Coconut oil intake and its effects on the cardiometabolic profile – A structured literature review

Effect of different forms of coconut on the lipid profile in normal free-living healthy subjects: A randomized controlled trial (Phase II)

Background

It has been postulated that the lipid effects of coconut could be mediated by its fatty acids, fiber and lysine/arginine ratio. Hence, the lipid effects of coconut oil could be different from the effects of the kernel flakes or milk extract because the constituents could be different in each coconut preparation. The present research investigated the lipid effects of different modes of coconut used in food preparation.

Methods

This study involved a total of 190 participants, randomized into four groups, which received coconut oil supplement (30 ml) (n = 53), kernel flakes (30 g) (n = 52) or coconut milk powder (30 g) (n = 44) for a period of 8 weeks. The control group (n = 41) received no supplement. Lipid assays were performed at baseline and at the end of the 4th and 8th weeks. The generalized estimating equations (GEE), ANOVA, and paired and independent t-tests were used in the analysis.

Result

The age range of the participants was 25-60 years, and 52.6% of them (n = 100) were men. Coconut milk supplementation induced beneficial changes in the lipid profile in that the LDL and non-HDL levels decreased while the HDL levels increased. The subgroup whose baseline LDL level was elevated appeared to benefit most from coconut milk supplementation. Coconut oil and kernel flakes failed to induce favorable lipid changes comparable to coconut milk supplementation.

Conclusion

Differing concentrations of protein, fat and fiber in coconut preparations could possibly explain the dissimilar effects on the lipid profile caused by the different coconut preparations. The benefits of coconut milk seen in the high basal LDL subgroup warrant a detailed study.

Reduction of lauric acid content in virgin coconut oil improved plasma lipid profile in high-fat diet-induced hypercholesterolemic mice

Virgin coconut oil (VCO) is claimed to have various health benefits, but favorable effects of its major component (∼50%), lauric acid, are controversial. Therefore, we aimed to reduce lauric acid content (∼30%) in VCO and evaluate its effect compared to VCO and medium-chain triglycerides (MCT), on food intake, bodyweight (BW), lipid profiles, and hepatic histology. Female C57BL/6 mice were treated with different diets for 3 months: control (normal diet), high-fat diet (HF), HF + VCO, HF + MCT, HF + low lauric acid VCO (LLA), and normal diet + LLA (C + LLA). LLA was prepared by enzymatic interesterification of VCO with methyl octanoate (methyl caprylate) and methyl decanoate (methyl caprate). Plasma and liver lipids, including total cholesterol (TC), high-density lipoprotein (HDL), and triglyceride, were measured by colorimetric assay, and hepatic fat accumulation was examined by oil-red-O staining. HF mice exhibited high plasma and liver TC and low-density lipoprotein (LDL). VCO or MCT treatment lowered liver TC and LDL, whereas LLA increased plasma HDL and markedly improved TC:HDL ratio. The HF-induced hepatic fat accumulation was attenuated by all treatments, of which VCO was the most effective. Control mice administered with LLA demonstrated lower liver TC and LDL, but higher plasma TC and HDL compared to controls. Lowest BW gain and food intake were found in mice treated with LLA. In conclusion, VCO, MCT, and LLA ameliorated hepatic histopathology caused by HF. VCO and MCT improved liver lipid profiles, whereas LLA has more beneficial effect on plasma lipids via a better TC:HDL ratio and showed promise for BW control.

Lauric Acid Overcomes Hypoxia-Induced Gemcitabine Chemoresistance in Pancreatic Ductal Adenocarcinoma

Although gemcitabine (GEM) is widely used in chemotherapy for pancreatic ductal adenocarcinoma (PDA), drug resistance restricts its clinical effectiveness. To examine the mechanism of GEM resistance, we established two GEM-resistant cell lines from human PDA cells by continuous treatment with GEM and CoCl₂-induced chemical hypoxia. One resistant cell line possessed reduced energy production and decreased mitochondrial reactive oxygen species levels, while the other resistant cell line possessed increased stemness. In both cell lines, ethidium bromide-stained mitochondrial DNA levels decreased, suggesting mitochondrial DNA damage. Inhibition of hypoxia-inducible factor-1α in both cell lines did not restore the GEM sensitivity. In contrast, treatment of both cell types with lauric acid (LAA), a medium-chain fatty acid, restored GEM sensitivity. These results suggest that decreased energy production, decreased mitochondrial reactive oxygen species levels, and increased stemness associated with mitochondrial damage caused by GEM lead to GEM resistance, and that hypoxia may promote this process. Furthermore, forced activation of oxidative phosphorylation by LAA could be a tool to overcome GEM resistance. Clinical verification of the effectiveness of LAA in GEM resistance is necessary in the future.

