The effects of canola and olive oils on insulin resistance, inflammation and oxidative stress in women with type 2 diabetes: a randomized and controlled trial

Effects of canola oil on body weight and composition in adults: an updated systematic review and meta-analysis of 32 randomized controlled trials

OBJECTIVE

We aim to provide an overview and update the current documents regarding the effect of canola oil (CO) compared to other dietary oils on body weight and composition in adults.

METHODS

PubMed, Scopus, Google Scholar, and ISI Web of Science were searched until Sepetember 2024 for randomized clinical trials (RCTs) that assessed the effect of CO on anthropometric measures.

RESULTS

In this systematic review and meta-analysis thirty-two studies were included. CO consumption significantly increased WHR (MD: 0.003 cm, 95% CI: 0.001, 0.005, P value: 0.003) and significantly decreased BMI (mean difference (MD): -0.127 kg/m2, 95% C: -0.231, -0.024, P value: 0.016) However, it did not significantly affect other anthropometric measures (P > 0.05). Based on subgroup analysis, CO supplementation significantly reduced BW in studies on T2DM patients, with parallel design, on patients over 50 years old and with a dose of more than 30 g/d. It also significantly increased WC in trials with parallel design and on hyperlipidemia patients. In addition, CO supplementation significantly increased WHR in the majority of subgroups.

CONCLUSIONS

Compared to other oil supplementation, CO could decrease BW, BMI and increase WHR, and WC in general or subgroup analysis. Further studies are needed to provide additional insight into how canola oil affects BW and composition in adults.

Impact of Dietary Fiber on Inflammation in Humans

Cohort studies consistently show that a high intake of cereal fiber and whole-grain products is associated with a decreased risk of type 2 diabetes (T2DM), cancer, and cardiovascular diseases. Similar findings are also reported for infectious and chronic inflammatory disorders. All these disorders are at least partially caused by inflammaging, a chronic state of inflammation associated with aging and Metabolic Syndrome. Surprisingly, insoluble (cereal) fiber intake consistently shows stronger protective associations with most long-term health outcomes than soluble fiber. Most humans consume soluble fiber mainly from sweet fruits, which usually come with high levels of sugar, counteracting the potentially beneficial effects of fiber. In both observational and interventional studies, high-fiber diets show a beneficial impact on inflammation, which can be attributed to a variety of nutrients apart from dietary fiber. These confounders need to be considered when evaluating the effects of fiber as part of complex dietary patterns. When assessing specific types of fiber, inulin and resistant starch clearly elicit anti-inflammatory short-term effects, while results for pectins, beta-glucans, or psyllium turn out to be less convincing. For insoluble fiber, promising but sparse data have been published so far. Hypotheses on putative mechanisms of anti-inflammatory fiber effects include a direct impact on immune cells (e.g., for pectin), fermentation to pleiotropic short-chain fatty acids (for fermentable fiber only), modulation of the gut microbiome towards higher levels of diversity, changes in bile acid metabolism, a differential release of gut hormones (such as the glucose-dependent insulinotropic peptide (GIP)), and an improvement of insulin resistance via the mTOR/S6K1 signaling cascade. Moreover, the contribution of phytate-mediated antioxidative and immune-modulatory means of action needs to be considered. In this review, we summarize the present knowledge on the impact of fiber-rich diets and dietary fiber on the human inflammatory system. However, given the huge heterogeneity of study designs, cohorts, interventions, and outcomes, definite conclusions on which fiber to recommend to whom cannot yet be drawn.

The effect of different edible oils on body weight: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Obesity is a major public health issue with no definitive treatment. The first-line approach for obesity is lifestyle modification, including a healthy diet. Although the amount of fat has been considered, there is no network meta-analysis (NMA) study investigating the effect of edible oils on body weight. Therefore, we sought to investigate the effect of different edible oils on body weight using a systematic review and NMA study of randomized controlled trials (RCTs).

METHOD

PubMed, Scopus, ISI Web of Science, and the Cochrane Library were searched from inception to April 2019. RCTs of different edible oils for body weight were included. A frequentist network meta-analysis was conducted to appraise the efficacy of different types of edible oils, and the Surface Under the Cumulative Ranking Curve (SUCRA) was estimated. The GRADE framework was used to assess the certainty of evidence.

