The effect of soy intervention on insulin-like growth factor 1 levels: A meta-analysis of clinical trials

From Garden to Pillow: Understanding the Relationship between Plant-Based Nutrition and Quality of Sleep

The effect of diet on sleep quality has been addressed in many studies; however, whether/how plant-based diets (PBDs) impact sleep-related parameters has not been explored in detail. This review aims to give an overview of the components of PBDs and the possible mechanisms through which PBDs may improve sleep quality. Studies have indicated that diets such as PBDs, which are typically high in fruits, vegetables, nuts, seeds, whole grains, and fiber, are associated with better sleep outcomes, including less fragmented sleep and improved sleep duration. Several mechanisms may explain how PBDs impact and/or improve sleep outcomes. Firstly, PBDs are characteristically rich in certain nutrients, such as magnesium and vitamin B6, which have been associated with improved sleep patterns. Secondly, PBDs are often lower in saturated fats and higher in fiber, which may contribute to better overall health, including sleep quality. Additionally, plant bioactive compounds like phytochemicals and antioxidants in fruits, vegetables, and herbs may have sleep-promoting effects. According to available data, PBD and Mediterranean diet elements promise to enhance sleep quality; however, it is crucial to note that diets should be customized based on each person's needs.

The skeletal safety of milk-derived proteins: A meta-analysis of randomized controlled trials

PURPOSE

There has been a persistent claim that dairy products contain calcium-leaching proteins, although the soundness of such a claim has been challenged. A meta-analysis of randomized controlled trials (RCTs) on the effects of milk-derived protein supplementation on bone health indices in adults was performed to reconcile the controversy surrounding the potential skeletal safety concerns of proteins of dairy origin.

METHODS

The PubMed and Web of Science databases were searched for relevant RCTs. A random-effects model was used to generate pooled effect sizes and 95% confidence intervals.

RESULTS

Milk-derived protein supplementation did not significantly affect whole-body BMD (n = 7 RCTs) and BMD at the lumbar spine (n = 10), hip (n = 8), femoral neck (n = 9), trochanter (n = 5), intertrochanter (n = 2), and ultradistal radius (n = 2). The concentrations of bone formation markers (bone-specific alkaline phosphatase [n = 11], osteocalcin [n = 6], procollagen type 1 amino-terminal propeptide [n = 5]), bone resorption markers (N-terminal telopeptide of type 1 collagen [n = 7], C-terminal telopeptide of type 1 collagen [n = 7], deoxypyridinoline [n = 4]), and parathyroid hormone (n = 7) were not significantly affected. However, increased insulin-like growth factor-1 (IGF-1) concentrations (n = 13) were observed. Reduced IGF-1 concentrations were observed when soy protein was used as a comparator, and increased IGF-1 concentrations were observed when carbohydrate was used.

CONCLUSION

Our findings do not support the claim that proteins of dairy origin are detrimental to bone health.

Weight loss efficiency and safety of tirzepatide: A Systematic review

OBJECTIVE

Tirzeptide is a novel glucagon-like peptide-1 receptor (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) drug, which shows good efficiency for weight loss. Therefore, we aim to investigate the efficacy and safety of tirzepatide for weight loss in type 2 diabetes mellitus (T2DM) and obesity patients in this meta-analysis study.

METHODS

Cochrane Library, PubMed, Embase, Clinical Trials, and Web of Science were searched from inception to October 5, 2022. All randomized controlled trials (RCTs) were included. The odds ratio (OR) was calculated using fixed-effects or random-effects models by Review Manager 5.3 software.

RESULTS

In total, ten studies (12 reports) involving 9,873 patients were identified. A significant loss body weight in the tirzepatide group versus the placebo by -9.81 kg (95% CI (-12.09, -7.52), GLP-1 RAs by -1.05 kg (95% CI (-1.48, -0.63), and insulin by -1.93 kg (95% CI (-2.81, -1.05), respectively. In sub-analysis, the body weight of patients was significantly reduced in three tirzepatide doses (5 mg, 10 mg, and 15 mg) when compared with those of the placebo/GLP-1 RA/insulin. In terms of safety, the incidence of any adverse events and adverse events leading to study drug discontinuation was higher in the tirzepatide group, but the incidence of serious adverse events and hypoglycaemia was lower. Additionally, the gastrointestinal adverse events (including diarrhea, nausea, vomiting and decreased appetite) of tirzepatide were higher than those of placebo/basal insulin, but similar to GLP-1 RAs.