Postprandial Fatty Acid Metabolism with Coconut Oil in Young Females: A Randomized, Single-blind, Cross-over Trial

BACKGROUND

Approximately 84% of fatty acids contained in coconut oil (CO) are saturated fatty acids (SFA), and approximately 47% of the SFA are lauric acid with 12 carbon atoms. Lauric acid carbon chain length is intermediate between medium and long chain fatty acids. We examined how CO acts on lipid-related substances in the blood to determine whether its properties were similar to medium-chain fatty acids (MCFA) or long-chain fatty acids (LCFA).

METHODS

This is a randomized controlled single-blind crossover study. 15 females were enrolled, using three test meals containing 30-g each of three different oils: CO (CO-meal), medium-chain triacylglycerol-oil (MCT-meal), and long-chain triacylglycerol-oil (LCT-meal). Blood samples were collected at fasted baseline and every 2 h for 8 h after the intake of each test meal.

RESULTS

Repeated measure analysis of variance (ANOVA) of the ketone bodies and triglyceride (TG) showed an interaction between time and the test meal (P < 0.01 and P < 0.001, respectively). In subsequent Tukey's honestly significant difference (HSD) test of the ketone bodies, statistically significant differences were observed between the CO-meal and the LCT-meal (P < 0.05) 83.8 (95% CI, 14.7,153.0) and between the MCT-meal and the LCT-meal (P < 0.05) 79.2 (95% CI, 10.0,148.4). The incremental area under the curve (iAUC) and maximum increase in very low-density lipoprotein cholesterol (VLDL-C) and intermediate-density lipoprotein cholesterol (IDL-C) were the lowest for CO-meal intakes.

CONCLUSIONS

The characteristics of lauric acid contained in coconut oil, including the kinetics of β-oxidation and effects on blood TG, were very similar to those of MCFA. Moreover, regarding the iAUC and peak increment, VLDL-C and IDL-C were the lowest with the CO-meal. These results suggest that the intake of CO after fasting does not increase the TG, VLDL-C, and IDL-C, and may help prevent dyslipidemia. This trial was registered at UMIN as UMIN000019959.

Lactobacillus fermentum MCC2760 abrogate high-fat induced perturbations in the enterohepatic circulation of bile acids in rats

AIM

This study in hyperlipidemic rats elucidated the effect of Lactobacillus fermentum MCC2760 on intestinal bile acid (BA) uptake, hepatic BA synthesis, and enterohepatic BA transporters.

MAIN METHODS

Diets rich in saturated fatty acids [coconut oil (CO)] and omega-6 fatty acids [sunflower oil (SFO)] at 25 g fat/100 g diet were fed to rats with or without MCC2760 (10⁹ cells/kg body weight). After 60 days of feeding, intestinal BA uptake and expression of Asbt, Osta/b mRNA and protein, and hepatic expression of Ntcp, Bsep, Cyp7a1, Fxr, Shp, Lrh-1, and Hnf4a mRNA were measured. Hepatic expression of HMG-CoA reductase protein and its activity and total BAs in serum, liver, and feces were assessed.

KEY FINDINGS

Hyperlipidaemic groups (HF-CO and HF-SFO) had: 1) increased intestinal BA uptake, Asbt and Osta/b mRNA expression, and ASBT staining 2) increased BA in serum, 3) decreased hepatic expression of Ntcp, Bsep, and Cyp7a1 mRNA, and NTCP staining 4) increased activity of HMG-CoA reductase, 5) increased hepatic expression of Fxr and Shp mRNA, 6) decreased hepatic expression of Lrh-1 and Hnf4a mRNA, and 7) decreased BA in Feces when compared to their respective controls (N-CO and N-SFO) and experimental groups (HF-CO + LF and HF-SFO + LF). Immunostaining revealed increased intestinal Asbt and hepatic Ntcp protein expression in the HF-CO and HF-SFO groups compared to control and experimental groups.

SIGNIFICANCE

Incorporating probiotics like MCC2760 abrogated hyperlipidemia-induced changes in the intestinal uptake, hepatic synthesis, and enterohepatic transporters of BA in rats. Probiotic MCC2760 can be used to modulate lipid metabolism in high-fat-induced hyperlipidemic conditions.

