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1.
Common and divergent molecular mechanisms of fasting and ketogenic diets.
Paoli, A, Tinsley, GM, Mattson, MP, De Vivo, I, Dhawan, R, Moro, T
Trends in endocrinology and metabolism: TEM. 2024;(2):125-141
Abstract
Intermittent short-term fasting (ISTF) and ketogenic diets (KDs) exert overlapping but not identical effects on cell metabolism, function, and resilience. Whereas health benefits of KD are largely mediated by the ketone bodies (KBs), ISTF engages additional adaptive physiological responses. KDs act mainly through inhibition of histone deacetylases (HDACs), reduction of oxidative stress, improvement of mitochondria efficiency, and control of inflammation. Mechanisms of action of ISTF include stimulation of autophagy, increased insulin and leptin sensitivity, activation of AMP-activated protein kinase (AMPK), inhibition of the mechanistic target of rapamycin (mTOR) pathway, bolstering mitochondrial resilience, and suppression of oxidative stress and inflammation. Frequent switching between ketogenic and nonketogenic states may optimize health by increasing stress resistance, while also enhancing cell plasticity and functionality.
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2.
Effects of probiotic supplementation on performance of resistance and aerobic exercises: a systematic review.
de Paiva, AKF, de Oliveira, EP, Mancini, L, Paoli, A, Mota, JF
Nutrition reviews. 2023;(2):153-167
Abstract
CONTEXT Strenuous exercise may lead to negative acute physiological effects that can impair athletic performance. Some recent studies suggest that probiotic supplementation can curtail these effects by reducing the permeability of the intestinal barrier, yet results are inconsistent. OBJECTIVE The aim of this systematic review is to assess the effects of probiotic supplementation on athletic performance. DATA SOURCES The PubMed/MEDLINE, Cochrane, and Scopus databases were searched for articles that assessed the effects of probiotic supplementation on athletic performance. DATA EXTRACTION THIS SYSTEMATIC REVIEW IS REPORTED ACCORDING TO PRISMA guidelines. Risk of bias was assessed through the Cochrane RoB 2.0 tool. Seventeen randomized clinical trials assessing athletic performance as the primary outcome were included. In total, 496 individuals (73% male) comprising athletes, recreationally trained individuals, and untrained healthy individuals aged 18 to 40 years were investigated. DATA ANALYSIS Three studies showed an increase or an attenuation of aerobic performance (decline in time to exhaustion on the treadmill) after supplementation with probiotics, while 3 found an increase in strength. However, most studies (n = 11) showed no effect of probiotic consumption on aerobic performance (n = 9) or muscular strength (n = 2). The most frequently used strain was Lactobacillus acidophilus, used in 2 studies that observed positive results on performance. Studies that used Lactobacillus plantarum TK10 and Lactobacillus plantarum PS128 also demonstrated positive effects on aerobic performance and strength, but they had high risk of bias, which implies low confidence about the actual effect of treatment. CONCLUSION There is not enough evidence to support the hypothesis that probiotics can improve performance in resistance and aerobic exercises. Further well-controlled studies are warranted.
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The bioelectrical impedance analysis (BIA) international database: aims, scope, and call for data.
Silva, AM, Campa, F, Stagi, S, Gobbo, LA, Buffa, R, Toselli, S, Silva, DAS, Gonçalves, EM, Langer, RD, Guerra-Júnior, G, et al
European journal of clinical nutrition. 2023;(12):1143-1150
Abstract
BACKGROUND Bioelectrical impedance analysis (BIA) is a technique widely used for estimating body composition and health-related parameters. The technology is relatively simple, quick, and non-invasive, and is currently used globally in diverse settings, including private clinicians' offices, sports and health clubs, and hospitals, and across a spectrum of age, body weight, and disease states. BIA parameters can be used to estimate body composition (fat, fat-free mass, total-body water and its compartments). Moreover, raw measurements including resistance, reactance, phase angle, and impedance vector length can also be used to track health-related markers, including hydration and malnutrition, and disease-prognostic, athletic and general health status. Body composition shows profound variability in association with age, sex, race and ethnicity, geographic ancestry, lifestyle, and health status. To advance understanding of this variability, we propose to develop a large and diverse multi-country dataset of BIA raw measures and derived body components. The aim of this paper is to describe the 'BIA International Database' project and encourage researchers to join the consortium. METHODS The Exercise and Health Laboratory of the Faculty of Human Kinetics, University of Lisbon has agreed to host the database using an online portal. At present, the database contains 277,922 measures from individuals ranging from 11 months to 102 years, along with additional data on these participants. CONCLUSION The BIA International Database represents a key resource for research on body composition.