CONCLUSION

In conclusion, tirzeptide can significantly reduce the weight of T2DM and patient with obesity, and it is a potential therapeutic regimen for weight-loss, but we need to be vigilant about its gastrointestinal reaction.

Soy Isoflavones and Bone Health: Focus on the RANKL/RANK/OPG Pathway

Bone remodels via resorption and formation, two phenomena that continuously occur in bone turnover. The RANKL/RANK/OPG pathway is one of the several mechanisms that affect bone turnover. The RANKL/OPG ratio has a substantial role in bone resorption. An imbalance between formation and resorption is related to an increased RANKL/OPG balance. OPG, a member of this system, can bind to RANKL and suppress RANK-RANKL interaction, and subsequently, inhibit further osteoclastogenesis. The serum levels of RANKL and OPG in the bone microenvironment are vital for osteoclasts formation. The RANK/RANKL/OPG system plays a role in the pathogenesis of bone disorders. This system can be considered a new treatment target for bone disorders. Soy isoflavones affect the RANK/RANKL/OPG system through numerous mechanisms. Soy isoflavones decrease RANKL levels and increase OPG levels. Therefore, isoflavones improve bone metabolism and decrease bone resorption. Soy isoflavones decrease serum markers of bone resorption and improve bone metabolism. However, while the available data are promising, the results of several studies reported no change in RANKL and OPG levels with isoflavones supplementation. In this regard, current evidence is insufficient for conclusive approval of the efficacy of isoflavones on RANKL/RANK/OPG and further research, including animal and human studies, are needed to confirm the effect of soy isoflavones on the RANKL/RANK/OPG pathway. This study was a review of available evidence to determine the role of isoflavones in bone hemostasis and the RANK/RANKL/OPG pathway. The identification of the effects of isoflavones on the RANKL/RANK/OPG pathway directs future studies and leads to the development of effective treatment strategies for bone disorders.

The Use of Post-Natal Skeleton Development as Sensitive Preclinical Model to Test the Quality of Alternative Protein Sources in the Diet

Dietary protein is necessary throughout all life stages. Adequate intake of protein during juvenile years is essential to enable appropriate synthesis of bone matrix and achieve the full peak bone mass (PBM). Due to socio-demographic changes, accompanied by environmental damage and ethical problems, a transition to the consumption of different and alternative protein sources in the human diet must occur. This transition requires the precise evaluation of protein quality. Here, we utilize a preclinical model of young rats during their post-natal developmental period to define the nutritive quality of a number of alternative protein sources (soy, spirulina, chickpea, and fly larvae) by their health impact on growth performance and skeletal development. We indicate that when restricted (10% of calories) not one of the tested alternative protein sources have succeeded in causing optimal growth, as compared to the referenced source, casein; yet fly larvae protein followed by chickpea flour were found to be superior to the rest. Growth-plate histology and µ-CT analyses demonstrated a number of changes in growth patterns and bone morphometric parameters. Bone mechanical testing, by three-point bending analyses, was sensitive in demonstrating the effect of the reduction in the amount of the dietary protein. Moreover, the rats' weight and length, as well as their eating patterns, were found to reflect the proteins' quality better than their amino acid composition. Hence, our study emphasizes the importance of evaluating protein as a whole food source, and suggests a new approach for this purpose.

