Supplementation-Dependent Effects of Vegetable Oils with Varying Fatty Acid Compositions on Anthropometric and Biochemical Parameters in Obese Women

Effects of chia (Salvia hispanica. L) on anthropometric measures and other cardiometabolic risk factors: A systematic review and dose-response meta-analysis

BACKGROUND

Findings of available randomized controlled trials (RCTs) on the effects of chia are inconsistent. Although previous meta-analyses summarized available findings in this regard, some limitations may distort their findings. Moreover, none of these meta-analyses examined the dose-response association of chia on cardiometabolic risk factors (CMRFs). Therefore, the present study aimed to evaluate the effect of chia consumption on CMRFs.

METHODS

Relevant RCTs were included by searching the ISI Web of Science, PubMed, and Scopus databases up to June 2, 2023. Mean differences (MD) and 95 % confidence intervals (CI) were pooled using random-effects model.

RESULTS

Ten publications were included in this systematic review and the meta-analysis. The results showed a significant reduction in systolic blood pressure (SBP) (MD = -7.87 mmHg; 95 % CI: - 12.92 to - 2.82; I2 = 71.3 %, P heterogeneity = 0.004), diastolic blood pressure (MD = -6.33 mmHg; 95 %CI: - 7.33 to - 5.34, I2 = 0 %, P heterogeneity = 0.42) and high-density lipoprotein cholesterol (HDL-c) (MD = -4.09 mg/dl; 95 %CI: - 6.76 to - 1.43, I2 = 12.4 %, P heterogeneity = 0.33). However, the effects of chia on the other risk factors were not significant. Based on the dose-response analysis, a 10-g/d increase in chia consumption significantly reduced SBP (MD = -2.20 mmHg; 95 %CI: - 3.75 to - 0.66, I2 = 78.9 %, P heterogeneity < 0.001) and HDL-c (MD = -1.10 mg/dl; 95 %CI: - 1.72 to - 0.49, I2 = 0 %, P heterogeneity = 0.52).

CONCLUSION

Chia consumption might have a beneficial effect on lowering blood pressure. Chia consumption can also lead to a slight reduction in HDL-c levels. As the quality of the included studies was mostly low, the findings should be interpreted with caution. Well-designed trials with larger sample sizes and longer duration of follow-up are needed to provide additional insight into the dose-dependent effects of chia consumption.

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 effectiveness of chia seed in improving glycemic status: A systematic review and meta-analysis

AIMS

This systematic review and meta-analysis aims to evaluate the effectiveness of chia seeds in improving glycemic status, including fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and insulin.

METHODS

A comprehensive literature search was conducted on PubMed, Scopus, Web of Science, Cochrane, and Google Scholar up to January 2024. Randomized controlled trials (RCTs) assessing the effect of chia seeds on FBG, HbA1c, and/or insulin that meet our eligibility criteria were included. Version 2 of the Cochrane risk-of-bias tool (RoB2) was used to assess the quality of the included studies. Data were extracted and analyzed using a random-effects model and reported as weighted mean differences (WMD) with 95 % confidence intervals (CI). Subgroup and sensitivity analyses were also performed. The registration number was CRD42023441766.

RESULTS

Out of 341 articles retrieved from the initial search, 8 RCTs (with 10 arms) involving 362 participants were included in the meta-analysis. The results showed that chia consumption had no significant effect on FBG (WMD: 0.79 %; 95 % CI: -0.97 to 2.55; p = 0.38), HbA1c (WMD: -0.12 %; 95 % CI: -0.27 to 0.02; p = 0.09), and insulin (WMD:1.23 %; 95 % CI: -1.77 to 4.22; p = 0.42).

CONCLUSIONS

Chia seed consumption shows no significant impact on FBG, HbA1c, and insulin levels. This study is limited by the small number of studies in the meta-analysis and the significant heterogeneity among them, necessitating further research with larger sample sizes.

Changes in serum lipids following consumption of coconut oil and palm olein oil: A sequential feeding crossover clinical trial

BACKGROUND

High incidence of cardiovascular disease (CVD) in South Asia is linked to genetic predisposition and diets high in saturated fatty acids (SFAs). Increased CVD prevalence correlates with rising palm oil consumption in some South Asian countries, where coconut oil and palm olein oil are primary SFA sources.

OBJECTIVE

Compare the effects of coconut oil and palm olein oil on serum lipoprotein lipids and biochemical parameters in healthy adults.

