Rice Bran Oil Compared to Atorvastatin for Treatment of Dyslipidemia in Patients with Type 2 Diabetes

Rice bran oil could favorably ameliorate atherogenicity and insulin resistance indices among men with coronary artery disease: post hoc analysis of a randomized controlled trial

BACKGROUND

Despite recent advances in recognizing more reliable indicators to estimate the coronary artery disease (CAD) patients' response to treatment and prognosis, less attention has been paid to evaluating them in clinical trials. Hence, the present research was conducted to study the impact of rice bran oil (RBO) versus sunflower oil (SFO) on various atherogenicity and insulin resistance markers.

METHODS

In the present 8-week randomized controlled trial, 40 CAD men with an average age of 56 years were allocated randomly into the intervention or control group to use RBO or SFO (30 g/day) plus a standardized dietary plan. As a further analysis, eight atherosclerosis-related indices were calculated before and after the study.

RESULTS

Analysis of covariance test in which potential confounders and baseline levels were considered, indicated that using RBO compared to SFO reduced Castelli's risk index I and II (adjusted means:3.29, 1.52 vs. 4.61, 2.20, respectively), atherogenic coefficient (2.29 vs. 3.61), lipoprotein combine index (6.54 vs. 17.53), and cholesterol index (0.46 vs. 1.20) after the trial (P-value ≤ 0.002). Also, the RBO group yielded significantly lower triglyceride glucose index (8.73 vs. 9.13) (P-value = 0.010). Further, marginally significant amelioration in triglyceride/HDL ratio and atherogenic index of plasma (1.48 and 0.13 vs. 1.86 and 0.24 respectively) were noted (P-value = 0.07). Spearman correlation analysis detected significant positive correlations between alterations in TNF-α serum levels (ng/L) and the majority of evaluated indices (P-value < 0.05).

CONCLUSION

Taken together, incorporating 30 g of RBO into the patient's usual diet appeared effective in ameliorating atherogenicity and insulin resistance indicators among men with CAD, probably in relation to its anti-inflammatory properties.

TRIAL REGISTRATION

The protocol of the current trial was retrospectively recorded in the Iranian clinical trial registration system (IRCT) with the registration number of IRCT20190313043045N1 (URL: https://en.irct.ir/trial/38346 ; Registration date: 2019-04-27).

Functional Profiling and Future Research Direction of Rice Bran Oil in Bangladesh

Rice bran oil (RBO) has been demonstrated to affect complex malfunctioned conditions such as oxidative stress, hyperlipidemia, hyperglycemia, hypertension, inflammation, abnormal cell growth (cancer), ulceration, immune and cognitive modulation. This unique effect of RBO is due to the presence of well-balanced fatty acid composition and several bioactive compounds, γ- oryzanol (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesterol ferulate, and β-sitosteryl ferulate), vitamin E (tocopherol and tocotrienol), phytosterols (β-sitosterol, campesterol and stigmasterol) and other nutrients. The RBO composition of bioactive compounds varied geographically, thus the clear-cut mechanisms of action on complex disease cascades are still required. This review article summarized the RBO compositional profiling and compared it with other edible oils. This article also summarized Bangladesh RBO profiling and their proposed mechanism of action as well as the first line of defense in the prevention, management, and control of complex disease conditions. This review indicates how Bangladesh RBO increase their opportunity to be functional food for 21st century's ailment.

Tropical Oil Consumption and Cardiovascular Disease: An Umbrella Review of Systematic Reviews and Meta Analyses

