Consumption of sesame seeds and sesame products has favorable effects on blood glucose levels but not on insulin resistance: A systematic review and meta-analysis of controlled clinical trials

The effects of extraction methods on the active ingredients and antioxidant activities of Sesamum indicum L. oils

As a premium-grade oil, Sesamum indicum L. oil is characterized by polyphenols and lignans. However, the influence of oil extraction methods (OEMs) on sesame oil's active ingredients and antioxidant activities lacks sufficient research. Herein, sesame oils were prepared with five OEMs, and their active ingredients and antioxidant activities were systematically investigated. The results demonstrated that the antioxidant activities of sesame oil extracts varied significantly among OEMs, and the ethanol extract of solvent extraction-ethanol (SEE) sesame oils possessed the highest inhibition rates of DPPH- (2,2'-diphenyl-1-picrylhydrazyl radical; 67.07 ± 0.78%) and ABTS+ (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt; 18.64 ± 1.34%), and the highest antioxidant ability to H2O2-induced HepG2 cells. Meanwhile, the highest total phenolic content (TPC) was found in SEE oil (152.96 ± 5.35 mg/kg). UPLC-QTOF-MS/MS illustrated that 52 ingredients were verified in sesame oils, including nine lignans, 33 phenols, and 10 non-phenols. Furthermore, high performance liquid chromatography (HPLC) presented that the content of phenol and lignan profiles varied significantly among OEMs, while the compositions remained unchanged. Besides, the correlation analysis revealed that 14 active ingredients exhibited a positive correlation with antioxidant activities. Among them, ethyl vanillate, (+)-justiciresinol, pinoresinol, kaempferol 3-O-[2-O-(trans-p-coumaroyl)-3-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (KTCRG), cistanoside F, and sesamolinol showed significant positive correlation with antioxidant activities (p < 0.05). It was believed that KTCRG, a glycosylated kaempferol, was responsible for the high antioxidant activities of sesame oils. Our results provided a viewpoint on OEMs for the quality of sesame oils. PRACTICAL APPLICATION: In the subsequent extraction of sesame oil, specific ingredients can be more selectively retained and enriched to improve the acquisition of high-quality sesame oil and promote the quality grading of sesame oil. Meanwhile, the results of this study also have certain research value for the high-quality extraction of other vegetable oils.

Cardiometabolic risk factors are affected by interaction between FADS1 rs174556 variant and dietary vegetable oils in patients with diabetes: a randomized controlled trial

FADS1 rs174556 polymorphism influences on dietary fats metabolism and type 2 diabetes (T2DM). This study aimed to compare the effect of three oils of sesame, canola and sesame-canola on cardio metabolic factors across genotypes of rs174556 variant in patients with type 2 of diabetes. This study was a randomized triple-blind three-way cross-over clinical trial. 95 Subjects with T2DM replaced their regular dietary oil with sesame oil, canola oil, or sesame-canola oil for three 9-week phases and completed the study. There were three anthropometric measurements, blood sampling and biochemical assessments at the beginning, middle, and at the end of each phase for assessments. Genotyping was conducted using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. In the crude model, there was an interaction between consumed oils and rs174556 variant on serum concentration of Apolipoprotein A-I (ApoA-1). During intake of sesame oil, lower levels of triglycerides (TG) were observed in individuals with TT genotype compared to C allele carriers' allele, which remained significant in adjusted models. Compared to C allele carrier's, the people with TT genotype experienced significant increase and decrease in serum levels of HDL and TG, respectively in adjusted models. Also, the subjects who consumed sesame-canola oil had lower serum concentrations of fasting blood glucose than those who received sesame and canola oils, regardless of used oils and genotypes. FADS1 Gene variant (rs174556) might modify cardiometabolic changes following dietary vegetable oils. Larger longitudinal studies especially randomized clinical trials are needed to clarify these associations.

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.

