Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial

The Impact of Diet on Lipoprotein(a) Levels

BACKGROUND

Lipoprotein(a) [Lp(a)] is recognized as an independent risk factor for cardiovascular diseases; however, the impact of fat-based diets on its levels remains unclear.

OBJECTIVE

This study aims to assess and analyze current evidence on the impact of various types of fat-based diets on Lp(a) levels.

MATERIAL AND METHODS

A comprehensive search of the PubMed database was conducted on 9 July 2024, focusing on clinical and randomized trials published since 2000. Out of 697 identified studies, 33 met the inclusion criteria and were selected for analysis.

RESULTS

The findings suggest that modifications in fat-based diets, particularly concerning the type and amount of consumed fats and fatty acids, can significantly influence plasma Lp(a) levels. Diets rich in unsaturated fats, including polyunsaturated and monounsaturated fatty acids, were associated with more favorable effects in lowering Lp(a) levels. In contrast, diets high in saturated fats were linked to elevated Lp(a) levels. However, these conclusions were not consistent across all studies considered.

CONCLUSIONS

This work highlights the importance of a personalized dietary approach, considering both genetic predispositions and dietary habits. While diet alone may not drastically alter Lp(a) levels due to their strong genetic determination, a comprehensive strategy involving a healthy diet rich in unsaturated fats, regular physical activity, and effective weight management is recommended to reduce the risk of cardiovascular diseases. Further research is needed to clarify the mechanisms through which different fats affect Lp(a) and to develop targeted dietary recommendations.

Cow's Milk Bioactive Molecules in the Regulation of Glucose Homeostasis in Human and Animal Studies

Obesity disrupts glucose metabolism, leading to insulin resistance (IR) and cardiometabolic diseases. Consumption of cow's milk and other dairy products may influence glucose metabolism. Within the complex matrix of cow's milk, various carbohydrates, lipids, and peptides act as bioactive molecules to alter human metabolism. Here, we summarize data from human studies and rodent experiments illustrating how these bioactive molecules regulate insulin and glucose homeostasis, supplemented with in vitro studies of the mechanisms behind their effects. Bioactive carbohydrates, including lactose, galactose, and oligosaccharides, generally reduce hyperglycemia, possibly by preventing gut microbiota dysbiosis. Milk-derived lipids of the milk fat globular membrane improve activation of insulin signaling pathways in animal trials but seem to have little impact on glycemia in human studies. However, other lipids produced by ruminants, including polar lipids, odd-chain, trans-, and branched-chain fatty acids, produce neutral or contradictory effects on glucose metabolism. Bioactive peptides derived from whey and casein may exert their effects both directly through their insulinotropic effects or renin-angiotensin-aldosterone system inhibition and indirectly by the regulation of incretin hormones. Overall, the results bolster many observational studies in humans and suggest that cow's milk intake reduces the risk of, and can perhaps be used in treating, metabolic disorders. However, the mechanisms of action for most bioactive compounds in milk are still largely undiscovered.

Wild Mushrooms as a Source of Bioactive Compounds and Their Antioxidant Properties-Preliminary Studies

The aim of this study was to preliminarily determine the content of bioactive components in the fruiting bodies of four previously unstudied mushroom species: Aleuria aurantia, Phallus hadriani, Phanus conchatus, Geastrum pectinatum, their antioxidant activity and the content of polyphenols, minerals and heavy metals.

METHODS

Determination of active compounds by gas chromatography-mass spectrometry was carried out in addition to thermogravimetric determinations, quantitative determination of total polyphenols by spectrophotometry using Folin-Ciocalteu reagent, determination of antioxidant activity using 2,2-diphenyl-1-picryl hydrazyl radical (DPPH) and 2,2'-azino-di-[3-ethylbentiazoline sulphonated] (ATBS). In addition, spectrometric analysis of selected minerals and heavy metals was performed by inductively coupled plasma optical emission spectroscopy (ICP-OES).

