Male reproductive traits are differentially affected by dietary macronutrient balance but unrelated to adiposity.

Dietary factors influence male reproductive function in both experimental and epidemiological studies. However, there are currently no specific dietary guidelines for male preconception health. Here, we use the Nutritional Geometry framework to examine the effects of dietary macronutrient balance on reproductive traits in C57BL/6 J male mice. Dietary effects are observed in a range of morphological, testicular and spermatozoa traits, although the relative influence of protein, fat, carbohydrate, and their interactions differ depending on the trait being examined. Interestingly, dietary fat has a positive influence on sperm motility and antioxidant capacity, differing to typical high fat diet studies where calorie content is not controlled for. Moreover, body adiposity is not significantly correlated with any of the reproductive traits measured in this study. These results demonstrate the importance of macronutrient balance and calorie intake on reproductive function and support the need to develop specific, targeted, preconception dietary guidelines for males.

Interleukin-18 Is a Potential Biomarker Linking Dietary Fatty Acid Quality and Insulin Resistance: Results from a Cross-Sectional Study in Northern Italy.

Dietary lipids are pivotal in modulating metabolic inflammation. Among the inflammatory mediators characterizing metabolic inflammation, interleukin 18 (IL-18) has been consistently associated with obesity and insulin resistance. This study aims to evaluate whether the quality of lipid intake impacts upon IL-18 plasma levels and the implications on insulin resistance computed by the homeostatic model assessment for insulin resistance (HOMA-IR). Using a cross-sectional design, this study confirmed that IL-18 correlated positively with insulin resistance and individuals with a HOMA-IR ≥ 2.5 displayed higher circulating IL-18 levels compared with their insulin-sensitive counterparts. In terms of the effect of the quality of dietary lipids on IL-18 circulating levels, the ratio between monounsaturated, omega-3, polyunsaturated and saturated fatty acids as well as the intake of eicosapentaenoic and docosahexaenoic acids correlated negatively with IL-18. Despite this, IL-18 circulating levels, but not dietary fatty acid quality, predicted insulin resistance. Nevertheless, the ratio between omega 3 and saturated fatty acids was a predictor of IL-18 plasma levels. Thus, the downregulation of IL-18 may underpin, at least partially, the beneficial metabolic effects of substituting omega 3 for saturated fatty acids with this cytokine potentially representing a biomarker linking dietary lipids and metabolic outcomes.

Dietary fatty acids differentially affect secretion of pro-inflammatory cytokines in human THP-1 monocytes.

Monocytes are a major population of circulating immune cells that play a crucial role in producing pro-inflammatory cytokines in the body. The actions of monocytes are known to be influenced by the combinations and concentrations of certain fatty acids (FAs) in blood and dietary fats. However, systemic comparisons of the effects of FAs on cytokine secretion by monocytes have not be performed. In this study, we compared how six saturated FAs (SFAs), two monounsaturated FAs (MUFAs), and seven polyunsaturated FAs (PUFAs) modulate human THP-1 monocyte secretion of TNF, IL-1ß, and IL-6 in the absence or presence of lipopolysaccharide. SFAs generally stimulated resting THP-1 cells to secrete pro-inflammatory cytokines, with stearic acid being the most potent species. In contrast, MUFAs and PUFAs inhibited lipopolysaccharide-induced secretion of pro-inflammatory cytokines. Interestingly, the inhibitory potentials of MUFAs and PUFAs followed U-shaped (TNF and IL-1ß) or inverted U-shaped (IL-6) dose-response curves. Among the MUFAs and PUFAs that were analyzed, docosahexaenoic acid (C22:6 n-3) exhibited the largest number of double bonds and was found to be the most potent anti-inflammatory compound. Together, our findings reveal that the chemical compositions and concentrations of dietary FAs are key factors in the intricate regulation of monocyte-mediated inflammation.

Polyunsaturated fatty acids-rich dietary lipid prevents high fat diet-induced obesity in mice.

