Search Results (12)

Context: Intermittent fasting (IF) and calorie restriction (CR) have gained interest as dietary strategies due to their potential for weight loss and multiple metabolic benefits. These strategies are often accompanied by exercise in an attempt to improve body composition and physical performance. However, further research is crucial to understanding whether or not physical performance is affected by the expected weight loss and related body composition changes in individuals on IF and CR, even when exercise is combined. Objective: We aimed to systematically evaluate the effects of IF and CR on exercise performance and body composition in adults aged 18 to 65 years. Data Source: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A systematic review was conducted up to April 2024 by searching electronic databases, including PubMed, Web of Science, and Scopus. There was no limit on publication dates. Data Extraction: The search explored the impact of IF and CR combined with exercise vs. exercise alone (control) on exercise performance outcomes: VO_2max, handgrip strength, bench press strength, knee extensor strength, leg press strength, countermovement jump (CMJ), 400 m walk test, and gait speed; body weight, body mass index (BMI), and body composition: fat-free mass (FFM), fat mass (FM), and body fat percentage (BFP). Analyses included calculation of weighted mean difference (WMD), standardized mean difference (SMD), and 95% confidence intervals (CIs) to assess outcomes. Data Analysis: The meta-analysis included a total of 35 studies, ranging from 4 to 52 weeks and involving 1266 participants. The results showed that IF (hypocaloric or eucaloric diet) and CR combined with exercise increased handgrip strength [WMD = 1.707 kg, p = 0.01] compared to exercise alone. Moreover, IF and CR combined with exercise did not significantly affect VO_2max [SMD = 0.005, p = 0.94], bench press strength [WMD = 0.377 kg, p = 0.778], knee extensor strength [WMD = −4.729 kg, p = 0.12], leg press strength [WMD = −2.874 kg, p = 0.415], countermovement jump [WMD = −0.226 cm, p = 0.80], 400 m walk test performance [WMD = −8.794 s, p = 0.06], or gait speed [WMD = 0.005 m/s, p = 0.82] compared to exercise alone. Moreover, IF and CR combined with exercise decreased body weight [WMD = −4.375 kg, p = 0.001], BMI [WMD = −1.194 kg·m⁻², p = 0.001], FFM [WMD = −1.653 kg, p = 0.001], FM [WMD = −2.858 kg, p = 0.001], BFP [WMD = −0.826%, p = 0.001] compared to exercise alone. Conclusions: IF (hypocaloric or eucaloric) and CR can be effectively integrated into exercise training without negatively impacting most measures of physical performance, while significantly enhancing weight loss and adiposity-related outcomes. The findings from this meta-analysis involving both athletes and non-athletes suggest that weight loss induced by IF and CR combined with exercise does not necessarily result in reduced physical performance. In real-world scenarios, however, different outcomes are conceivable, as body composition, physical capacity, diet and exercise can vary considerably based on individual conditions. Full article

Background: Tribulus terrestris L. Zygophyllaceae (TT) is a plant that has been claimed to increase testosterone levels and improve sexual function, particularly erectile dysfunction, with potential benefits for male sexual health. Purpose: This systematic review aimed to evaluate the effectiveness of TT supplementation in improving sexual function and serum testosterone levels in men. Methods: We conducted a systematic review adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After searching the literature (n = 162), 52 studies were selected for full-text reading, and 10 studies were eligible for this review, comprising 9 clinical trials and 1 quasi-experimental study (a study without a control). The Jadad score revealed low methodological quality for 50% of the studies. Results: The studies involved 15 to 172 participants (total = 483) aged between 16 and 70 years with different health conditions: healthy men (n = 5), oligozoospermia (n = 1), erectile dysfunction (n = 1), erectile dysfunction associated with hypogonadism (n = 2), and unexplained infertility (n = 1). TT supplementation at doses of 400 to 750 mg/d for 1 to 3 months improved erectile dysfunction in 3 of the 5 studies that assessed this parameter. Eight out of ten studies did not report significant changes in androgen profile following TT supplementation, but the subjects in the neutral studies did not have low androgen levels at baseline. Therefore, only 2 studies showed significant intra-group increase in total testosterone levels, which had low clinical magnitude (60–70 ng/dL) and involved subjects with hypogonadism. Conclusions: TT supplementation has a low level of evidence regarding its effectiveness in improving erectile function in men with erectile dysfunction, and no robust evidence was found for increasing testosterone levels. Full article