Effect of sesame supplementation on body composition and lipid profile in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials

AIMS

The aim of this study was to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) that evaluated the impact of sesame supplementation on body weight (BW), body mass index (BMI), triglycerides (TGs), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) in patients with type 2 diabetes mellitus (T2DM).

DATA SYNTHESIS

PubMed, Scopus, ISI Web of Science, and Embase were searched without any restrictions until September 2023.Only RCTs reporting the effects of sesame supplementation on body composition and lipid profiles were included, while observational studies and animal models were excluded. The methodological quality of the studies was assessed using the Cochrane risk of bias tool. Out of 997 studies identified, 10 were included in the systematic review and meta-analysis. Our meta-analysis suggested a significant association between sesame supplementation and reduction in TG (weighted mean difference (WMD): -37.61 mg/dl, 95 % CI: -61.48, 13.73), TC (WMD: -32.69 mg/dl, 95 % CI: -47.26, 18.12), and LDL-C (WMD: -28.72 mg/dl, 95 % CI: -44.68, 12.76). However, our meta-analysis indicated that the supplementary intake of sesame had no significant effect on HDL-C, BW, and BMI in patients with T2DM.

CONCLUSIONS

This study showed that sesame consumption significantly lowered TG, TC, and LDL-C levels, which may have contributed to the improvement of clinical symptoms in T2DM. However, given the limited number of trials included in the analysis, additional large-scale studies are needed to confirm the effects of sesame consumption on the lipid profile and body composition in patients with T2DM.

PROSPERO CODE

CRD42023460630.

Nut and seed consumption is inversely associated with metabolic syndrome in females but not males: findings from the 2005-2018 NHANES data

PURPOSE

To assess the association between nut and seed consumption, both combined and separately, and metabolic syndrome and its components, including fasting glucose, triglycerides, high-density lipoprotein (HDL) cholesterol, central obesity, and blood pressure.

METHODS

This cross-sectional analysis used data from 22,687 adults (aged ≥ 18 years) involved in seven cycles (2005-2018) of the National Health and Nutrition Examination Survey (NHANES). Habitual nut and seed intakes were estimated by the Multiple Source Method using data from two 24-h dietary recalls. Metabolic syndrome was ascertained using biochemical data and self-reported medication use. Sex-specific effect estimates were obtained using logistic and linear regressions adjusting for lifestyle and socioeconomic confounders.

RESULTS

Compared to non-consumers, female, but not male, habitual consumers of either nuts or seeds had lower odds of having metabolic syndrome (OR: 0.83, 95% CI 0.71, 0.97). Both nut intake alone and seed intake alone were inversely associated with high fasting glucose and low HDL-cholesterol in females compared to non-consumers. When restricted to habitual consumers only, the combined intake of nuts and seeds at 6 g/day was associated with the lowest triglycerides and highest HDL-cholesterol in females. Combined consumption of nuts and seeds up to one ounce-equivalent (15 g) per day, but not in higher intake levels, was inversely associated with metabolic syndrome, high fasting glucose, central obesity, and low HDL-cholesterol in females.

CONCLUSIONS

Nut and seed consumption, both separately or combined, below 15 g/day was inversely associated with metabolic syndrome and its component conditions in females but not males.

Quality of Edible Sesame Oil as Obtained by Green Solvents: In Silico versus Experimental Screening Approaches

