Trans-unsaturated fatty acid activates NLRP3 inflammasome in macrophages and exacerbates intestinal inflammation in mice.

Higher consumption of trans fatty acid (TFA) is a risk factor for several inflammatory diseases including inflammatory bowel disease (IBD). However, the detailed mechanisms by which TFA intake affects IBD pathology remain unclear. We demonstrate here that elaidate, a trans-isomer of oleate, enhances interleukin (IL)-1ß production through the activation of NLRP3 inflammasome in mouse bone marrow-derived macrophages (BMDMs). Oleate has no effect on IL-1ß production. Elaidate also induces oxidative stress and activates endoplasmic reticulum stress in BMDMs. The elaidate-induced IL-1ß production is suppressed by co-treatments with antioxidants and a chemical chaperone. Furthermore, we analyze the effects of elaidate administration on intestinal inflammation using 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model in mice. Increased colonic damage and myeloperoxidase activity after TNBS treatment are elevated by elaidate administration. Also, TNBS treatment induces IL-1ß production in colonic mucosa; elaidate administration enhances the induction. We believe that these data reveal some mechanisms by which the TFA intake is associated with increased risk for IBD.

Identifying and exploring biohydrogenating rumen bacteria with emphasis on pathways including trans-10 intermediates.

BACKGROUND: Bacteria involved in ruminal formation of trans-10 intermediates are unclear. Therefore, this study aimed at identifying rumen bacteria that produce trans-10 intermediates from 18-carbon unsaturated fatty acids. RESULTS: Pure cultures of 28 rumen bacterial species were incubated individually in the presence of 40 µg/mL 18:3n-3, 18:2n-6 or trans-11 18:1 under control or lactate-enriched (200 mM Na lactate) conditions for 24 h. Of the 28 strains, Cutibacterium acnes (formerly Propionibacterium acnes) was the only bacterium found to produce trans-10 intermediates from 18:3n-3 and 18:2n-6, irrespective of the growth condition. To further assess the potential importance of this species in the trans-11 to trans-10 shift, different biomass ratios of Butyrivibrio fibrisolvens (as a trans-11 producer) and C. acnes were incubated in different growth media (control, low pH and 22:6n-3 enriched media) containing 40 µg/mL 18:2n-6. Under control conditions, a trans-10 shift, defined in the current study as trans-10/trans-11 ≥ 0.9, occurred when the biomass of C. acnes represented between 90 and 98% of the inoculum. A low pH or addition of 22:6n-3 inhibited cis-9, trans-11 CLA and trans-10, cis-12 CLA formation by B. fibrisolvens and C. acnes, respectively, whereby C. acnes seemed to be more tolerant. This resulted in a decreased biomass of C. acnes required at inoculation to induce a trans-10 shift to 50% (low pH) and 90% (22:6n-3 addition). CONCLUSIONS: Among the bacterial species studied,C. acnes was the only bacterium that have the metabolic ability to produce trans-10 intermediates from 18:3n-3 and 18:2n-6. Nevertheless, this experiment revealed that it is unlikely that C. acnes is the only or predominant species involved in the trans-11 to trans-10 shift in vivo.

Trans fatty acid intake among Chinese population: a longitudinal study from 1991 to 2011.

OBJECTIVE: This study was aimed to roughly describe individual Trans Fatty Acids (TFAs) intake and the percentage of energy intake(E%), and identify major food sources in the Chinese population, taking gender, age, and regional distribution into the consideration, as well as examining temporal changes over the course of 20 years. METHOD: This multi-center study, covering nine provinces among populations aged ≥ 3 in China, was conducted to collect food consumption information from 1991 to 2011. A classical assessment method was used to estimate the level of dietary TFA intake. RESULTS: Over the 20-year period, the intake of TFAs in Chinese populations had increased, but remained at a relatively lower level (from 0.25 g/d(0.11% for E%) to 0.53 g/d(0.24% for E%)) compared with that of other countries and the World Health Organization (WHO) recommended level. Collectively, males and participants aged 19-60 generally consumed more TFA-containing foods. People in eastern regions consumed more TFAs and had a higher E% than those in western area. Industrial sources of TFAs, especially vegetable oil, ranked as the principal food sources of TFAs in the Chinese population. Natural sources of TFAs have gradually increased in proportion among children and adolescents. CONCLUSIONS: TFA intake and the E% are commonly under the recommended level in the general population in China. Presently, restriction of vegetable oil could be a crucial method to reduce TFA intake. It would be critical to facilitate and promote public health that food recommendations might be based on the dietary preferences for population separated by different ages and regions.