Although the link between gut microbiota and obesity is increasingly reported, the pathophysiological mechanisms and clinical outcomes are still under debate. This overview of human and animal data addresses several pathophysiologic mechanisms, dietary habits, exercise and probiotic and symbiotic supplementation in the fields of gut microbiota and obesity. Overall, obesity impairs gut microbiota composition due to factors that may be linked to the onset of the disease, such as excessive consumption of high-energy foods, sugars and fats, as well as a low fiber intake and physical inactivity. Conversely, low-energy diets, physical exercise, and probiotic and prebiotic supplementations can enhance gut microbiota in patients with obesity, in addition to improving cardiometabolic markers. As for perspectives, further research is warranted to ascertain proper dietary manipulation, physical exercise protocols and dosing regimens of probiotics. Regarding the latter, the effects on indicators of obesity are clinically modest, and hence skepticism must be exercised. Full article

Myostatin, a secreted growth factor belonging to the transforming growth factor β (TGF-β) family, performs a role in hindering muscle growth by inhibiting protein kinase B (Akt) phosphorylation and the associated activation of hypertrophy pathways (e.g., IGF-1/PI3K/Akt/mTOR pathway). In addition to pharmacological agents, some supplements and nutraceutical agents have demonstrated modulatory effects on myostatin levels; however, the clinical magnitude must be appraised with skepticism before translating the mechanistic effects into muscle hypertrophy outcomes. Here, we review the effects of dietary supplements, nutraceutical agents, and physical exercise on myostatin levels, addressing the promise and pitfalls of relevant randomized clinical trials (RCTs) to draw clinical conclusions. RCTs involving both clinical and sports populations were considered, along with wasting muscle disorders (e.g., sarcopenia) and resistance training-induced muscle hypertrophy, irrespective of disease status. Animal models were considered only to expand the mechanisms of action, and observational data were consulted to elucidate potential cutoff values. Collectively, the effects of dietary supplements, nutraceutical agents, and physical exercise on myostatin mRNA expression in skeletal muscle and serum myostatin levels are not uniform, and there may be reductions, increases, or neutral effects. Large amounts of research using resistance protocols shows that supplements or functional foods do not clearly outperform placebo for modulating myostatin levels. Thus, despite some biological hope in using supplements or certain functional foods to decrease myostatin levels, caution must be exercised not to propagate the hope of the food supplement market, select health professionals, and laypeople. Full article

This study aimed to (i) characterise the body composition of professional and semi-professional male futsal players, (ii) assess the validity of commonly used equations to estimate FM%, (iii) develop and cross-validate a futsal-specific FM% prediction equation. In a cross-sectional design, 78 adult male futsal players were assessed for body mass, stature, skinfolds, and girths as per the International Society for the Advancement of Kinanthropometry protocol and completed a dual-energy X-ray absorptiometry (DXA) scan for reference body composition data. Using paired-sample t-tests, the FM% from the DXA and nine published equations were compared. New sport-specific models were developed by stepwise multiple regression. Existing equations were cross-validated using the least squares regression, concordance correlation coefficient, and the Bland–Altman analyses. New equations were further cross-validated using the PRESS approach. None of the existing equations accurately predicted the DXA-derived FM% (p < 0.001; R² ≤ 0.76, SEE ≥ 1.59; CCC ≤ 0.83; bias = −8.2% to −1.3%, limited agreement, and varying trends). The novel Bettery^® equation: −0.620 + (0.159 ∗ Σ4SKF [triceps, abdominal, iliac crest, and front thigh (mm)]) + (0.120 ∗ waist girth (cm)), demonstrated a high accuracy (R² = 0.85, SEE = 1.32%), a moderate strength of agreement (CCC = 0.92), no bias (0.2%), good agreement (±2.5%), and no trend (r = −0.157; p = 0.170) against the DXA. The Bettery^® equation is the first to allow for a valid and sport-specific assessment of FM% in male futsal players. Full article

