The effect of herbs and spices on risk factors for cardiometabolic diseases: a review of human clinical trials

Ginger intervention on body weight and body composition in adults: a GRADE-assessed systematic review and dose-response meta-analysis of 27 randomized controlled trials

CONTEXT

Ginger consumption may have an inverse relationship with obesity and metabolic syndrome parameters; however, clinical trials have reported contradictory results.

OBJECTIVE

To systematically review and analyze randomized controlled trials (RCTs) assessing the effects of ginger on body weight and body composition parameters.

METHODS

Databases were searched for appropriate articles up to August 20, 2022. All selected RCTs investigated the impact of ginger on glycemic indices in adults. A random effects model was used to conduct a meta-analysis, and heterogeneity was assessed using the I2 statistic. Net changes in body weight, body mass index (BMI), waist circumference (WC), and percent body fat were used to calculate the effect size, which was reported as a weighted mean difference (WMD) and 95% confidence intervals (CIs). The risk of bias was assessed.

RESULTS

A total of 27 RCTs involving 1309 participants were included. The certainty in the evidence was very low for WC and BMI, and low for body weight and percent body fat as assessed by the GRADE evidence profiles. The meta-analysis showed a significant association between ginger supplementation and a reduction in body weight (WMD, -1.52 kg; 95%CI, -2.37, -0.66; P < 0.001), BMI (WMD, -0.58 kg/m2; 95%CI, -0.87, -0.30; P < 0.001), WC (WMD, -1.04 cm; 95%CI: -1.93, -0.15; P = 0.021), and percent body fat consumption (WMD, -0.87%; 95%CI, -1.71, -0.03; P = 0.042). The results of the nonlinear dose-response analysis showed a significant association between the ginger dose with body weight (Pnonlinearity = 0.019) and WC (Pnonlinearity = 0.042). The effective dose of ginger intervention for body mass reduction was determined to be 2 g/d in dose-response analysis. The duration of ginger intervention had a significant nonlinear relationship with body weight (Pnonlinearity = 0.028) with an effective duration of longer than 8 weeks.

CONCLUSIONS

Our findings provide evidence that ginger consumption may significantly affect body composition parameters nonlinearly. More, well-constructed RCTs are needed.

Causal Relationship between Meat Intake and Biological Aging: Evidence from Mendelian Randomization Analysis

Existing research indicates that different types of meat have varying effects on health and aging, but the specific causal relationships remain unclear. This study aimed to explore the causal relationship between different types of meat intake and aging-related phenotypes. This study employed Mendelian randomization (MR) to select genetic variants associated with meat intake from large genomic databases, ensuring the independence and pleiotropy-free nature of these instrumental variables (IVs), and calculated the F-statistic to evaluate the strength of the IVs. The validity of causal estimates was assessed through sensitivity analyses and various MR methods (MR-Egger, weighted median, inverse-variance weighted (IVW), simple mode, and weighted mode), with the MR-Egger regression intercept used to test for pleiotropy bias and Cochran's Q test employed to evaluate the heterogeneity of the results. The findings reveal a positive causal relationship between meat consumers and DNA methylation PhenoAge acceleration, suggesting that increased meat intake may accelerate the biological aging process. Specifically, lamb intake is found to have a positive causal effect on mitochondrial DNA copy number, while processed meat consumption shows a negative causal effect on telomere length. No significant causal relationships were observed for other types of meat intake. This study highlights the significant impact that processing and cooking methods have on meat's role in health and aging, enhancing our understanding of how specific types of meat and their preparation affect the aging process, providing a theoretical basis for dietary strategies aimed at delaying aging and enhancing quality of life.