A trans fatty acid substitute enhanced development of liver proliferative lesions induced in mice by feeding a choline-deficient, methionine-lowered, L-amino acid-defined, high-fat diet.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a form of liver disease characterized by steatosis, necroinflammation, and fibrosis, resulting in cirrhosis and cancer. Efforts have focused on reducing the intake of trans fatty acids (TFAs) because of potential hazards to human health and the increased risk for NASH. However, the health benefits of reducing dietary TFAs have not been fully elucidated. Here, the effects of TFAs vs. a substitute on NASH induced in mice by feeding a choline-deficient, methionine-lowered, L-amino acid-defined, high-fat diet (CDAA-HF) were investigated. METHODS: Mice were fed CDAA-HF containing shortening with TFAs (CDAA-HF-T(+)), CDAA-HF containing shortening without TFAs (CDAA-HF-T(-)), or a control chow for 13 or 26 weeks. RESULTS: At week 13, NASH was induced in mice by feeding CDAA-HF-T(+) containing TFAs or CDAA-HF-T(-) containing no TFAs, but rather mostly saturated fatty acids (FAs), as evidenced by elevated serum transaminase activity and liver changes, including steatosis, inflammation, and fibrosis. CDAA-HF-T(-) induced a greater extent of hepatocellular apoptosis at week 13. At week 26, proliferative (preneoplastic and non-neoplastic) nodular lesions were more pronounced in mice fed CDAA-HF-T(-) than CDAA-HF-T(+). CONCLUSIONS: Replacement of dietary TFAs with a substitute promoted the development of proliferation lesions in the liver of a mouse NASH model, at least under the present conditions. Attention should be paid regarding use of TFA substitutes in foods for human consumption, and a balance of FAs is likely more important than the particular types of FAs.

The potential role of nutritional components in improving brain function among patients with Alzheimers disease: a meta-analysis of RCT studies.

OBJECTIVE: To find out the potential role of nutritional components in improving brain function among patients with Alzheimer`s disease (AD). METHODS: The correlation between nutrition and cerebral function in cases of AD has been the focus of 19 prospective randomised controlled trials (RCTs) with a combined research sample of 2297 patients. These RCTs are subject to systematic review and meta-analysis in the current paper RESULTS: Findings showed that chain-free secondary saturated fatty acids (SFA) and trans fatty acids (TFA) occurred in higher concentrations in AD patients` brains than in controls. Furthermore, neuroinflammation was caused by remodelling of the lipid membrane and AD patients` cognitive function was impacted by alterations in tyrosine, tryptophan, purine, and tocopherol pathway metabolomics. Moreover, in cases of mild-to-moderate AD, reduction in functionality was induced by administration of alpha-tocopherol for more than 12 months. Consumption of Souvenaid helps in synaptic synthesis, which enhances functional connectivity. Furthermore, consumption of the B vitamins folate, cobalamin and pyridoxine at dosages of 0.8 mg, 0.5 mg and 20 mg per day, respectively, over a period of one year resulted in lower plasma tHcy levels and brain atrophy. CONCLUSION: Chain-free SFA and TFA occur in greater amounts in the brains of individuals with AD than in those without AD.

Biological effects of trans fatty acids and their possible roles in the lipid rafts in apoptosis regulation.