RESULTS

The mushrooms analysed varied in terms of their bioactive constituents. They contained components with varying effects on human health, including fatty acids, oleamide, 1,2-dipalmitoylglycerol, (2-phenyl-1,3-dioxolan-4-yl)-methyl ester of oleic acid, deoxyspergualin, 2-methylenocholestan-3-ol, hexadecanoamide, isoallochan, 2,6-diaminopurine, and adenine. All contained polyphenols and varying amounts of minerals (calcium, magnesium, iron, zinc, potassium, phosphorus, sodium, copper, silicon and manganese) and exhibited antioxidant properties of varying potency. No exceedances of the permissible concentration of lead and cadmium were observed in any of them.

CONCLUSIONS

All of the mushrooms studied can provide material for the extraction of various bioactive compounds with physiological effects. In addition, the presence of polyphenols and minerals, as well as antioxidant properties and the absence of exceeding the permissible concentration of heavy metals, indicate that these species could be interesting material in the design of foods with health-promoting properties, nutraceuticals or dietary supplements. However, the use of the fruiting bodies of these mushrooms requires mandatory toxicological and clinical studies.

Encapsulation of conjugated linoleic acid and ruminant trans fatty acids to study the prevention of metabolic syndrome-a review

Studies have reported the potential benefits of consuming conjugated linoleic acid (CLA) and ruminant trans fatty acids (R-TFAs) in reducing the risk factors of metabolic syndrome (MetS). In addition, encapsulation of CLA and R-TFAs may improve their oral delivery and further decrease the risk factors of MetS. The objectives of this review were (1) to discuss the advantages of encapsulation; (2) to compare the materials and techniques used for encapsulating CLA and R-TFAs; and (3) to review the effects of encapsulated vs non-encapsulated CLA and R-TFAs on MetS risk factors. Examination of papers citing micro- and nano-encapsulation methods used in food sciences, as well as the effects of encapsulated vs non-encapsulated CLA and R-TFAs, was conducted using the PubMed database. A total of 84 papers were examined; of these, 18 studies were selected that contained information on the effects of encapsulated CLA and R-TFAs. The 18 studies that described encapsulation of CLA or R-TFAs indicated that micro- or nano-encapsulation processes stabilized CLA and prevented oxidation. CLA was mainly encapsulated using carbohydrates or proteins. So far, oil-in-water emulsification followed by spray-drying were the frequently used techniques for encapsulation of CLA. Further, 4 studies investigated the effects of encapsulated CLA on MetS risk factors compared with non-encapsulated CLA. A limited number of studies investigated the encapsulation of R-TFAs. The effects of encapsulated CLA or R-TFAs on the risk factors for MetS remain understudied; thus, additional studies comparing the effects of encapsulated and non-encapsulated CLA or R-TFAs are needed.

Allele-specific effect of various dietary fatty acids and ETS1 transcription factor on SCD1 expression

Overnutrition and genetic predisposition are major risk factors for various metabolic disorders. Stearoyl-CoA desaturase-1 (SCD1) plays a key role in these conditions by synthesizing unsaturated fatty acids (FAs), thereby promoting fat storage and alleviating lipotoxicity. Expression of SCD1 is influenced by various saturated and cis-unsaturated FAs, but the possible role of dietary trans FAs (TFAs) and SCD1 promoter polymorphisms in its regulations has not been addressed. Therefore, we aimed to investigate the impact of the two main TFAs, vaccenate and elaidate, and four common promoter polymorphisms (rs1054411, rs670213, rs2275657, rs2275656) on SCD1 expression in HEK293T and HepG2 cell cultures using luciferase reporter assay, qPCR and immunoblotting. We found that SCD1 protein and mRNA levels as well as SCD1 promoter activity are markedly elevated by elaidate, but not altered by vaccenate. The promoter polymorphisms did not affect the basal transcriptional activity of SCD1. However, the minor allele of rs1054411 increased SCD1 expression in the presence of various FAs. Moreover, this variant was predicted in silico and verified in vitro to reduce the binding of ETS1 transcription factor to SCD1 promoter. Although we could not confirm an association with type 2 diabetes mellitus, the FA-dependent and ETS1-mediated effect of rs1054411 polymorphism deserves further investigation as it may modulate the development of lipid metabolism-related conditions.

