Effects of a Paleolithic diet compared to a diabetes diet on leptin binding inhibition in secondary analysis of a randomised cross-over study.

BACKGROUND: Beneficial effects from practising a Paleolithic diet as compared to a diabetes diet on weight, waist circumference, satiety, leptin, HbA1c and glucose control in randomised controlled trial participants with type 2 diabetes could be due to lower leptin resistance. Support for this hypothesis comes from an in vitro experiment that showed that digested wheat gluten, which is excluded from a Paleolithic diet, inhibits leptin from binding to its receptor, thus indicating a possible dietary cause of leptin resistance. However, the clinical relevance of the latter finding is unclear since removal of enzyme activity from the gluten digest by heat treatment also abolished leptin binding inhibition. Assessment of leptin binding inhibition in vivo is possible by comparison of total leptin levels with those of 'biologically active' leptin bound to its receptor (bioLep). OBJECTIVES: To assess the effects of a Paleolithic diet compared to a diabetes diet on leptin binding inhibition and to replicate our in vitro study. METHODS: BioLep and total leptin levels were measured in secondary analysis of fasting plasma samples from our open label random order three plus three-month long cross-over trial performed in 2005-2007, that compared a Paleolithic diet with a diabetes diet in participants with type 2 diabetes without insulin treatment (per protocol). BioLep was also measured in vitro for known recombinant leptin concentrations incubated with a series of concentrations of 10 kDa spin-filtered digested wheat gluten, with or without prior heat treatment, at 100ºC for 30 min and centrifugation. RESULTS: There was no difference between diets when comparing differences between bioLep and total leptin levels and their ratio in the 13 participants, three women and 10 men, aged 52-74 years with a mean BMI of 30 kg/m2 and a mean diabetes duration of eight years. We found no carry-over or period effect for bioLep and total leptin. In vitro, wheat gluten digest inhibited leptin binding in a dose-dependent manner but not after heat treatment. CONCLUSIONS: We found no leptin binding inhibition after the Paleolithic or diabetes diet, possibly due to its abolishment from cooking-related heat treatment of wheat gluten. TRIAL REGISTRATION: Registered on 14/02/2007 at ClinicalTrials.gov Identifier: NCT00435240.

Total adiponectin in indigenous Melanesians on Kitava.

OBJECTIVES: Experimental and small human studies have indicated that high total adiponectin levels have beneficial cardiometabolic effects. In contrast, however, high total adiponectin levels are also associated with higher all-cause and cardiovascular mortality in thoroughly adjusted epidemiological studies. To gain further insight into these seemingly contradictory results, we report results on total adiponectin from the indigenous Melanesian population of Kitava, Trobriand Islands, Papua New Guinea, where an apparent absence of cardiometabolic disease has been previously reported. METHODS: Fasting levels of serum total adiponectin were measured cross-sectionally in ≥40-year-old Kitavans (n = 102) and Swedish controls matched for age and sex (n = 108). Multivariable linear regression was used for the analysis of associations with total adiponectin when controlled for group, sex, smoking, hypertension and/or type 2 diabetes, age, and body mass index. RESULTS: Total adiponectin was lower for Kitavans compared to Swedish controls (Median [Mdn] 4.6 µg/mL, range 1.0-206 µg/mL and Mdn 9.7 µg/mL, range 3.1-104 µg/mL, respectively, r = .64, p < .001). Lower total adiponectin was associated with Kitavan group, male sex (only in Swedish controls), smoking (only in Kitavans and Swedish controls combined), younger age (not in Swedish controls), higher BMI, lower total, low-density lipoprotein, high-density lipoprotein (HDL) (only in Kitavans and Swedish controls combined), and non-HDL cholesterol, and higher anti-PC IgG (only in Kitavans and Swedish controls combined). CONCLUSION: Total adiponectin in Kitavans was significantly lower than in Swedish controls.

Total Number of Sets as a Training Volume Quantification Method for Muscle Hypertrophy: A Systematic Review.