Effects of Coconut Oil and Palm Oil on Growth, Rumen Microbiota, and Fatty Acid Profile of Suckling Calves

This study aimed to evaluate the effects of coconut oil and palm oil in milk replacer (MR) on the growth performance, blood lipids, rumen fermentation, rumen microbiota, and fatty acid profile of hepatic and muscle of suckling calves. Thirty-six Holstein male calves were randomly assigned to three treatments. Three milk replacers containing different fat sources were as follows: control group (CON, milk fat), coconut oil group (CCO, coconut oil powder as fat), and palm oil group (PLO, palm oil powder as fat). Calves were weighed and blood sampled at 14, 28, 42, and 56 days old, respectively, and the feed intake and fecal score were recorded daily. Fat sources in milk replacers had no effects on body weight, ADG, DMI, fecal score, or days of abnormal fecal in suckling calves among the three groups, while the PLO group tended to decrease starter intake compared with the other groups. Serum concentrations of TC, HDL-C, LDL-C, and VLDL-C in the CCO group increased compared with those of the CON group. Palm oil also decreased the serum GLU concentration of calves but had no effects on serum lipids compared with milk fat. Coconut oil or palm oil had no effects on rumen fermentation, rumen chyme enzyme activity, rumen bacterial community richness and diversity, and dominant phyla and genera when compared with milk fat. However, compared with the CON group, the CCO group increased the proportion of MCFAs and n-6 PUFAs, and decreased the proportion of UFAs and MUFAs in liver tissue, while the PLO group increased the proportion of PUFAs and decreased the proportion of n-3 PUFAs in liver tissue. In addition, compared with the CON group, the CCO group increased the proportion of MCFAs, and decreased the proportion of UFAs and n-3 PUFAs in longissimus dorsi, while the PLO group increased the proportion of PUFAs and decreased the proportion of n-3 PUFAs in longissimus dorsi. In conclusion, compared with milk fat, coconut oil or palm oil in MR had no effects on growth performance, rumen fermentation, and rumen microflora but significantly increased serum lipids concentration and changed some proportions of MCFAs and PUFAs in liver and longissimus dorsi in suckling calves. These results indicate that coconut oil or palm oil as the sole fat source for MRs has no adverse effect on calf rumen fermentation and rumen microbiota but has a detrimental effect on n-3 PUFAs deposition in the liver and longissimus dorsi muscle.

Effects of time-restricted feeding (16/8) combined with a low-sugar diet on the management of non-alcoholic fatty liver disease: A randomized controlled trial

OBJECTIVES

Emerging studies have employed time-restricted feeding (TRF) and a low-sugar diet alone in the management of non-alcoholic fatty liver disease (NAFLD), but their combination has not been tested. The aim of this study was to investigate the effects of TRF combined with a low-sugar diet on NAFLD parameters, cardiometabolic and inflammatory biomarkers, and body composition in patients with NAFLD.

METHODS

A 12-wk randomized controlled trial was performed to compare the effects of TRF (16 h fasting/8 h feeding daily [16/8]) plus a low-sugar diet versus a control diet based on traditional meal distribution in patients with NAFLD. Changes in body composition, anthropometric indices, and liver and cardiometabolic markers were investigated.

RESULTS

TRF 16/8 with a low-sugar diet reduced body fat (26.7 ± 5.4 to 24.2 ± 4.9 kg), body weight (83.8 ± 12.7 to 80.5 ± 12.1 kg), waist circumference (104.59 ± 10.47 to 101.91 ± 7.42 cm), and body mass index (29.1 ± 2.6 to 28 ± 2.7 kg/m²), as well as circulating levels of fasting blood glucose and liver (alanine aminotransferase, 34 ± 13.9 to 21.2 ± 5.4 U/L; aspartate aminotransferase, 26.3 ± 6.2 to 20.50 ± 4 U/L; γ-glutamyl transpeptidase, 33 ± 15 to 23.2 ± 11.1 U/L; fibrosis score, 6.3 ± 1 to 5.2 ± 1.2 kPa; and controlled attenuation parameter, 322.9 ± 34.9 to 270.9 ± 36.2 dB/m), lipids (triacylglycerols, 201.5 ± 35.3 to 133.3 ± 48.7 mg/dL; total cholesterol, 190 ± 36.6 to 157.8 ± 33.6 mg/dL; and low-density lipoprotein cholesterol, 104.6 ± 27.3 to 84 ± 26.3 mg/dL), and inflammatory markers (high-sensitivity C-reactive protein, 3.1 ± 1.1 to 2 ± 0.9 mg/L; and cytokeratin-18, 1.35 ± 0.03 to 1.16 ± 0.03 ng/mL). These results were statistically significant (P < 0.05) compared with the control group.