METHODS

A sequential feeding crossover clinical trial with two feeding periods of 8 weeks each was conducted among 40 healthy adults. Participants were provided palm olein oil in the first feeding period followed by coconut oil with a 16-week washout period in between. The outcomes measured were the difference in serum low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), TC/HDL-C ratio, triglycerides (TG), very-low-density lipoprotein cholesterol (VLDL-C), fasting plasma glucose (FPG), and liver enzymes.

RESULTS

Thirty-seven participants completed the study. LDL-C decreased by 13.0 % with palm olein oil (p < 0.001) and increased by 5.6 % with coconut oil (p = 0.044), showing a significant difference (p < 0.001). TC decreased by 9.9 % with palm olein oil (p < 0.001) and increased by 4.0 % with coconut oil (p = 0.044).

CONCLUSION

Palm olein oil consumption resulted in more favorable changes in lipid-related CVD risk factors (TC, LDL-C, TC:HDL-C, and FPG) compared to coconut oil. Clinical Trial Registry number and website where it was obtained: (SLCTR/2019/034); https://slctr.lk/trials/slctr-2019-034.

The Lipid-Heart Hypothesis and the Keys Equation Defined the Dietary Guidelines but Ignored the Impact of Trans-Fat and High Linoleic Acid Consumption

In response to a perceived epidemic of coronary heart disease, Ancel Keys introduced the lipid-heart hypothesis in 1953 which asserted that high intakes of total fat, saturated fat, and cholesterol lead to atherosclerosis and that consuming less fat and cholesterol, and replacing saturated fat with polyunsaturated fat, would reduce serum cholesterol and consequently the risk of heart disease. Keys proposed an equation that would predict the concentration of serum cholesterol (ΔChol.) from the consumption of saturated fat (ΔS), polyunsaturated fat (ΔP), and cholesterol (ΔZ): ΔChol. = 1.2(2ΔS - ΔP) + 1.5ΔZ. However, the Keys equation conflated natural saturated fat and industrial trans-fat into a single parameter and considered only linoleic acid as the polyunsaturated fat. This ignored the widespread consumption of trans-fat and its effects on serum cholesterol and promoted an imbalance of omega-6 to omega-3 fatty acids in the diet. Numerous observational, epidemiological, interventional, and autopsy studies have failed to validate the Keys equation and the lipid-heart hypothesis. Nevertheless, these have been the cornerstone of national and international dietary guidelines which have focused disproportionately on heart disease and much less so on cancer and metabolic disorders, which have steadily increased since the adoption of this hypothesis.

The Impact of an 8-Week Supplementation with Fermented and Non-Fermented Aronia Berry Pulp on Cardiovascular Risk Factors in Individuals with Type 2 Diabetes

Aronia berries contain antioxidants that may be health-promoting, e.g., demonstrated positive effects on hypertension and dyslipidaemia. There is a close link between cardiovascular diseases and hypertension and dyslipidaemia, and cardiovascular events are the leading cause of death among subjects with type 2 diabetes (T2D). Thus, we investigated the effect of an 8-week supplementation with fermented aronia extract (FAE), non-fermented aronia extract (AE), and placebo on cardiovascular risk factors. Snack bars were produced containing 34 g (37%) aronia extract, or 17 g (21%) wheat bran for placebo, as well as raisins and coconut oil. The study was randomized and blinded with a triple-crossover design. We examined the effects of aronia extracts on blood pressure, adiponectin, and high-sensitive C-reactive protein, and found no effects. After supplementation with placebo, there were significantly higher blood concentrations of total cholesterol, LDL-cholesterol, and HDL-cholesterol, with the placebo group showing significantly higher increases in total cholesterol and LDL-cholesterol than the AE group. Furthermore, we observed an increase in HDL-cholesterol in the FAE group and an increase in triglyceride in the AE group. Thus, we assume that the raisins may have increased the participants' cholesterol levels, with both AE and FAE having the potential to prevent this increase.