Effects of Soy Isoflavones on Biochemical Markers of Bone Metabolism in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis of randomized controlled trials was performed to more completely assess potential changes in bone turnover marker levels in postmenopausal women during the intake of soy isoflavones. PubMed (Medline) and EMBASE were searched for relevant studies, and their quality was evaluated according to Cochrane criteria. The levels of markers were evaluated in a total of 1114 women who ingested mean daily doses of 98.2 mg (30.9 to 300) of soy isoflavones for 3 to 24 months, in comparison to those of 1081 subjects who used a placebo. Ten, eighteen, eight, and fourteen comparison studies were finally selected for an estimation of the effects on osteocalcin (OC), bone alkaline phosphatase (BAP), pyridinoline (PYD), and deoxypyridinoline (DPD), respectively. A summary of the results of intervention was as follows: 4.16%, 95% CI: -7.72-16.04, p = 0.49 for OC; 5.50%, 95% CI: -3.81-14.82, p = 0.25 for BAP; -12.09%, 95% CI: -25.37-1.20, p = 0.07 for PYD; and -7.48%, 95% CI: -15.37-0.41, p = 0.06 for DPD. The meta-analysis of the included studies revealed some statistically insignificant observations that soy isoflavones intake is associated with a trend in increased levels of OC and BAP, as well as a trend in reduced levels of PYD and DPD. Soy isoflavones may have a beneficial effect on bone formation markers, but this requires extensive multi-center research.

Soy intake is associated with lowering blood pressure in adults: A systematic review and meta-analysis of randomized double-blind placebo-controlled trials

BACKGROUND

Soy has several beneficial effects on cardiovascular disease (CVD); however, results of clinical trial studies are equivocal. Thus, the present study sought to discern the efficacy of soy intake on blood pressure.

METHODS

The search process was conducted in PubMed, Scopus, Web of Science, and Cochrane Library, to ascertain studies investigating the efficacy of soy intake on blood pressure in adults, published up to June 2020. A random-effects model was applied to pool mean difference and 95 % confidence interval (CI). Begg's and Egger's methods were conducted to assess publication bias.

RESULTS

Pooled effects from 17 effect sizes revealed a significant improvement in systolic blood pressure (SBP) (-1.70; -3.34 to -0.06 mmHg; I² = 45.4 %) and diastolic blood pressure (DBP) (-1.27; -2.36 to -0.19 mmHg, I² = 43.9 %) following soy consumption, in comparison with controls. Subgroup analysis demonstrated a reduction in both SBP and DBP in younger participants with lower baseline DBP and intervention durations of <16 weeks.

CONCLUSION

Our results suggest that soy intake is associated with an ameliorating effect on blood pressure in adults.

Impact of dehydroepianrosterone (DHEA) supplementation on serum levels of insulin-like growth factor 1 (IGF-1): A dose-response meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Inconsistencies exist with regard to the influence of dehydroepiandrosterone (DHEA) supplementation on insulin-like growth factor 1 (IGF-1) levels. The inconsistencies could be attributed to several factors, such as dosage, gender, and duration of intervention, among others. To address these inconsistencies, we conducted a systematic review and meta-analysis to combine findings from randomized controlled trials (RCTs) on this topic.

METHODS

Electronic databases (Scopus, PubMed/Medline, Web of Science, Embase and Google Scholar) were searched for relevant literature published up to February 2020.

RESULTS

Twenty-four qualified trials were included in this meta-analysis. It was found that serum IGF-1 levels were significantly increased in the DHEA group compared to the control (weighted mean differences (WMD): 16.36 ng/ml, 95% CI: 8.99, 23.74; p = .000). Subgroup analysis revealed that a statistically significant increase in serum IGF-1 levels was found only in women (WMD: 23.30 ng/ml, 95% CI: 13.75, 32.87); in participants who supplemented 50 mg/d DHEA (WMD: 15.75 ng/ml, 95% CI: 7.61, 23.89); in participants undergoing DHEA intervention for >12 weeks (WMD: 17.2 ng/ml, 95% CI: 8.02, 26.22); in participants without an underlying comorbidity (WMD: 19.11 ng/ml, 95% CI: 10.69, 27.53); and in participants over the age of 60 years (WMD: 19.79 ng/ml, 95% CI: 9.86, 29.72).

CONCLUSION

DHEA supplementation may increase serum IGF-I levels especially in women and older subjects. However, further studies are warranted before DHEA can be recommended for clinical use.