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Effect of resistance training on bioelectrical phase angle in older adults: a systematic review with Meta-analysis of randomized controlled trials.
Campa, F, Colognesi, LA, Moro, T, Paoli, A, Casolo, A, Santos, L, Correia, RR, Lemes, ÍR, Milanez, VF, Christofaro, DD, et al
Reviews in endocrine & metabolic disorders. 2023;(3):439-449
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Abstract
Resistance training has been proposed as a valid practice to counteract the aging effect on body mass and its components, which can be easily evaluated though the bioelectrical impedance analysis. This study aimed to achieve a systematic review with meta-analysis on the impact of resistance training on bioelectrical proprieties in older adults.A literature review was done in four electronic databases up to 1 January 2022. The inclusion criteria were: (i) participants aged ≥ 60 years; (ii) resistance training lasted ≥ 8 weeks; (iii) measurement of raw bioelectrical parameters in randomized controlled study designs.The outcomes of the trial had to be bioelectrical phase angle (PhA), resistance (R), and reactance (Xc). The methodological quality was assessed using the Rosendal scale.Overall, seven studies with a total of 344 participants were eligible for the analysis. The quality assessment yielded a score of 71.3%. Bioelectrical PhA (0.52 degree [95%CI 0.32, 0.71], p < 0.001) and Xc (3.58 ohms [95%CI 1.97, 5.19], p < 0.001) increased, whereas R decreased (-28.50 ohms [95%CI -41.39, -15.60], p < 0.001) after the resistance training programs.In this meta-analysis, resistance training promoted increases of PhA, which result from an increase in Xc concomitant with a reduction in R. According to the bioimpedance vector analysis, resistance-trained people experienced a beneficial leftward vector displacement, whilst inactivity induced a rightward vector displacement within the R-Xc graph. In future, more sophisticated and rigorous studies that address specific criteria, methods and targeted designs are required to identify which equipment and protocols allow for an optimization of the resistance training effects.Registration code in PROSPERO CRD42020168057.
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Investigating the Link between Ketogenic Diet, NAFLD, Mitochondria, and Oxidative Stress: A Narrative Review.
Paoli, A, Cerullo, G
Antioxidants (Basel, Switzerland). 2023;(5)
Abstract
Together with the global rise in obesity and metabolic syndrome, the prevalence of individuals who suffer from nonalcoholic fatty liver disease (NAFLD) has risen dramatically. NAFLD is currently the most common chronic liver disease and includes a continuum of liver disorders from initial fat accumulation to nonalcoholic steatohepatitis (NASH), considered the more severe forms, which can evolve in, cirrhosis, and hepatocellular carcinoma. Common features of NAFLD includes altered lipid metabolism mainly linked to mitochondrial dysfunction, which, as a vicious cycle, aggravates oxidative stress and promotes inflammation and, as a consequence, the progressive death of hepatocytes and the severe form of NAFLD. A ketogenic diet (KD), i.e., a diet very low in carbohydrates (<30 g/die) that induces "physiological ketosis", has been demonstrated to alleviate oxidative stress and restore mitochondrial function. Based on this, the aim of the present review is to analyze the body of evidence regarding the potential therapeutic role of KD in NAFLD, focusing on the interplay between mitochondria and the liver, the effects of ketosis on oxidative stress pathways, and the impact of KD on liver and mitochondrial function.