Could Natural Products Help in the Control of Obesity? Current Insights and Future Perspectives

Obesity is a global issue faced by many individuals worldwide. However, no drug has a pronounced effect with few side effects. Green tea, a well-known natural product, shows preventive effects against obesity by decreasing lipogenesis and increasing fat oxidation and antioxidant capacity. In contrast, other natural products are known to contribute to obesity. Relevant articles published on the therapeutic effect of natural products on obesity were retrieved from PubMed, Web of Science, and Scopus. The search was conducted by entering keywords such as "obesity", "natural product", and "clinical trial". The natural products were classified as single compounds, foods, teas, fruits, herbal medicines-single extract, herbal medicines-decoction, and herbal medicines-external preparation. Then, the mechanisms of these medicines were organized into lipid metabolism, anti-inflammation, antioxidation, appetite loss, and thermogenesis. This review aimed to assess the efficacy and mechanisms of effective natural products in managing obesity. Several clinical studies reported that natural products showed antiobesity effects, including Coffea arabica (coffee), Camellia sinensis (green tea), Caulerpa racemosa (green algae), Allium sativum (garlic), combined Ephedra intermedia Schrenk, Thea sinensis L., and Atractylodes lancea DC extract (known as Gambisan), Ephedra sinica Stapf, Angelica Gigantis Radix, Atractylodis Rhizoma Alba, Coicis semen, Cinnamomi cortex, Paeoniae radix alba, and Glycyrrhiza uralensis (known as Euiiyin-tang formula). Further studies are expected to refine the pharmacological effects of natural products for clinical use.

The Effects of a Low Linoleic Acid/α-Linolenic Acid Ratio on Lipid Metabolism and Endogenous Fatty Acid Distribution in Obese Mice

A reduced risk of obesity and metabolic syndrome has been observed in individuals with a low intake ratio of linoleic acid/α-linolenic acid (LA/ALA). However, the influence of a low ratio of LA/ALA intake on lipid metabolism and endogenous fatty acid distribution in obese patients remains elusive. In this investigation, 8-week-old C57BL/6J mice were randomly assigned to four groups: low-fat diet (LFD) as a control, high-fat diet (HFD), high-fat diet with a low LA/ALA ratio (HFD+H3L6), and high-fat diet with a high LA/ALA ratio (HFD+L3H6) for 16 weeks. Our results show that the HFD+H3L6 diet significantly decreased the liver index of HFD mice by 3.51%, as well as the levels of triacylglycerols (TGs) and low-density lipoprotein cholesterol (LDL-C) by 15.67% and 10.02%, respectively. Moreover, the HFD+H3L6 diet reduced the pro-inflammatory cytokines interleukin-6 (IL-6) level and aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio and elevated the level of superoxide dismutase (SOD) in the liver. The HFD+H3L6 diet also resulted in the downregulation of fatty acid synthetase (FAS) and sterol regulatory element binding proteins-1c (SREBP-1c) expression and the upregulation of peroxisome proliferator-activated receptor-α (PPAR-α) and acyl-CoA oxidase 1 (ACOX1) gene expression in the liver. The low LA/ALA ratio diet led to a notable increase in the levels of ALA and its downstream derivative docosahexaenoic acid (DHA) in the erythrocyte, liver, perienteric fat, epididymal fat, perirenal fat, spleen, brain, heart, and gastrocnemius, with a strong positive correlation. Conversely, the accumulation of LA in abdominal fat was more prominent, and a high LA/ALA ratio diet exacerbated the deposition effect of LA. In conclusion, the low LA/ALA ratio not only regulated endogenous fatty acid levels but also upregulated PPAR-α and ACOX1 and downregulated SREBP-1c and FAS gene expression levels, thus maintaining lipid homeostasis. Optimizing dietary fat intake is important in studying lipid nutrition. These research findings emphasize the significance of understanding and optimizing dietary fat intake.

Nutritional Composition of Plant Protein Beverages on China's Online Market: A Cross-Sectional Analysis

Plant protein beverages are gaining popularity due to various reasons such as lactose intolerance, veganism and health claims. This study aimed to conduct a cross-sectional analysis of plant protein beverages sold online in China, with a focus on assessing their nutritional composition. A total of 251 kinds of plant protein beverages were analyzed, including coconut (n = 58), soy (n = 52), oats (n = 49), walnut (n = 14), almond (n = 11), peanut (n = 5), rice (n = 4), other beans (n = 5), mixed nuts (n = 5) and mixed beverages (n = 48), according to the nutrition label on the commercial package and retailer websites. The results showed that, except for soy beverages, plant protein beverages generally had low protein content, cereal beverages showed relatively high energy and carbohydrate levels, and all plant protein beverages had low sodium content. Additionally, the fortification rate of vitamins and minerals in the analyzed plant protein beverages was found to be extremely low, at only 13.1%. Given the substantial variation in the nutritional composition of plant protein beverages, consumers should pay more attention to the nutrition facts and ingredient information when choosing these beverages.

