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Impact of α-Linolenic Acid, the Vegetable ω-3 Fatty Acid, on Cardiovascular Disease and Cognition.
Sala-Vila, A, Fleming, J, Kris-Etherton, P, Ros, E
Advances in nutrition (Bethesda, Md.). 2022;13(5):1584-1602
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α-Linolenic acid (ALA) is an omega-3 fatty acid found in seeds and nuts such as flaxseeds, chia seeds, and walnuts and in oils such as canola oil, soybean oil, flaxseed oil and walnut oil. It has been shown to reduce the risk of coronary heart disease and cardiovascular disease. This meta-analysis examined the results of various studies, including epidemiologic studies, randomized controlled trials, and systematic reviews, to evaluate the beneficial effects of ALA in improving cognitive function and reducing the risk of cardiovascular disease and coronary heart disease. The included studies showed a correlation between ALA intake and a decreased risk of cardiovascular disease and coronary heart disease, possibly due to ALA's anti-inflammatory properties, as well as its ability to reduce total cholesterol, LDL cholesterol, triglycerides, and blood pressure. The analysis also found that ALA intake may reduce the risk of type 2 diabetes and cognitive impairment. Healthcare professionals can leverage the findings of this analysis to educate individuals about the benefits of dietary ALA in improving cardiovascular and cognitive outcomes. However, further studies are necessary to establish definitive conclusions and determine therapeutic dosage.
Abstract
Given the evidence of the health benefits of plant-based diets and long-chain n-3 (ω-3) fatty acids, there is keen interest in better understanding the role of α-linolenic acid (ALA), a plant-derived n-3 fatty acid, on cardiometabolic diseases and cognition. There is increasing evidence for ALA largely based on its major food sources (i.e., walnuts and flaxseed); however, this lags behind our understanding of long-chain n-3 fatty acids. Meta-analyses of observational studies have shown that increasing dietary ALA is associated with a 10% lower risk of total cardiovascular disease and a 20% reduced risk of fatal coronary heart disease. Three randomized controlled trials (RCTs) [AlphaOmega trial, Prevención con Dieta Mediterránea (PREDIMED) trial, and Lyon Diet Heart Study] all showed benefits of diets high in ALA on cardiovascular-related outcomes, but the AlphaOmega trial, designed to specifically evaluate ALA effects, only showed a trend for benefit. RCTs have shown that dietary ALA reduced total cholesterol, LDL cholesterol, triglycerides, and blood pressure, and epidemiologic studies and some trials also have shown an anti-inflammatory effect of ALA, which collectively account for, in part, the cardiovascular benefits of ALA. A meta-analysis reported a trend toward diabetes risk reduction with both dietary and biomarker ALA. For metabolic syndrome and obesity, the evidence for ALA benefits is inconclusive. The role of ALA in cognition is in the early stages but shows promising evidence of counteracting cognitive impairment. Much has been learned about the health benefits of ALA and with additional research we will be better positioned to make strong evidence-based dietary recommendations for the reduction of many chronic diseases.
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Eight-hour time-restricted feeding improves endocrine and metabolic profiles in women with anovulatory polycystic ovary syndrome.
Li, C, Xing, C, Zhang, J, Zhao, H, Shi, W, He, B
Journal of translational medicine. 2021;19(1):148
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Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine and metabolic disorders that affects up to 10% women of childbearing age. The aim of this study was to explore the effects of time-restricted feeding (TRF) on menstruation, gonadal and metabolic parameters in women with anovulatory PCOS and propose a basis for its inclusion in the treatment of PCOS. This study is a 6-week trial with 2 consecutive periods: (1) 1-week baseline weight stabilization period; and (2) 5-week TRF period. Fifteen subjects were included in the study whose age varied between 18 and 31 years. Results show that five weeks of TRF improved menstruation, gonadal profiles, body weight, body mass index, body composition profiles, hyperinsulinemia and insulin resistance profiles, decreasing chronic inflammation markers and increasing insulin growth factor –1 [hormone]. Authors conclude that TRF may be suitable for PCOS women with appropriate counselling and patient management.
