Mixed Spices at Culinary Doses Have Prebiotic Effects in Healthy Adults: A Pilot Study.
Plain language summary
An increasing body of evidence suggests that the gut microbiota has a profound impact on human health. While the microbiome of a healthy individual is relatively stable, gut microbial dynamics can be influenced by host lifestyle and dietary choices. The aim of this study was to investigate the effects of mixed spices (cinnamon, oregano, ginger, black pepper, and cayenne pepper) at culinary doses consumed over 2 weeks in a standardized 5g capsule on the production of gut microbiota and short-chain fatty acids The study is a randomised, placebo-controlled, double-blind pilot study carried out with a total of 31 healthy women and men aged between 18 and 65. The subjects were randomly allocated to one of the two intervention groups. Results indicate that daily intake of 5g of mixed spices for 2 weeks in healthy subjects resulted in a significant reduction in the relative abundance of the phylum Firmicutes (bacteria), and a trend of increasing in phylum Bacteroidetes (bacteria) as compared with a matched control group. Authors conclude that a mixture of spices at culinary doses affects the composition of gut microbiota.
undefined: Spices were used as food preservatives prior to the advent of refrigeration, suggesting the possibility of effects on microbiota. Previous studies have shown prebiotic activities in animals and in vitro, but there has not been a demonstration of prebiotic or postbiotic effects at culinary doses in humans. In this randomized placebo-controlled study, we determined in twenty-nine healthy adults the effects on the gut microbiota of the consumption daily of capsules containing 5 g of mixed spices at culinary doses by comparison to a matched control group consuming a maltodextrin placebo capsule. The 16S ribosomal RNA sequencing data were used for microbial characterization. Spice consumption resulted in a significant reduction in Firmicutes abundance ( < 0.033) and a trend of enrichment in Bacteroidetes ( < 0.097) compared to placebo group. Twenty-six operational taxonomic units (OTUs) were different between the spice and placebo groups after intervention. Furthermore, there was a significant negative correlation between fecal short-chain fatty acid propionate concentration and Firmicutes abundance in spice intervention group ( < 0.04). The production of individual fecal short-chain fatty acid was not significantly changed by spice consumption in this study. Mixed spices consumption significantly modified gut microbiota, suggesting a prebiotic effect of spice consumption at culinary doses.
A whole-grain diet reduces peripheral insulin resistance and improves glucose kinetics in obese adults: A randomized-controlled trial.
Metabolism: clinical and experimental. 2018;82:111-117
Plain language summary
Literature shows that dietary whole-grain intake is associated with a lower incidence of type 2 diabetes. The aim of the study was to investigate the association between a whole-grain diet and insulin resistance and glucose use in individuals at risk for type 2 diabetes. The study was a randomized, double-blind, controlled crossover trial involving fourteen middle-aged, obese adults at risk for diabetes. Randomisation was carried out prior to metabolic testing. Results indicate that whole-grain intake as part of a mixed-meal diet significantly improved post-prandial (after a meal) glucose metabolism in middle-aged obese adults. Furthermore, both whole-grain and refined-grain interventions induced about 3–6% weight and fat loss. Authors conclude that whole-grain intake effectively promotes glycaemic control by improving insulin action.
BACKGROUND Whole-grain intake is associated with lower risk of type 2 diabetes but the mechanisms are unclear. PURPOSE We tested the hypothesis that a WG diet reduces insulin resistance and improves glucose use in individuals at risk for type 2 diabetes compared with an isocaloric-matched refined-grain diet. METHODS A double-blind, randomized, controlled, crossover trial of 14 moderately obese adults (Age, 38 ± 2 y; BMI, 34.0 ± 1.1 kg/m ). Insulin resistance and glucose metabolism was assessed using an oral glucose tolerance test combined with isotopic tracers of [6,6- H ]-glucose and [U- C]-glucose, and indirect calorimetry. Peripheral and hepatic insulin resistance was assessed as 1/(rate of disposal/insulin), and endogenous glucose rates of appearance (R ) iAUC × insulin iAUC , respectively. Both diets met ADA nutritional guidelines and contained either whole-grain (50 g per 1000 kcal) or equivalent refined-grain. All food was provided for 8 wk. with an 8-10 wk. washout period between diets. RESULTS Post-prandial glucose tolerance, peripheral insulin sensitivity, and metabolic flexibility (insulin-stimulated - fasting carbohydrate oxidation) improvements were greater after whole-grain compared to the refined-grain diet (P < 0.05). Compared to baseline, body fat (~2 kg) and hepatic R insulin resistance was reduced by both diets, while fasting glucose and exogenous glucose-meal were unchanged after both interventions. Changes in peripheral insulin resistance and metabolic flexibility correlated with improved glucose tolerance (P < 0.05). CONCLUSION Whole-grains reduced diabetes risk and the mechanisms appear to work through reduced post-prandial blood glucose and peripheral insulin resistance that were statistically linked to enhanced metabolic flexibility.