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Fat-free mass estimation in male elite futsal players: Development and validation of a new bioelectrical impedance-based predictive equation.
Matias, CN, Campa, F, Cavaca, M, Paoli, A, Teixeira, FJ
Nutrition (Burbank, Los Angeles County, Calif.). 2023;:111931
Abstract
OBJECTIVES The present study aimed to develop and cross-validate a futsal-specific bioelectrical equation for estimating fat-free mass (FFM) in male players. METHODS A total of 66 futsal players (age 23.3 ± 5.4 years) from the Major Portuguese Futsal League "LIGA PLACARD" and from the 2nd and 3rd National Futsal Leagues were included in this cross-sectional, observational study. The participants underwent a foot-to-hand bioelectrical impedance analysis (BIA) at 50 kHz and completed a dual-energy X-ray absorptiometry (DXA) scan for reference body composition data. The sport-specific model was developed by stepwise multiple regression using bioelectrical raw parameters [resistance (R) and reactance (Xc)] as independent variables. Validation was performed using the PRESS approach, least squares regression, concordance correlation coefficient (CCC) and Bland-Altman analyses. RESULTS A BIA-based model was developed for FFM [FFM (kg) = -8.865 + 0.437 * Body Mass (kg) + 0.186 * Xc + 0.415 * stature (cm)2/R (R2 = 0.89, standard error of estimation = 2.38 kg)]. Results showed a substantial strength of agreement (CCC = 0.953), an r2 of 0.88 with a standard error of estimation equal to 2.31 kg, no mean bias (0.04 kg, p>0.05), low limits of agreement (ranged from -4.5 to 4.6 kg), and no trend (r = -0.170, p = 0.172). CONCLUSIONS The present equation is the first to allow for a valid, accurate, and sport-specific assessment of FFM in male futsal players.
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Does Stretching Training Influence Muscular Strength? A Systematic Review With Meta-Analysis and Meta-Regression.
Thomas, E, Ficarra, S, Nunes, JP, Paoli, A, Bellafiore, M, Palma, A, Bianco, A
Journal of strength and conditioning research. 2023;(5):1145-1156
Abstract
Thomas, E, Ficarra, S, Nunes, JP, Paoli, A, Bellafiore, M, Palma, A, and Bianco, A. Does stretching training influence muscular strength? A systematic review with meta-analysis and meta-regression. J Strength Cond Res 37(5): 1145-1156, 2023-The aim of this study was to review articles that performed stretching training and evaluated the effects on muscular strength. Literature search was performed using 3 databases. Studies were included if they compared the effects on strength following stretching training vs. a nontraining control group or stretching training combined with resistance training (RT) vs. an RT-only group, after at least 4 weeks of intervention. The meta-analyses were performed using a random-effect model with Hedges' g effect size (ES). A total of 35 studies ( n = 1,179 subjects) were included in this review. The interventions lasted for a mean period of 8 weeks (range, 4-24 weeks), 3-4 days per week, applying approximately 4 sets of stretching of approximately 1-minute duration. The meta-analysis for the stretching vs. nontraining control group showed a significant small effect on improving dynamic (k = 14; ES = 0.33; p = 0.007) but not isometric strength (k = 8; ES = 0.10; p = 0.377), following static stretching programs (k = 17; ES = 0.28; p = 0.006). When stretching was added to RT interventions, the main analysis indicated no significant effect (k = 17; ES = -0.15; p = 0.136); however, moderator analysis indicated that performing stretching before RT sessions has a small but negative effect (k = 7; ES = -0.43; p = 0.014); the meta-regression revealed a significant negative association with study length (β = -0.100; p = 0.004). Chronic static stretching programs increase dynamic muscular strength to a small magnitude. Performing stretching before RT and for a prolonged time (>8 weeks) can blunt the strength gains to a small-to-moderate magnitude. Performing stretching in sessions distant from RT sessions might be a strategy to not hinder strength development.