ABSTRACT: Baz-Valle, E, Fontes-Villalba, M, and Santos-Concejero, J. Total number of sets as a training volume quantification method for muscle hypertrophy: A systematic review. J Strength Cond Res 35(3): 870-878, 2021-This review aimed to determine whether assessing the total number of sets is a valid method to quantify training volume in the context of hypertrophy training. A literature search on 2 databases (PubMed and Scopus) was conducted on May 18, 2018. After analyzing 2,585 resultant articles, studies were included if they met the following criteria: (a) studies were randomized controlled trials, (b) studies compared the total number of sets, repetition range, or training frequency, (c) interventions lasted at least 6 weeks, (d) subjects had a minimum of 1 year of resistance training experience, (e) subjects' age ranged from 18 to 35 years, (f) studies reported morphologic changes through direct or indirect assessment methods, (g) studies involved subjects with no known medical conditions, and (h) studies were published in peer-reviewed journals. Fourteen studies met the inclusion criteria. According to the results of this review, the total number of sets to failure, or near to, seems to be an adequate method to quantify training volume when the repetition range lies between 6 and 20+ if all the other variables are kept constant. This approach requires further development to assess whether specific numbers of sets are key to inducing optimal muscle gains.

C-reactive protein in traditional melanesians on Kitava.

BACKGROUND: Population-based levels of the chronic low-grade systemic inflammation biomarker, C-reactive protein (CRP), vary widely among traditional populations, despite their apparent absence of chronic conditions associated with chronic low-grade systemic inflammation, such as type 2 diabetes, metabolic syndrome and cardiovascular disease. We have previously reported an apparent absence of aforementioned conditions amongst the traditional Melanesian horticulturalists of Kitava, Trobriand Islands, Papua New Guinea. Our objective in this study was to clarify associations between chronic low-grade systemic inflammation and chronic cardiometabolic conditions by measuring CRP in a Kitava population sample. For comparison purposes, CRP was also measured in Swedish controls matched for age and gender. METHODS: Fasting levels of serum CRP were measured cross-sectionally in ≥ 40-year-old Kitavans (N = 79) and Swedish controls (N = 83). RESULTS: CRP was lower for Kitavans compared to Swedish controls (Mdn 0.5 mg/L range 0.1-48 mg/L and Mdn 1.1 mg/L range 0.1-33 mg/L, respectively, r = .18 p = .02). Among Kitavans, there were small negative associations between lnCRP for CRP values < 10 and total, low-density lipoprotein (LDL) and non-high-density lipoprotein (non-HDL) cholesterol. Among Swedish controls, associations of lnCRP for CRP values < 10 were medium positive with weight, body mass index, waist circumference, hip circumference and waist-hip ratio and low positive with triglyceride, total cholesterol-HDL cholesterol ratio, triglyceride-HDL cholesterol ratio and serum insulin. CONCLUSIONS: Chronic low-grade systemic inflammation, measured as CRP, was lower among Kitavans compared to Swedish controls, indicating a lower and average cardiovascular risk, respectively, for these populations.

Lower Cardiovascular Stress during Resistance Training Performed with Inter-Repetition Rests in Elderly Coronary Patients.

Background and Objectives: Hemodynamic stress during resistance training is often a reason why this training method is not used in cardiac patients. A lifting protocol that imposes rests between repetitions (IRRT) may provide less hemodynamic stress compared to traditional resistance training (TT). The aim of this study was to verify differences between set configurations on hemodynamic stress responses in resistance training. Materials and Methods: We compared hemodynamic (heart rate (HR), systolic blood pressure (SBP), and rate pressure product (RPP)) responses assessed with the auscultatory method in elderly (age = 75.3 ± 7.3 years) coronary male patients who were participating in a cardiac rehabilitation program allocated to either TT or IRRT with the same load (kg) and total number of repetitions (24) in the bilateral leg extension exercise. Results: IRRT resulted in significant lower values than TT for RPP at repetitions 8 (p = 0.024; G = 0.329; 95% CI: 0.061, 0.598) and 16 (p = 0.014; G = 0.483; 95% CI: 0.112, 0.854). Conclusions: IRRT appears to be a viable method of reducing the hemodynamic response (i.e., RPP) to resistance training and, thus, may contribute to the safety of cardiac rehabilitation programs. Further studies with more cardiac patients and other measurement techniques should be conducted to confirm these important findings.

Palaeolithic diet decreases fasting plasma leptin concentrations more than a diabetes diet in patients with type 2 diabetes: a randomised cross-over trial.