CONCLUSIONS

TRF plus a low-sugar diet can reduce adiposity and improve liver, lipid, and inflammatory markers in patients with NAFLD.

Diet and carcinogenesis of gastric cancer

PURPOSE OF REVIEW

Several recent studies have corroborated a strong association between diet and gastric cancer risk; investigators have also identified dietary factors that protect against gastric cancer. This review summarizes the literature on this topic and guides future research directions.

RECENT FINDINGS

High-salt intake disrupts the gastric mucosal defense barrier, promoting Helicobacter pylori colonization and penetration of other carcinogenic compounds. Processed foods, processed meats, red meat, alcohol, foods with high dietary fat, and dietary cholesterol increase the risk of gastric carcinogenesis. On the other hand, increased consumption of fruits, vegetables, whole grains, nuts, and a low-salt diet may offer a protective effect.

SUMMARY

Despite decreases in gastric cancer incidence because of increased identification and treatment of H. pylori , gastric cancer remains one of the most common cancers worldwide with a high mortality rate. This disturbing statistic highlights the importance of reducing and eliminating other risk factors for gastric cancer. There is a strong body of evidence that alcohol, processed foods, high salt intake, high fat intake, and foods with animal products (meats, eggs, and dairy) increase the risk of gastric cancer. A diet that is high in whole grains, fruits, vegetables, nuts and is low in salt may reduce the risk of gastric cancer.

The effects of coconut oil on the cardiometabolic profile: a systematic review and meta-analysis of randomized clinical trials

Background

Despite having a 92% concentration of saturated fatty acid composition, leading to an apparently unfavorable lipid profile, body weight and glycemic effect, coconut oil is consumed worldwide. Thus, we conducted an updated systematic review and meta-analysis of randomized clinical trials (RCTs) to analyze the effect of coconut oil intake on different cardiometabolic outcomes.

Methods

We searched Medline, Embase, and LILACS for RCTs conducted prior to April 2022. We included RCTs that compared effects of coconut oil intake with other substances on anthropometric and metabolic profiles in adults published in all languages, and excluded non-randomized trials and short follow-up studies. Risk of bias was assessed with the RoB 2 tool and certainty of evidence with GRADE. Where possible, we performed meta-analyses using a random-effects model.

Results

We included seven studies in the meta-analysis (n = 515; 50% females, follow up from 4 weeks to 2 years). The amount of coconut oil consumed varied and is expressed differently among studies: 12 to 30 ml of coconut oil/day (n = 5), as part of the amount of SFAs or total daily consumed fat (n = 1), a variation of 6 to 54.4 g/day (n = 5), or as part of the total caloric energy intake (15 to 21%) (n = 6). Coconut oil intake did not significantly decrease body weight (MD -0.24 kg, 95% CI -0.83 kg to 0.34 kg), waist circumference (MD -0.64 cm, 95% CI -1.69 cm to 0.41 cm), and % body fat (-0.10%, 95% CI -0.56% to 0.36%), low-density lipoprotein cholesterol (LDL-C) (MD -1.67 mg/dL, 95% CI -6.93 to 3.59 mg/dL), and triglyceride (TG) levels (MD -0.24 mg/dL, 95% CI -5.52 to 5.04 mg/dL). However, coconut oil intake was associated with a small increase in high-density lipoprotein cholesterol (HDL-C) (MD 3.28 mg/dL, 95% CI 0.66 to 5.90 mg/dL). Overall risk of bias was high, and certainty of evidence was very-low. Study limitations include the heterogeneity of intervention methods, in addition to small samples and short follow-ups, which undermine the effects of dietary intervention in metabolic parameters.

Conclusions

Coconut oil intake revealed no clinically relevant improvement in lipid profile and body composition compared to other oils/fats. Strategies to advise the public on the consumption of other oils, not coconut oil, due to proven cardiometabolic benefits should be implemented.

Registration

PROSPERO CRD42018081461.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01685-z.

Individual SFA intake and risk of overweight/obesity: findings from a population-based nationwide cohort study