Production of conjugated linoleic acid by lactic acid bacteria; important factors and optimum conditions

Conjugated linoleic acid (CLA) has recently attracted significant attention as a health-promoting compound. CLA is a group of positional isomers of linoleic acid (LA) with a conjugated double bond naturally occurring in dairy and ruminant meat products. Microbial biosynthesis of CLA is a practical approach for commercial production due to its high safety and purity. There are some factors for the microbial CLA production such as strain type, microbial growth phase, pH, temperature and incubation time, based on which the amount and type of CLA can be controlled. Understanding the interplay of these factors is essential in optimizing the quantity and composition of microbial CLA, as discussed in the current study. Further exploration of CLA and its influences on human health remains a dynamic and evolving area of study.

Gas chromatography/mass spectrometry analysis and uv absorptivity of bio-oils extracted from some locally grown plant seeds in nothern Nigeria

Oils play vital roles in various ramifications including health, and food industries. Oils which are components of plant seeds can be extracted using various extraction techniques. This research is an exposition into the chemistry of oils with possible repositioning for purposeful use in the cosmetic, pharmaceutical, and food industries especially as sunscreen. In this work, oils were extracted from nine different seeds and subjected to gas chromatography coupled to mass spectrometry, and Ultraviolet analysis. The extraction method adopted in this work shows that 5 out of the 9 seeds have a relatively high percentage yield ranging from 20.9 to 36.8 % which indicates their potential for use in commercial quantity. The GC- MS analysis shows that (Z, Z)- 9, 12-Octadecadienoic acid is the most abundant components of all the oil samples. n-Hexadecanoic acid and cis-Vaccenic acid are the major constituents of Swietenia macrophylla (mahogany) seed oil. The lead components in the oil samples are usually responsible for their physico-chemical and Ultraviolet interactivities. All the samples were found to have adequate absorbance for Ultraviolet radiation ranging from Ultraviolet C to Ultraviolet A region. Citrullus lanatus, Hyptis spicigera, and Swietenia macrophylla (mahogany) have the highest absorbance ranges of 1.394-1.718, 1.449 to 1.70,2 and 1.402 to 1.711 respectively at Ultraviolet A region. The finding shows that all the samples have the ability to protect the skin from Ultraviolet radiation when expose to the sun, whereas only Citrullus lanatus, Hyptis spicigera and Swietenia macrophylla (mahogany) have the potentials for use as sunscreen with high sun protection factor. Further studies on the antimicrobial activities, cosmeceutical and nutraceutical potentials of the various components of these samples are encouraged.

Integration of hepatic lipidomics and transcriptomics reveals the effect of butter-derived ruminant trans fatty acids on lipid metabolism in C57BL/6J mice

Dysregulation of lipid metabolism results in metabolism-related diseases. Our previous research indicated that 1.3% E and 4% E ruminant trans fatty acids (R-TFA) caused dyslipidemia and promoted atherosclerotic plaques in ApoE-/- mice, presenting detrimental effects. However, the effect of R-TFA on the lipid metabolism of normal mice remains unclear. Therefore, our current research aims to explore the effects of butter-derived R-TFAs on the lipid metabolism of C57BL/6J mice through the integration of lipidomics and transcriptomics. As a result, we found that 1.3% E butter-derived R-TFA promoted dyslipidemia and impaired hepatic function in C57BL/6J mice fed a high-fat diet, which was associated with an increase in DG (18:1/22:5), TG (18:1/18:2/22:4) and FA (24:5) as determined through lipidomics analysis, but had a less significant effect on C57BL/6J mice fed a low-fat diet. Through a combination analysis and verification of gene expression, we found that the arachidonic acid pathway might be involved in the disruption of lipid metabolism by butter-derived R-TFA. In addition, butter-derived R-TFA up-regulated the expression of unigene thromboxane-A synthase 1 (Tbxas1), arachidonate lipoxygenase 3 (Aloxe3), acyl-coenzyme A thioesterase 2 (Acot2), epoxide hydrolase 2 (Ephx2) and carbonyl reductase 3 (Cbr3) in C57BL/6J mice fed a high-fat diet. Herein, our research provides a new perspective for exploring the effects of butter-derived R-TFA on lipid metabolism and speculates on the possible mechanism of lipid metabolism disorder induced by butter-derived R-TFA in C57BL/6J mice fed a high-fat diet.