Effects of Dietary Linoleic Acid on Blood Lipid Profiles: A Systematic Review and Meta-Analysis of 40 Randomized Controlled Trials

Th aim of this meta-analysis was to elucidate whether dietary linoleic acid (LA) supplementation affected blood lipid profiles, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), compared with other fatty acids. Embase, PubMed, Web of Science and the Cochrane Library databases, updated to December 2022, were searched. The present study employed weighted mean difference (WMD) and a 95% confidence interval (CI) to examine the efficacy of the intervention. Out of the 3700 studies identified, a total of 40 randomized controlled trials (RCTs), comprising 2175 participants, met the eligibility criteria. Compared with the control group, the dietary intake of LA significantly decreased the concentrations of LDL-C (WMD: -3.26 mg/dL, 95% CI: -5.78, -0.74, I² = 68.8%, p = 0.01), and HDL-C (WMD: -0.64 mg/dL, 95% CI: -1.23, -0.06, I² = 30.3%, p = 0.03). There was no significant change in the TG and TC concentrations. Subgroup analysis showed that the LA intake was significantly reduced in blood lipid profiles compared with saturated fatty acids. The effect of LA on lipids was not found to be dependent on the timing of supplementation. LA supplementation in an excess of 20 g/d could be an effective dose for lowering lipid profiles. The research results provide further evidence that LA intake may play a role in reducing LDL-C and HDL-C, but not TG and TC.

Coconut oil consumption and bodyweight reduction: a systematic review and meta-analysis

INTRODUCTION

Due to the composition and biological properties of coconut oil, there is still considerable debate regarding potential benefits for the management of obesity, including the specific impact on body weight (BW) reduction. This systematic review and meta-analysis of clinical trials aims to assess the impact of coconut oil on BW reduction in comparison to other oils and fats.

EVIDENCE ACQUISITION

The databases, PubMed^®, Web of Science^®, EMBASE^®, and SciVerse Scopus^® were systematically searched. A combination of medical subject headings and words linked to coconut oil and obesity parameters were utilized. Any clinical trials comparing coconut oil to any other form of oil or fat, with more than one month feeding period among adults were considered.

EVIDENCE SYNTHESIS

From the 540 potentially relevant papers, 9 were included. The period of coconut oil intake varied from four to twelve weeks, apart from one long-term trial where coconut oil was consumed for two years. When compared to other oils and fats, coconut oil substantially decreased BW (N.=546), Body Mass Index (BMI) (N.=551), and percentage of fat mass (FM%) (N.=491) by 0.75 kg (P=0.04), 0.28 kg/m² (P=0.03), and 0.35% (P=0.008), respectively. Coconut oil consumption did not result in any significant alteration in waist circumference (WC) (N.=385) (-0.61 cm; P=0.30), waist-to-hip ratio (WHR) (N.=330) (-0.01; P=0.39) and FM (N.=86) (-0.25 kg; P=0.29).

CONCLUSIONS

Results indicate a small statistically significant reduction in BW, BMI, and FM% in the coconut oil group. In contrast, consumption of coconut oil had no statistically significant effect on WC, WHR, or FM.

The effect of coconut oil on anthropometric measurements and irisin levels in overweight individuals

AIM

This study aimed to discover the effects of coconut oil intake and diet therapy on anthropometric measurements, biochemical findings and irisin levels in overweight individuals.

MATERIALS AND METHODS

Overweight individuals (n = 44, 19-30 years) without any chronic disease were included. In this randomized controlled crossover study, the participants were divided into two groups (Group 1: 23 people, Group 2: 21 people). In the first phase, Group 1 received diet therapy to lose 0.5-1 kg of weight per week and 20 mL of coconut oil/day, while Group 2 only received diet therapy. In the second phase, Group 1 received diet therapy while Group 2 received diet therapy and 20 mL of coconut oil/day. Anthropometric measurements were taken four times. Irisin was measured four times by enzyme-linked immunosorbent (ELISA) method and other biochemical findings were measured twice. Statistical analysis was made on SPSS 20.