Diet is the primary factor affecting host nutrition and metabolism, with excess food intake, especially high-calorie diets, such as high-fat and high-sugar diets, causing an increased risk of obesity and related disorders. Obesity alters the gut microbial composition and reduces microbial diversity and causes changes in specific bacterial taxa. Dietary lipids can alter the gut microbial composition in obese mice. However, the regulation of gut microbiota and host energy homeostasis by different polyunsaturated fatty acids (PUFAs) in dietary lipids remains unknown. Here, we demonstrated that different PUFAs in dietary lipids improved host metabolism in high-fat diet (HFD)-induced obesity in mice. The intake of the different PUFA-enriched dietary lipids improved metabolism in HFD-induced obesity by regulating glucose tolerance and inhibiting colonic inflammation. Moreover, the gut microbial compositions were different among HFD and modified PUFA-enriched HFD-fed mice. Thus, we have identified a new mechanism underlying the function of different PUFAs in dietary lipids in regulating host energy homeostasis in obese conditions. Our findings shed light on the prevention and treatment of metabolic disorders by targeting the gut microbiota.

Effects of dietary fat type and emulsification on carotenoid absorption: a randomized crossover trial.

BACKGROUND: Although emerging evidence has suggested that the type and emulsification of dietary fat may be important to carotenoid absorption, these effects have not yet been validated in a human trial. OBJECTIVES: This study aimed to examine the effects of dietary fat type and emulsification on the bioaccessibility and bioavailability of carotenoids from a carotenoid-rich salad. METHODS: An identical salad was used for the in vitro and the human trial. This was paired with 28 g of one of the following 4 different fats: 1) nonemulsified olive oil, 2) emulsified olive oil, 3) nonemulsified coconut oil, and 4) emulsified coconut oil. The bioaccessibility of total carotenoids (TCs) was assessed by a simulated in vitro digestion model. Sixteen subjects consumed salad with 4 test fats in random order, and plasma triglyceride and carotenoid (lutein, zeaxanthin, α-carotene, ß-carotene, and lycopene) concentrations were determined hourly for 10 h following the consumption. The absorption of TC and individual carotenoids was evaluated by the positive incremental AUC (iAUC) of plasma carotenoid concentrations. RESULTS: The bioaccessibility of TC was greater with olive oil (24.0%) than with coconut oil (14.9%), and with the oil being emulsified (23.5%) rather than that being nonemulsified (15.4%). Similarly, the positive iAUC1-10h of TC, α-carotene, and lycopene were 55.2%, 110.8%, and 45.8%, respectively, higher with olive oil than with coconut oil. Emulsified fat induced 40.0% greater positive iAUC1-10h of TC than nonemulsified fat. CONCLUSIONS: The type and emulsification of dietary fat are both essential to carotenoid absorption. Findings from this study may provide scientific support for designing excipient emulsions as potential dietary strategies to optimize the absorption of fat-soluble compounds. This study was registered at clinicaltrials.gov as NCT04323826.

Saturated Fatty Acids Consumed in Smoothies Increase Glucose and Metabolic Load Index in Young Adults Compared to Polyunsaturated Omega-3-Fatty Acids.

