period of 1 to 4 months. Studies reported a decrease in fasting blood glucose, insulinemia, HOMA-IR, and fructosamine, but no change in HbA1c. Lower concentrations of miR-192 and miR-375 were also found, which correlated positively with HOMA-IR. The synergism between PUFA, MUFA, polyphenols and carotenoids present in pistachios can modulate specific miRNA, increasing insulin sensitivity through the PI3K-AKT signaling pathway. This modulation can be used as a tool to monitor the response to interventions, favoring the prevention and treatment of complications related to diabetes.

Effect of a high-fat meal containing conventional or high-oleic peanuts on post-prandial lipopolysaccharide concentrations in overweight/obese men.

BACKGROUND: An increased plasma lipopolysaccharide (LPS) concentration may favour metabolic disorders such as insulin resistance. The meal composition influences plasma LPS concentrations. The present study aimed to investigate the effect of the acute consumption of a high-fat meal (49% of energy from fat) containing conventional or high-oleic peanuts on post-prandial LPS concentrations and its relationship with lipaemia and insulinaemia in overweight and obese men. METHODS: The test meal consisted of a shake containing conventional peanuts (CVP; n = 21), high-oleic peanuts (HOP; n = 23) or a control biscuit (CT; n = 21). Blood samples were collected in the fasting state and 1, 2 and 3 h post-prandially. LPS, insulin, lipids and glucose concentrations were assessed. RESULTS: LPS concentrations were lower in CVP [mean (SE) 0.7 (0.5) EU mL(-1) ] and HOP [1.0 (0.9) EU mL(-1) ] groups compared to CT [1.6 (1.2) EU mL(-1) ] at 3 h post-prandially. Triacylglycerol and insulin concentrations increased in all groups. Triacylglycerol started to increase only after 2 h in the CVP and HOP groups. LPS correlated positively with triacylglycerol. Insulin returned to basal concentrations at 3 h only in the CVP and HOP groups. CONCLUSIONS: The acute consumption of peanuts delayed the increase in serum triacylglycerol and favoured the quicker return of insulin to basal concentrations, especially in the CVP group. Our results suggest that the consumption of conventional or high-oleic peanuts may help to reduce the risk of endotoxaemia and metabolic disorders.

Could the beneficial effects of dietary calcium on obesity and diabetes control be mediated by changes in intestinal microbiota and integrity?

Evidence from animal and human studies has associated gut microbiota, increased translocation of lipopolysaccharide (LPS) and reduced intestinal integrity (II) with the inflammatory state that occurs in obesity and type 2 diabetes mellitus (T2DM). Consumption of Ca may favour body weight reduction and glycaemic control, but its influence on II and gut microbiota is not well understood. Considering the impact of metabolic diseases on public health and the role of Ca on the pathophysiology of these diseases, this review critically discusses possible mechanisms by which high-Ca diets could affect gut microbiota and II. Published studies from 1993 to 2015 about this topic were searched and selected from Medline/PubMed, Scielo and Lilacs databases. High-Ca diets seem to favour the growth of lactobacilli, maintain II (especially in the colon), reduce translocation of LPS and regulate tight-junction gene expression. We conclude that dietary Ca might interfere with gut microbiota and II modulations and it can partly explain the effect of Ca on obesity and T2DM control. However, further research is required to define the supplementation period, the dose and the type of Ca supplement (milk or salt) required for more effective results. As Ca interacts with other components of the diet, these interactions must also be considered in future studies. We believe that more complex mechanisms involving extraintestinal disorders (hormones, cytokines and other biomarkers) also need to be studied.

Consumption of Branched-Chain Amino Acids Is Inversely Associated with Central Obesity and Cardiometabolic Features in a Population of Brazilian Middle-Aged Men: Potential Role of Leucine Intake.

OBJECTIVE: To assess the potential associations of branched-chain amino acids (BCAA) consumption with central obesity (CObesity) and cardiometabolic risk factors in a population of Brazilian middle-aged men. Special attention was given to leucine intake. DESIGN: Cross-sectional study. SETTING: Universidade Federal de Viçosa, Viçosa, Brazil. PARTICIPANTS: Two-hundred ninety-six middle-aged men (Age: 50.5 ± 5.0 years; Body mass index: 25.8 ± 3.5 kg/m2). MEASUREMENTS: Anthropometry, lifestyle features, blood biochemical parameters were assessed and dietary intake was estimated by a food frequency questionnaire. Participants were classified by the occurrence of CObesity, hypertriglyceridemia (HTG), hypertriglyceridemic waist phenotype (HWP) and metabolic syndrome (MetS). RESULTS: Subjects in the BCAA highest tertile (≥0.17 g/kg/d) presented lower occurrence of CObesity (36.0% vs 72.4%, P<0.01, z=-5.10), HTG (17.0% vs 30.6% P<0.032, z=-2.32), HWP (23.0% vs 46.9%, P<0.01, z=-3.57) and MetS (19.0% vs 34.7%, P<0.01, z=-2.57). They also exhibited lower values for Castelli index (total cholesterol:HDL-c) and triglycerides: HDL-c ratio than those in the first tertile, regardless of interfering factors (i.e. habitual physical activity, work position, smoking habit, and energy intake). Interestingly, leucine consumption showed similar associations with cardiometabolic risk factors, as compared to BCAA consumption (P<0.05). CONCLUSION: BCAA consumption was cross-sectionally and negatively associated with relevant cardiometabolic risk factors in a population of Brazilian middle-aged men. The content of leucine in BCAA consumption may have contributed to such relationship.