The present study aimed to investigate the qualitative and quantitative performance of five green solvents, namely 2-methyltetrahydrofuran (MeTHF), cyclopentyl methyl ether (CPME), p-cymene, d-limonene and ethanol to substitute n-hexane, for sesame seed oil extraction. In fact, both CPME and MeTHF gave higher crude yields than n-hexane (58.82, 54.91 and 50.84%, respectively). The fatty acid profile of the sesame seed oils remained constant across all the solvent systems, with a predominance of oleic acid (39.27-44.35%) and linoleic acid (38.88-43.99%). The total sterols gained the upmost amount with CPME (785 mg/100 g oil) and MeTHF (641 mg/100 g oil). CPME and MeTHF were also characterized by the optimum content of tocopherols (52.3 and 50.6 mg/100 g oil, respectively). The highest contents of total phenols in the sesame seed oils were extracted by CPME (23.51 mg GAE/g) and MeTHF (22.53 mg GAE/g) as compared to the other solvents, especially n-hexane (8 mg GAE/g). Additionally, sesame seed oils extracted by MeTHF and CPME also had the highest antioxidant and anti-inflammatory properties as compared to the other green solvents and n-hexane, encouraging their manufacturing use for sesame seed oil extraction.

Comprehensive review of composition distribution and advances in profiling of phenolic compounds in oilseeds

A wide range of phenolic compounds participate in oilseed growth, regulate oxidative stability of corresponding vegetable oil, and serve as important minor food components with health-promoting effects. Composition distribution of phenolic compounds varied in oilseeds. Isoflavones, sinapic acid derivatives, catechin and epicatechin, phenolic alcohols, chlorogenic acid, and lignans were the main phenolic compounds in soybean, rapeseed, peanut skin, olive, sunflower seed, sesame and flaxseed, respectively. Among which, the total isoflavones content in soybean seeds reached from 1,431 to 2,130 mg/100 g; the main phenolic compound in rapeseed was sinapine, representing 70–90%; chlorogenic acid as the predominant phenolic compound in sunflower kernels, represented around 77% of the total phenolic content. With the rapid development of analytical techniques, it is becoming possible for the comprehensive profiling of these phenolic compounds from oilseeds. This review aims to provide recently developments about the composition distribution of phenolic compounds in common oilseeds, advanced technologies for profiling of phenolic compounds by the metabolomics approaches based on mass spectrometry. As there is still limited research focused on the comprehensive extraction and determination of phenolics with different bound-forms, future efforts should take into account the non-targeted, pseudo-targeted, and spatial metabolomic profiling of phenolic compounds, and the construction of phenolic compound database for identifying and quantifying new types of phenolic compounds in oilseeds and their derived products.

Effects of Seed Roasting Temperature on Sesame Oil Fatty Acid Composition, Lignan, Sterol and Tocopherol Contents, Oxidative Stability and Antioxidant Potential for Food Applications

Roasting is a key step for preparing sesame oil that leads to important changes in its organoleptic properties and quality. In this study, white sesame seeds were roasted for 20 min in an electric oven at different temperatures (120, 150, 180, 210, 250 and 300 °C). The oils extracted from unroasted and roasted seeds were compared for their chemical composition: fatty acids (including trans isomers), phytosterols, lignans (sesamin and sesamolin), tocopherols and total phenolic compounds, as well as their oxidative stability and antiradical capacity. There were no obvious differences in the oil densities, refractive indexes or iodine values, but the saponification values were affected by temperature. Relevant primary and secondary lipid oxidation were observed at T > 250 °C, resulting in a higher p-anisidine value and K232 as well as K268 values. Roasting improved oil yield (from 33.5 to 62.6%), increased its induction period (from 5.5 to 10.5 h) and enhanced the total phenolic content (from 152 to 194 mg/100 g) and antiradical activity of the extracted oil. Depending on roasting temperature, a gradual decline was recorded in total amounts of phytosterols (up to 17.4%), γ-tocopherol (up to 10.6%), sesamolin (maximum of 27.5%) and sesamin (maximum of 12.5%). All the investigated oils presented a low quantity in triglyceride polymers, clearly below the maximum tolerated quantity according to the European regulation. The optimal roasting temperature for obtaining high nutritional grade oil within the permissible values was 210 °C. The unsaponifiable components (including lignans and sterols) extracted from roasted seeds have been shown to be natural additives to fresh meatball products to extend shelf life. The results of this study may help to boost the nutritional content of plant-based diets by allowing for the use of roasted sesame seed oil and its components.