Burden of ischemic heart disease attributable to trans fatty acids, 1990-2019

BACKGROUND & AIM

The impact of cardiovascular disease attributable to trans fatty acids (TFAs) in the Brazilian population has not been systematically evaluated. This study aims to analyze the burden of ischemic heart disease (IHD) attributable to TFAs in Brazil between 1990 and 2019.

METHODS

Data from the Global Burden of Disease Study 2019 were used to investigate the attributable burden in Brazil and its 27 federative units, for both sexes-pooled adults aged ≥25 years. Mortality and disability-adjusted life years (DALYs) from IHD attributable to TFAs were expressed as crude and age-standardized rates and differences from 1990 to 2019 by percentage and annualized rate of change. Linear regression was used to investigate trends. National voluntary and regulatory policies for industrial TFAs (iTFAs) implemented until 2019, summary exposure value (SEV) and sociodemographic index (SDI) were examined.

RESULTS

Between 1990 and 2019, crude and age-standardized mortality rates from IHD attributable to TFAs decreased by -15.9% and -58.0%, respectively, in Brazil. A decrease in crude (-23.3%) and age-standardized (-56.4%) DALY rates of IHD attributable to TFAs was also noticed in the country. States of the South, Southeast, and the Federal District had the largest declines of IHD attributable to TFAs, while states of the Northeast and North had the smallest or even an increase. The policies already adopted had little effect on the IHD burden. A lower SEV and higher SDI value seemed to reduce the burden of IHD.

CONCLUSIONS

Although a downward trend in IHD attributable to TFAs and a reduction in exposure to TFAs were observed, this burden is still relevant in Brazil, reinforcing the importance of diet policies, such as banning iTFAs.

Vegetarian and vegan diets: benefits and drawbacks

Plant-based diets have become increasingly popular thanks to their purported health benefits and more recently for their positive environmental impact. Prospective studies suggest that consuming vegetarian diets is associated with a reduced risk of developing cardiovascular disease (CVD), diabetes, hypertension, dementia, and cancer. Data from randomized clinical trials have confirmed a protective effect of vegetarian diets for the prevention of diabetes and reductions in weight, blood pressure, glycosylated haemoglobin and low-density lipoprotein cholesterol, but to date, no data are available for cardiovascular event rates and cognitive impairment, and there are very limited data for cancer. Moreover, not all plant-based foods are equally healthy. Unhealthy vegetarian diets poor in specific nutrients (vitamin B12, iron, zinc, and calcium) and/or rich in highly processed and refined foods increase morbidity and mortality. Further mechanistic studies are desirable to understand whether the advantages of healthy, minimally processed vegetarian diets represent an all-or-nothing phenomenon and whether consuming primarily plant-based diets containing small quantities of animal products (e.g. pesco-vegetarian or Mediterranean diets) has beneficial, detrimental, or neutral effects on cardiometabolic health outcomes. Further, mechanistic studies are warranted to enhance our understanding about healthy plant-based food patterns and the biological mechanisms linking dietary factors, CVD, and other metabolic diseases.

Plasma fatty acid composition and some markers of dietary habits are associated with cardiovascular disease risk determined by an atherogenic plasma index in postmenopausal women

It is hypothesized that plasma proportion of selected fatty acids (FAs) and dietary habits are linked with the risk of cardiovascular disease (CVD) in postmenopausal women. Therefore, this study was designed to determine the association of plasma FA composition and markers of dietary habits with an atherogenic index of plasma (AIP), a predictor of CVD risk in postmenopausal women. In total, 87 postmenopausal women with an average age of 57 ± 7 years were recruited and their dietary intake, anthropometric and biochemical parameters, and FA status in total plasma lipid proportions were determined, showing that 65.5% of the participants had a high risk of CVD according to their AIP value. After adjusting for some confounders (age, body mass index, and physical activity level), the risk of CVD was only positively associated with the frequency of consumption of animal fat spreads (butter and lard) of terrestrial origin. Regarding the FA profile, CVD risk was positively associated with the percentages of vaccenic acid, dihomo-γ-linolenic acid, and monounsaturated fatty acids (MUFA; mainly n-7) in total FA, as well as the MUFA/SFA ratio in total plasma and stearoyl-CoA desaturase-16 activity (16:1/16:0 ratio). In contrast, the risk of CVD was negatively associated with percentages of α-linolenic acid, total polyunsaturated fatty acids (PUFA), and PUFA/MUFA ratio in total plasma lipid, and the estimated activity of Δ5-desaturase (20:4/20:3 n-6 ratio). These results support the current recommendations to decrease the frequency of animal fat spread intake because it is associated with a reduced CVD risk based on AIP in postmenopausal women. In accordance with these plasma percentages of ALA, vaccenic acid, dihomo-γ-linolenic acid, PUFA, PUFA/MUFA ratio, and 16:1/16:0 ratio may be important parameters in CVD risk assessment.