RESULTS

The irisin level decreased significantly when the participants only took coconut oil (p ≤ 0.05). There was a significant decrease in the participants' body weight, body mass index (BMI) level and body fat percentage (p ≤ 0.01). Insulin, total cholesterol, low density lipoproteins (LDL) cholesterol, and triglyceride (TG) levels of all participants decreased significantly (p ≤ 0.05). There was no significant difference in irisin level due to body weight loss (p ≤ 0.05); coconut oil provided a significant decrease in irisin level (p ≤ 0.05).

CONCLUSION

Diet therapy and weight loss did not have an effect on irisin level, but coconut oil alone was found to reduce irisin level. Coconut oil had no impact on anthropometric and biochemical findings.

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.

Misinformation in nutrition through the case of coconut oil: An online before-and-after study

BACKGROUND AND AIMS

Despite recent scientific evidence indicating absence of cardiometabolic benefit resulting from coconut oil intake, its consumption has increased in recent years, which can be attributed to a promotion of its use on social networks. We evaluated the patterns, reasons and beliefs related to coconut oil consumption and its perceived benefits in an online survey of a population in southern Brazil.

METHODS AND RESULTS

We conducted a before-and-after study using an 11-item online questionnaire that evaluated coconut oil consumption. In the same survey, participants who consumed coconut oil received an intervention to increase literacy about the health effects of coconut oil intake. We obtained 3160 valid responses. Among participants who consumed coconut oil (59.1%), 82.5% considered it healthy and 65.4% used it at least once a month. 81.2% coconut oil consumers did not observe any health improvements. After being exposed to the conclusions of a meta-analysis showing that coconut oil does not show superior health benefits when compared to other oils and fats, 73.5% of those who considered coconut oil healthy did not change their opinion. Among individuals who did not consume coconut oil, 47.6% considered it expensive and 11.6% deemed it unhealthy.

CONCLUSIONS

Coconut oil consumption is motivated by the responders' own beliefs in its supposed health benefits, despite what scientific research demonstrates. This highlights the difficulty in deconstructing inappropriate concepts of healthy diets that are disseminated in society.

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.

Chia seed (Salvia hispanica L.) consumption and lipid profile: a systematic review and meta-analysis

Chia (Salvia hispanica L.) is an annual herbaceous plant, originally from southern Mexico and northern Guatemala - nowadays grown all over the world. In recent years, there has been an increase in demand for plant foods with health-promoting properties, and chia is a main actor in this process due to its high nutritional and functional value and its chemical composition rich in PUFAs, mainly ω-3, as well as protein, dietary fiber, and bioactive compounds. Chia has been explored in different research models for health and the prevention of human diseases. Evidence has suggested potential for improving insulin resistance, disordered lipid profiles, glucose tolerance and even adiposity. The aim of this study was to evaluate the effect of consumption of chia seeds on the lipid profile, triglycerides, and serum ω-3 fatty acids in adults. This systematic review included all randomized controlled trials (parallel or crossover design) published up to August 2020 in the main databases Medline, Embase, Scopus, Web of Science, and Scielo. Two independent authors selected and extracted data from those articles. After the selection process, 10 clinical trials were included. Forest plots and summary tables were constructed to present data and sensitivity subgroup analyses were performed for some of the outcomes. The results showed that chia consumption suggests a protective effect on the lipid profile, decreasing TC (MD = -2.98, 95% CI = [-9.98; 4.02]), TG (MD = -14.09 mg dL-1, 95% CI = [-33.46; 5.28]), and LDL (MD = 2.07 mg dL-1; 95% CI = [-5.05; 9.19]) and increasing HDL (MD = -2.92 mg dL-1, 95% CI = [-5.91; 0.06]). Regarding serum fatty acids, chia reduced FFA and SFA and increased PUFAs, ALA, EPA, and LA. It has also reduced DHA while not changing DPA. The intake of chia appears to have a neutral or beneficial effect on some markers of the lipid and fatty acid profile.

Coconut oil supplementation during development reduces brain excitability in adult rats nourished and overnourished in lactation

INTRODUCTION

Coconut oil has been considered as a therapeutic alternative in several pathologies, but there is limited information regarding its effects on brain functioning.

OBJECTIVE

This study analyzed whether early virgin coconut oil (VCO) supplementation interferes with electrical activity of the adult rat brain and its lipid peroxidation. Moreover, it investigated whether the putative effect on brain electrophysiology could be affected by overnutrition occurring during lactation, and/or by environmental enrichment (EE). Electrophysiology was measured through cortical spreading depression (CSD), a phenomenon related to brain excitability.