A large number of recent studies are focused on evaluating the mechanism of action of trans fatty acids (TFAs) on the progression of apoptosis. A strong positive association has been reported between TFA and coronary heart disease (CHD), obesity and nonalcoholic steatohepatitis and so on. The present study reviewed the biological effects of trans fatty acids (TFA) and their possible roles in lipid rafts in regulating apoptosis. The following aspects of TFA were included: the research about TFA and diseases affecting serum lipid levels, inducing system inflammation and immune response, and the correlation between TFA and apoptosis. The primary purpose of the review article was to comprehensively evaluate the potential correlation between lipid rafts and apoptosis induced by different structures of TFA and provide some new research progress and future directions about it.

Membrane engineering via trans-unsaturated fatty acids production improves succinic acid production in Mannheimia succiniciproducens.

Engineering of microorganisms to produce desired bio-products with high titer, yield, and productivity is often limited by product toxicity. This is also true for succinic acid (SA), a four carbon dicarboxylic acid of industrial importance. Acid products often cause product toxicity to cells through several different factors, membrane damage being one of the primary factors. In this study, cis-trans isomerase from Pseudomonas aeruginosa was expressed in Mannheimia succiniciproducens to produce trans-unsaturated fatty acid (TUFA) and to reinforce the cell membrane of M. succiniciproducens. The engineered strain showed significant decrease in membrane fluidity as production of TUFA enabled tight packing of fatty acids, which made cells to possess more rigid cell membrane. As a result, the membrane-engineered M. succiniciproducens strain showed higher tolerance toward SA and increased production of SA compared with the control strain without membrane engineering. The membrane engineering approach employed in this study will be useful for increasing tolerance to, and consequently enhancing production of acid products.

Edible lipids modification processes: A review.

Lipid is the general name given to fats and oils, which are the basic components of cooking oils, shortening, ghee, margarine, and other edible fats. The chosen term depends on the physical state at ambient temperature; fats are solids and oils are liquids. The chemical properties of the lipids, including degree of saturation, fatty acid chain length, and acylglycerol molecule composition are the basic determinants of physical characteristics such as melting point, cloud point, solid fat content, and thermal behavior. This review will discuss the major lipid modification strategies, hydrogenation, and chemical and enzymatic interesterification, describing the catalysts used mechanisms, kinetics, and impacts on the health-related properties of the final products. Enzymatic interesterification will be emphasized as method that produces a final product with good taste, zero trans fatty acids, and a low number of calories, requires less contact with chemicals, and is cost efficient.

Maternal intake of trans-unsaturated or interesterified fatty acids during pregnancy and lactation modifies mitochondrial bioenergetics in the liver of adult offspring in mice.

The quality of dietary lipids in the maternal diet can programme the offspring to diseases in later life. We investigated whether the maternal intake of palm oil or interesterified fat, substitutes for trans-unsaturated fatty acids (FA), induces metabolic changes in the adult offspring. During pregnancy and lactation, C57BL/6 female mice received normolipidic diets containing partially hydrogenated vegetable fat rich in trans-unsaturated fatty acids (TG), palm oil (PG), interesterified fat (IG) or soyabean oil (CG). After weaning, male offspring from all groups received the control diet until day 110. Plasma glucose and TAG and liver FA profiles were ascertained. Liver mitochondrial function was accessed with high-resolution respirometry by measuring VO2, fluorimetry for detection of hydrogen peroxide (H2O2) production and mitochondrial Ca2+ uptake. The results showed that the IG offspring presented a 20 % increase in plasma glucose and both the IG and TG offspring presented a 2- and 1·9-fold increase in TAG, respectively, when compared with CG offspring. Liver MUFA and PUFA contents decreased in the TG and IG offspring when compared with CG offspring. Liver MUFA content also decreased in the PG offspring. These modifications in FA composition possibly affected liver mitochondrial function, as respiration was impaired in the TG offspring and H2O2 production was higher in the IG offspring. In addition, mitochondrial Ca2+ retention capacity was reduced by approximately 40 and 55 % in the TG and IG offspring, respectively. In conclusion, maternal consumption of trans-unsaturated and interesterified fat affected offspring health by compromising mitochondrial bioenergetics and lipid metabolism in the liver.

Trans-fatty acids and mortality in patients referred for coronary angiography: the Ludwigshafen Risk and Cardiovascular Health Study.