Can individual fatty acids be used as functional biomarkers of dairy fat consumption in relation to cardiometabolic health? A narrative review

In epidemiological studies, dairy food consumption has been associated with minimal effect or decreased risk of some cardiometabolic diseases (CMD). However, current methods of dietary assessment do not provide objective and accurate measures of food intakes. Thus, the identification of valid and reliable biomarkers of dairy product intake is an important challenge to best determine the relationship between dairy consumption and health status. This review investigated potential biomarkers of dairy fat consumption, such as odd-chain, trans- and branched-chain fatty acids (FA), which may improve the assessment of full-fat dairy product consumption. Overall, the current use of serum/plasma FA as biomarkers of dairy fat consumption is mostly based on observational evidence, with a lack of well-controlled, dose-response intervention studies to accurately assess the strength of the relationship. Circulating odd-chain SFA and trans-palmitoleic acid are increasingly studied in relation to CMD risk and seem to be consistently associated with a reduced risk of type 2 diabetes in prospective cohort studies. However, associations with CVD are less clear. Overall, adding less studied FA such as vaccenic and phytanic acids to the current available evidence may provide a more complete assessment of dairy fat intake and minimise potential confounding from endogenous synthesis. Finally, the current evidence base on the direct effect of dairy fatty acids on established biomarkers of CMD risk (e.g. fasting lipid profiles and markers of glycaemic control) mostly derives from cross-sectional, animal and in vitro studies and should be strengthened by well-controlled human intervention studies.

Effects of Hay, Baleage, and Soybean Hulls Waste Used as Supplemental Feeds on the Nutritional Profile of Grass-Finished Beef

Grass-finished beef (GFB) has demonstrated wide nutritional variations with some GFB having a considerably higher n-6:n-3 ratio compared to grain-finished beef. To better understand these variations, the current study investigated the effects of commonly used supplemental feeds on the nutritional profile of GFB. This two-year study involved 117 steers randomly allocated to one of four diets: (1) grass+hay (G-HAY), (2) grass+baleage (G-BLG), (3) grass+soybean hulls (G-SH), and (4) baleage+soybean hulls in feedlot (BLG-SH). Feed samples were analyzed for their nutritional value, and beef samples underwent analysis for fatty acids (FAs), vitamin E, minerals, lipid oxidation, and shear force. FAs were measured by GC-MS, vitamin E was analyzed chromatographically, minerals were analyzed by ICP-MS, and lipid oxidation was measured via a thiobarbituric acid reactive substances (TBARS) assay. G-SH beef had the highest n-6:n-3 ratio (p < 0.001), while BLG-SH beef contained less vitamin E (p < 0.001) and higher TBARS values (p < 0.001) compared to the other groups. G-HAY beef contained more long-chain n-3 polyunsaturated FAs compared to the other groups (p < 0.001). In conclusion, G-HAY beef had the most beneficial nutritional profile, while soybean hulls increased the n-6:n-3 ratio of beef.

Fatty Acid and Micronutrient Profile of Longissimus Lumborum from Red Angus and Red Angus x Akaushi Cattle Finished on Grass or Grain

Cattle diet and breed modify the nutritional profile of beef. The objective of this study was to compare the fatty acid (FA) and micronutrient profiles of Red Angus (RA) and RA x Akaushi (AK) crossbreed steers fed either a grass or grain diet. This two-year study randomly assigned steers to the diets using a 2 × 2 factorial experiment. FAs and micronutrients were analyzed. Diet effect was the strongest with grass-finished beef being higher in n-3 polyunsaturated FAs (p < 0.001), conjugated linoleic acid (p < 0.05), vaccenic acid (p < 0.05), iron (p < 0.001), and vitamin E (p < 0.001) compared to grain-finished beef. Breed effects were observed for lauric and myristic acids (p < 0.05), selenium (p < 0.05), and zinc (p < 0.01) with AK containing more of these compounds than RA. Diet × breed effects were non-existent. These results indicate that diet has a stronger influence than breed on modifying the nutritional profile of beef. Because of a more favorable FA and antioxidant profile, consumption of grass-finished beef could benefit human health.

