Effects of a low-carbohydrate/high-protein diet on metabolic health in individuals with chronic spinal cord injury: An exploratory analysis of results from a randomized controlled trial

Unraveling Spinal Cord Injury Nutrition: Effects of Diet on the Host and Microbiome

Spinal cord injury (SCI) leads to severe neurological dysfunction with significant nutritional alterations. These alterations are closely associated with gut dysbiosis and neurogenic gut dysfunction after SCI, creating complex interactions that further exacerbate metabolic disturbances and impede neurological recovery. In the context of SCI, diet not only fulfills basic nutritional needs but also serves as an important therapeutic tool to modulate these interactions. This review provides a broad overview of existing research findings, analyzes the impact of existing dietary interventions on SCI, and attempts to clarify the complex relationship between diet and host and gut microbiota. We hope to provide a clear direction for future research and a scientific basis for the development of personalized dietary interventions to improve the nutritional status of SCI patients, reduce the incidence of complications such as metabolic disorders, and promote the recovery of neurological function and overall quality of life of SCI patients. STATEMENT OF SIGNIFICANCE: This review evaluates the nutritional changes in patients with spinal cord injury, comprehensively elucidating the effects of dietary interventions on SCI patients from both the host and gut microbiota perspectives. By revealing the complex interactions among them, it lays the foundation for developing personalized nutritional intervention strategies to optimize recovery and improve long-term health outcomes in the future.

Impact of other macronutrient composition within high-protein diet on body composition and cardiometabolic health: a systematic review, pairwise, and network meta-analysis of randomized controlled trials

BACKGROUND/OBEJCTIVE

Although the high-protein diets (HPDs) on weight control and body composition management are well investigated, mix results have been reported across studies and this variability may be attributed to differences in the composition of other macronutrients within HPDs. The aim of this study was to evaluate the impacts of HPDs with varied macronutrient compositions on body composition and cardiometabolic health outcomes through a systematic review, pairwise, and network meta-analysis.

METHODS

A comprehensive search of four databases (PubMed, Embase, CINAHL, and Web of Science) was conducted to identify relevant randomized controlled trials. A total of 83 articles were selected for systematic review and both meta-analyses.

RESULTS

Significant reduction in body mass (BM) (standardized mean difference [SMD] = -0.25; 95% CI: -0.40, -0.11), body mass index (BMI) (SMD = -0.26; 95% CI: -0.38, -0.15), waist circumference (WC) (SMD = -0.19; 95% CI: -0.33, -0.04), fat mass (FM) (mean difference [MD] = -0.64 kg; 95% CI: -0.98, -0.29), along with increase in lean body mass (LBM) (MD = 0.34 kg; 95% CI: 0.11, 0.57) were observed with HPDs regiments compared to normal-protein diets. Specifically, the high-protein, moderate-carbohydrate and high-fat diet ranked the best in reducing BM, BMI, WC, FM, systolic blood pressure, diastolic blood pressure and increasing LBM; while the high-protein, low-carbohydrate and high-fat diet obtained the highest score in reducing triglyceride and increasing high-density lipoprotein cholesterol.

CONCLUSION

HPDs effectively reduce FM and increase LBM, and offers potential cardiometabolic benefits. Additionally, the manipulation of carbohydrate content in HPDs may further influence these outcomes.

REGISTRATION

PROSPERO (CRD42023483907).

The effect of low-carbohydrate diets, based on changes in intake of dietary saturated fats on circulating TNF-α and interleukin- 6 levels in adults: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Low-carbohydrate diets (LCDs) have been associated with inflammation while there is still conflicting evidence regarding the effects of this type of diet on inflammatory markers and the clinical benefit of them remains uncertain. So, we aimed to ascertain the effects of LCDs on serum concentrations of tumor necrosis factor alpha (TNF-α) and interleukin- 6 (IL- 6) by performing a systematic review and meta-analysis of randomized clinical trials (RCTs).

METHODS

The online databases PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Web of Science, and Scopus were comprehensively searched up to February 2024, to find pertinent RCTs. Pooled weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated using the random-effects model.

RESULTS

This meta-analysis of 33 studies assessed a total of 2106 adults irrespective of their health status. Compared with control group, participants on LCDs experienced a decline in IL- 6 levels (WMD: - 0.31 pg/mL; 95% CI: - 0.49 to - 0.12; P = 0.001). However, no significant effect was revealed for TNF-α (WMD: - 0.02 pg/mL; 95% CI: - 0.08 to - 0.03; P = 0.449). Stratification analyses indicated that beneficial effects of LCDs on inflammatory cytokines (WMD: - 0.28 pg/mL; 95% CI: - 0.47 to - 0.10; P = 0.003, WMD: - 0.26 pg/mL; 95% CI: - 0.48 to - 0.03; P = 0.027, for TNF-α and IL- 6, respectively) were stronger when carbohydrate intake was < 10%. The results of Meta-regression analyses suggested that baseline level of both markers remained as a strong predictor of the effect size (P = 0.038 and P = 0.001 for TNF-α and IL- 6, respectively).

CONCLUSION

Adherence to LCDs appeared to be effective at improving inflammatory cytokines particularly, when carbohydrate intake was restricted to less than 10% of total energy. Nevertheless, further rigorously designed clinical trials considering factors such as race and genetic, the sources and quality of dietary carbohydrates, protein, and fat are required to gain a deeper understanding of the impact of LCDs on inflammatory markers.