Potential Benefit of Spices for Glycemic Control

The prevalence of hyperglycemia is increasing worldwide in large part due to the escalating prevalence of obesity. It can occur along with other disorders and diseases, contributing to escalating health costs and accumulating disabilities. Besides dietary approaches and availability of antidiabetic medications, other complementary approaches and adjunct therapies using biologically active botanical phytochemicals have received growing attention for managing type 2 diabetes mellitus. Spices are one source of these bioactive plant constituents, and considerable preclinical studies have investigated their possible health benefits. There also are an increasing number of human clinical trials assessing the ability of spices and their individual plant constituents to improve glucose homeostasis in those with type 2 diabetes mellitus and other dysglycemic conditions. This narrative review provides a summary of the human studies evaluating the effects of select spices on glucose homeostasis and highlights areas for future research.

Barriers to accessing care for cardiometabolic disorders in Malawi: partners as a source of resilience for people living with HIV

BACKGROUND

People living with HIV (PLWH) are at increased risk of cardiometabolic disorders (CMD). Adequate access to care for both HIV and CMD is crucial to improving health outcomes; however, there is limited research that have examined couples' experiences accessing such care in resource-constrained settings. We aimed to identify barriers to accessing CMD care among PLWH in Malawi and the role of partners in mitigating these barriers.

METHODS

We conducted a qualitative investigation of barriers to CMD care among 25 couples in Malawi. Couples were eligible if at least one partner was living with HIV and had hypertension or diabetes (i.e., the index patient). Index patients were recruited from HIV care clinics in the Zomba district, and their partners were enrolled thereafter. Interviews were conducted separately with both partners to determine barriers to CMD care access and how partners were involved in care.

RESULTS

Participants framed their experiences with CMD care by making comparisons to HIV treatment, which was free and consistently available. The main barriers to accessing CMD care included shortage of medications, cost of tests and treatments, high cost of transportation to health facilities, lengthy wait times at health facilities, faulty or unavailable medical equipment and supplies, inadequate monitoring of patients' health conditions, some cultural beliefs about causes of illness, use of herbal therapies as an alternative to prescribed medicine, and inadequate knowledge about CMD treatments. Partners provided support through decision-making on accessing medical care, assisting partners in navigating the healthcare system, and providing financial assistance with transportation and treatment expenses. Partners also helped manage care for CMD, including communicating health information to their partners, providing appointment reminders, supporting medication adherence, and supporting recommended lifestyle behaviors.

CONCLUSIONS

Couples identified many barriers to CMD care access, which were perceived as greater challenges than HIV care. Partners provided critical forms of support in navigating these barriers. With the rise of CMD among PLWH, improving access to CMD care should be prioritized, using lessons learned from HIV and integrated care approaches. Partner involvement in CMD care may help mitigate most barriers to CMD care.

A Scoping Review of the Clinical Evidence for the Health Benefits of Culinary Doses of Herbs and Spices for the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is a growing global health problem. Evidence suggests that diets rich in phytochemical-containing herbs and spices can contribute to reducing the risk of chronic diseases. This review assesses the scope of evidence supporting the use of herbs and spices in the diet for the prevention or treatment of MetS and its associated health conditions. A search of the PubMed, Scopus and Google Scholar databases was carried out to assess the available clinical evidence for culinary doses of commonly used herbs and spices. Trials that were measuring health factors related to metabolic disorders in healthy individuals, or the health of individuals with MetS or associated diseases, were included. Out of a total of 1738 papers identified, there were 142 relevant studies on black pepper, chilli, cardamom, cinnamon, coriander, cumin, fennel, fenugreek, garlic, ginger, nigella seed, rosemary, sage and turmeric. No relevant research was found for cloves, mint, oregano, parsley or thyme. Cinnamon, fenugreek and ginger were the herbs/spices with the most published trials on them and that showed promise for glycaemic control. Cardamom appears to have potential to reduce inflammatory markers, and cinnamon, ginger and turmeric to reduce blood lipids. Patients with type 2 diabetes were the population most likely to be included in studies, but the preventative benefits of herbs/spices in healthy populations were also investigated, particularly for chilli, ginger and cinnamon. There is evidence for the beneficial effect of culinary doses of many common herbs/spices in the prevention and treatment of MetS and associated disorders.