Introduction: Chronic diets high in saturated fat (SF) and omega-6-fatty acids (O6FAs) elevate fasting triglycerides (TRGs) and glucose (GLU). Postprandial TRGs, GLU, and Metabolic Load Index (MLI) are better predictors of disease risk compared to fasting levels alone. Conversely, diets high in omega-3 fatty acids (O3FAs) may be cardioprotective. Unfortunately, many existing postprandial studies are not standardized to body weight and given in an amount individuals would typically consume in their daily lives; the MLI is not calculated, and varying types of fat content are not examined. Therefore, we sought to determine whether SF, O3FAs, or O6FAs altered postprandial TRGs, GLU, and MLI from a standardized mixed meal. Methods: Fifteen individuals (6 M and 9 F) visited the laboratory three times, separated by at least 48 h, to consume HFM smoothies with varying FA composition (SF, high O6FAs, and high O3FAs). The smoothies were standardized to 12 kcal/kg body weight, 63% total fat, and 0.72 g/kg sugar. TRGs and GLU were collected at baseline and at 2 h and 4 h postprandially; the MLI was calculated by summing the TRG and GLU responses at each time point. Results: There was a significant increase in TRGs across time points (p < 0.001). For TRGs, there was a trend toward a significant interaction between smoothie type and time (p = 0.06) due to the increase in TRGs in the SF compared to the O3FA smoothie. There was an increase in postprandial GLU that varied across smoothie types (p = 0.036). Taken together, the MLI was elevated in the SF smoothie compared to the O3FAs at 2 h (p = 0.041). Conclusion: A SF smoothie in the morning elevated the metabolic load compared to an O3FA smoothie. Mechanisms of action in the competing clearance of TRGs and GLU warrant further investigation.

Gene-Nutrient Interactions in Obesity: COBLL1 Genetic Variants Interact with Dietary Fat Intake to Modulate the Incidence of Obesity.

The COBLL1 gene is associated with leptin, a hormone important for appetite and weight maintenance. Dietary fat is a significant factor in obesity. This study aimed to determine the association between COBLL1 gene, dietary fat, and incidence of obesity. Data from the Korean Genome and Epidemiology Study were used, and 3055 Korean adults aged ≥ 40 years were included. Obesity was defined as a body mass index ≥ 25 kg/m2. Patients with obesity at baseline were excluded. The effects of the COBLL1 rs6717858 genotypes and dietary fat on incidence of obesity were evaluated using multivariable Cox proportional hazard models. During an average follow-up period of 9.2 years, 627 obesity cases were documented. In men, the hazard ratio (HR) for obesity was higher in CT, CC carriers (minor allele carriers) in the highest tertile of dietary fat intake than for men with TT carriers in the lowest tertile of dietary fat intake (Model 1: HR: 1.66, 95% confidence interval [CI]: 1.07-2.58; Model 2: HR: 1.63, 95% CI: 1.04-2.56). In women, the HR for obesity was higher in TT carriers in the highest tertile of dietary fat intake than for women with TT carriers in the lowest tertile of dietary fat intake (Model 1: HR: 1.49, 95% CI: 1.08-2.06; Model 2: HR: 1.53, 95% CI: 1.10-2.13). COBLL1 genetic variants and dietary fat intake had different sex-dependent effects in obesity. These results imply that a low-fat diet may protect against the effects of COBLL1 genetic variants on future obesity risk.

Genetic Val66Met BDNF Variant Increases Hyperphagia on Fat-rich Diets in Mice.

High prevalence of obesity is attributable in part to consumption of highly palatable, fat-rich foods. However, the mechanism controlling dietary fat intake is largely unknown. In this study we investigated the role of brain-derived neurotrophic factor (BDNF) in the control of dietary fat intake in a mouse model that mimics the common human Val-to-Met (Val66Met) polymorphism that impairs BDNF release via the regulated secretory pathway. BdnfMet/Met mice gained weight much faster than wild-type (WT) mice and developed severe obesity due to marked hyperphagia when they were fed HFD. Hyperphagia in these mice worsened when the fat content in their diet was increased. Conversely, mice lacking leptin exhibited similar hyperphagia on chow and HFD. When 2 diets were provided simultaneously, WT and BdnfMet/Met mice showed a comparable preference for the more palatable diet rich in either fat or sucrose, indicating that increased hyperphagia on fat-rich diets in BdnfMet/Met mice is not due to enhanced hedonic drive. In support of this interpretation, WT and BdnfMet/Met mice increased calorie intake to a similar extent during the first day after chow was switched to HFD; however, WT mice decreased HFD intake faster than BdnfMet/Met mice in subsequent days. Furthermore, we found that refeeding after fasting or nocturnal feeding with HFD activated TrkB more strongly than with chow in the hypothalamus of WT mice, whereas TrkB activation under these 2 conditions was greatly attenuated in BdnfMet/Met mice. These results indicate that satiety factors generated during HFD feeding induce BDNF release to suppress excess dietary fat intake.