The relationship between SFA consumption and the risk of overweight/obesity remains unclear. Epidemiological evidence is lacking among Chinese population. This study aimed to investigate the association between individual dietary SFA intake and the risk of overweight/obesity in Chinese adults. Data from 8465 adults with BMI < 24 kg/m² at entry in the China Health and Nutrition Survey (1989-2011) were analysed. Three-day 24-h dietary records were used to collect dietary data. Cox proportional hazards regression models were constructed to estimate hazard ratios (HR) and 95 % CI for the risk of developing overweight or obesity. A total of 3171 incident cases of overweight/obesity were identified (1649 for women and 1522 for men) during a median of 11 years of follow-up. Compared with the lowest category, the intake of total SFA (TSFA) showed no significant association with the risk of overweight/obesity. However, an increased risk of overweight/obesity was observed with a higher intake of medium chain SFA (MCSFA) (P_trend = 0·004), especially decanoic acid (10:0) (HR was 1·25 (95 % CI 1·10, 1·42) comparing the highest category with the reference group; P_trend < 0·001), whereas an inverse relationship was observed for hexanoic acid (6:0) consumption; compared with non-consumers, 6:0 intake was associated with 32 % lower risk of overweight/obesity (HR: 0·68 (95 % CI 0·56, 0·84); P_trend < 0·001). Overall, the intake of subtypes of MCSFA but not TSFA was associated with the risk of overweight/obesity. Increasing hexanoic acid (6:0) and limiting decanoic acid (10:0) consumption may be protective for overweight/obesity among Chinese population.

Fermentation Enhances the Anti-Inflammatory and Anti-Platelet Properties of Both Bovine Dairy and Plant-Derived Dairy Alternatives

Within the present study, the effects of fermentation on the anti-inflammatory and anti-platelet properties of both homemade and commercially purchased bovine dairy and almond, coconut, and rice-based dairy alternatives were evaluated. The extracted total lipids (TL) from homemade and commercially purchased fermented and unfermented bovine, almond, coconut, and rice-based products were further separated into their neutral lipids (NL) and polar lipids (PL) fractions by counter current distribution. The TL, PL, and NL of each sample were assessed in human platelets against the inflammatory and thrombotic mediator, platelet-activating factor (PAF), and the well-established platelet agonist, adenosine 5′ diphosphate (ADP). In all samples, the PL fractions showed significantly stronger inhibitory effects against human platelet aggregation induced by PAF or ADP, in comparison to the TL and NL, with higher specificity against PAF. PL of all fermented products (bovine yogurt and fermented dairy alternatives from almond, rice, and coconut), exhibited the strongest anti-inflammatory and anti-platelet potency, in comparison to PL from their initial pasteurized materials (bovine milk and rice, almond, and coconut-based dairy alternative drinks). PL of the pasteurized rice-based drink and, especially PL from the novel homemade rice-based fermented product (HMFRD), showed the strongest anti-PAF and anti-ADP potency compared to all samples, with anti-PAF activity being most potent overall. The unfermented pasteurized coconut-based drink showed the lowest anti-inflammatory and anti-platelet potency, and the bovine and almond-based fermented products showed an intermediate effect. Further lipidomics with LC-MS analysis of all these PL fractions revealed that fermentation altered their fatty acid content in a way that decreased their degree of saturation and increased the content of unsaturated fatty acids, thus providing a rationale for the stronger anti-inflammatory and anti-platelet potency of the more unsaturated PL fractions of the fermented products. This study has shown that fermentation alters the fatty acid content and the bio-functionality of the PL bioactives in both fermented bovine dairy and plant-based dairy alternatives, and subsequently improved their anti-inflammatory and anti-platelet functional properties.

Effects of consumption of coconut oil or coconut on glycemic control and insulin sensitivity: A systematic review and meta-analysis of interventional trials

BACKGROUND AND AIMS

The often purported claim that coconut fat is beneficial for cardiovascular health and was disputed in several recent meta-analyses. However, the evidence on the effects of coconut fat intake on glycemic control remains equivocal. We conducted a systematic review and meta-analysis in accordance with the PRISMA guidelines to determine the effects of dietary coconut fats on markers of acute and long-term glycemic control.

METHODS AND RESULTS

PubMed, Scopus, ProQuest, and Web-of-Science databases were searched and the records were screened by three independent reviewers to identify interventional studies examining acute and long-term (i.e., >10 days) effects of coconut fat on glycemic control. DerSimonian-Laird random-effects meta-analyses were performed using the meta-package in R (4.0.2). Seven interventional studies on acute effects and 11 interventional studies on long-term effects of coconut fat were included. Meals with coconut fat acutely increased the incremental area under the curve (AUC) of glucose (p = 0.046) and decreased the incremental AUC of insulin (p = 0.037) vs. control meals. Long-term coconut fat intake increased HOMA-IR (p = 0.049), but did not significantly affect fasting glucose, insulin, or HOMA-β vs. control meals.

CONCLUSIONS

Coconut fat in meals seems to be associated with a diminished postprandial insulin response, resulting in a subtle increase in the postprandial glycemic response. Long-term intake of coconut fat seems to increase insulin resistance, yet does not seem to be beneficial for long-term glycemic control. Thus, our results disprove the popular claim that coconut fat improves glycemic control.