Herbs and Spices Modulate Gut Bacterial Composition in Adults at Risk for CVD: Results of a Prespecified Exploratory Analysis from a Randomized, Crossover, Controlled-Feeding Study

BACKGROUND

Herbs and spices are rich in polyphenolic compounds that may influence gut bacterial composition. The effect of culinary doses of herbs and spices consumed as part of a well-defined dietary pattern on gut bacterial composition has not been previously studied.

OBJECTIVES

The aim of this prespecified exploratory analysis was to examine gut bacterial composition following an average American diet (carbohydrate: 50% kcal; protein: 17%; total fat: 33%; saturated fat: 11%) containing herbs and spices at 0.5, 3.3, and 6.6 g.d^-1.2100 kcal^-1 [low-, moderate-, and high-spice diets, respectively (LSD, MSD, and HSD)] in adults at risk for CVD.

METHODS

Fifty-four adults (57% female; mean ± SD age: 45 ± 11 y; BMI: 29.8 ± 2.9 kg/m²; waist circumference: 102.8 ± 7.1 cm) were included in this 3-period, randomized, crossover, controlled-feeding study. Each diet was provided for 4 wk with a minimum 2-wk washout period. At baseline and the end of each diet period, participants provided a fecal sample for 16S rRNA gene (V4 region) sequencing. QIIME2 was used for data filtration, sequence clustering, taxonomy assignment, and statistical analysis.

RESULTS

α-diversity assessed by the observed features metric ( P = 0.046) was significantly greater following the MSD as compared with the LSD; no other between-diet differences in α-diversity were detected. Differences in β-diversity were not observed between the diets ( P = 0.45). Compared with baseline, β-diversity differed following all diets ( P < .02). Enrichment of the Ruminococcaceae family was observed following the HSD as compared with the MSD (relative abundance = 22.14%, linear discriminant analysis = 4.22, P = 0.03) and the LSD (relative abundance = 24.90%, linear discriminant analysis = 4.47, P = 0.004).

CONCLUSIONS

The addition of herbs and spices to an average American diet induced shifts in gut bacterial composition after 4 wk in adults at risk for CVD. The metabolic implications of these changes merit further investigation. This trial was registered at clinicaltrials.gov as NCT03064932.

Phytochemical Characterization and Evaluation of the Antioxidant and Anti-Enzymatic Activity of Five Common Spices: Focus on Their Essential Oils and Spent Material Extractives

The essential oil industry of aromatic herbs and spices is currently producing a significant amount of by-products, such as the spent plant materials remaining after steam or hydrodistillation, that are simply discarded. The aim of this study was to comparatively investigate the phytochemical composition, antioxidant and multi-enzymatic inhibitory potential of the essential oils and spent plant material extractives obtained from cinnamon, cumin, clove, laurel, and black pepper. The essential oils were characterized by the presence of several phytochemical markers (cinnamaldehyde, cuminaldehyde, eugenol, eucalyptol, α-terpinene, limonene, β-caryophyllene or β-pinene). On the other hand, the LC-HRMS/MS profiling of the spent material extracts allowed the annotation of species specific and non-specific metabolites, such as organic acids, phenolic acids, flavonoids, proanthocyanidins, hydrolysable tannins, fatty acids, or piperamides. All samples exhibited very strong antioxidant effects, with the clove essential oil displaying the strongest radical scavenging (525.78 and 936.44 mg TE/g in DPPH and ABTS assays), reducing (2848.28 and 1927.98 mg TE/g in CUPRAC and FRAP), and total antioxidant capacity (68.19 mmol TE/g). With respect to the anti-acetylcholinesterase (0.73-2.95 mg GALAE/g), anti-butyrylcholinesterase (0-3.41 mg GALAE/g), anti-tyrosinase (0-76.86 mg KAE/g), anti-amylase and anti-glucosidase (both 0-1.00 mmol ACAE/g) assays, the spice samples showed a modest activity. Overall, our study reports that, not only the volatile fractions of common spices, but also their spent plant materials remaining after hydrodistillation can be regarded as rich sources of bioactive molecules with antioxidant and multi-enzymatic inhibitory effects.