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Ketogenic diets, physical activity and body composition: a review.
Ashtary-Larky, D, Bagheri, R, Bavi, H, Baker, JS, Moro, T, Mancin, L, Paoli, A
The British journal of nutrition. 2022;(12):1898-1920
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Abstract
Obesity remains a serious relevant public health concern throughout the world despite related countermeasures being well understood (i.e. mainly physical activity and an adjusted diet). Among different nutritional approaches, there is a growing interest in ketogenic diets (KD) to manipulate body mass (BM) and to enhance fat mass loss. KD reduce the daily amount of carbohydrate intake drastically. This results in increased fatty acid utilisation, leading to an increase in blood ketone bodies (acetoacetate, 3-β-hydroxybutyrate and acetone) and therefore metabolic ketosis. For many years, nutritional intervention studies have focused on reducing dietary fat with little or conflicting positive results over the long term. Moreover, current nutritional guidelines for athletes propose carbohydrate-based diets to augment muscular adaptations. This review discusses the physiological basis of KD and their effects on BM reduction and body composition improvements in sedentary individuals combined with different types of exercise (resistance training or endurance training) in individuals with obesity and athletes. Ultimately, we discuss the strengths and the weaknesses of these nutritional interventions together with precautionary measures that should be observed in both individuals with obesity and athletic populations. A literature search from 1921 to April 2021 using Medline, Google Scholar, PubMed, Web of Science, Scopus and Sportdiscus Databases was used to identify relevant studies. In summary, based on the current evidence, KD are an efficient method to reduce BM and body fat in both individuals with obesity and athletes. However, these positive impacts are mainly because of the appetite suppressive effects of KD, which can decrease daily energy intake. Therefore, KD do not have any superior benefits to non-KD in BM and body fat loss in individuals with obesity and athletic populations in an isoenergetic situation. In sedentary individuals with obesity, it seems that fat-free mass (FFM) changes appear to be as great, if not greater, than decreases following a low-fat diet. In terms of lean mass, it seems that following a KD can cause FFM loss in resistance-trained individuals. In contrast, the FFM-preserving effects of KD are more efficient in endurance-trained compared with resistance-trained individuals.
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Royal jelly plus coenzyme Q10 supplementation improves high-intensity interval exercise performance via changes in plasmatic and salivary biomarkers of oxidative stress and muscle damage in swimmers: a randomized, double-blind, placebo-controlled pilot trial.
Ovchinnikov, AN, Paoli, A, Seleznev, VV, Deryugina, AV
Journal of the International Society of Sports Nutrition. 2022;(1):239-257
Abstract
BACKGROUND Excessive production of free radicals caused by many types of exercise results in oxidative stress, which leads to muscle damage, fatigue, and impaired performance. Supplementation with royal jelly (RJ) or coenzyme Q10 (CoQ10) has been shown to attenuate exercise-induced oxidant stress in damaged muscle and improve various aspects of exercise performance in many but not all studies. Nevertheless, the effects of treatments based on RJ plus CoQ10 supplementation, which may be potentially beneficial for reducing oxidative stress and enhancing athletic performance, remain unexplored. This study aimed to examine whether oral RJ and CoQ10 co-supplementation could improve high-intensity interval exercise (HIIE) performance in swimmers, inhibiting exercise-induced oxidative stress and muscle damage. METHODS Twenty high-level swimmers were randomly allocated to receive either 400 mg of RJ and 60 mg of CoQ10 (RJQ) or matching placebo (PLA) once daily for 10 days. Exercise performance was evaluated at baseline, and then reassessed at day 10 of intervention, using a HIIE protocol. Diene conjugates (DC), Schiff bases (SB), and creatine kinase (CK) were also measured in blood plasma and saliva before and immediately after HIIE in both groups. RESULTS