Abstract
BACKGROUND Time-restricted feeding (TRF) is a form of intermittent fasting, which is beneficial for weight loss and cardiometabolic health. Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine and metabolic diseases affecting women of childbearing age. It is associated with an increased prevalence of metabolic syndrome, cardiovascular diseases and type 2 diabetes. The effects of TRF on PCOS patients remains undefined, here we investigated the impact of TRF on women with anovulatory PCOS. METHODS Eighteen PCOS women aged between 18 and 31 with anovulation participated in a 6-week trial which were divided into two consecutive periods: (1) 1-week baseline weight stabilization period and (2) 5-week TRF period. Fifteen participants completed the study. Changes in body weight, body mass index (BMI), Waist-to-Hip Ratio, skeletal muscle mass, body fat mass (BFM), body fat percentage (BF%), visceral fat area (VFA), luteinizing hormone (LH), follicle-stimulating hormone (FSH), LH/FSH, total testosterone (TT), sex hormone-binding globulin (SHBG), free androgen index (FAI), fasting glucose, fasting insulin (FINS), homeostasis model assessment-insulin resistance (HOMA-IR), area under the curve (AUC) for insulin (AUCIns), area under the curve (AUC) for glucose (AUCGlu), AUCIns/AUCGlu Ratio, lipids, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase, high-sensitivity C-reactive protein (hsCRP), insulin-like growth factor (IGF-1), menstrual cycle and eating behaviors were evaluated. RESULTS Significant changes in body weight, BMI, BFM, BF%, VFA, TT, SHBG, FAI, FINS, HOMA-IR, AUCIns, AUCIns/AUCGlu Ratio, ALT, hsCRP and IGF-1 were found after the TRF period. An improvement in menstrual cycle irregularity was detected in 73.3% (11/15) patients. CONCLUSION The diet of TRF may be beneficial to anovulatory PCOS on weight loss especially reducing body fat, improving menstruation, hyperandrogenemia, insulin resistance and chronic inflammation. Trial registration Clinicaltrial.gov, NCT04580433, registered October 8, 2020, https://clinicaltrials.gov/ct2/show/NCT04580433.
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Effect of a Nutritional and Behavioral Intervention on Energy-Reduced Mediterranean Diet Adherence Among Patients With Metabolic Syndrome: Interim Analysis of the PREDIMED-Plus Randomized Clinical Trial.
Sayón-Orea, C, Razquin, C, Bulló, M, Corella, D, Fitó, M, Romaguera, D, Vioque, J, Alonso-Gómez, ÁM, Wärnberg, J, Martínez, JA, et al
JAMA. 2019;322(15):1486-1499
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Excess caloric intake and poor nutritional quality are associated with overweight and obesity. A traditional Mediterranean diet has been shown to reduce all-cause mortality, and in particular to reduce risk of cardiovascular disease, type 2 diabetes mellitus and overweight. The aim of this randomised, prospective, single-blinded study was to evaluate the effectiveness of an intensive lifestyle intervention programme in 6874 overweight or obese men and women with metabolic syndrome in Spain. The intervention group was advised on an energy-reduced Mediterranean diet and exercise and received behavioural support, with initial group sessions and interviews, and monthly follow-up phone calls for one year. The control group received advice on a Mediterranean diet and usual care, with 6 monthly follow-ups. After 12 months, the more intensively counselled patients showed a significantly better adherence to an energy-reduced Mediterranean diet than the control group. They had greater reductions in refined grains, pastries, red and processed meats and greater increases in vegetable, fruit and nut consumption than the control group. The intervention group had also better improvements in cardiovascular risk factors.