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.

On account of trans fatty acids and cardiovascular disease risk - There is still need to upgrade the knowledge and educate consumers

AIMS

Trans fatty acids (TFAs) are unsaturated lipids either of industrial origin or naturally occurring in ruminant meat and milk. TFAs generated through food processing (industrial) is the main source in our diet and studies provide converging evidence on their negative effect on cardiovascular health. Since April 2021, the European Commission has put into effect a regulation for TFAs providing maximum 2% of total fat in all industrially produced foods. In light of this development, we review the evidence regarding the health attributes of different types of TFAs, their dietary sources and current intakes, and we describe the history of TFA-related legislative actions in an attempt to anticipate the efficiency of new measures.

DATA SYNTHESIS

The PubMed database was searched including original research (observational and intervention studies), systematic reviews and meta-analyses. Scientific reports of competent authorities and organizations have also been screened.

CONCLUSIONS

Trans-fat elimination provides a fine example of how evidence has led to the application of horizontal regulatory measures regarding legal food ingredients in order to protect consumers' health. In EU Member States, TFAs currently provide on average less than 1% of energy (1%E) and intakes marginally exceed recommendations primarily among young adults. Large dietary surveys however provide evidence for additional, less-well known sources of TFAs in the diet. Raising public awareness of "hidden" trans-fat found naturally in foods such as cheese, as well as of the trans-fat generated through traditional cooking practices is needed, if the goal to eliminate trans-fat from the diet is to be met.

Attention to the Details: How Variations in U.S. Grass-Fed Cattle-Feed Supplementation and Finishing Date Influence Human Health

As the global population increases, so does meat consumption. This trend is accompanied by concerns regarding the meat industry, and consumers are demanding transparency on the environmental and health effects of the products they are purchasing. Many leading health organizations recommend reducing red meat consumption. Nevertheless, no differentiation is made among red meats and beef. The beef production system is generally ignored despite nutritional differences between grain- and grass-fed beef. Compared to grain-fed beef, grass-fed beef contains a healthier fatty acid profile, including more omega-3 polyunsaturated fatty acids and conjugated linoleic acid, and increased concentrations of phytochemicals desired by health-conscious customers. However, there is a lack of consistency among grass-fed beef in the United States regarding clear product labeling and cattle dietary components. Grass-fed beef labeling confusion has emerged, including misunderstandings between grass-fed and grass-finished beef. Along with this, previous studies observed significant nutritional variation among grass-finished beef from different producers across the country. Cattle diet has the strongest influence on the nutritional composition of beef. Therefore, understanding differences in feeding practices is key to understanding differing nutritional quality of grass-fed beef. Feeding cattle diverse pastures composed of multiple plant species including grasses and legumes managed in a rotational grazing fashion results in higher omega-3 polyunsaturated fatty acids and phytochemical levels in beef compared to feedlots and monocultures. Seasonal differences including changes in temperature, rainfall, grazing practices, and plant growth cycles affect the nutritional composition of feeds and ultimately meat. Additional feeds utilized in grass-fed beef production systems such as conserved forages may reduce or increase health-promoting nutrients in grass-fed beef, while supplements such as grape byproducts and flaxseed may improve its nutritional profile. Further research should measure the effects of individual feedstuff and the finishing period on the nutritional profile on grass-fed beef. A better understanding of these details will be a step toward the standardization of pasture-raised ruminant products, strengthening the relationship between grass-fed beef consumption and human health.