Effects of n-3 fatty acids and exercise on oxidative stress parameters in type 2 diabetic: a randomized clinical trial.
Journal of the International Society of Sports Nutrition. 2018;15:18
Plain language summary
An elevated blood glucose level is one of the key metabolic abnormalities associated with complications in type 2 diabetes. Literature shows that individuals with type 2 diabetes have higher inflammatory levels than those with normal blood glucose tolerance. The aim of this study was to examine if omega-3 polyunsaturated fatty acid (PUFA) supplementation can reduce the inflammatory response associated with high-intensity exercise in type 2 diabetic individuals. This was a randomised, double-blind controlled study, which recruited 30 type 2 diabetic men and women aged between 30 and 60 years. Results indicate that after 8 weeks, omega-3 PUFA supplementation diminished the concentration of the total reactive antioxidant potential and triglyceride levels after high intensity exercise, however did not reduce the inflammatory response.
Background: The relationship between diabetes and oxidative stress has been previously reported. Exercise represents a useful non-pharmacological strategy for the treatment in type 2 diabetic (T2DM) patients, but high intensity exercise can induce a transient inflammatory state and increase oxidative stress. Nutritional strategies that may contribute to the reduction of oxidative stress induced by acute exercise are necessary. The aim of this study was to examine if n-3 PUFA supplementation intervention can attenuate the inflammatory response and oxidative stress associated with high intensity exercise in this population. As a primary outcome, lipoperoxidation measurements (TBARS and F2-isoprostanes) were selected. Methods: Thirty T2DM patients, without chronic complications, were randomly allocated into two groups: placebo (gelatin capsules) or n-3 PUFA (capsules containing 180 mg of eicosapentaenoic acid and 120 mg of docosahexaenoic acid). Blood samples were collected fasting before and after 8 weeks supplementation. In the beginning and at the end of protocol, an acute exercise was performed (treadmill), and new blood samples were collected before and immediately after the exercise for measurements of oxidative stress and high-sensitivity C-reactive protein (hs-CRP). Results: After the supplementation period, a decrease in triglycerides levels was observed only in n-3 PUFA supplementation group (mean difference and 95% CI of 0.002 (0.000-0.004), = 0.005). Supplementation also significantly reduced TRAP levels after exercise (mean difference and 95% CI to 9641 (- 20,068-39,351) for - 33,884 (- 56,976 - -10,793), = 0.004, Cohen's effect size = 1.12), but no significant difference was observed in n-3 PUFA supplementation group in lipoperoxidation parameters as TBARS (mean difference and 95% CI to - 3.8 (- 10-2.4) for - 2.9 (- 1.6-7.4) or F2-isoprostanes (mean difference and 95% CI -0.05 (- 0.19-0.10) for - 0.02 (- 0.19-0.16), > 0.05 for both. Conclusion: PUFA n-3 supplementation reduced triglycerides as well as TRAP levels after exercise, without a significant effect on inflammatory and oxidative stress markers.This study is registered at ClinicalTrials.gov with the registration number of NCT03182712.
Untargeted metabolomic on urine samples after α-lipoic acid and/or eicosapentaenoic acid supplementation in healthy overweight/obese women.