AIMS: Trans-fatty acids (TFAs) are generated by the food industry and also occur naturally in trace amounts in dairy products. For the latter, beneficial health effects have been claimed, while there are numerous reports about TFA of industrial origin being hazardous to human health. Therefore, we aimed to investigate the association of TFA with mortality in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. METHODS AND RESULTS: The fatty acid composition of erythrocyte membranes was analysed using the HS-Omega-3 Index(®) methodology in 3259 participants of the LURIC study at baseline. During a median of 10.0 years of follow-up, a total of 975 (29.9%) study participants died, 614 (18.8%) from cardiovascular causes including 254 (7.8%) sudden cardiac deaths (SCDs). Association of TFA with clinical outcome was investigated with Cox proportional hazards regression. Total TFAs were inversely associated with mortality due to cardiovascular causes or SCD. This was mainly driven by the naturally occurring TFA C16:1n-7t (trans-palmitoleic acid). The reduced risk of SCD associated with C16:1n-7t persisted after multivariate adjustment with a hazard ratio of 0.63 (0.46-0.86) for the third tertile compared with the first tertile. There was no association of any TFA subgroup with an increased risk of adverse outcomes. CONCLUSIONS: In contrast to previous findings, the low concentrations of total TFAs found in LURIC were inversely associated with adverse cardiac outcomes. While the naturally occurring TFA C16:1n-7t was associated with reduced risk, no increased risk was found for industrially produced TFAs.

Consumption of Oxidized and Partially Hydrogenated Oils Differentially Induces Trans-Fatty Acids Incorporation in Rats' Heart and Dyslipidemia.

OBJECTIVES: A direct effect of process-induced trans-fatty acids (TFAs) on nonalcoholic fatty liver disease (NAFLD) as a cardiovascular disease (CVD) risk factor has previously been shown. We hypothesized that TFAs directly induced CVD. This article describes an investigation of the association between TFAs, provided by the consumption of oxidized soybean oil and margarine, and plasma lipid profiles, coronary artery lesions, and coronary fatty acids distribution in rats. Male rats were fed a standard chow or high-fat diet containing different TFA levels ranging from <1%, <2%, and >2% of total fat in fresh soybean oil, oxidized soybean oil, and margarine, respectively, for 4 weeks. RESULTS: The results indicated that the high-fat diets differently changed the plasma lipid profiles by significantlt increasing triglycerides, total cholesterol, low-density lipoprotein cholesterol, and the ratio of low-density to high-density lipoprotein cholesterol compared to control rats. Compared to fresh soybean oil, oxidized oil further increased plasma lipid markers. The strongest inflammatory effect was induced by margarine, which contains the highest level of TFAs, or 2% of total fat. Total TFAs in the heart of the margarine-fed group were increased by 4.7 regarding to control and by 2.17 and 2.6 relative to groups receiving oxidized and fresh oil, respectively. Increased TFAs consumption was associated with increased histological aspects of atherosclerotic lesions in a dose-dependent manner. CONCLUSION: In conclusion, process-induced TFAs cause changes including proatherogenic plasma lipid markers, heart fatty acid profiles, and coronary artery histology depending on the TFA level in the supplemented fat and therefore on the type of technological process used.

Effect of dietary sugar concentration and sunflower seed supplementation on lactation performance, ruminal fermentation, milk fatty acid profile, and blood metabolites of dairy cows.