Researchers and health practitioners seek to understand the upper limit of muscle hypertrophy under different conditions. Although there are models to estimate the muscle-building threshold in drug-free resistance training practitioners, little is known about the population using anabolic–androgenic steroids (AASs) in this regard. Because of a plateau effect of muscle hypertrophy upon AAS regimens, there is a hypothesis among clinicians and enthusiasts that AASs downregulate skeletal muscle androgen receptors (ARs). Conversely, in this narrative review, we show that seminal and recent evidence—primarily using testosterone and oxandrolone administration as human experimental models—support that AASs upregulate ARs, eliciting greater anabolic effects on skeletal muscle receptors through a dose-dependent relationship. Thus, to date, there is no scientific basis for claiming that myocyte AR downregulation is the cause of the AAS-induced plateau in muscle gains. This phenomenon is likely driven by the neutral nitrogen balance, but further research is imperative to clarify the intrinsic mechanisms related to this landscape. Full article

Increased risk of prostate diseases triggered by testosterone replacement therapy (TRT) remains a worldwide concern. That said, we reviewed the safety of TRT in the spheres of benign prostatic hyperplasia (BPH) and prostate cancer (PCa), exploring clinical findings in this regard. Compelling evidence based on meta-analyses of randomized and observational studies indicates safety for TRT in patients suffering from prostate disorders such as BPH and PCa, at the same time improving lower tract urinary symptoms. Thus, the harmful relationship geared toward androgens and BPH seems to be overestimated as TRT has sufficient safety and, if properly prescribed, may counteract several metabolic problems. Even after PCa treatment, the benefits of TRT could outweigh the risk of recurrence, but further long-term randomized clinical trials are needed to elucidate unresolved questions. Full article

Clinical studies addressing the benefits of intermittent fasting (IF) diets have evoked interest in the treatment of obesity. Herein, the overall effects of IF regimens on fat-mass loss are explained in a brief review through a recent literature update. To date, human studies show a reduction in fat mass from 0.7 to 11.3 kg after IF regimens, in which the duration of interventions ranges from two weeks to one year. In light of this, IF regimens can be considered a reasonable approach to weight (fat mass) loss. However, the benefits of IF regimens occur thanks to energy restriction and cannot hence be considered the best dietary protocol compared to conventional diets. Full article

Cardiovascular diseases remain a global challenge, and lipid-associated biomarkers can predict cardiovascular events. Extensive research on cardiovascular benefits of omega-3 polyunsaturated fatty acids (n3-PUFAs) is geared towards fish oil supplementation and fish-rich diets. Nevertheless, vegetarianism and veganism are becoming more popular across all segments of society, due to reasons as varied as personal, ethical and religious values, individual preferences and environment-related principles, amongst others. Due to the essentiality of PUFAs, plant sources of n3-PUFAs warrant further consideration. In this review, we have critically appraised the efficacy of plant-derived n3-PUFAs from foodstuffs and supplements upon lipid profile and selected cardiometabolic markers. Walnuts and flaxseed are the most common plant sources of n3-PUFAs, mainly alpha-linolenic acid (ALA), and feature the strongest scientific rationale for applicability into clinical practice. Furthermore, walnuts and flaxseed are sources of fibre, potassium, magnesium, and non-essential substances, including polyphenols and sterols, which in conjunction are known to ameliorate cardiovascular metabolism. ALA levels in rapeseed and soybean oils are only slight when compared to flaxseed oil. Spirulina and Chlorella, biomasses of cyanobacteria and green algae, are important sources of n3-PUFAs; however, their benefits upon cardiometabolic markers are plausibly driven by their antioxidant potential combined with their n3-PUFA content. In humans, ALA is not sufficiently bioconverted into eicosapentaenoic and docosahexaenoic acids. However, evidence suggests that plant sources of ALA are associated with favourable cardiometabolic status. ALA supplementation, or increased consumption of ALA-rich foodstuffs, combined with reduced omega-6 (n6) PUFAs intake, could improve the n3/n6 ratio and improve cardiometabolic and lipid profile. Full article