METHODS

Wistar rats were suckled in litters of either nine or three pups, forming nourished (N) or overnourished (ON) groups, respectively. Between the 7th and 30th days of life, half of the animals in each group received VCO (10 mg kg^-1 d^-1; by gavage). The other half received an equivalent amount of vehicle (V, 0.009% cremophor). On day 36, animals from both groups were subjected to EE for 4 weeks. At 105 ± 15 days of life, each animal was subjected to CSD recordings and lipid peroxidation analyses.

RESULTS

Overnutrition during lactation enhanced body and brain weights. VCO decelerated the CSD propagation velocity (control - 3.57 ± 0.23 mm min^-1versus VCO - 3.27 ± 0.18 mm min^-1; p < 0.001), regardless of whether subjected to overnourishment or EE exposure. Neither VCO nor EE modified the cerebral lipid peroxidation (p > 0.05).

CONCLUSION

VCO supplementation impaired the spreading of CSD, indicating reduction of brain excitability. VCO effects occurred regardless of the nutritional state during lactation.

In vitro bioaccessibility of macular xanthophylls from commercial microalgal powders of Arthrospira platensis and Chlorella pyrenoidosa

The bioaccessibility of the major carotenoids present in two commercial microalgal supplements in powder form was investigated through a standardized in vitro digestion method. The dried biomass of Arthrospira platensis contained β-carotene (36.8 mg/100 g) and zeaxanthin (20.8 mg/100 g) as the main carotenoids as well as a high content of saturated fatty acids (61% of total fatty acids), whereas that of Chlorella pyrenoidosa was rich in lutein (37.8 mg/100 g) and had a high level of unsaturated fatty acids (65% of total fatty acids). In the case of the latter, lutein bioaccessibility was not statistically enhanced after the replacement of porcine bile extract with bovine bile extract in the in vitro digestion protocol and after the addition of coconut oil (17.8% as against to 19.2% and 19.2% vs. 18.5%, respectively). In contrast, the use of bovine bile extract along with co-digestion with coconut oil significantly enhanced the bioaccessibility of zeaxanthin from A. platensis, reaching the highest bioaccessibility of 42.8%.

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.

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.

Effect of coconut oil on cardio-metabolic risk: A systematic review and meta-analysis of interventional studies

BACKGROUND AND AIMS

High total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) could be major risk factors for cardiovascular disease burden among high risk populations especially in South Asians. This systematic review and meta-analysis aimed to quantify the effects of coconut oil compared with other oils and fats on cardio-metabolic parameters.

METHODS

PubMed, Scopus and Web of Science were systematically searched. The main outcomes included are lipid and glycemic parameters. Subgroup analyses were performed to evaluate individual comparisons of vegetable oils and animal fat with coconut oil. Data were pooled using random-effects meta-analysis.

RESULTS

Coconut oil consumption significantly increased TC by 15.42 mg/dL (95% CI, 8.96-21.88, p < 0.001), LDL-C by 10.14 mg/dL (95% CI, 4.44-15.84, p < 0.001) and high density lipoprorein cholesterol (HDL-C) by 2.61 mg/dL (95% CI, 0.95-4.26, p = 0.002), and significantly decreased glycosylated hemoglobin (HbA1c) by 0.39 mg/dL (95% CI, -0.50 to -0.27, p < 0.001) but, it had no effects on triglycerides (TG), (4.25 mg/dL; 95% CI, -0.49-8.99, p = 0.08) when compared with the control group. Sub-group analysis demonstrated that coconut oil significantly increased TC and LDL-C over corn, palm, soybean and safflower oils and not over olive oil. Compared with butter, coconut oil showed a better pattern in cardio-metabolic markers by significantly increasing HDL-C (4.38 mg/dL, 95% CI, 0.40 to 8.36, p = 0.03) and decreasing LDL-C (-14.90 mg/dL, 95% CI, -23.02 to-6.77, p < 0.001).

CONCLUSIONS

Our results suggest that coconut oil consumption results in significantly higher TC, LDL-C and HDL-C than other oils. Consumption of coconut oil can be one of the risk factors for CVDs in South Asians.