Abstract
Importance: High-quality dietary patterns may help prevent chronic disease, but limited data exist from randomized trials about the effects of nutritional and behavioral interventions on dietary changes. Objective: To assess the effect of a nutritional and physical activity education program on dietary quality. Design, Setting, and Participants: Preliminary exploratory interim analysis of an ongoing randomized trial. In 23 research centers in Spain, 6874 men and women aged 55 to 75 years with metabolic syndrome and no cardiovascular disease were enrolled in the trial between September 2013 and December 2016, with final data collection in March 2019. Interventions: Participants were randomized to an intervention group that encouraged an energy-reduced Mediterranean diet, promoted physical activity, and provided behavioral support (n = 3406) or to a control group that encouraged an energy-unrestricted Mediterranean diet (n = 3468). All participants received allotments of extra-virgin olive oil (1 L/mo) and nuts (125 g/mo) for free. Main Outcomes and Measures: The primary outcome was 12-month change in adherence based on the energy-reduced Mediterranean diet (er-MedDiet) score (range, 0-17; higher scores indicate greater adherence; minimal clinically important difference, 1 point). Results: Among 6874 randomized participants (mean [SD] age, 65.0 [4.9] years; 3406 [52%] men), 6583 (96%) completed the 12-month follow-up and were included in the main analysis. The mean (SD) er-MedDiet score was 8.5 (2.6) at baseline and 13.2 (2.7) at 12 months in the intervention group (increase, 4.7 [95% CI, 4.6-4.8]) and 8.6 (2.7) at baseline and 11.1 (2.8) at 12 months in the control group (increase, 2.5 [95% CI, 2.3-2.6]) (between-group difference, 2.2 [95% CI, 2.1-2.4]; P < .001). Conclusions and Relevance: In this preliminary analysis of an ongoing trial, an intervention that encouraged an energy-reduced Mediterranean diet and physical activity, compared with advice to follow an energy-unrestricted Mediterranean diet, resulted in a significantly greater increase in diet adherence after 12 months. Further evaluation of long-term cardiovascular effects is needed. Trial Registration: isrctn.com Identifier: ISRCTN89898870.
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Dietary fiber intake and glycemic control: coronary artery calcification in type 1 diabetes (CACTI) study.
Basu, A, Alman, AC, Snell-Bergeon, JK
Nutrition journal. 2019;18(1):23
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The incidence of type 1 diabetes and cardiovascular disease, the major vascular complication of diabetes, have been increasing wordwide. The aim of the study is to identify the associations of dietary fibre with glycaemic control. The study is a cross-sectional longitudinal study which enrolled 1257 individuals in the cross-sectional analysis and a total of 990 participants were included in the longitudinal analysis. The participants had no known history of coronary heart disease. Results indicate an inverse association between total fibre intake and the average blood glucose levels for the last two to three months in both diabetic and nondiabetic participants. Authors conclude that their study provides some evidence on the role dietary fibre intake plays on glycaemic control, which is important in the management of type 1 diabetes in patients at high risk of cardiovascular disease.
Abstract
BACKGROUND Dietary fiber has been recommended for glucose control, and typically low intakes are observed in the general population. The role of fiber in glycemic control in reported literature is inconsistent and few reports are available in populations with type 1 diabetes (T1D). METHODS Using data from the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study [n = 1257; T1D: n = 568; non-diabetic controls: n = 689] collected between March 2000 and April 2002, we examined cross-sectional (baseline) and longitudinal (six-year follow-up in 2006-2008) associations of dietary fiber and HbA1c. Participants completed a validated food frequency questionnaire, and a physical examination and fasting biochemical analyses (12 h fast) at baseline visit and at the year 6 visit. We used a linear regression model stratified by diabetes status, and adjusted for age, sex and total calories, and diabetes duration in the T1D group. We also examined correlations of dietary fiber with HbA1c. RESULTS Baseline dietary fiber intake and serum HbA1c in the T1D group were 16 g [median (IQ): 11-22 g) and 7.9 ± 1.3% mean (SD), respectively, and in the non-diabetic controls were 15 g [median (IQ): 11-21 g) and 5.4 ± 0.4%, respectively. Pearson partial correlation coefficients revealed a significant but weak inverse association of total dietary fiber with HbA1c when adjusted for age, sex, diabetes status and total calories (r = - 0.07, p = 0.01). In the adjusted linear regression model at baseline, total dietary fiber revealed a significant inverse association with HbA1c in the T1D group [β ± SE = - 0.32 ± 0.15, p = 0.034], as well as in the non-diabetic controls [- 0.10 ± 0.04, p = 0.009]. However, these results were attenuated after adjustment for dietary carbohydrates, fats and proteins, or for cholesterol and triglycerides. No such significance was observed at the year 6 follow-up, and with the HbA1c changes over 6 years. CONCLUSION Thus, at observed levels of intake, total dietary fiber reveals modest inverse associations with poor glycemic control. Future studies must further investigate the role of overall dietary quality adjusting for fiber-rich foods in T1D management.