Medium-chain fatty acids suppress lipotoxicity-induced hepatic fibrosis via the immunomodulating receptor GPR84.

Medium-chain triglycerides (MCTs), which consist of medium-chain fatty acids (MCFAs), are unique forms of dietary fat with various health benefits. G protein-coupled 84 (GPR84) acts as a receptor for MCFAs (especially C10:0 and C12:0); however, GPR84 is still considered an orphan receptor, and the nutritional signaling of endogenous and dietary MCFAs via GPR84 remains unclear. Here, we showed that endogenous MCFA-mediated GPR84 signaling protected hepatic functions from diet-induced lipotoxicity. Under high-fat diet (HFD) conditions, GPR84-deficient mice exhibited nonalcoholic steatohepatitis (NASH) and the progression of hepatic fibrosis but not steatosis. With markedly increased hepatic MCFA levels under HFD, GPR84 suppressed lipotoxicity-induced macrophage overactivation. Thus, GPR84 is an immunomodulating receptor that suppresses excessive dietary fat intake-induced toxicity by sensing increases in MCFAs. Additionally, administering MCTs, MCFAs (C10:0 or C12:0, but not C8:0), or GPR84 agonists effectively improved NASH in mouse models. Therefore, exogenous GPR84 stimulation is a potential strategy for treating NASH.

Cuminaldehyde ameliorates hyperglycemia in diabetic mice.

BACKGROUND: Animal-fats are rich in long-chain saturated fatty-acids, well known to induct diabetic distress among ingested insulin-insensitive individuals. In the current-study, bovine-fat was fed to selective mice breeds highly sensitized to heavy dietary lipid load. METHODS: The later high fat diet (HFD) group indeed undergone diabetic-onset within weeks with a drastically altered feed-behavior pattern. It consumed more food, gained body mass, elevated homeostatic model assessment value and extensively glycosylated Hb transporters. RESULTS: However, the hypothetical test drug (Cuminaldehyde or CA) with known therapeutic-potential worked-well to balance food efficiency-ratio and Hb- counts closer to control. The fat-soluble phytochemical mono-terpenoid (CA) promoted constitutive mono-hexose (glucose) consuming catabolic-cycles via mono-glycoprotein (insulin) signal-transduction. It resolved diabetogenic-upsurge of gluconeogenic-enzymes, reduced non-sugar (amino/fatty acids) utilization by restricting transamination/dephosphorylation and restored liver-glycogen reserves near to normal-group effectively at 10 mg/kg b.w dose. CONCLUSIONS: Hence, the nutraceutical-potential (anti-diabetes/transaminitis ability) of administered exogenous redox-active agent CA can be entertained for evoking therapeutic-heath in diabetic human-community.

Fat Quality Impacts the Effect of a High-Fat Diet on the Fatty Acid Profile, Life History Traits and Gene Expression in Drosophila melanogaster.

Feeding a high-fat diet (HFD) has been shown to alter phenotypic and metabolic parameters in Drosophila melanogaster. However, the impact of fat quantity and quality remains uncertain. We first used butterfat (BF) as an example to investigate the effects of increasing dietary fat content (3-12%) on male and female fruit flies. Although body weight and body composition were not altered by any BF concentration, health parameters, such as lifespan, fecundity and larval development, were negatively affected in a dose-dependent manner. When fruit flies were fed various 12% HFDs (BF, sunflower oil, olive oil, linseed oil, fish oil), their fatty acid profiles shifted according to the dietary fat qualities. Moreover, fat quality was found to determine the effect size of the response to an HFD for traits, such as lifespan, climbing activity, or fertility. Consistently, we also found a highly fat quality-specific transcriptional response to three exemplary HFD qualities with a small overlap of only 30 differentially expressed genes associated with the immune/stress response and fatty acid metabolism. In conclusion, our data indicate that not only the fat content but also the fat quality is a crucial factor in terms of life-history traits when applying an HFD in D. melanogaster.