BACKGROUND: We have previously shown that a Palaeolithic diet consisting of the typical food groups that our ancestors ate during the Palaeolithic era, improves cardiovascular disease risk factors and glucose control compared to the currently recommended diabetes diet in patients with type 2 diabetes. To elucidate the mechanisms behind these effects, we evaluated fasting plasma concentrations of glucagon, insulin, incretins, ghrelin, C-peptide and adipokines from the same study. METHODS: In a randomised, open-label, cross-over study, 13 patients with type 2 diabetes were randomly assigned to eat a Palaeolithic diet based on lean meat, fish, fruits, vegetables, root vegetables, eggs and nuts, or a diabetes diet designed in accordance with current diabetes dietary guidelines during two consecutive 3-month periods. The patients were recruited from primary health-care units and included three women and 10 men [age (mean ± SD) 64 ± 6 years; BMI 30 ± 7 kg/m(2); diabetes duration 8 ± 5 years; glycated haemoglobin 6.6 ± 0.6 % (57.3 ± 6 mmol/mol)] with unaltered diabetes treatment and stable body weight for 3 months prior to the start of the study. Outcome variables included fasting plasma concentrations of leptin, adiponectin, adipsin, visfatin, resistin, glucagon, insulin, C-peptide, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1 and ghrelin. Dietary intake was evaluated by use of 4-day weighed food records. RESULTS: Seven participants started with the Palaeolithic diet and six with the diabetes diet. The Palaeolithic diet resulted in a large effect size (Cohen's d = -1.26) at lowering fasting plasma leptin levels compared to the diabetes diet [mean difference (95 % CI), -2.3 (-5.1 to 0.4) ng/ml, p = 0.023]. No statistically significant differences between the diets for the other variables, analysed in this study, were observed. CONCLUSIONS: Over a 3-month study period, a Palaeolithic diet resulted in reduced fasting plasma leptin levels, but did not change fasting levels of insulin, C-peptide, glucagon, incretins, ghrelin and adipokines compared to the currently recommended diabetes diet. TRIAL REGISTRATION: ClinicalTrials.gov NCT00435240.

Randomised controlled trial of lifestyle interventions for abdominal obesity in primary health care.

AIM: Assess effects on waist circumference from diet with or without cereal grains and with or without long-term physical exercise. BACKGROUND: Elevated waist circumference is an indicator of increased abdominal fat storage and is accordingly associated with increased cardiovascular mortality. This is likely due to the association between lifestyle-induced changes in waist circumference and cardiovascular risk factors. Reductions in waist circumference may be facilitated by diet without cereal grains combined with long-term physical exercise. METHODS: Two-year randomised controlled trial with factorial trial design in individuals at increased risk of cardiovascular disease with increased waist circumference. Participants were allocated diet based on current Swedish dietary guidelines with or without cereal grains (baseline diet information supported by monthly group sessions) and with or without physical exercise (pedometers and two initial months of weekly structured exercise followed by written prescription of physical activity) or control group. The primary outcome was the change in waist circumference. FINDINGS: The greatest mean intervention group difference in the change in waist circumference among the 73 participants (47 women and 26 men aged 23-79 years) was at one year between participants allocated a diet without cereal grains and no exercise and participants allocated a diet with cereal grains and no exercise [M = -5.3 cm and -0.9 cm, respectively; mean difference = 4.4 cm, 4.0%, 95% CI (0.0%, 8.0%), P = 0.051, Cohen's d = 0.75]. All group comparisons in the change in waist circumference were non-significant despite the greatest group difference being more than double that estimated in the pre-study power calculation. The non-significance was likely caused by too few participants and a greater than expected variability in the change in waist circumference. The greatest mean intervention group difference strengthens the possibility that dietary exclusion of cereal grains could be related to greater reduction in waist circumference.

Serum Zonulin and Endotoxin Levels in Exceptional Longevity versus Precocious Myocardial Infarction.

Endotoxemia-induced inflammation has been associated with insulin resistance and atherosclerosis, ultimately increasing the risk of coronary heart disease. Increased intestinal permeability is an important event leading to endotoxemia. This study aims to elucidate the possible association between endotoxin (lipopolysaccharide) and zonulin (a biomarker of intestinal permeability) levels and the risk of coronary heart disease, and thus healthy aging. Serum levels of zonulin, lipopolysaccharide and soluble CD14 (a protein that binds lipopolysaccharide) were measured in disease-free centenarians, young healthy controls and patients with precocious acute myocardial infarction. Disease-free centenarians had significantly lower levels of serum zonulin (P<0.01) and lipopolysaccharide (P<0.001) than young patients with acute myocardial infarction, and had significantly lower concentrations of serum lipopolysaccharide than young healthy controls (P<0.05). No significant differences were found for soluble CD14 between groups. Our findings may stimulate further research into the role played by intestinal permeability and endotoxemia not only in coronary heart disease but also in lifespan modulation.