RESULTS

Forty-two eligible studies were included. Most of the included trials examined the effect of olive oil compared to canola oil (n = 7 studies), followed by canola oil compared to sunflower oil (n = 6 studies), and olive oil compared to sunflower oil (n = 4 studies). Sesame oil had the highest SUCRA value for reducing weight (SUCRA value = 0.9), followed by the mixture of canola and sesame oil (0.8). Palm oil and soy oil were ranked the lowest (SUCRA value = 0.2).

CONCLUSION

There is low to moderate certainty of evidence showing that soybean, palm, and sunflower oils were associated with weight gain, while sesame oil produced beneficial anti-obesity effects.

The Effect of a Nutritional Intervention with the Use of Biofortified Beef Meat on Selected Biochemical Parameters in Blood from Older Adults

This study aimed to investigate the effects of meat biofortified with antioxidants and canola oil on the health of older adults through blood parameters. Eighty institutionalized older persons were divided into four groups who received the following treatments: C-control meat with 46 µg/kg of meat with selenium, 3.80 g/kg of meat with vitamin E and 0.78 g/100 g of meat with conjugated linoleic acid (CLA); A-antioxidant meat with 422 µg/kg of meat with selenium, 7.65 g/kg of meat with vitamin E and 0.85 g/100 g of meat with CLA; O-oil meat with 57 µg/kg of meat with selenium, 3.98 g/kg of meat with vitamin E and 1.27 g/100 g of meat with CLA; OA-oil and antioxidant meat with 367 µg/kg of meat with selenium, 7.78 g/kg of meat with vitamin E and 1.08 g/100 g of meat with CLA. Blood samples were collected at 0, 45 and 90 days after the start of meat intake. Older adults who consumed ANT (A and AO) meat had higher concentrations of selenium (p = 0.039), vitamin E and HDL (higher concentrations of high-density lipoprotein, p = 0.048) in their blood. This study demonstrates that the consumption of Se- and vitamin E-biofortified meat increases the concentration of these metabolites in blood from older adults.

Diverse impacts of red palm olein, extra virgin coconut oil and extra virgin olive oil on cardiometabolic risk markers in individuals with central obesity: a randomised trial

PURPOSE

Dietary fats with an abundance of phytonutrients have garnered public attention beyond fatty acids per se. This study was set to investigate the impact of consuming diets with red palm olein (RPOO), extra virgin coconut oil (EVCO) and extra virgin olive oil (EVOO, as a control) on cardiometabolic risk biomarkers and lipid profile.

METHODS

We recruited a total of 156 individuals with central obesity, aged 25-45 years, with waist circumference ≥ 90 cm for men and ≥ 80 cm for women in a parallel single-blind 3-arm randomised controlled trial. The participants consumed isocaloric diets (~ 2400 kcal) enriched with respective test fats (RPOO, EVCO or EVOO) for a 12-week duration.

RESULTS

The mean of the primary outcome plasma high sensitivity C-reactive protein was statistically similar between the three diets after a 12-week intervention. EVOO resulted in significantly lower mean LDL cholesterol compared with RPOO and EVCO, despite similar effects on LDL and HDL cholesterol subfractions. The RPOO diet group showed elevated mean α and β -carotenes levels compared with EVCO and EVOO diet groups (P < 0.05), corresponding with the rich carotenoid content in RPOO.

CONCLUSION

The three oils, each of which has unique phytonutrient and fatty acid compositions, manifested statistically similar cardiometabolic effects in individuals with central obesity at risk of developing cardiovascular diseases with distinct circulating antioxidant properties.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT05791370).

Effect of Extra Virgin Olive Oil on Anthropometric Indices, Inflammatory and Cardiometabolic Markers: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND

A large body of literature associated extra virgin olive oil (EVOO) consumption with low risk of cardiovascular disease and mortality. However, findings from clinical trials related to EVOO consumption on blood pressure, lipid profile, and anthropometric and inflammation parameters are not univocal.

OBJECTIVES

The aim of this systematic review and meta-analysis was to evaluate the effect of EVOO consumption on cardiometabolic risk factors and inflammatory mediators.