Carotenoid consumption is related to lower lipid oxidation and DNA damage in middle-aged men.

The present cross-sectional study assessed the potential relationships of carotenoid intake with lipid and oxidative stress markers in middle-aged men. A total of 296 apparently healthy middle-aged men (mean age 50.5 (SD 5.0) years, BMI 25.8 (SD 3.5) kg/m(2)) were recruited to participate in the study. Dietary intake, anthropometry, blood pressure, lifestyle features, blood and urine biomarkers were assessed using validated procedures. The lipid markers included NEFA, Castelli index, and TAG:HDL ratio; oxidative stress markers included urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-iso-PGF2α and plasma oxidised-LDL (ox-LDL). We observed a significant inverse association (P < 0.05) between NEFA concentrations and consumption of lutein plus zeaxanthin, ß-carotene, α-carotene and total carotenoid, while Castelli index was negatively associated with daily intake of lycopene, ß-carotene and total carotenoids. Regarding oxidative stress biomarkers, urinary 8-OHdG and ox-LDL concentrations were also inversely associated (P < 0.05) with consumption of lycopene, lutein plus zeaxanthin, ß-carotene, α-carotene and total carotenoids, regardless of confounding variables. Moreover, there was a negative association of urinary 8-iso-PGF2α concentration with dietary lutein plus zeaxanthin (ß - 0.135, 95% CI - 0.268, - 0.001), ß-carotene (ß - 0.156, 95% CI - 0.277, - 0.034) and with the sum of all carotenoids (ß - 0.189, 95% CI - 0.333, - 0.046). In conclusion, total daily carotenoid intake based on five investigated carotenoid types (ß-cryptoxanthin, lycopene, lutein plus zeaxanthin, ß-carotene and α-carotene) was inversely associated with relevant lipid and oxidative stress markers in middle-aged men, with emphasis on ß-carotene that was negatively associated with five of the six lipid and oxidative stress markers evaluated in the present study.

Calcium ingestion and obesity control.

INTRODUCTION: Obesity is a risk factor for other nontransmissible chronic diseases. It has been suggested calcium intake helps to control obesity, but there is no consensus about this. OBJECTIVE: Analyze the studies published on this topic in order to highlight issues to be further explored in future studies. METHODS: A literature review was conducted using the PUBMED, Science Direct, Scielo, Scopus, Medline and CAPES electronic scientific basis. Studies, which evaluated the effect of calcium ingestion in energy metabolism, body weight, and body composition, published from 2000 through 2011, were analyzed. RESULTS AND DISCUSSION: The results of most of the interventional studies selected suggest that calcium ingestion may favor the reduction of the anthropometric measures and improve body composition. The discrepancy in the results of the observational studies is probably due to methodological differences. It seems that the benefits are only detected when a low calcium habitual ingestion (≈ 700 mg/day or lower) is increased to about 1,200-1,300 mg/day. CONCLUSION: When assessing the effect of calcium derived from supplements, the investigators should test higher bioavailability compounds. If the calcium source is the dairy product, it is necessary that to consider and isolate the impact of other nutrients present in these foods. Longer term studies should be conducted to assess the effect of calcium on energy metabolism.

Impact of different protein sources in the glycemic and insulinemic responses.

OBJECTIVE: The maintenance of normal blood glucose concentrations is a crucial factor to the achievement of a good health status throughout life. However, the occurrence of abnormalities in this parameter has become increasingly common, which can result in several non-transmissible diseases, such as type 2 diabetes and cardiovascular diseases. Therefore, the purpose of this study was to discuss the role of protein sources in the glycemic and insulinemic responses. METHODS: In this review paper, we critically analyzed recently published studies that discussed the role of different protein sources in the glycemic and insulinemic responses in healthy individuals and in those who have cardiovascular diseases or type 2 diabetes. RESULTS: The results of some of these studies suggest that the daily ingestion of at least one high protein meal containing low to moderate amounts of carbohydrate increases insulin secretion and glucose uptake, improving insulin sensitivity. Furthermore, the results indicate that these effects are particularly associated with the consumption of animal protein (p.e. hydrolyzed whey protein), which has a high content of branched-chain amino acids such as leucine, valine and others such as arginine, which leads to improvements in insulin secretion and uptake glucose, since it increases insulin sensitivity. However, there is still no consensus in the literature about the quantity and quality of protein capable of reducing or maintaining blood-glucose concentrations at the desirable range, without causing adverse effects. The difference in the results of the studies may be associated to methodological problems presented by these studies. CONCLUSIONS: Well designed studies should be conducted to identify the quantity and quality of protein that can lead to the improvement on blood glucose concentrations, without negative effects to health. These studies should also identify the mechanisms and the magnitude by which protein may affect glycemic response.