HIIE performance expressed as number of points according to a single assessment system developed and approved by the International Swimming Federation (FINA points) significantly improved in RJQ group (p = 0.013) compared to PLA group. Exercise-induced increase in DC, SB, and CK levels in plasma and saliva significantly diminished only in RJQ group (p < 0.05). Regression analysis showed that oral RJQ administration for 10 days was significantly associated with reductions in HIIE-induced increases in plasmatic and salivary DC, SB, and CK levels compared to PLA. Principal component analysis revealed that swimmers treated with RJQ are grouped by both plasmatic and salivary principal components (PC) into a separate cluster compared to PLA. Strong negative correlation between the number of FINA points and plasmatic and salivary PC1 values was observed in both intervention groups. CONCLUSION The improvements in swimmers' HIIE performance were due in significant part to RJQ-induced reducing in lipid peroxidation and muscle damage in response to exercise. These findings suggest that RJQ supplementation for 10 days is potentially effective for enhancing HIIE performance and alleviating oxidant stress. ABBREVIATIONS RJ, royal jelly; CoQ10, coenzyme Q10; HIIE, high-intensity interval exercise; DC, diene conjugates; SB, Schiff bases; CK, creatine kinase; RJQ, royal jelly plus coenzyme Q10; PLA, placebo; FINA points, points according to a single assessment system developed and approved by the International Swimming Federation; ROS, reactive oxygen species; 10H2DA, 10-hydroxy-2-decenoic acid; AMPK, 5'-AMP-activated protein kinase; FoxO3, forkhead box O3; MnSOD, manganese-superoxide dismutase; CAT, catalase; E, optical densities; PCA, principal component analysis; PC, principal component; MCFAs, medium-chain fatty acids; CaMKKβ, Ca2+/calmodulin-dependent protein kinase β; TBARS, thiobarbituric acid reactive substances; MDA, malondialdehyde.
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Thyroidectomies in Italy: A Population-Based National Analysis from 2001 to 2018.
Pierannunzio, D, Fedeli, U, Francisci, S, Paoli, A, Toffolutti, F, Serraino, D, Zoppini, G, Borsatti, E, Di Felice, E, Falcini, F, et al
Thyroid : official journal of the American Thyroid Association. 2022;(3):263-272
Abstract
Background: The incidence of thyroid disease is generally increasing, and it is subject to major geographic variability, between and within countries. Moreover, the incidence rates and the proportion of overdiagnosis for thyroid cancer in Italy are among the highest worldwide. This study aimed to estimate population-based frequency and trends of thyroidectomies in Italy by type of surgical procedure (total/partial), indication (tumors/other conditions), sex, age, and geographical region. Materials and Methods: Age-standardized rates (ASRs) of thyroidectomies were estimated from 2001 to 2018 using the national hospital discharges database. Results: In Italy, ASRs of thyroidectomies were nearly 100 per 100,000 women in 2002-2004 and decreased to 71 per 100,000 women in 2018. No corresponding variation was shown in men (ASR 27 per 100,000 men) in the overall period. A more than twofold difference between Italian regions emerged in both sexes. The proportion of total thyroidectomies (on the sum of total and partial thyroidectomies) in the examined period increased from 78% to 86% in women and from 72% to 81% in men. Thyroidectomies for goiter and nonmalignant conditions decreased consistently throughout the period (from 81 per 100,000 women in 2002 to 49 in 2018 and from 22 to 16 per 100,000 men), while thyroidectomies for tumors increased until 2013-2014 up to 24 per 100,000 women (9 per 100,000 men) and remained essentially stable thereafter. Conclusions: The decrease in thyroidectomies for nonmalignant diseases since early 2000s in Italy may derive from the decrease of goiter prevalence, possibly as a consequence of the reduction of iodine deficiency and the adoption of conservative treatments. In a context of overdiagnosis of thyroid cancer, recent trends have suggested a decline in the diagnostic pressure with a decrease in geographic difference. Our results showed the need and also the possibility to implement more conservative surgical approaches to thyroid diseases, as recommended by international guidelines.