METHODS

We searched PubMed/MEDLINE, Scopus, and Cochrane up through 31 March, 2023, without any particular language limitations, in order to identify randomized controlled trials (RCTs) that examined the effects of EVOO consumption on cardiometabolic risk factors, inflammatory mediators, and anthropometric indices. Outcomes were summarized as standardized mean difference (SMD) with 95% confidence intervals (CIs) estimated from Hedge's g and random-effects modeling. Heterogeneity was assessed by Cochran Q-statistic and quantified (I2).

RESULTS

Thirty-three trials involving 2020 participants were included. EVOO consumption was associated with a significant decrease in insulin (n = 10; SMD: -0.28; 95% CI: -0.51, -0.05; I2 = 48.57%) and homeostasis model assessment of insulin resistance levels (HOMA-IR) (n = 9; SMD: -0.19; 95% CI: -0.35, -0.03; I2 = 00.00%). This meta-analysis indicated no significant effect of consuming EVOO on fasting blood glucose, triglycerides, total cholesterol, low density lipoproteins, very low density lipoproteins, high density lipoproteins, Apolipoprotein (Apo) A-I and B, lipoprotein a, blood pressure, body mass index, waist circumference, waist to hip ratio, C-reactive protein, interleukin-6, interleukin-10, and tumor necrosis factor α levels (P > 0.05).

CONCLUSIONS

The present evidence supports a beneficial effect of EVOO consumption on serum insulin levels and HOMA-IR. However, larger well-designed RCTs are still required to evaluate the effect of EVOO on cardiometabolic risk biomarkers. This study was registered in PROSPERO as CRD42023409125.

Daily consumption of γ-oryzanol-fortified canola oil, compared with unfortified canola and sunflower oils, resulted in a better improvement of certain cardiometabolic biomarkers of adult subjects with type 2 diabetes: a randomized controlled clinical trial

BACKGROUND

This study was undertaken to examine the effects of daily consumption of γ-oryzanol (ORZ)-fortified canola oil, as compared with plain canola and sunflower oils, on certain cardiometabolic indicators.

METHODS

Ninety-two adult subjects from both sexes with T2D were randomly assigned to one of the three groups to receive: (a) ORZ-fortified canola oil (Group 1; n1 = 30); (b) unfortified canola oil (Group 2; n2 = 32); or (c) sunflower oil (Group 3; n3 = 30) for 12 weeks. The participants were instructed to use only the given oils for all cooking (but frying) purposes. Anthropometric, dietary and biochemical assessments were done initially and finally.

RESULTS

Though body mass index (BMI) significantly decreased in all three groups, only in Groups 1 and 2 waist circumference (WC) showed a significant decrement (-2.6 ± 0.1 and -2.2 ± 0.1 cm in Groups 1 and 2 respectively, p < 0.001 for both) which was accompanied by a significant reduction of blood pressure just in Group 1. Fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) showed a significant decrease only in ORZ-fortified canola oil group (-7.7 ± 0.4 mg/dL, p = 0.039 and -0.7 ± 0.1%, p < 0.001, respectively). However, insulin resistance, as judged by HOMA-IR, did not change significantly. In addition, serum triglyceride (TG) concentrations decreased in all three groups but only in ORZ-fortified canola oil was this decrement statistically significant (-17.9 ± 2.1 mg/dL, p = 0.005). Other components of serum lipid profile did not change significantly in either group.

CONCLUSIONS

Consumption of either sunflower or canola oils for 12 weeks improved certain studied biomarkers. However, only ORZ-fortified canola oil resulted in a significant decrease of blood pressure, WC, FBG, HbA1c and TG. These findings can help both clinicians and public health authorities for dietary recommendations to subjects with T2D and presumably the whole community.

TRIAL REGISTRATION

number at clinicaltrials.gov (NCT05271045).

Is There More to Olive Oil than Healthy Lipids?

The Mediterranean diet is a healthy dietary pattern whose main characteristic is olive oil consumption. The potential health benefits of olive oil have been extensively investigated and the present review provides the more recent clinical evidence supporting the positive impact of olive oil intake on human health. PubMed (n = 227) and Scopus (n = 308) databases were searched for published clinical studies in English over the past six years (October 2016 to December 2022), following key word searches of "olive oil" and "health". Major findings associated olive oil with antioxidant and anti-inflammatory effects, improvement in endothelial function and lipid profile, prevention of obesity, diabetes, cardiovascular and neurodegenerative diseases, and modulation of the gut microbiota. These benefits are attributed to the nutritional composition of olive oil, which has a high content of monounsaturated fatty acids (MUFA) (oleic acid in particular) and minor compounds such as polyphenols (oleuropein and hydroxytyrosol). Although additional research continues to be required, the more recently generated evidence supports the potential of olive oil to contribute beneficially to health and to the prevention and management of a variety of non-communicable diseases, as a consequence of the synergism between its components' complexity.