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Men and women respond differently to rapid weight loss: Metabolic outcomes of a multi-centre intervention study after a low-energy diet in 2500 overweight, individuals with pre-diabetes (PREVIEW).
Christensen, P, Meinert Larsen, T, Westerterp-Plantenga, M, Macdonald, I, Martinez, JA, Handjiev, S, Poppitt, S, Hansen, S, Ritz, C, Astrup, A, et al
Diabetes, obesity & metabolism. 2018;20(12):2840-2851
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Overweight and obesity are major risk factors for developing type 2 diabetes mellitus. Men and women respond differently to weight loss programmes, with men typically losing more weight and more abdominal fat, whilst women lose more subcutaneous fat. The aim of this large multinational study was to compare the effects of weight loss induced by an 8‐week low energy diet on metabolic outcomes in overweight men and women with prediabetes. Study participants followed the Cambridge Weight Plan which is based on four formula meals, with a total of approximately 810kcal, per day, for eight weeks. Small amounts of non-starchy vegetables were allowed, as were psyllium husks in case of digestive problems. Men lost significantly more weight than women, 11.8% versus 10.3%. Insulin resistance improved similarly in men and women, but metabolic syndrome score improved more in men than in women. Men lost more fat than women and generally had more beneficial metabolic changes. Women had higher reductions in fat-free mass, bone mineral content and HDL cholesterol than men, raising the question whether rapid weight loss may have negative longer term effects for women.
Abstract
AIMS: The PREVIEW lifestyle intervention study (ClinicalTrials.gov Identifier: NCT01777893) is, to date, the largest, multinational study concerning prevention of type-2 diabetes. We hypothesized that the initial, fixed low-energy diet (LED) would induce different metabolic outcomes in men vs women. MATERIALS AND METHODS All participants followed a LED (3.4 MJ/810 kcal/daily) for 8 weeks (Cambridge Weight Plan). Participants were recruited from 8 sites in Europe, Australia and New Zealand. Those eligible for inclusion were overweight (BMI ≥ 25 kg/m2 ) individuals with pre-diabetes according to ADA-criteria. Outcomes of interest included changes in insulin resistance, fat mass (FM), fat-free mass (FFM) and metabolic syndrome Z-score. RESULTS In total, 2224 individuals (1504 women, 720 men) attended the baseline visit and 2020 (90.8%) completed the follow-up visit. Following the LED, weight loss was 16% greater in men than in women (11.8% vs 10.3%, respectively) but improvements in insulin resistance were similar. HOMA-IR decreased by 1.50 ± 0.15 in men and by 1.35 ± 0.15 in women (ns). After adjusting for differences in weight loss, men had larger reductions in metabolic syndrome Z-score, C-peptide, FM and heart rate, while women had larger reductions in HDL cholesterol, FFM, hip circumference and pulse pressure. Following the LED, 35% of participants of both genders had reverted to normo-glycaemia. CONCLUSIONS An 8-week LED induced different effects in women than in men. These findings are clinically important and suggest gender-specific changes after weight loss. It is important to investigate whether the greater decreases in FFM, hip circumference and HDL cholesterol in women after rapid weight loss compromise weight loss maintenance and future cardiovascular health.
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Weight loss and metabolic health effects from energy-restricted Mediterranean and Central-European diets in postmenopausal women: A randomized controlled trial.