Previous research has shown that both sunflower seed (SF) and sucrose (SC) supplementation can result in variation in milk fat concentration and composition, possibly due to altered fermentation patterns and biohydrogenation of fatty acids in the rumen. The objective of this study was to determine the effects of different sugar concentrations with or without SF supplementation on lactation performance, ruminal fermentation, and milk fatty acid profile in lactating dairy cows. Eight multiparous Holstein dairy cows (body weight=620±15kg, 60±10 d in milk, mean ± standard deviation) were randomly assigned to treatments in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Each 21-d period consisted of a 14-d diet adaptation period and 7-d collection period. Dairy cows were fed 1 of the following 4 diets: (1) no additional SC without SF supplementation (NSC-SF), (2) no additional SC with SF supplementation (NSC+SF), (3) SC without SF supplementation (SC-SF), and (4) SC with SF supplementation (SC+SF). The diets contained the same amount of forages (corn silage and alfalfa hay). Four isonitrogenous and isoenergetic diets were formulated by replacing corn grain with SC and SF and balanced using change in proportions of canola meal and sugar beet pulp. No interaction was detected between SC and SF supplementation with respect to dry matter intake, milk yield, and composition. A tendency was found for an interaction between inclusion of SC and SF on energy-corrected milk with the highest amount in the SC-SF diet. Ruminal pH and the molar proportion of acetate were affected by SC inclusion, with an increase related to the SC-SF diet. Diets containing SF decreased the concentrations of short-chain fatty acids (4:0 to 10:0) and medium-chain fatty acids (12:0 to 16:0) in milk fat. The addition of SC tended to decrease the concentration of total trans-18:1. These data provide evidence that exchanging SC for corn at 4% of dietary dry matter influenced milk fat content and rumen pH, resulting in a tendency for decreased concentration of trans-18:1 in milk fat. Sucrose alone did not alter the milk fatty acid profile when cows were fed a combination of unsaturated fat and sugar, although several significant interactions between sugar and unsaturated fat were observed.

Trans-Fatty Acids Aggravate Obesity, Insulin Resistance and Hepatic Steatosis in C57BL/6 Mice, Possibly by Suppressing the IRS1 Dependent Pathway.

Trans-fatty acid consumption has been reported as a risk factor for metabolic disorders and targeted organ damages. Nonetheless, little is known about the roles and mechanisms of trans-fatty acids in obesity, insulin resistance (IR) and hepatic steatosis. Adult C57BL/6 male mice were fed with four different diets for 20 weeks: normal diet (ND), high fat diet (HFD), low trans-fatty acids diet (LTD) and high trans-fatty acid diet (HTD). The diet-induced metabolic disorders were assessed by evaluating body weight, glucose tolerance test, hepatic steatosis and plasma lipid profiles post 20-week diet. Histological (H&E, Oil-Red-O) staining and western blot analysis were employed to assess liver steatosis and potential signaling pathways. After 20-weeks of diet, the body weights of the four groups were 29.61 ± 1.89 g (ND), 39.04 ± 4.27 g (HFD), 34.09 ± 2.62 g (LTD) and 43.78 ± 4.27 g (HTD) (p < 0.05), respectively. HFD intake significantly impaired glucose tolerance, which was impaired further in the mice consuming the HTD diet. The effect was further exacerbated by HTD diet. Moreover, the HTD group exhibited significantly more severe liver steatosis compared with HFD group possibly through regulating adipose triglyceride lipase. The group consuming the HTD also exhibited significantly reduced levels of IRS1, phosphor-PKC and phosphor-AKT. These results support our hypothesis that consumption of a diet high in trans-fatty acids induces higher rates of obesity, IR and hepatic steatosis in male C57BL/6 mice, possibly by suppressing the IRS1dependent pathway.

New data on harmful effects of trans-fatty acids.

Various margarines containing trans-fatty acids were marketed as being healthier because of the absence of cholesterol, suggesting to use margarine instead of butter. Fifteen years ago, research documented the grave health risk of trans-fats (T-fat). US FDA in 2015 finalized its decision that T-fat is not safe and set a three-year time limit for complete removal of T-fat from all foods. The greatest danger from T-fat lies in its capacity to distort the cell membranes. The primary health risk identified for T-fat consumption is an elevated risk of coronary heart disease. T-fats have an adverse effect on the brain and nervous system. T-fat from the diet is incorporated into brain cell membranes and alter the ability of neurons to communicate. This can diminish mental performance. Relationship between T-fat intake and depression risk was observed. There is growing evidence for a possible role of T-fat in the development of Alzheimer´s disease and cognitive decline with age.

Comparison of the nutritional regulation of milk fat secretion and composition in cows and goats.