New iridoids from Patrinia scabiosaefolia and their hypoglycemic effects by activating PI3K/Akt signaling pathway

Growing in regions of Asia and North America, Patrinia scabiosaefolia is a wild vegetable and herb that has demonstrated health-promoting properties. Iridoids are one of the most bioactive phytochemicals in P. scabiosaefolia but the in-depth study is scarce. Herein we reported the separation and characterization of nine iridoids (compounds 1-9) from P. scabiosaefolia, and two compounds (2 and 6) were new. All the structures of the nine iridoids were characterized and confirmed with NMR (1D & 2D), HRMS, IR and UV. Compound 2 is a five-member ring iridoid, reminiscent of a broken C-1 and C-2 bond. Compound 6 has a typical monoene valerian iridoid, but the 5-deoxyglucose moiety at C-11 position is uncommon in this genus. The anti-diabetic evaluation of the isolated compounds revealed that compounds 1, 2, and 9 significantly increased the glucose absorption in 3 T3-L1 cells (P < 0.01). Further mechanism investigations have demonstrated that compound 1 promoted glucose uptake in dexamethasone-treated 3 T3-L1 adipocytes by activating PI3K/Akt signaling pathway. The expression of GLUT4 mRNA and protein was also upregulated. These results provide scientific references for the potential use of P. scabiosaefolia as a functional food to manage hyperglycemia.

High-fat low-carbohydrate enteral feeding enriched with olive oil and acute respiratory failure: A double-blind, randomized, controlled trial

BACKGROUND AND AIM

The study evaluated the impact of two types of high fat diet on the outcomes of acute pulmonary failure.

METHODS

A total of 93 Ventilated acute pulmonary failure patients with enteral feeding were assigned randomly to the control group with carbohydrate-based formula (protein: 20%, fat: 30%, carbohydrate: 50%) and two study groups with fat-based formula, including group A (protein: 20%, In equal proportions of olive and sunflower oil 45%, charbohydrate:35%) and group B (protein: 20%, sunflower oil:45%, charbohydrate:35%). The diets were prescribed for 14 days.

RESULTS

In each group, 16 patients completed the study. The PaCO2 decreased significantly in the study group A compared with the control group at weaning. The risk of separation from mechanical ventilation during study period was eight times higher in the study group A than the control group. On day 10 of intervention, serum hs-CRP decreased significantly in the control group and the study group A compared to the baseline. Serum concentration of total antioxidant capacity was increased significantly in the study group A on day 10 of the intervention, but in the other two groups it was reduced. Gastrointestinal complications, including diarrhea and high gastric residual volume, were not different between the groups.

CONCLUSION

With a fat-based diet high in olive oil, more patients were weaned during the study period. This diet reduced the PaCo₂ at weaning, reduced the serum level of hs-CRP, and increased the serum level of total antioxidant capacity concentration. Fat-based diet high in sunflower oil did not have any beneficial effects on outcomes.

Efficacy and safety of semaglutide in glycemic control, body weight management, lipid profiles and other biomarkers among obese type 2 diabetes patients initiated or switched to semaglutide from other GLP-1 receptor agonists

Purpose

Evidence of the efficacy and safety of semaglutide among patients with type 2 diabetes who were initiated on or were switched to semaglutide from other GLP-1 RAs remains limited. The objective of this study was to investigate the short-term effects of switching to semaglutide from other GLP-1 RAs.

Methods

This retrospective cohort study evaluated patients with type 2 diabetes who were initiated on or were switched to semaglutide due to poor diabetes control with other GLP-1 RAs or other medications, or obesity. HbA1c, body weight, serum creatinine, serum uric acid, parameters of lipid metabolism, and parameters of liver function were measured before and 6 months after administration of semaglutide.