The health effects of saturated fat, particularly tropical oil, on cardiovascular disease are unclear. We investigated the effect of tropical oil (palm and coconut oils), lard, and other common vegetable oils (soybean and rice bran oils) that are widely used in tropical and Asian countries on lipid profiles. We performed an umbrella review of meta-analyses and systematic reviews. Electronic databases (Medline, Scopus, Embase, and Cochrane) were searched up to December 2018 without language restriction. We identified nine meta-analyses that investigated the effect of dietary oils on lipid levels. Replacement of polyunsaturated fatty-acid-rich oils (PUFAs) and monounsaturated FA-rich oils (MUFAs) with palm oil significantly increased low-density lipoprotein cholesterol (LDL-c), by 3.43 (0.44-6.41) mg/dL and 9.18 (6.90-11.45) mg/dL, respectively, and high-density lipoprotein cholesterol (HDL-c), by 1.89 (1.23-2.55) mg/dL and 0.94 (-0.07-1.97) mg/dL, respectively. Replacement of PUFAs with coconut oil significantly increased HDL-c and total cholesterol -by 2.27 (0.93-3.6) mg/dL and 5.88 (0.21-11.55) mg/dL, respectively-but not LDL-c. Substituting lard for MUFAs and PUFAs increased LDL-c-by 8.39 (2.83-13.95) mg/dL and 9.85 (6.06-13.65) mg/dL, respectively-but not HDL-c. Soybean oil substituted for other PUFAs had no effect on lipid levels, while rice bran oil substitution decreased LDL-c. Our findings show the deleterious effect of saturated fats from animal sources on lipid profiles. Replacement of unsaturated plant-derived fats with plant-derived saturated fats slightly increases LDL-c but also increases HDL-c, which in turn may exert a neutral effect on cardiovascular health.

The effects of rice bran oil on left ventricular systolic function, cardiometabolic risk factors and inflammatory mediators in men with coronary artery disease: a randomized clinical trial

BACKGROUND/OBJECTIVE

In the current study, we aimed to explore the effects of rice bran oil (RBO) in adjunct to conventional medical therapy on left ventricular ejection fraction (LVEF), cardiometabolic risk factors, and inflammatory mediators in male patients with coronary artery disease (CAD).

SUBJECTS/METHODS

The present randomized controlled trial included 40 men diagnosed with CAD (mean age = 55.76 years) who were randomly allocated into two groups to receive either 30 grams per day of RBO (intervention group) or sunflower oil (control group) plus a standard diet for eight weeks. At the initial visit, demographic and anthropometric data and blood samples were collected. LVEF levels and serum concentrations of lipid profile, glucose, uric acid, hs-CRP, and TNF-α were investigated.

RESULTS

A total of 37 participants completed the study (n = 18 in the intervention group, n = 19 in the control group). Analysis of covariance (ANCOVA) adjusted for baseline values, age and body mass index revealed that RBO significantly improved LVEF (51.34%) and reduced triglyceride (125.01 mg dl^-1), blood sugar (110.4 mg dl^-1), total cholesterol (123.01 mg dl^-1) and low density lipoprotein (56.88 mg dl^-1) levels compared to sunflower oil ((45.56%), (155.93 mg dl^-1), (128.94 mg dl^-1), (163.93 mg dl^-1) and (83.79 mg dl^-1), respectively) following a 8-week trial (P-values < 0.05). Additionally, the test demonstrated that RBO consuming patients had significantly lower levels of serum uric acid (4.60 mg dl^-1), TNF-α (6.99 ng L^-1) and hs-CRP (2.11 mg L^-1) compared to the control group ((5.92 mg dl^-1), (15.23 ng L^-1), (4.47 mg L^-1), respectively) (P-value < 0.05). However, no significant changes were found regarding weight, blood pressure or serum HDL levels throughout the trial.

CONCLUSION

Consumption of 30 grams per day RBO within a standard diet could be considered an effective non-pharmacological approach in improving LVEF, cardiometabolic risk factors, and inflammatory state in CAD. However, future trials are recommended for more clarification.

The impact of rice bran oil consumption on the serum lipid profile in adults: a systematic review and meta-analysis of randomized controlled trials

Dyslipidemia/hyperlipidemia is recognized among the risk factors for lifestyle related diseases. A healthy diet, rich in vegetable oils such as rice bran oil (RBO), may aid to improve serum lipid levels. Thus, the aim of this study was to assess the effects of rice bran oil (RBO) consumption on serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c) and triglyceride (TG) levels in adults. The following online databases were searched for manuscripts published until October 7^th 2020: PubMed/Medline, Scopus, Clarivate Analytics' Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar. The effect sizes were expressed as weighted mean difference (WMD) with 95% confidence intervals (CI). A total of 8 eligible trials with 14 effect sizes were included in this meta-analysis. Our analysis revealed that the consumption of RBO significantly decreased serum TC (WMD: -7.29 mg/dL, 95% CI: -11.32, -3.25, P = 0.000), LDL-c (WMD: -7.62 mg/dL, 95% CI: -11.10, -4.14, P = 0.000) and TG (WMD: -9.19 mg/dL, 95% CI: -17.99, -0.38, P = 0.041) levels. So, available evidence suggests that RBO consumption can significantly decrease serum TC, LDL-c and TG levels. Hence, it may play a role in reducing dyslipidemia/hyperlipidemia risk.