A study with 2 ruminant species (goats and cows) with inherent differences in lipid metabolism was performed to test the hypothesis that milk fat depression (MFD) due to marine lipid supplements or diets containing high amounts of starch and plant oil is caused by different mechanisms and that each ruminant species responds differently. Cows and goats were allocated to 1 of 3 groups (4 cows and 5 goats per group) and fed diets containing no additional oil (control) or supplemented with fish oil (FO) or sunflower oil and wheat starch (SOS) according to a 3 × 3 Latin square design with 26-d experimental periods. In cows, milk fat content was lowered by FO and SOS (-31%), whereas only FO decreased milk fat content in goats (-21%) compared with the control. Furthermore, FO and SOS decreased milk fat yield in cows, but not in goats. In both species, FO and SOS decreased the secretion of C16 FA output. However, SOS increased milk secretion of >C16 FA in goats. Compared with the control, SOS resulted in similar increases in milk trans-10,cis-12 conjugated linoleic acid (CLA) in both species, but caused a 2-fold larger increase in trans-10 18:1 concentration in cows than for goats. Relative to the control, responses to FO in both species were characterized by a marked decrease in milk concentration of 18:0 (-74%) and cis-9 18:1 (-62%), together with a ~5-fold increase in total trans 18:1, but the proportionate changes in trans-10 18:1 were lower for goats. Direct comparison of animal performance and milk FA responses to FO and SOS treatments demonstrated interspecies differences in mammary lipogenesis, suggesting a lower sensitivity to the inhibitory effects of trans-10,cis-12 CLA in goats and that ruminal biohydrogenation pathways are more stable and less prone to diet-induced shifts toward the formation of trans-10-containing intermediates in goats compared with cows. Even though a direct cause and effect could not be established, results suggest that regulation of milk fat synthesis during FO-induced MFD may be related to a shortage of 18:0 for endogenous mammary cis-9 18:1 synthesis, increase in the incorporation of trans FA in milk triacylglycerols, and limitations in the synthesis of FA de novo to maintain milk fat melting point. However, the possible contribution of biohydrogenation intermediates with putative antilipogenic effects in the mammary gland, including trans-9,cis-11 CLA, trans-10 18:1, or cis-11 18:1 to FO-induced MFD cannot be excluded.

Trans Fatty Acid Levels in Foods and Intakes among Population Aged 3 Years and above in Beijing and Guangzhou Cities, China.

OBJECTIVE: To understand the dietary intake levels of trans fatty acids (TFA) in a Chinese population and establish a basis for health risk assessment of trans fatty acids. METHODS: The TFA contents data of 2613 food items and food consumption data of 10,533 people aged 3 years and above in two large cities in China were matched and a simple assessment method was used to estimate the distribution of dietary TFA intake. RESULTS: The mean content of TFA was highest in margarine (1.68 ± 0.83 g/100g), followed by chocolate and candy (0.89 ± 2.68 g/100g), edible vegetable oils (0.86 ± 0.82 g/100g), milk (0.83 ± 1.56 g/100g), and bakery foods (0.41 ± 0.91 g/100g). TFA intake accounted for 0.34%, 0.30%, 0.32%, and 0.29% of the total energy intake in the 3-6, 7-12, 13-17, and ⋝18 year age groups, respectively. Of the populations studied, 0.42% demonstrated TFA intakes (as percentage of energy intake) greater than 1%. The main sources of dietary TFA intake were edible vegetable oils, milk, mutton, and beef, and baked foods, which accounted for 49.8%, 16.56%, 12.21%, and 8.87%, respectively. CONCLUSION: The current intake of TFA among people in two cities did not appear to be of major health concern regarding the threshold of TFA intake as the percentage of total energy recommended by the World Health Organization. Because most TFA were derived from industrially processed foods, the government should reinforce nutrition labeling and regulate food producers to further reduce TFA in food and to provide scientific instruction for consumers to make sound choices.

Adipose tissue trans-fatty acids and changes in body weight and waist circumference.