REGISTRATION

PROSPERO registry (CRD42020183450).

An Intricate Review on Nutritional and Analytical Profiling of Coconut, Flaxseed, Olive, and Sunflower Oil Blends

Vegetable oils (VOs), being our major dietary fat source, play a vital role in nourishment. Different VOs have highly contrasting fatty acid (FA) profiles and hence possess varying levels of health protectiveness. Consumption of a single VO cannot meet the recommended allowances of various FA either from saturated FA (SFA), monounsaturated FA (MUFA), polyunsaturated FA (PUFA), Ω-3 PUFAs, and medium-chain triglycerides (MCTs). Coconut oil (CO), flaxseed oil (FO), olive oil (OO), and sunflower oil (SFO) are among the top listed contrast VOs that are highly appreciated based on their rich contents of SFAs, Ω-3 PUFAs, MUFAs, and Ω-6 PUFA, respectively. Besides being protective against various disease biomarkers, these contrasting VOs are still inappropriate when consumed alone in 100% of daily fat recommendations. This review compiles the available data on blending of such contrasting VOs into single tailored blended oil (BO) with suitable FA composition to meet the recommended levels of SFA, MUFA, PUFA, MCTs, and Ω-3 to Ω-6 PUFA ratios which could ultimately serve as a cost-effective dietary intervention towards the health protectiveness and improvement of the whole population in general. The blending of any two or more VOs from CO, FO, OO, and SFO in the form of binary, ternary, or another type of blending was found to be very conclusive towards balancing FA composition; enhancing physiochemical and stability properties; and promising the therapeutic protectiveness of the resultant BOs.

Impact of Dietary Lipids on the Reverse Cholesterol Transport: What We Learned from Animal Studies

Reverse cholesterol transport (RCT) is a physiological mechanism protecting cells from an excessive accumulation of cholesterol. When this process begins in vascular macrophages, it acquires antiatherogenic properties, as has been widely demonstrated in animal models. Dietary lipids, despite representing a fundamental source of energy and exerting multiple biological functions, may induce detrimental effects on cardiovascular health. In the present review we summarize the current knowledge on the mechanisms of action of the most relevant classes of dietary lipids, such as fatty acids, sterols and liposoluble vitamins, with effects on different steps of RCT. We also provide a critical analysis of data obtained from experimental models which can serve as a valuable tool to clarify the effects of dietary lipids on cardiovascular disease.

High Dietary Intervention of Lauric Triglyceride Might be Harmful to Its Improvement of Cholesterol Metabolism in Obese Rats

Hypercholesterolemia is often considered to be a major risk factor for atherosclerosis, and medium-chain fatty acids have been found to reduce the total cholesterol (TC) level and maintain low-density lipoprotein cholesterol (LDL-c) stability. However, we unexpectedly found that the levels of TC and LDL-c were increased in obese rats treated with high-dose lauric triglycerides (LT). The study aimed to investigate the effect and mechanism of LT on cholesterol metabolism in obese rats. Our results showed that LT intervention could reduce cholesterol biosynthesis by downregulating the expression of HMG-CoA reductase in obese rats. LT increased the expression levels of PPARγ1, LXRα, ABCA1, and ABCG8 in the liver. These results indicated that LT could improve the lipid transfer and bile acid efflux. However, LT significantly increased the expression of PCSK 9, resulting in accelerated degradation of LDLR, thus reducing the transport of very LDL (VLDL) and LDL to the liver. Together with the increased expression of NPC1L1 protein, LT impaired the uptake of VLDL/LDL by the liver and increased the reabsorption of sterols, leading to an increase in the levels of TC and LDL-c in obese rats.

Garcinia mangostana extract and curcumin ameliorate oxidative stress, dyslipidemia, and hyperglycemia in high fat diet-induced obese Wistar albino rats

The aim of this study was to explore the effects of Garcinia mangostana (mangosteen) and Curcuma longa independently and synergistically in modulating oxidative stress, dyslipidemia, and hyperglycemia commonly observed in high-fat diet-induced obesity in rodent models. Male albino Wistar rats were divided into eight experimental groups, fed on a normal diet or high-fat diet (HFD), then given mangosteen extract (400 mg /kg /day) and/or curcumin (80 mg/kg /day) for 6 weeks. Oxidative stress markers, glucose, and lipid fractions were measured in the sera. Mangosteen pericarp extract (MPE) induced a remarkable decrease in BMI (from 0.86 to 0.81 gm/cm2), while curcuma either alone or in combination was more effective, as treated rats recorded BMIs of 0.78 and 0.79 gm/cm2, respectively. Regarding the antioxidant effects, MPE induced a significant increase of GSH in obese rats (123.86 ± 15.53 μg/ml vs 288.72 ± 121.37 μg/ml). As anti-atherogenic agents MPE demonstrate significant effect recorded higher level of HDL-C in treated animals, but ineefective as anti-dyslipidemic agent. Curcumin was more effective in reducing LDL-C levels in obese rats. Both extracts effectively reduced blood glucose. The present study demonstrated that MPE and curcumin were independently and synergistically effective in treating obesity-induced atherogenesis.