Bajerska, J, Chmurzynska, A, Muzsik, A, Krzyżanowska, P, Mądry, E, Malinowska, AM, Walkowiak, J
Scientific reports. 2018;8(1):11170
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During menopause women commonly gain weight, in particular around the waist. This abdominal obesity is a risk factor for diabetes and heart disease. The aim of this randomised trial in Poland was to compare the effectiveness of two energy-restricted diets on weight loss and metabolic syndrome (MetS) in post-menopausal women with abdominal obesity and at least one other marker for MetS. The diets used were the Mediterranean diet (MED), which is moderate in fat, in particular mono-unsaturated fat, and the so-called Central European diet (CED), which is low in fat, moderate in carbohydrates, and high in dietary fiber (DF) derived from central European food items. Participants were counselled on their respective diet plans and provided with one prepared main meal per day and followed their diet for 16 weeks. Both groups had a significant weight loss (7.5kg MED, 7.7kg CED), reductions in waist circumference (7.4cm both), fat mass and abdominal fat. Both groups also had significant improvements in blood sugar control, blood pressure, homocysteine and triglycerides but not in LDL and HDL cholesterol. There were no significant differences between groups for any of the outcomes. Adherence to the respective diets decreased over the course of the study for both the MED and the CED and weight loss was highest for those who adhered best to the respective diet. The authors concluded that short-term dietary treatment using the CED or the MED was associated with similar improvements in weight and markers of MetS.
Abstract
We conducted a randomized controlled trial to examine the effect of two energy-restricted diets on body weight (BW), visceral fat (VF) loss, and the risk factors for metabolic syndrome. A total of 144 centrally obese postmenopausal women were assigned to the moderate in fat Mediterranean diet (MED) or to the Central European diet (CED), which is moderate in carbohydrates and high in dietary fiber (DF), for 16 weeks. BW, waist circumference and VF were significantly reduced by 8.8%, 7.0%, and 24.6%, respectively, over the trial (P < 0.001), with no difference between groups. A similar trend was seen for total cholesterol, triglycerides, glucose, and blood pressure. Within each diet group, the more adherent participants lost significantly more BW than did their less adherent counterparts. VF was significantly reduced only in women who were more adherent to the CED, and the reduction in VF correlated with an increase in the proportion of DF. Short-term dietary treatment with the CED or the MED was associated with similar improvements in some anthropometric, lipid, and nonlipid parameters; however, adequate adherence to the prescribed diet is important in weight loss success and in achieving improvements in metabolic health.
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Effect of Vitamin D Supplementation on Obesity-Induced Insulin Resistance: A Double-Blind, Randomized, Placebo-Controlled Trial.
Cefalo, CMA, Conte, C, Sorice, GP, Moffa, S, Sun, VA, Cinti, F, Salomone, E, Muscogiuri, G, Brocchi, AAG, Pontecorvi, A, et al
Obesity (Silver Spring, Md.). 2018;26(4):651-657
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Vitamin D concentration has been inversely associated with impaired glucose regulation, insulin resistance and risk of metabolic dysfunction. The aim of the study was to evaluate whether Vitamin D supplementation could improve insulin sensitivity in patients with a high risk of diabetes. The study is a randomised, double-blind, placebo-controlled trial. The participants with obesity were supplemented with Vitamin D or placebo on top of a hypocaloric diet. Results indicate that Vitamin D supplementation combined with weight loss is linked with a significant improvement in insulin sensitivity in vitamin D deficient participants with obesity.
Abstract
OBJECTIVE The aim was to investigate whether vitamin D supplementation, combined with a hypocaloric diet, could have an independent effect on insulin sensitivity in subjects with both overweight and hypovitaminosis D. Changes from baseline in anthropometric parameters, body composition, glucose tolerance, and insulin secretion were considered as secondary outcomes. METHODS Eighteen volunteers who were nondiabetic and vitamin D deficient and had BMI > 25 kg/m2 were randomized (1:1) in a double-blind manner to a hypocaloric diet + either oral cholecalciferol at 25,000 IU/wk or placebo for 3 months. Hyperinsulinemic-euglycemic clamp to measure insulin sensitivity was performed at baseline and after intervention. RESULTS Body weight in both groups decreased significantly (-7.5% in the vitamin D group and -10% in the placebo group; P < 0.05 for both), with no between-group differences. Serum 25-hydroxyvitamin D levels in the vitamin D group increased considerably (from 36.7 ± 13.2 nmol/L to 74.8 ± 18.7 nmol/L; P < 0.001). Insulin sensitivity in the vitamin D group improved (from 4.6 ± 2.0 to 6.9 ± 3.3 mg·kg-1 ·min-1 ; P < 0.001), whereas no changes were observed in the placebo group (from 4.9 ± 1.1 to 5.1 ± 0.3 mg·kg-1 ·min-1 ; P = 0.84). CONCLUSIONS Cholecalciferol supplementation, combined with a weight loss program, significantly improves insulin sensitivity in healthy subjects with obesity and might represent a personalized approach for insulin-resistant subjects with obesity.