A scientific interest has emerged to identify pharmaceutical and nutritional strategies in the clinical management of coronavirus disease 2019 (COVID-19). The purpose of this narrative review is to critically assess and discuss pharmaconutrition strategies that, secondary to accepted treatment methods, could be candidates in the current context of COVID-19. Oral medicinal doses of vitamin C (1–3 g/d) and zinc (80 mg/d elemental zinc) could be promising at the first signs and symptoms of COVID-19 as well as for general colds. In critical care situations requiring parenteral nutrition, vitamin C (3–10 g/d) and glutamine (0.3–0.5 g/kg/d) administration could be considered, whereas vitamin D3 administration (100,000 IU administered intramuscularly as a one-time dose) could possess benefits for patients with severe deficiency. Considering the presence of n-3 polyunsaturated fatty acids and arginine in immune-enhancing diets, their co-administration may also occur in clinical conditions where these formulations are recommended. However, despite the use of the aforementioned strategies in prior contexts, there is currently no evidence of the utility of any nutritional strategies in the management of SARS-CoV-2 infection and COVID-19. Nevertheless, ongoing and future clinical research is imperative to determine if any pharmaconutrition strategies can halt the progression of COVID-19. Full article

Background: Our aim was to associate serum uric acid (UA) with muscle mass, strength and functional capacity in kidney transplant patients (KTPs). Methods: A cross-sectional study was performed on 113 KTPs. The fat-free mass and total and appendicular muscle mass were estimated by performing a bioelectrical impedance analysis. The strength was evaluated using the handgrip strength test (HGS) and the five times sit to stand test (5STS). The functional capacity was evaluated using the 4 m walk test and the short physical performance battery (SPPB). Results: Linear regression showed that the UA levels were positively associated with the muscle mass, fat-free mass, appendicular muscle mass, muscle mass index and appendicular muscle mass index. The 5STS results (seconds) were inversely associated with the UA levels, showing that individuals with higher UA were more likely to have more strength. However, UA was not associated with the HGS, 4 m walk test and SPPB results. Conclusion: UA levels were positively associated with muscle mass and strength, but not with functional capacity, in KTPs. Full article

The origin of the hepatitis B virus is a subject of wide deliberation among researchers. As a result, increasing academic interest has focused on the spread of the virus in different animal species. However, the sources of viral infection for many of these animals are unknown since transmission may occur from animal to animal, human to human, animal to human, and human to animal. The aim of this study was to evaluate hepadnavirus circulation in wild and farm animals (including animals raised under wild or free conditions) from different sites in Brazil and Uruguay using serological and molecular tools. A total of 487 domestic wild and farm animals were screened for hepatitis B virus (HBV) serological markers and tested via quantitative and qualitative polymerase chain reaction (PCR) to detect viral DNA. We report evidence of HBsAg (surface antigen of HBV) and total anti-HBc (HBV core antigen) markers as well as low-copy hepadnavirus DNA among domestic and wild animals. According to our results, which were confirmed by partial genome sequencing, as the proximity between humans and animals increases, the potential for pathogen dispersal also increases. A wider knowledge and understanding of reverse zoonoses should be sought for an effective One Health response. Full article