Association of Coffee Consumption and Its Types According to Addition of Sugar and Creamer with Metabolic Syndrome Incidence in a Korean Population from the Health Examinees (HEXA) Study

Coffee is widely consumed worldwide, and numerous studies indicate that coffee consumption may potentially affect the development of chronic diseases. Metabolic syndrome (MetS) may constitute a risk factor for chronic diseases. We aimed to prospectively evaluate the association between coffee consumption and MetS incidence. All participants were selected from the Health Examinees study. MetS was defined by the Adult Treatment Panel III criteria of the National Cholesterol Education Program. A multivariate Cox proportional hazards regression model was used to assess the relationship between coffee consumption and MetS incidence. In comparison with non-consumers, male moderate consumers (≤3 cups/day) showed a lower risk for low high-density lipoprotein cholesterol (HDL-C) (≤1 cup/day, hazard ratio (HR): 0.445, 95% confidence interval (CI): 0.254-0.780; 1-3 cups/day, HR: 0.507, 95% CI: 0.299-0.859) and high fasting blood glucose (FPG) (≤1 cup/day, HR: 0.694, 95% CI: 0.538-0.895; 1-3 cups/day, HR: 0.763, 95% CI: 0.598-0.972). Male 3-in-1 coffee (coffee with sugar and creamer) consumers also showed a lower risk for low HDL-C (HR: 0.423, 95% CI: 0.218-0.824) and high FPG (HR: 0.659, 95% CI: 0.497-0.874). These findings indicate a negative association between moderate coffee consumption and low HDL-C and high FPG among Korean male adults.

Effects of virgin coconut oil consumption on metabolic syndrome components and asymmetric dimethylarginine: A randomized controlled clinical trial

BACKGROUND AND AIMS

There is some promising evidence regarding the beneficial effect of coconut oil on cardiometabolic risk factors. This study aimed to assess the effects of virgin coconut oil (VCO) consumption on metabolic syndrome (MetS) components, as well as, asymmetric dimethylarginine (ADMA) in adults with MetS.

METHODS AND RESULTS

In this randomized controlled trial, 48 subjects, aged 20-50 years, with MetS were allocated into two groups; the intervention group was given 30 ml of VCO per day to substitute the same amounts of fat in their usual diet for four weeks. The control group was advised to follow their usual diet. VCO consumption significantly reduced serum levels of triglyceride (TG) (P = 0.001), very low-density lipoprotein (VLDL) (P = 0.001), and fasting blood sugar (FBS) (P = 0.015) compared to the control group. The levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) were significantly increased in the VCO group when compared to the control group (P = 0.001). Circulatory ADMA also increased in the VCO group compared to the control group (P = 0.003). No significant differences were observed in the LDL-C/HDL-C ratio, anthropometric parameters, and blood pressure measurements between the two groups at the end of the study (P > 0.05).

CONCLUSION

VCO consumption increased the values of HDL-C while reduced TG and FBS levels. Blood pressure and waist circumference did not change. However, levels of TC, LDL-C, and ADMA elevated by VCO consumption. Caution is warranted until the results of further studies become available to explain the long-term effects of VCO consumption.

REGISTRATION NUMBER

IRCT20131125015536N11.

In vitro antagonistic inhibitory effects of palm seed crude oils and their main constituent, lauric acid, with oxacillin in Staphylococcus aureus

Infections caused by Staphylococcus aureus are a serious global threat, and with the emergence of antibiotic resistance, even more difficult to treat. One of the possible complications in antistaphylococcal therapy represents negative interactions of antibiotics with food. In this study, the in vitro interaction between oxacillin and crude palm seed oil from Astrocaryum vulgare, Cocos nucifera, and Elaeis guineensis against nine strains of S. aureus was determined using the checkerboard method. Lauric acid was identified as a major constituent of all tested oils by gas chromatography. The results showed strong concentration dependent antagonistic interactions between palm oils and oxacillin with values of fractional inhibitory concentrations indices ranging from 4.02 to 8.56 at concentrations equal or higher than 1024 µg/mL of the tested oils. Similarly, lauric acid in combination with oxacillin produced antagonistic action with fractional inhibitory concentration indices ranging from 4.01 to 4.28 at 1024 µg/mL. These findings suggest that interference between oxacillin and palm oils and their constituents can negatively affect the treatment of staphylococcal infections in humans and other animals.