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Improvement of Nonalcoholic Fatty Liver Disease With Carnitine-Orotate Complex in Type 2 Diabetes (CORONA): A Randomized Controlled Trial.
Bae, JC, Lee, WY, Yoon, KH, Park, JY, Son, HS, Han, KA, Lee, KW, Woo, JT, Ju, YC, Lee, WJ, et al
Diabetes care. 2015;38(7):1245-52
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Non-alcoholic fatty liver disease (NAFLD) is recognized as the hepatic component of metabolic syndrome, and it is associated with insulin resistance independent of obesity and other metabolic components. Carnitine is a modulator of mitochondrial free fatty acid transport and oxidation, and several studies have demonstrated the antioxidant activity of carnitine in hepatocytes. The aim of this study was to evaluate the effects of carnitine-orotate complex in patients with NAFLD and diabetes. This study is a multicentre, randomised, double-blind, placebo-controlled trial. Patients were randomly assigned to receive carnitine-orotate complex or placebo during the 12-week treatment period. Results show that treatment with carnitine-orotate complex improves hepatic steatosis in patients with diabetes and NAFLD, and has a beneficial effect on glucose metabolism, particularly in relation to improvement of hepatic steatosis. Authors conclude that further studies using more advanced magnetic resonance imaging and liver histology as an end point are needed to assess its efficacy in NAFLD.
Abstract
OBJECTIVE We aimed to evaluate the effects of carnitine-orotate complex in patients with nonalcoholic fatty liver disease (NAFLD) and diabetes. RESEARCH DESIGN AND METHODS Eight hospitals in Korea participated in this randomized, controlled, double-blind trial of patients with diabetes and NAFLD. Seventy-eight patients were randomly assigned in a 1:1 ratio to receive carnitine-orotate complex (824 mg, three times daily) or matching placebo. The primary study outcome was decline in alanine aminotransferase (ALT) to the normal range. Secondary study outcomes were change in ALT, radiological hepatic steatosis, parameters for anthropometry, liver function, lipid profiles, and glycemic control. Hepatic steatosis was assessed using Hounsfield units on noncontrast computed tomography (CT) imaging with hepatic attenuation. RESULTS After 12 weeks of treatment, compared with placebo group, carnitine-orotate complex-treated participants had a significantly higher rate of normalization of serum ALT level (17.9% vs. 89.7%, P < 0.001). On hepatic CT analysis, participants treated with carnitine-orotate complex showed an increased liver attenuation index (0.74 ± 8.05 vs. 6.21 ± 8.96, P < 0.008). A significant decrease in HbA1c was observed in the carnitine-orotate complex group (-0.33 ± 0.82% [-3.6 ± 9.0 mmol/mol], P = 0.007), but no significant change was seen in the placebo group. CONCLUSIONS Treatment with carnitine-orotate complex improves serum ALT and may improve hepatic steatosis as assessed by CT in patients with diabetes and NAFLD. Further studies using more advanced magnetic resonance imaging and liver histology as an end point are needed to assess its efficacy in NAFLD.
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Favourable effects of consuming a Palaeolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-study.