Lipids in health and disease. 2018;17(1):103
Plain language summary
Eicosapentaenoic acid (EPA - an omega-3 fatty acid) and alpha-lipoic acid (an antioxidant) have both been investigated for their beneficial impacts on weight loss and heart health. The aim of this double-blind randomised placebo-controlled intervention lasting 8 weeks was to assess the effect of dietary supplementation with EPA and alpha-lipoic acid, separately or in combination, and together with a calorie restricted diet, on breakdown products (metabolites) present in the urine. The study recruited a group of 70 healthy overweight/obese sedentary females. Results indicate a higher reduction in body mass index and fat mass in those groups supplemented with alpha-lipoic acid. EPA supplementation had no effect on urinary breakdown products. Authors conclude that alpha-lipoic acid administration has beneficial effects on body weight reduction, mainly through its antioxidant properties.
BACKGROUND Eicosapentaenoic acid (EPA) and α-lipoic acid (α-LA) have been investigated for their beneficial effects on obesity and cardiovascular risk factors. In the current research, the goal was to evaluate metabolomic changes following the dietary supplementation of these two lipids, alone or combined in healthy overweight/obese sedentary women following an energy-restricted diet. For this purpose, an untargeted metabolomics approach was conducted on urine samples using liquid chromatography coupled with time of flight mass spectrometry (HPLC-TOF-MS). METHODS This is a short-term double blind placebo-controlled study with a parallel nutritional design that lasted 10 weeks. Participants were assigned to one of the 4 experimental groups [Control, EPA (1.3 g/d), α-LA (0.3 g/d) and EPA+α-LA (1.3 g/d + 0.3 g/d)]. All intervention groups followed an energy-restricted diet of 30% less than total energy expenditure. Clinically relevant biochemical measurements were analyzed. Urine samples (24 h) were collected at baseline and after 10 weeks. Untargeted metabolomic analysis on urine samples was carried out, and principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were performed for the pattern recognition and characteristic metabolites identification. RESULTS Urine samples were scattered in the PCA scores plots in response to the supplementation with α-LA. Totally, 28 putative discriminant metabolites in positive ionization, and 6 in negative ionization were identified among groups clearly differentiated according to the α-LA administration. Remarkably is the presence of an ascorbate intermediate metabolite (one of the isomers of trihydroxy-dioxohexanoate, or dihydroxy-oxohexanedionate) in the groups supplemented with α-LA. This fact might be associated with antioxidant properties of both α-LA and ascorbic acid. Correlations between phenotypical parameters and putative metabolites of provided additional information on whether there is a direct or inverse relationship between them. Especially interesting are the negative correlation between ascorbate intermediate metabolite and asymmetric dimethylarginine (ADMA) and the positive one between superoxide dismutase (SOD) and α-LA supplementation. CONCLUSIONS This metabolomic approach supports that the beneficial effects of α-LA administration on body weight reduction may be partly explained by the antioxidant properties of this organosulfur carboxylic acid mediated by isomers of trihydroxy-dioxohexanoate, or dihydroxy-oxohexanedionate. TRIAL REGISTRATION Clinicaltrials.gov NCT01138774 .
Effects of green tea supplementation on elements, total antioxidants, lipids, and glucose values in the serum of obese patients.
Biological trace element research. 2012;149(3):315-22
Plain language summary
Obesity is associated with low-grade inflammation and oxidative stress, both of which play roles in the development of many obesity-related diseases and metabolic imbalances. Previous studies show that green tea (GT) supplementation may have favourable effects on body weight and body composition, and there’s growing evidence for its use in the prevention of obesity and coexisting diseases. The aim of this randomised double-blind trial was to assess the effects of supplementation with GT extract on body mass, glucose levels, mineral concentrations, lipid profile and antioxidant status in obese patients. The study included 46 obese participants, who received either 379 mg GT extract or placebo daily for three months. The study found that 3-month supplementation with GT extract significantly decreased body mass index, waist circumference, total cholesterol, LDL cholesterol, triglycerides, glucose and iron levels, while the levels of HDL cholesterol, total anti-oxidants, magnesium and zinc were increased. The authors conclude that GT extract may be beneficial in improving antioxidant and mineral status, body mass index, lipid profile and glucose levels in obese people.