Consumption of fish oil high-fat diet induces murine hair loss via epidermal fatty acid binding protein in skin macrophages.

Fats are essential in healthy diets, but how dietary fats affect immune cell function and overall health is not well understood. Mimicking human high-fat diets (HFDs), which are rich in different fatty acid (FA) components, we fed mice various HFDs from different fat sources, including fish oil and cocoa butter. Mice consuming the fish oil HFD exhibit a hair-loss phenotype. Further studies show that omega-3 (n-3) FAs in fish oil promote atypical infiltration of CD207- (langerin-) myeloid macrophages in skin dermis, which induce hair loss through elevated TNF-α signaling. Mechanistically, epidermal fatty acid binding protein (E-FABP) is demonstrated to play an essential role in inducing TNF-α-mediated hair loss by activating the n-3 FA/ROS/IL-36 signaling pathway in dermal resident macrophages. Absence of E-FABP abrogates fish oil HFD-induced murine hair loss. Altogether, these findings support a role for E-FABP as a lipid sensor mediating n-3 FA-regulated macrophage function and skin health.

Cholesterol and fat in diet disrupt bone and tooth homeostasis in mice.

Dyslipidemia is a condition of high levels of triglycerides and cholesterol in the blood, and high levels of cholesterol is associated with a variety of systemic diseases. The effects of a high-fat diet on bone have been reported, however, it is not clear which components of a high-fat diet affect bone. This study was conducted to examine the effects of dietary lipids and cholesterol on bone homeostasis maintenance. Eight-week-old male mice (C57BL/6 J) were fed five types of feed with different amounts of fat (14 %, 36 %) and cholesterol (0.01 %, 1.25 %, 5 %) for 12 weeks. Blood, femur, tibia, and tooth samples were examined, and serum lipid markers and bone morphology were determined using µCT and histological analysis. Additionally, bone marrow cells were obtained and cultured, and osteoclast differentiation markers analyzed using qPCR. Mice fed a diet high in both fat (36 %) and cholesterol (1.25 %) showed increased total cholesterol and low-density lipoprotein levels in blood, and decreased bone volume fraction as compared to the standard diet group. However, bone mass was unaffected in the high fat only (36 %) and high cholesterol only (1.25 %, 5 %) groups. Mice given a high fat (36%) diet also demonstrated significantly narrowed incisor pulp. In contrast, osteoclast formation was not significantly different among the groups. These results suggest that a diet with high amounts of both fat and cholesterol induces bone loss.

Maternal Metformin Treatment Reprograms Maternal High-Fat Diet-Induced Hepatic Steatosis in Offspring Associated with Placental Glucose Transporter Modifications.

Maternal high-fat (HF) diet exposure in utero may affect fetal development and cause metabolic problems throughout life due to lipid dysmetabolism and oxidative damage. Metformin has been suggested as a potential treatment for body weight reduction and nonalcoholic fatty liver disease, but its reprogramming effect on offspring is undetermined. This study assesses the effects of maternal metformin treatment on hepatic steatosis in offspring caused by maternal HF diet. Female rats were fed either a control or an HF diet before conception, with or without metformin treatment during gestation, and placenta and fetal liver tissues were collected. In another experiment, the offspring were fed a control diet until 120 d (adult stage). Metformin treatment during pregnancy ameliorates placental oxidative stress and enhances placental glucose transporter 1 (GLUT1), GLUT3, and GLUT4 expression levels through 5' adenosine monophosphate-activated protein kinase (AMPK) activation. Maternal metformin treatment was shown to reprogram maternal HF diet-induced changes in offspring fatty liver with the effects observed in adulthood as well. Further validation is required to develop maternal metformin therapy for clinical applications.