Boers, I, Muskiet, FA, Berkelaar, E, Schut, E, Penders, R, Hoenderdos, K, Wichers, HJ, Jong, MC
Lipids in health and disease. 2014;13:160
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The prevalence of metabolic syndrome (MetS) is increasing rapidly worldwide and is a major risk factor for type 2 diabetes (DM2) and cardiovascular disease (CVD). Modern lifestyle-induced insulin resistance and chronic systemic low grade inflammation are considered at the root of the MetS. Therefore, dietary patterns of our Palaeolithic ancestors may be ideal for prevention and treatment of metabolic disorders since they are thought to be in line with the evolution of human physiology and metabolism. The aim of this randomized controlled pilot study was to assess the efficacy of a Palaeolithic-type diet in improving the characteristics of MetS, compared to a diet based on healthy eating guidelines. The study included 34 participants with MetS who consumed their allocated diets for two weeks. Efforts were made to prevent weight loss so that any favourable effects could be explained by the dietary intervention and not by the positive health effects of weight loss. The findings of this study showed that the Palaeolithic-type diet significantly lowered blood pressure, total cholesterol and triglycerides, as well as improved HDL-cholesterol, compared to the reference diet. The participants in the Palaeolithic diet intervention also had fewer characteristics of MetS and a tendency to higher insulin sensitivity at the end of the study. Despite efforts to keep body-weight stable, more weight was lost by the participants in the Palaeolithic group. No changes were observed in the secondary outcomes of inflammation, intestinal permeability and salivary cortisol, which the authors explain by the short duration of the intervention and the attempt to prevent weight loss. The authors conclude that future studies should take full additional advantage of the greater weight loss with the Palaeolithic diet, which may be more satiating than other diets, hence allowing weight loss to happen.
Abstract
BACKGROUND The main goal of this randomized controlled single-blinded pilot study was to study whether, independent of weight loss, a Palaeolithic-type diet alters characteristics of the metabolic syndrome. Next we searched for outcome variables that might become favourably influenced by a Paleolithic-type diet and may provide new insights in the pathophysiological mechanisms underlying the metabolic syndrome. In addition, more information on feasibility and designing an innovative dietary research program on the basis of a Palaeolithic-type diet was obtained. METHODS Thirty-four subjects, with at least two characteristics of the metabolic syndrome, were randomized to a two weeks Palaeolithic-type diet (n = 18) or an isoenergetic healthy reference diet, based on the guidelines of the Dutch Health Council (n = 14). Thirty-two subjects completed the study. Measures were taken to keep bodyweight stable. As primary outcomes oral glucose tolerance and characteristics of the metabolic syndrome (abdominal circumference, blood pressure, glucose, lipids) were measured. Secondary outcomes were intestinal permeability, inflammation and salivary cortisol. Data were collected at baseline and after the intervention. RESULTS Subjects were 53.5 (SD9.7) year old men (n = 9) and women (n = 25) with mean BMI of 31.8 (SD5.7) kg/m2. The Palaeolithic-type diet resulted in lower systolic blood pressure (-9.1 mmHg; P = 0.015), diastolic blood pressure (-5.2 mmHg; P = 0.038), total cholesterol (-0.52 mmol/l; P = 0.037), triglycerides (-0.89 mmol/l; P = 0.001) and higher HDL-cholesterol (+0.15 mmol/l; P = 0.013), compared to reference. The number of characteristics of the metabolic syndrome decreased with 1.07 (P = 0.010) upon the Palaeolithic-type diet, compared to reference. Despite efforts to keep bodyweight stable, it decreased in the Palaeolithic group compared to reference (-1.32 kg; P = 0.012). However, favourable effects remained after post-hoc adjustments for this unintended weight loss. No changes were observed for intestinal permeability, inflammation and salivary cortisol. CONCLUSIONS We conclude that consuming a Palaeolithic-type diet for two weeks improved several cardiovascular risk factors compared to a healthy reference diet in subjects with the metabolic syndrome. TRIAL REGISTRATION Nederlands Trial Register NTR3002.
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L-carnitine ameliorated fasting-induced fatigue, hunger, and metabolic abnormalities in patients with metabolic syndrome: a randomized controlled study.