Nutritional strategies for skeletal and cardiovascular health: hard bones, soft arteries, rather than vice versa.

The focus of this paper is to explore better strategies for optimising bone strength and reducing risk of fracture, while at the same time decreasing risk of cardiovascular disease. The majority of Americans do not consume the current recommended dietary allowance for calcium, and the lifetime risk of osteoporosis is about 50%. However, traditional mononutrient calcium supplements may not be ideal. We comprehensively and systematically reviewed the scientific literature in order to determine the optimal dietary strategies and nutritional supplements for long-term skeletal health and cardiovascular health. To summarise, the following steps may be helpful for building strong bones while maintaining soft and supple arteries: (1) calcium is best obtained from dietary sources rather than supplements; (2) ensure that adequate animal protein intake is coupled with calcium intake of 1000 mg/day; (3) maintain vitamin D levels in the normal range; (4) increase intake of fruits and vegetables to alkalinise the system and promote bone health; (5) concomitantly increase potassium consumption while reducing sodium intake; (6) consider increasing the intake of foods rich in vitamins K1 and K2; (7) consider including bones in the diet; they are a rich source of calcium-hydroxyapatite and many other nutrients needed for building bone.

A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study--Alimentation and Diabetes in Lanzarote--ADILAN.

BACKGROUND: Research on the role of nutrition in type 2 diabetes has largely focused on macro/micronutrient composition and dietary fiber intake, while fewer studies have tested the effects of differing food choice. Some observational studies and short-term intervention studies suggest that a food pattern mimicking the diet with which humans evolved positively influences glucose control and associated endocrine systems. Such a food pattern mainly differs from other common healthy food patterns in its absence of cereal grains and dairy products. The primary aim of this pilot study is to determine the effect of two healthy diets with or without cereal grains and dairy products on glucose control, while keeping participants' weight stable and other food parameters, such as macro/micronutrient composition, dietary fiber and glycemic load, the same in both diets. METHODS/DESIGN: We intend to include 15 adult patients with a medical diagnosis of type 2 diabetes mellitus with or without medication and with an increased waist circumference (≥ 80 cm for women and ≥ 94 cm for men) in a random-order cross-over diet intervention study during two periods of four-weeks separated by a six-week washout period. Patients will be instructed to eat two healthy diets according to official dietary guidelines with respect to macro/micronutrient composition and fiber content, but differing in the type of food included, with one diet being without cereal grains and dairy products. Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of the meals will be eaten at home according to specific directions. The energy content of the diets will be individually adjusted to maintain a stable body weight during the two four-week intervention periods. Primary outcomes will be change in fasting plasma glucagon and fructosamine, while secondary outcomes include change in fasting glucose and glycated hemoglobin, glucose and glucagon response during oral glucose tolerance test, blood lipids, blood pressure, C-reactive protein, body composition, quality of life, subjective experience with the two diets, satiety scores and changes in medication. DISCUSSION: Using these results, we will assess the need to conduct larger and longer studies with similar design. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT01891955 and Spanish Agency of Medication and Sanitary Products (AEMPS) registration code: MFV-ADI-2013-01.

The feasibility of a Paleolithic diet for low-income consumers.

Many low-income consumers face a limited budget for food purchases. The United States Department of Agriculture developed the Thrifty Food Plan to address this problem of consuming a healthy diet given a budget constraint. This dietary optimization program uses common food choices to build a suitable diet. In this article, the United States Department of Agriculture data sets are used to test the feasibility of consuming a Paleolithic diet given a limited budget. The Paleolithic diet is described as the diet that humans are genetically adapted to, containing only the preagricultural food groups of meat, seafood, fruits, vegetables, and nuts. Constraints were applied to the diet optimization model to restrict grains, dairy, and certain other food categories. Constraints were also applied for macronutrients, micronutrients, and long-chain polyunsaturated fatty acids. The results show that it is possible to consume a Paleolithic diet given the constraints. However, the diet does fall short of meeting the daily recommended intakes for certain micronutrients. A 9.3% increase in income is needed to consume a Paleolithic diet that meets all daily recommended intakes except for calcium.