Effects of proportions of carbohydrates and fats in diets on mucin concentration and bile composition in gallbladder of dogs.

The associations of diet compositions with mucin secretion in gallbladder have not been investigated in dogs. This study aimed to examine the effects of a low-carbohydrate diet (LC) and a low-fat diet (LF) on bile mucin concentration and composition of gallbladder bile in six clinically healthy beagle dogs. After feeding of both diets, the bile mucin concentration was significantly decreased. In addition, there were significant decreases in the concentrations of taurochenodeoxycholic acid in bile, which is considered to promote mucin secretion, after feeding of both diets. The present study suggested that the proportions of carbohydrate and fat in diet affect the composition of gallbladder bile in dogs.

Dietary D-Allulose Reduces Body Fat Accumulation in Rats with and without Medium-Chain Triacylglycerol Supplementation.

d-Allulose (d-psicose) is a rare sugar, that contains no calories and exhibits 70% relative sweetness when compared with sucrose. Recently, several studies have demonstrated the anti-obesity effect of d-allulose, mediated by suppressing lipogenesis and increasing energy expenditure. Medium-chain triacylglycerols (MCTs) are lipids formed by 3 medium-chain fatty acids (MCFAs) with 6-12 carbon atoms attached to glycerol. MCTs have been expensively studied to reduce body fat accumulation in rats and humans. The anti-obesity effect of MCTs was not confirmed depending on the nutritional conditions because MCT might promote lipogenesis. In the present study, we examined the effects of simultaneous intake of diets containing low (5%) or high (13%) MCTs, with or without 5% d-allulose, on body fat accumulation in rats (Experiment 1). Furthermore, we assessed the interaction between 5% MCT and 5% d-allulose in the diet (Experiment 2). In Experiment 1, intra-abdominal adipose tissue weight was significantly greater in the high MCT diet groups than in the commercial diet (control) group. d-Allulose significantly decreased weights of intra-abdominal adipose tissue, carcass fat, and total body fat, however, these weights increased as the amount of MCT added increased. In Experiment 2, d-allulose significantly decreased almost all body fat indicators, and these values were not influenced by the presence or absence of MCT addition. The anti-obesity effect of d-allulose was observed with or without dietary MCT, and no synergistic effect was detected between d-allulose and MCT. These results suggest that d-allulose is a beneficial food ingredient in diets aimed at reducing body fat accumulation. However, further research is required on the synergistic effects between d-allulose and MCTs.

Short-term high-fat diet consumption increases body weight and body adiposity and alters brain stem taste information processing in rats.

Diet-induced obesity is known to develop whether exposed to a high-energy diet (HED) or a high-fat diet (HFD). However, it is still not clear whether the elevated energy content or the macronutrient imbalance is the key factor in early disease progression. Therefore, this study compared the short-term effects of 2 widely used rodent obesogenic diets, an HFD with 60 kcal% fat content and a carbohydrate-based HED, on the body weight, body fat content, glucose tolerance, and neuronal taste responses in rats. We found that only HFD induced an early significant body weight increase compared with the control normal diet (ND) group, starting on week 4, and resulting in a significantly elevated body adiposity compared with both the ND and HED groups. Oral glucose tolerance test revealed no difference across groups. Subsequently, we also found that HFD resulted in a significant body weight gain even under energy-restricted (isocaloric to ND) conditions. In vivo electrophysiological recordings revealed that only the ad libitum HFD and not the isocaloric-HFD altered the brain stem gustatory neural responses to oral taste stimulation. In conclusion, this study showed that increased fat intake might result in significant body weight gain even under isocaloric and metabolically healthy conditions and demonstrated changes in central taste processing in an early stage of dietary obesity. A better understanding of these initial physiological changes may offer new drug targets for preventing obesity.

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.

Molecular effects of the consumption of margarine and butter varying in trans fat composition: a parallel human intervention study.