Rice bran oil ameliorates hepatic insulin resistance by improving insulin signaling in fructose fed-rats

Background

Insulin resistance is an inadequate metabolic response of the peripheral tissue to circulating insulin. It plays an important pathophysiological role in type 2 diabetes mellitus. The purpose of the study was to investigate the molecular effects of rice bran oil (RBO) on the gene expression of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), glucose transporters-4 and 5 (GLUT-4 and 5) in insulin-resistant rats induced by high fructose diet (HFD).

Methods

Rats were divided into six groups (10 rats each) as follows: Groups 1 and 2: rats received a standard diet with corn oil or RBO (as the sole source of fat), respectively. Group 3: animals fed on HFD, which was furtherly divided into 2 sub-groups: rats fed HFD either for one (HFD1) or for 2 months (HFD2). Group 4, rats fed HFD containing RBO for 1 month (HFD1 + RBO), while rats in group 5 fed HFD for 30 days then RBO was added to the diet for another 30 days (HFD2 + RBO). Serum levels of glucose and insulin, as well as hepatic gene expression of insulin receptors and glucose transporters were determined. Livers were isolated for histopathological study.

Results

HFD induced insulin resistance with a reduction in the hepatic level of insulin receptor and glucose transporters at both protein and molecular levels. Addition of RBO improved the insulin sensitivity and up-regulated the expression of the tested genes.

Conclusion

HFD impaired the insulin sensitivity of the hepatocytes by down-regulating the insulin receptor genes. Addition of RBO alleviated all the hazardous effects.

Dietary Wheat Bran Oil Is Equally as Effective as Rice Bran Oil in Reducing Plasma Cholesterol

Rice bran oil (RBO) possesses a plasma cholesterol-lowering activity, while effect of wheat bran oil (WBO) on plasma cholesterol remains unknown. The present study compared the cholesterol-lowering activity of WBO with that of RBO in hamsters. Fifty-four male hamsters were divided into seven groups fed either a noncholesterol diet (NCD) or one of six high-cholesterol diets, namely HCD diet (0.2% cholesterol +9.5% lard), HCD+C diet (0.2% cholesterol +9.5% lard +0.5% cholestyramine), WL diet (0.2% cholesterol +4.8% Lard +4.8% WBO), WH diet (0.2% cholesterol +9.5% WBO), RL diet (0.2% cholesterol +4.8% Lard +4.8% RBO), and RH diet (0.2% cholesterol +9.5% RBO). Plasma total cholesterol (TC) in HCD group was 327.4 ± 31.8 mg/dL, while plasma TC in two WBO and two RBO groups was 242.2 ± 20.8, 243.1 ± 31.7, 257.1 ± 16.3, and 243.4 ± 46.0 mg/dL, respectively, leading to a decrease in plasma TC by 22-26% ( P < 0.01). No significant difference in cholesterol-lowering potency was seen between WBO and RBO. Plasma cholesterol-lowering activity of WBO and RBO was accompanied by down-regulation of hepatic 3-hydroxy-3-methylglutaryl-CoA reductase and fatty acid synthase, while up-regulation of cholesterol-7α-hydroxylase. WL, WH, RL, and RH diets increased the fecal excretion of total neutral sterols by 72.8%, 106.9%, 5.4%, and 36.8% ( P < 0.01) respectively. Results indicated WBO and RBO could inhibit cholesterol absorption via down-regulation of intestinal Niemann-Pick C1 like 1 protein, acyl CoA:cholesterol acyltransferase 2, and ATP binding cassette transporter 5. In summary, WBO was equally effective as RBO in decreasing plasma cholesterol in hypercholesterolemia hamsters.