The Glucose-Lowering Effects of Coconut Oil: A Case Report and Review of the Literature

Background

Coconut oil, a saturated fat comprised mostly of the medium-chain fatty acid, lauric acid, has become increasingly popular over the past few decades due to its touted anti-inflammatory, metabolic, and lipid-lowering properties. There have been many studies with mixed results evaluating the effects of coconut oil consumption on lipid metabolism and cardiometabolic risk. However, the effects on glucose metabolism are less clear. There are few trials on the effects of coconut oil on glucose homeostasis but no case reports prior to the current one.

Case

We present a case of a 66-year-old man with a history of type 2 diabetes managed with insulin who developed recurrent hypoglycemia and required reduction in insulin therapy quickly after consuming coconut oil supplementation.

Conclusion

This is the first known case report of coconut oil supplementation in a diabetic patient on insulin resulting in hypoglycemia. Review of the literature shows that coconut oil supplementation can have a favorable effect on glycemic control, possibly through phenolic compounds mediating anti-inflammatory effects. This effect is inconsistent throughout the studies reviewed, likely due to variations in types of coconut oil supplementation and scarcity of trials. Further research is required both in animal models and in humans before coconut oil intake is widely advised and popularized. This is especially true in patients with diabetes, who are at increased risk of cardiovascular disease, and in whom reduction in saturated fat intake is advised.

Oleochemistry potential from Brazil northeastern exotic plants

Caatinga is a Brazilian semi-arid ecosystem that stands out for presenting unique environmental characteristics with a dry, spiny and deciduous shrub/forest vegetation with several species that can be renewable oil sources with potential applicability in oleochemical and nutrition. Caatinga oilseeds have a high content of unsaturated fatty acids, phytosterols and sterols, and this composition is related to its nutritional potential. The present review summarizes the knowledge on the oil contents and fatty acid profiles of seeds from six representatives caatinga species. It was observed that plants species like Caju (Anacardium occidentale L.), Favela (Cnidoscolus quercifolius Pohl), Licuri (Syagrus coronata (Mart.) Becc.), Pinhão-bravo (Jatropha mollissima Pohl Baill), Pequi (Caryocar brasiliense Camb) and Oiticica (Licania rígida Benth) contains approximately 33.1, 33.5, 49.2, 18.3, 70.16 and 57.0% w/w of oil, respectively, on a dry weight basis. Their fatty acid profiles are mostly saturated for Licuri oil, with a high content of lauric acid (up to 40%) and unsaturated for Favela, Pinhão-bravo, Cashew nut, Pequi and Oiticica oils. Oiticica oil shows a high concentration of unusual conjugated polyunsaturated fatty acids, like α-Eleostearic and Licanic acid with 16.90 and 43.20% w/w, respectively.

High-fat diet-induced obesity and impairment of brain neurotransmitter pool

Obesity and the brain are linked since the brain can control the weight of the body through its neurotransmitters. The aim of the present study was to investigate the effect of high-fat diet (HFD)-induced obesity on brain functioning through the measurement of brain glutamate, dopamine, and serotonin metabolic pools. In the present study, two groups of rats served as subjects. Group 1 was fed a normal diet and named as the lean group. Group 2 was fed an HFD for 4 weeks and named as the obese group. Markers of oxidative stress (malondialdehyde, glutathione, glutathione-s-transferase, and vitamin C), inflammatory cytokines (interleukin [IL]-6 and IL-12), and leptin along with a lipid profile (cholesterol, triglycerides, high-density lipoprotein, and low-density lipoprotein levels) were measured in the serum. Neurotransmitters dopamine, serotonin, and glutamate were measured in brain tissue. Fecal samples were collected for observing changes in gut flora. In brain tissue, significantly high levels of dopamine and glutamate as well as significantly low levels of serotonin were found in the obese group compared to those in the lean group (P > 0.001) and were discussed in relation to the biochemical profile in the serum. It was also noted that the HFD affected bacterial gut composition in comparison to the control group with gram-positive cocci dominance in the control group compared to obese. The results of the present study confirm that obesity is linked to inflammation, oxidative stress, dyslipidemic processes, and altered brain neurotransmitter levels that can cause obesity-related neuropsychiatric complications.