Results

A total of 50 patients were registered in the study. After switching to semaglutide (n = 43), HbA1c and body weight significantly decreased (p < 0.01, p < 0.01), respectively. The same findings were observed in semaglutide-naïve patients (p = 0.04, p < 0.02) (n = 7). Serum uric acid, total cholesterol, triglycerides, and urinary albumin-creatinine ratio decreased significantly as well (p = 0.04, p = 0.04, p = 0.02, p = 0.04), whereas serum creatinine did not change significantly (p = 0.51).

Conclusions

Semaglutide showed excellent efficacy, even in patients switched from other GLP-1 RAs. Semaglutide appears to be a promising agent for blood glucose and body weight control in obese type 2 diabetes mellitus patients and could be more potent in treating type 2 diabetes than existing GLP-1 RAs.

Dietary intake and food behaviours of Senegalese adolescent girls

BACKGROUND

Malnutrition is a public health concern in low- and middle-income countries. In Senegal, 35% of adolescent girls are undernourished and 56% are anemic.

METHODS

This study assessed the dietary intake of 14-18-year-old adolescent girls in Dakar, Senegal. Specifically, the study 1) assessed their intake in energy, fibre, macro- and micronutrients, 2) described the types and the quality of the foods they consume, and 3) assessed some of their eating behaviours. Dietary intake was measured using three non-consecutive 24-h recalls from 136 adolescent girls attending two colleges. Energy and nutrient intakes were measured and compared to recommendations. Foods were classified by food group and by whether they were healthy or unhealthy. Adolescents' daily intake (g) of fruits and vegetables, as well as the proportion of girls who ate breakfast and who consumed three meals a day were calculated.

RESULTS

Sodium intake was high, while fibre intake was low. On average, 40% of the adolescents' total energy intake came from fats. Mean intakes of zinc and calcium were higher on the weekend than on weekdays, while the opposite was observed for sodium. Eighty-three percent of adolescents had an inadequate intake of iron and 99% were at risk of calcium deficiency. Approximately 60% of the foods consumed were classified as healthy, however, the majority came from grains.

CONCLUSIONS

Adolescent nutrition deserves attention given the poor quality of their dietary intake which may put them at risk of malnutrition and chronic diseases. These findings may be used to help improve programs targeting Senegalese adolescent girls' nutrition.

Dietary oleic acid supplementation and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to analyze data from randomized controlled trials (RCTs) assessing the effects of oleic acid (OA) supplementation on blood inflammatory markers in adults. PubMed, EMBASE and Cochrane Library databases were systematically searched from 1950 to 2019, with adults and a minimum intervention duration of 4 weeks. The effect size was estimated, adopting standardized mean difference (SMD) and 95% confidence interval (CI). Of the 719 identified studies, thirty-one RCTs involving 1634 subjects were eligible. The results of this study revealed that increasing OA supplementation significantly reduced C-reactive protein (CRP) (SMD: -0.11, 95% CI: -0.21, -0.01, P = 0.038). However, dietary OA consumption did not significantly affect tumor necrosis factor (TNF) (SMD: -0.05, 95% CI: -0.19, 0.10, P = 0.534), interleukin 6 (IL-6) (SMD: 0.01, 95% CI: -0.10, 0.13, P = 0.849), fibrinogen (SMD: 0.08, 95% CI: -0.16, 0.31, P = 0.520), plasminogen activator inhibitor type 1 (PAI-1) activity (SMD: -0.11, 95% CI: -0.34, 0.12, P = 0.355), soluble intercellular adhesion molecule-1 (sICAM-1) (SMD: -0.06, 95% CI: -0.26, 0.13, P = 0.595) or soluble vascular cell adhesion molecule-1 (sVCAM-1) (SMD: -0.04, 95% CI: -0.27, 0.18, P = 0.701). Overall, the meta-analysis demonstrated that dietary OA supplementation significantly reduced CRP, yet did not affect other inflammatory markers including TNF, IL-6, fibrinogen, PAI-1 activity, sICAM-1or sVCAM-1.

Protection by pure and genistein fortified extra virgin olive oil, canola oil, and rice bran oil against acetic acid-induced ulcerative colitis in rats

Conjugation of genistein and dietary oils improves the anti-inflammatory and antioxidant effects of genistein on colitis in rats.