Oils' Impact on Comprehensive Fatty Acid Analysis and Their Metabolites in Rats

Fatty acids, especially polyunsaturated, and their metabolites (eicosanoids) play many pivotal roles in human body, influencing various physiological and pathological processes. The aim of the study was to evaluate the effect of supplementation with edible oils diverse in terms of fatty acid composition on fatty acid contents, activities of converting their enzymes, and on lipoxygenase metabolites of arachidonic and linoleic acids (eicosanoids) in rat serum. Female Sprague-Dawley rats divided into seven groups were used in the study. Animals from six groups were fed one of oils daily (carotino oil, made up by combining of red palm oil and canola oil, linseed oil, olive oil, rice oil, sesame oil, or sunflower oil). One group received a standard diet only. Fatty acids were determined using gas chromatography with flame ionization detection. Eicosanoids—hydroxyeicosatetraenoic (HETE) and hydroxyoctadecadienoic acids (HODE) were extracted using a solid-phase extraction method and analyzed with HPLC. Vegetable oils given daily to rats caused significant changes in serum fatty acid profile and eicosanoid concentrations. Significant differences were also found in desaturases’ activity, with the linseed and olive oil supplemented groups characterized by the highest D6D and D5D activity. These findings may play a significant role in various pathological states.

The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials

BACKGROUND

Coconut oil is high in saturated fat and may, therefore, raise serum cholesterol concentrations, but beneficial effects on other cardiovascular risk factors have also been suggested. Therefore, we conducted a systematic review of the effect of coconut oil consumption on blood lipids and other cardiovascular risk factors compared with other cooking oils using data from clinical trials.

METHODS

We searched PubMed, SCOPUS, Cochrane Registry, and Web of Science through June 2019. We selected trials that compared the effects of coconut oil consumption with other fats that lasted at least 2 weeks. Two reviewers independently screened articles, extracted data, and assessed the study quality according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The main outcomes included low-density lipoprotein cholesterol (LDL-cholesterol), high-density lipoprotein cholesterol (HDL-cholesterol), total cholesterol, triglycerides, measures of body fatness, markers of inflammation, and glycemia. Data were pooled using random-effects meta-analysis.

RESULTS

16 articles were included in the meta-analysis. Results were available from all trials on blood lipids, 8 trials on body weight, 5 trials on percentage body fat, 4 trials on waist circumference, 4 trials on fasting plasma glucose, and 5 trials on C-reactive protein. Coconut oil consumption significantly increased LDL-cholesterol by 10.47 mg/dL (95% CI: 3.01, 17.94; I² = 84%, N=16) and HDL-cholesterol by 4.00 mg/dL (95% CI: 2.26, 5.73; I² = 72%, N=16) as compared with nontropical vegetable oils. These effects remained significant after excluding nonrandomized trials, or trials of poor quality (Jadad score <3). Coconut oil consumption did not significantly affect markers of glycemia, inflammation, and adiposity as compared with nontropical vegetable oils.

CONCLUSIONS

Coconut oil consumption results in significantly higher LDL-cholesterol than nontropical vegetable oils. This should inform choices about coconut oil consumption.

Comparison of the Effects of Brazil Nut Oil and Soybean Oil on the Cardiometabolic Parameters of Patients with Metabolic Syndrome: A Randomized Trial

Recent evidence suggests that replacing saturated fat with unsaturated fat is beneficial for cardiovascular health. This study compared the effects of Brazil nut oil (BNO) and soybean oil (SO) supplementation for 30 days on anthropometric, blood pressure, biochemical, and oxidative parameters in patients with metabolic syndrome (MS). Thirty-one patients with MS were randomly allocated to receive 30 sachets with 10 mL each of either BNO (n = 15) or SO (n = 16) for daily supplementation. Variables were measured at the beginning of the study and after 30 days of intervention. No change in anthropometric and blood pressure variables were observed (p > 0.05). Total (p = 0.0253) and low-density lipoprotein (p = 0.0437) cholesterol increased in the SO group. High-density lipoprotein cholesterol decreased (p = 0.0087) and triglycerides increased (p = 0.0045) in the BNO group. Malondialdehyde levels decreased in the BNO group (p = 0.0296) and total antioxidant capacity improved in the SO group (p = 0.0110). Although the addition of oils without lifestyle interventions did not affect anthropometric findings or blood pressure and promoted undesirable results in the lipid profile in both groups, daily supplementation of BNO for 30 days decreased lipid peroxidation, contributing to oxidative stress reduction.