Zhang, JJ, Wu, ZB, Cai, YJ, Ke, B, Huang, YJ, Qiu, CP, Yang, YB, Shi, LY, Qin, J
Nutrition journal. 2014;13:110
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Metabolic syndrome increases the risk of heart disease and diabetes. Modified fasting therapy, such as a very-low-calorie diet is considered an effective way to tackle obesity and metabolic syndrome. When fasting, calorie restriction may cause fatigue and intense hunger, which may tempt individuals to stop fasting. L-Carnitine is an amino acid that transports long-chain fatty acids to mitochondria and helps them be oxidised to produce energy. L-Carnitine intravenous therapy is more bioavailable, better absorbed, and cleared than oral supplementation. This randomised, single-blinded, placebo-controlled pilot study included 30 individuals with metabolic syndrome who were randomly assigned to receive either 4 g/day of intravenous L-carnitine or saline for seven days to evaluate the effect of L-Carnitine on fatigue, hunger, body mass, lipid profile, and other CHD risk factors during a modified fasting period. The L-Carnitine group showed a significant reduction in waist-hip ratio, body mass, serum insulin levels, γ-glutamyltransferase, mental and physical fatigue, fatigue severity, weight loss, and greater reduction in waist circumference, total cholesterol and hunger when compared to the control group. Healthcare professionals can use the results of this study to understand the beneficial effects of L-Carnitine administration during modified fasting therapy in reducing weight, metabolic risk factors, hunger and fatigue. Long-term studies are required to confirm the benefits of L-carnitine.
Abstract
BACKGROUND The present study aimed to determine that whether L-carnitine infusion could ameliorate fasting-induced adverse effects and improve outcomes. METHOD In this 7-day, randomized, single-blind, placebo-controlled, pilot study, 15 metabolic syndrome (MetS) patients (11/4 F/M; age 46.9 ± 9.14 years; body mass index [BMI] 28.2 ± 1.8 kg/m2) were in the L-carnitine group (LC) and 15 (10/5 F/M; age 46.8 ± 10.9 years; BMI 27.1 ± 2.3 kg/m2) were in the control group (CT). All participants underwent a 5-day modified fasting therapy introduced with 2-day moderate calorie restriction. Patients in the LC group received 4 g/day of intravenous L-carnitine, while patients in the CT group were injected with saline. Blood pressure (BP), anthropometric characteristics, markers of liver function, metabolic indices (plasma glucose, lipid profiles, uric acid, free fatty acid and insulin) and hypersensitivity C-reactive protein were measured. Perceived hunger was recorded daily by self-rating visual analogue scales. Fatigue was evaluated by Wessely and Powell scores. RESULTS In contrast to the CT group, total cholesterol, alanine aminotransferase, systolic and diastolic BP did not change significantly in the LC group after prolonged fasting. There were significant differences in weight loss (LC -4.6 ± 0.9 vs. CT -3.2 ± 1.1 kg, P = 0.03), and waist circumference (LC -5.0 ± 2.2 vs. CT -1.7 ± 1.16 cm, P < 0.001), waist hip ratio (LC -0.023 ± 0.017 vs. CT 0.012 ± 0.01, P < 0.001), insulin concentration (LC -9.9 ± 3.58 vs. CT -6.32 ± 3.44 µU/mL, P = 0.046), and γ-glutamyltransferase concentration (LC -7.07 ± 6.82 vs. CT -2.07 ± 4.18, P = 0.024). Perceived hunger scores were significantly increased (P < 0.05) in the CT group during starvation, which was alleviated with L-carnitine administration in the LC group. Physical fatigue (LC -3.2 ± 3.17 vs. CT 1.8 ± 2.04, P < 0.001) and fatigue severity (LC -11.6 ± 8.38 vs. CT 8.18 ± 7.32, P < 0.001) were significantly reduced in the LC group but were aggravated in the CT group. CONCLUSION Intravenous L-carnitine can ameliorate fasting-induced hunger, fatigue, cholesterol abnormalities and hepatic metabolic changes and facilitate fasting-induced weight loss in MetS patients. TRIAL REGISTRATION ChiCTR-TNRC-12002835.