TRIAL REGISTRATION

PROSPERO, registration no: CRD42023387452.

The Long-Term Treatment of Drug-Resistant Migraine with the Modified Atkins Ketogenic Diet: A Single-Center, Retrospective Study

Despite advances in pharmacological therapies, migraine patients are often drug resistant. Further therapeutic options in this field are, therefore, desirable. Recent studies have highlighted the efficacy of ketogenic diet (KD) on improving migraine, but data on their long-term efficacy and safety are lacking. In this study, we retrospectively evaluated the long-term effectiveness of the modified Atkins ketogenic diet (MAD) in episodic or chronic drug-resistant migraine patients. 52 patients diagnosed with episodic or chronic drug-resistant migraine under modified Atkins ketogenic diet (MAD) were evaluated. In total, 41 patients followed the diet for 6 months and 33 for 12 months. After both 6 and 12 months, frequency, length, and intensity of migraine episodes, as well as the number of medications significantly decreased with respect to the start of the diet. Body mass index, high sensitivity PCR, diastolic blood pressure, fasting plasma insulin and HOMA index were also significantly reduced both after 6 and 12 months. No major metabolic changes were observed during MAD treatment. In conclusion, KD has been shown to be effective and safe in the long-term treatment of drug-resistant migraine. A high dropout rate still remains an important factor, which often limits its use.

The comparison of total energy and protein intake relative to estimated requirements in chronic spinal cord injury

In chronic spinal cord injury (SCI), individuals experience dietary inadequacies complicated by an understudied research area. Our objectives were to assess (1) the agreement between methods of estimating energy requirement (EER) and estimated energy intake (EEI) and (2) whether dietary protein intake met SCI-specific protein guidelines. Persons with chronic SCI (n = 43) completed 3-day food records to assess EEI and dietary protein intake. EER was determined with the Long and Institute of Medicine (IOM) methods and the SCI-specific Farkas method. Protein requirements were calculated as 0·8-1·0 g/kg of body weight (BW)/d. Reporting accuracy and bias were calculated and correlated to body composition. Compared with IOM and Long methods (P < 0·05), the SCI-specific method did not overestimate the EEI (P = 0·200). Reporting accuracy and bias were best for SCI-specific (98·9 %, -1·12 %) compared with Long (94·8 %, -5·24 %) and IOM (64·1 %, -35·4 %) methods. BW (r = -0·403), BMI (r = -0·323) and total fat mass (r = -0·346) correlated with the IOM reporting bias (all, P < 0·05). BW correlated with the SCI-specific and Long reporting bias (r = -0·313, P = 0·041). Seven (16 %) participants met BW-specific protein guidelines. The regression of dietary protein intake on BW demonstrated no association between the variables (β = 0·067, P = 0·730). In contrast, for every 1 kg increase in BW, the delta between total and required protein intake decreased by 0·833 g (P = 0·0001). The SCI-specific method for EER had the best agreement with the EEI. Protein intake decreased with increasing BW, contrary to protein requirements for chronic SCI.

A Randomized, Placebo-Controlled Crossover Study to Evaluate Postprandial Glucometabolic Effects of Mulberry Leaf Extract, Vitamin D, Chromium, and Fiber in People with Type 2 Diabetes

INTRODUCTION

Reducing postprandial (PP) hyperglycemia and PP glucose excursions is important for overall glycemic management. Although most therapeutic lifestyle interventions that reduce caloric intake would affect this, there is no particular nutritional intervention favored.

METHODS

We evaluated the effects of a novel natural food adjuvant combining mulberry leaf extract (MLE) with other bioactive ingredients, in people with type 2 diabetes (T2D) originating from Asia, on improving PP glucometabolic response in a randomized controlled exploratory crossover, two-center study (USA, Singapore). A 2-g blend of 250 mg MLE [containing 12.5 mg of 1-deoxynojirimycin (DNJ)], fiber (1.75 g), vitamin D₃ (0.75 μg), and chromium (75 μg), compared with a similar blend without the MLE, was sprinkled over a 350-kcal breakfast meal (55.4 g carbs) and PP blood glucose (primary exploratory endpoint), insulin, and incretin hormones (GLP-1, GIP) were evaluated in blood samples over 3 h. Changes in incremental areas under the concentration curve (iAUC) and maximum concentrations (C_max) were compared.

RESULTS

Thirty individuals (12 women, mean age 59 years, HbA1c 7.1%, BMI 26.5 kg/m²) were enrolled and the MLE-based blend relative to the blend without MLE significantly reduced glucose iAUC at 1 h (- 20%, p < 0.0001), 2 h (- 17%, p = 0.0001), and 3 h (- 15%, p = 0.0032) and C_max [mean (95% CI) difference - 0.8 (- 1.2, - 0.3) mmol/L, p = 0.0006]. A statistically significant reduction in 1 h insulin iAUC (- 24%, p = 0.0236) was observed, but this reduction was no longer present at either 2 h or 3 h. No difference in GLP-1 was seen, but GIP response (iAUC and C_max) was less with the MLE-based blend.

CONCLUSIONS

The observation of a significant glucose reduction paralleled with a significant lower insulin response supports a reduced gastrointestinal glucose absorption. These results support the use of a 2-g natural blend of MLE, fiber, vitamin D, and chromium in T2D as a convenient dietary adjuvant to improve PP glucometabolic response.

CLINICALTRIALS

gov identifier NCT04877366.