Previous studies have suggested that the intake of trans-fatty acids (TFA) plays a role in the development of obesity. The proportions of adipose tissue fatty acids not synthesised endogenously in humans, such as TFA, usually correlate well with the dietary intake. Hence, the use of these biomarkers may provide a more accurate measure of habitual TFA intake than that obtained with dietary questionnaires. The objective of the present study was to investigate the associations between the proportions of specific TFA in adipose tissue and subsequent changes in weight and waist circumference (WC). The relative content of fatty acids in adipose tissue biopsies from a random sample of 996 men and women aged 50-64 years drawn from a Danish cohort study was determined by GC. Baseline data on weight, WC and potential confounders were available together with information on weight and WC 5 years after enrolment. The exposure measures were total trans-octadecenoic acids (18:1t), 18:1 Δ6-10t, vaccenic acid (18:1 Δ11t) and rumenic acid (18:2 Δ9c, 11t). Data were analysed using multiple regression with cubic spline modelling. The median proportion of total adipose tissue 18:1t was 1.52% (90% central range 0.98, 2.19) in men and 1.47% (1.01, 2.19) in women. No significant associations were observed between the proportions of total 18:1t, 18:1 Δ6-10t, vaccenic acid or rumenic acid and changes in weight or WC. The present study suggests that the proportions of specific TFA in adipose tissue are not associated with subsequent changes in weight or WC within the exposure range observed in this population.

Low intake of ruminant trans fatty acids ameliorates the disordered lipid metabolism in C57BL/6J mice fed a high-fat diet.

Currently, the health benefits of ruminant trans fatty acids (R-TFA) are still controversial. Our previous investigations indicated that R-TFA at higher dosages (1.3% and 4% E) caused disordered lipid metabolism in mice; however, through collecting R-TFA intake data in 9 provinces of China, it was suggested that, in 2021, the range of R-TFA intake for Chinese residents was about 0.053-0.307 g d-1. Based on the 2022 Nutritional Dietary Guidelines for Chinese Residents, the recommended daily energy supply from R-TFA was about 0.11%-0.15% E. However, the health effects of R-TFA at a lower dosage are still unknown; therefore, our current research aims to further explore the effects of R-TFA on health. Through in vivo experiments, it was shown that R-TFA (0.15% E) decreased body weight gain and serum cholesterol levels in C57BL/6J mice fed a high-fat diet, while it had no significant effect on mice fed a low-fat diet. Besides, hepatic histopathology analysis suggested that R-TFA (0.15% E) ameliorated the degree of hepatic steatosis and reduced intrahepatocyte lipid droplet accumulation in C57BL/6J mice fed a high-fat diet. Through lipidomics analysis, we further screened 8 potential lipid metabolites that participate in regulating the dysregulation of lipid metabolism. Finally, it was suggested that R-TFA (0.15% E) down-regulated the expression of genes related to inflammation and cholesterol synthesis while up-regulated the expression of genes related to cholesterol clearance, which might partially explain the salutary effect of R-TFA (0.15% E) in ameliorating the hepatic steatosis and improving disordered lipid metabolism in mice fed a high-fat diet. Our current research will provide a reference for the intake of R-TFA and, furthermore, give some insights into understanding the health effects of R-TFA.

Trans-fatty acids, dangerous bonds for health? A background review paper of their use, consumption, health implications and regulation in France.

INTRODUCTION: Trans-fatty acids (TFAs) can be produced either from bio-hydrogenation in the rumen of ruminants or by industrial hydrogenation. While most of TFAs' effects from ruminants are poorly established, there is increasing evidence that high content of industrial TFAs may cause deleterious effects on human health and life span. MATERIAL AND METHODS: Indeed, several epidemiological and experimental studies strongly suggest that high content of most TFA isomers could represent a higher risk of developing cardiovascular diseases by a mechanism that lowers the "good HDL cholesterol" and raises the "bad LDL cholesterol." RESULTS: With respect to the general precautionary principle and considering the existence of an international policy consensus regarding the need for public health action, some industrialized countries, such as France, are still not sufficiently involved in preventive strategies that aim to efficiently reduce TFAs content and TFAs consumption and produce alternative healthier fat sources. CONCLUSION: In this manuscript, we provide an overview about TFAs origins, their use and consumption among French population. We also discuss their potential human health implications as well as the preventive and regulatory measures undertaken in France.