BACKGROUND: Whereas the dietary intake of industrial trans fatty acids (iTFA) has been specifically associated with inflammation, cardiovascular disease, and type 2 diabetes, understanding the impact of dietary fats on human health remains challenging owing to their complex composition and individual effects of their lipid components on metabolism. The aim of this study is to profile the composition of blood, measured by the fatty acid (FAs) profile and untargeted metabolome of serum and the transcriptome of blood cells, in order to identify molecular signatures that discriminate dietary fat intakes. METHODS: In a parallel study, the molecular effects of consuming dairy fat containing ruminant TFA (rTFA) or margarine containing iTFA were investigated. Healthy volunteers (n = 42; 45-69 y) were randomly assigned to diets containing margarine without TFA as major source of fat (wTFA control group with 0.4 g TFA per 100 g margarine), margarine with iTFA (iTFA group with 4.1 g TFA per 100 g margarine), or butter with rTFA (rTFA group with 6.3 g TFA per 100 g butter) for 4 weeks. The amounts of test products were individually selected so that fat intake contributed to 30-33% of energy requirements and TFA in the rTFA and iTFA groups contributed to up to 2% of energy intake. Changes in fasting blood values of lipid profiles (GC with flame-ionization detection), metabolome profiles (LC-MS, GC-MS), and gene expression (microarray) were measured. RESULTS: Eighteen FAs, as well as 242 additional features measured by LC-MS (185) and GC-MS (54) showed significantly different responses to the diets (PFDR-adjusted < 0.05), mainly distinguishing butter from the margarine diets while gene expression was not differentially affected. The most abundant TFA in the butter, i.e. TFA containing (E)-octadec-11-enoic acid (C18:1 t11; trans vaccenic acid), and margarines, i.e. TFA containing (E)-octadec-9-enoic acid (C18:1 t9; elaidic acid) were reflected in the significantly different serum levels of TFAs measured after the dietary interventions. CONCLUSIONS: The untargeted serum metabolome differentiates margarine from butter intake although the identification of the discriminating features remains a bottleneck. The targeted serum FA profile provides detailed information on specific molecules differentiating not only butter from margarine intake but also diets with different content of iTFAs in margarine. TRIAL REGISTRATION: ClinicalTrials.gov NCT00933322.

Diets enriched with palm olein, cocoa butter, and extra virgin olive oil exhibited similar lipid response: a randomized controlled study in young healthy adults.

Vegetable oils having unsaturated fatty acids in the sn-2 position of triglyceride (TG) backbone might not raise serum cholesterol levels. We investigated the chronic effects of diets enriched with palm olein (IV64) (PO), cocoa butter (CB), or extra virgin olive oil (EVOO) with oleic acid primarily at the sn-2 position (66%, 75%, 87% sn-2 oleic acid, respectively) of the TG molecule in 40 healthy volunteers participated in this randomized, controlled, single-blinded, crossover trial. Following a 2-week run-in period, the subjects were given standardization meals (breakfast, lunch, and dinner) cooked with palm olein (IV72). Subjects were randomized to 1 of the 3 intervention groups; receiving baked products (brownies for breakfast and cookies for teatime) prepared with respective test fats accompanied with standardized low-fat meals for breakfast, lunch, and dinner prepared with palm olein (IV72) for all groups for 4 weeks in a crossover manner with 2-week washout period (given standardization meals). Anthropometric measurements, blood samples, and dietary intakes were measured before run-in and pre- and post-intervention. No significant difference was observed on the primary outcome of the study total: high-density lipoprotein cholesterol. All 3 test fats were found to exhibit similar lipid responses (total cholesterol, TG, lipoprotein (a), apolipoprotein-A1, apolipoprotein-B/A-1). Statistical difference was found on low-density lipoprotein cholesterol (CB>EVOO by 0.3 mmol/L, P = .003), high-density lipoprotein cholesterol (PO>CB by 0.04 mmol/L, P = .02) and apolipoprotein-B (EVOO