Ground roasted peanuts leads to a lower post-prandial glycemic response than raw peanuts.

INTRODUCTION: Few studies have evaluated the effect of nuts processing on the glycemic response and satiety. OBJECTIVE: To evaluate the effect of peanut processing on glycemic response, and energy and nutrients intake. METHOD: Thirteen healthy subjects (4 men and 9 women), with a mean age of 28.5 ± 10 years, BMI 22.7 ± 2.5 kg/m², and body fat 23.7 ± 5.7% participated in this randomized crossover clinical trial. After 10-12 h of fasting, one of the following types of test meals were consumed: raw peanuts with skin (RPS), roasted peanuts without skin, ground-roasted peanuts without skin (GRPWS) or control meal. The test meals had the same nutrient composition, and were consumed with 200 ml of water in 15 minutes. Glycemic response was evaluated 2 hours after each meal. Energy and nutrients intake were assessed through diet records reflecting the habitual food intake and food consumption 24 hours after the ingestion of test meal. RESULT: The area under the glycemic response curve after GRPWS was lower (p = 0.02) the one obtained for RPS. There was no treatment effect on energy intake, macronutrients and fiber consumption after the test meal. CONCLUSION: The consumption of ground-roasted peanuts may favor the control and prevention of diabetes due to its reduction on postprandial glucose response. However, more prospective studies are needed to confirm this hypothesis.

Effect of the diet components on adiponectin levels.

The prevalence of obesity has reached epidemic proportions worldwide, which requires nutritional interventions for its effective control. Adiponectin has antiinflammatory capacity, improves glucose tolerance and presents decreased plasma expression and concentration in obese individuals. Studies with animals reveal improvement in insulin resistance after the infusion of adiponectin; in humans, caloric restriction increases its levels. The present study aimed to analyze the effects of dietary components on gene expression and plasma concentration of adiponectin. Sixteen articles were found following a literature review--seven with interventions in animal models and nine in human. The results in animal models demonstrate that the consumption of hyperlipidemic diets, rich in saturated fat, reduces the levels of adiponectin, while the diets rich in polyunsaturated fatty acids and supplementation with omega-3 and eicosapentaenoic acid increase its gene expression and plasma levels. In humans, the consumption of a healthy and Mediterranean diet are positively associated with adiponectin levels, although the mechanisms are not fully understood. Due to the importance of adiponectin in preventing metabolic diseases and reducing cardiovascular risk, more research are needed on food strategies to promote the increase of adiponectin levels. Therefore, studies must be carried out to evaluate the response to different sources and levels of various dietary components and the safety of the supplementation of specific nutrients.

Peanut digestion and energy balance.

OBJECTIVE: To explore the effects of peanut consumption on fecal energy excretion with a balanced, non-vegetarian diet. DESIGN: Four arm parallel group design (that is, whole peanut (P), peanut butter (PB), peanut oil (PO) or peanut flour (PF) consumption) with one crossover (control and intervention). SUBJECTS: In total 63 healthy men and women from Ghana, Brazil and USA (N=15-16 per group) with an average body mass index of 21.8 kg m(-2). MEASUREMENTS: Percent fat of fecal wet weight daily energy excretion during the control and the treatment periods. RESULTS: Compared to control, the percentage of fat in the feces increased significantly for the P group (5.22+/-0.29%) relative to the other three groups ((PO=3.07+/-0.36%, PB=3.11+/-0.31% (P=0.001), and PF=3.75+/-0.40% (P=0.019)). The same findings held for kJ g(-1) of feces excreted. During the P supplementation period, the energy excretion was 21.4+/-1.0 kJ g(-1) versus 18.7+/-1.0 kJ g(-1) for PO (P=0.034), 18.8+/-0.7 kJ g(-1) for PB (P=0.042) and 18.5+/-0.8 kJ g(-1) for PF (P=0.028). CONCLUSION: Fecal fat and energy loss is greater with consumption of whole peanuts compared to peanut butter, oil or flour. This may contribute to the less than predicted change of body weight observed with peanut consumption. There were no cultural differences.