Plasma Industrial and Ruminant Trans Fatty Acids and Incident Type 2 Diabetes in the EPIC-Potsdam Cohort

OBJECTIVE

Although dietary intake of trans fatty acid (TFA) is a major public health concern because of the associated increase in the risk of cardiovascular events, it remains unclear whether TFAs also influence risk of type 2 diabetes (T2D) and whether industrial TFAs (iTFAs) and ruminant TFAs (rTFAs) exert the same effect on health.

RESEARCH DESIGN AND METHODS

To investigate the relationship of 7 rTFAs and iTFAs, including 2 conjugated linoleic acids (CLAs), plasma phospholipid TFAs were measured in a case-cohort study nested within the European Prospective Investigation Into Cancer and Nutrition-Potsdam cohort. The analytical sample was a random subsample (n = 1,248) and incident cases of T2D (n = 801) over a median follow-up of 6.5 years. Using multivariable Cox regression models, we examined associations of TFAs with incident T2D.

RESULTS

The TFA subtypes were intercorrelated with each other, with other fatty acids, and with different food sources. After controlling for other TFAs, the iTFAs (18:1n-6t, 18:1n-9t, 18:2n-6,9t) were not associated with diabetes risk. Some rTFA subtypes were inversely associated with diabetes risk: vaccenic acid (18:1n-7t; hazard ratio [HR] per SD 0.72; 95% CI 0.58-0.89) and t10c12-CLA (HR per SD 0.81; 95% CI 0.70-0.94), whereas c9t11-CLA was positively associated (HR per SD 1.39; 95% CI 1.19-1.62). Trans-palmitoleic acid (16:1n-7t) was not associated with diabetes risk when adjusting for the other TFAs (HR per SD 1.08; 95% CI 0.88-1.31).

CONCLUSIONS

The TFAs' conformation plays an essential role in their relationship to diabetes risk. rTFA subtypes may have opposing relationships to diabetes risk. Previous observations for reduced diabetes risk with higher levels of circulating trans-palmitoleic acid are likely due to confounding.

Effects of Repeated Heating on Fatty Acid Composition of Plant-Based Cooking Oils

Several polyunsaturated fatty acids are considered to have beneficial health effects, while saturated fatty acids and industrial trans fatty acids (TFAs) are linked to negative health consequences. Given the increased formation of TFAs during heating, many studies already investigated compositional changes in oils after prolonged heating or at extremely high temperatures. In contrast, our aim was to measure changes in fatty acid composition and in some health-related indices in edible oils after short-time heating that resembles the conventional household use. Potatoes were fried in palm, rapeseed, soybean, sunflower and extra virgin olive oils at 180 °C for 5 min, and samples were collected from fresh oils and after 1, 5 and 10 consecutive heating sequences. Regardless of the type of oil, the highest linoleic acid and alpha-linolenic acid values were measured in the fresh samples, whereas significantly lower values were detected in almost all samples following the heating sequences. In contrast, the lowest levels of TFAs were detected in the fresh oils, while their values significantly increased in almost all samples during heating. Indices of atherogenicity and thrombogenicity were also significantly higher in these oils after heating. The present data indicate that prolonged or repeated heating of vegetable oils should be avoided; however, the type of oil has a greater effect on the changes of health-related indices than the number of heating sequences.

Molecular Immune-Inflammatory Connections between Dietary Fats and Atherosclerotic Cardiovascular Disease: Which Translation into Clinics?

Current guidelines recommend reducing the daily intake of dietary fats for the prevention of ischemic cardiovascular diseases (CVDs). Avoiding saturated fats while increasing the intake of mono- or polyunsaturated fatty acids has been for long time the cornerstone of dietary approaches in cardiovascular prevention, mainly due to the metabolic effects of these molecules. However, recently, this approach has been critically revised. The experimental evidence, in fact, supports the concept that the pro- or anti-inflammatory potential of different dietary fats contributes to atherogenic or anti-atherogenic cellular and molecular processes beyond (or in addition to) their metabolic effects. All these aspects are hardly translatable into clinics when trying to find connections between the pro-/anti-inflammatory potential of dietary lipids and their effects on CVD outcomes. Interventional trials, although providing stronger potential for causal inference, are typically small sample-sized, and they have short follow-up, noncompliance, and high attrition rates. Besides, observational studies are confounded by a number of variables and the quantification of dietary intakes is far from optimal. A better understanding of the anatomic and physiological barriers for the absorption and the players involved in the metabolism of dietary lipids (e.g., gut microbiota) might be an alternative strategy in the attempt to provide a first step towards a personalized dietary approach in CVD prevention.