The consumption of green tea has been associated with cardiovascular and metabolic diseases. There have been some studies on the influence of green tea on the mineral status of obese subjects, but they have not yielded conclusive results. The aim of the present study is to examine the effects of green tea extract on the mineral, body mass, lipid profile, glucose, and antioxidant status of obese patients. A randomized, double-blind, placebo-controlled study was conducted. Forty-six obese patients were randomly assigned to receive either 379 mg of green tea extract, or a placebo, daily for 3 months. At baseline, and after 3 months of treatment, the anthropometric parameters, blood pressure, and total antioxidant status were assessed, as were the levels of plasma lipids, glucose, calcium, magnesium, iron, zinc, and copper. We found that 3 months of green tea extract supplementation resulted in decreases in body mass index, waist circumference, and levels of total cholesterol, low-density cholesterol, and triglyceride. Increases in total antioxidant level and in zinc concentration in serum were also observed. Glucose and iron levels were lower in the green tea extract group than in the control, although HDL-cholesterol and magnesium were higher in the green tea extract group than in the placebo group. At baseline, a positive correlation was found between calcium and body mass index, as was a negative correlation between copper and triglycerides. After 3 months, a positive correlation between iron and body mass index and between magnesium and HDL-cholesterol, as well as a negative correlation between magnesium and glucose, were observed. The present findings demonstrate that green tea influences the body's mineral status. Moreover, the results of this study confirm the beneficial effects of green tea extract supplementation on body mass index, lipid profile, and total antioxidant status in patients with obesity.
Sex and menopausal status influence human dietary requirements for the nutrient choline.
The American journal of clinical nutrition. 2007;85(5):1275-85
Plain language summary
Choline is used to form cell membranes, and it is a precursor for the neurotransmitter acetylcholine. Other than from the diet, choline can also be derived from the de novo biosynthesis of phosphatidylcholine. The current Adequate Intake for choline is considered sufficient to prevent deficiency, however an Estimated Average Requirement cannot be generated due to lack of availability of adequate human data. The aim of this study was to evaluate the dietary choline requirement in healthy men and women (pre- and postmenopausal), and to identify the clinical and metabolic sequelae of choline deficiency. Fifty-seven adult participants (26 healthy men, 16 premenopausal women and 15 postmenopausal women) were recruited for the study. A randomised double-blind protocol was followed to assign participants in one of the 2 arms; folate only (100 DFE) vs a dietary supplement of 400μg folic acid/d (768 DFE). Results show that independent of folate status, most men and postmenopausal women developed liver or muscle dysfunction when fed a low-choline diet, whereas premenopausal women were more resistant to developing such organ dysfunction. AP activity increased in all subjects in response to the low-choline diet regardless of whether they manifested organ dysfunction. Liver and muscle dysfunction occurred in response to a low-choline diet in both men and women. The current AI for choline was not be sufficient for some of the participants who became depleted despite this level of intake.
BACKGROUND Although humans require dietary choline for methyl donation, membrane function, and neurotransmission, choline can also be derived from the de novo synthesis of phosphatidylcholine, which is up-regulated by estrogen. A recommended Adequate Intake (AI) exists for choline; however, an Estimated Average Requirement has not been set because of a lack of sufficient human data. OBJECTIVE The objective of the study was to evaluate the dietary requirements for choline in healthy men and women and to investigate the clinical sequelae of choline deficiency. DESIGN Fifty-seven adult subjects (26 men, 16 premenopausal women, 15 postmenopausal women) were fed a diet containing 550 mg choline x 70 kg(-1) x d(-1) for 10 d followed by <50 mg choline x 70 kg(-1) x d(-1) with or without a folic acid supplement (400 microg/d per randomization) for up to 42 d. Subjects who developed organ dysfunction during this diet had normal organ function restored after incremental amounts of choline were added back to the diet. Blood and urine were monitored for signs of toxicity and metabolite concentrations, and liver fat was assessed by using magnetic resonance imaging. RESULTS When deprived of dietary choline, 77% of men and 80% of postmenopausal women developed fatty liver or muscle damage, whereas only 44% of premenopausal women developed such signs of organ dysfunction. Moreover, 6 men developed these signs while consuming 550 mg choline x 70 kg(-1) x d(-1), the AI for choline. Folic acid supplementation did not alter the subjects' response. CONCLUSION Subject characteristics (eg, menopausal status) modulated the dietary requirement for choline, and a daily intake at the current AI was not sufficient to prevent organ dysfunction in 19 of the subjects.