The Effect of Trans Fatty Acids on Human Health: Regulation and Consumption Patterns

Health effects of trans fatty acids (TFAs) on human organisms can vary according to their type, structure, composition, and origin. Even though the adverse health effects of industrial TFAs (iTFAs) have been widely discussed, the health effects of natural TFAs (nTFAs) are still questionable. Hence, it is important to review the literature and provide an overall picture on the health effects of different TFAs coming from industrial and ruminant sources, underlining those types that have adverse health effects as well as suggesting methods for reducing their harmful effects. Multiple databases (PubMed, Medline, Cochrane Library, etc.) were searched with the key words "trans fatty acid sources", "ruminant", "industrial", "conjugated trans linoleic acid", "human", "coronary heart disease", "cancer", etc. Reference lists of the studies were scanned discussing the health effects of iTFAs and nTFAs. The review of the literature showed that iTFAs are found to be more harmful than ruminant-produced nTFAs. Although several beneficial effects (such as reduced risk of diabetes) for nTFAs have been observed, they should be used with caution. Since during labeling it is usually not mentioned whether the TFAs contained in food are of industrial or natural origin, the general suggestion is to reduce their consumption.

Trans-10 18:1 in ruminant meats: A review

Trans (t) fatty acids (TFA) from partially hydrogenated vegetable oils (i.e., industrial trans) have been phased out of foods in many countries due to their promotion of cardiovascular disease. This leaves ruminant-derived foods as the main source of TFA. Unlike industrial TFA where catalytic hydrogenation yields a broad distribution of isomers, ruminant TFA are enzymatically derived and can result in enrichment of specific isomers. Comparisons between industrial and ruminant TFA have often exonerated ruminant TFA due to their lack or at times positive effects on health. At extremes, however, ruminant-sourced foods can have either high levels of t10- or t11-18:1, and when considering enriched sources, t10-18:1 has properties similar to industrial TFA, whereas t11-18:1 can be converted to an isomer of conjugated linoleic acid (cis(c)9,t11-conjugated linoleic acid), both of which have potential positive health effects. Increased t10-18:1 in meat-producing ruminants has not been associated with negative effects on live animal production or meat quality. As such, reducing t10-18:1 has not been of immediate concern to ruminant meat producers, as there have been no economic consequences for its enrichment; nevertheless at high levels, it can compromise the nutritional quality of beef and lamb. In anticipation that regulations regarding TFA may focus more on t10-18:1 in beef and lamb, the present review will cover its production, analysis, biological effects, strategies for manipulation, and regulatory policy.

Differential Effects of Ruminant and Industrial 18-Carbon trans-Monounsaturated Fatty Acids (trans Vaccenic and Elaidic) on the Inflammatory Responses of an Endothelial Cell Line

Endothelial dysfunction and inflammation are recognised factors in the development of atherosclerosis. Evidence suggests that intake of industrial trans fatty acids (TFAs) promotes endothelial dysfunction, while ruminant TFAs may have the opposite effect. The aim of this study was to compare the effects of elaidic acid (EA (18:1n-9t); an industrially produced TFA) and trans vaccenic acid (TVA (18:1n-7t); a natural TFA found in ruminant milk and meat) on inflammatory responses of endothelial cells (ECs). ECs (EA.hy926 cells) were cultured under standard conditions and exposed to TFAs (1 to 50 μM) for 48 h. Then, the cells were cultured for a further 6 or 24 h with tumour necrosis factor alpha (TNF-α, 1 ng/mL) as an inflammatory stimulant. ECs remained viable after treatments. TFAs were incorporated into ECs in a dose-dependent manner. Preincubation with EA (50 µM) increased production of MCP-1, RANTES, and IL-8 in response to TNF-α, while preincubation with TVA (1 µM) decreased production of ICAM-1 and RANTES in response to TNF-α. Preincubation with EA (50 µM) upregulated toll-like receptor 4 and cyclooxygenase 2 gene expression in response to TNF-α. In contrast, preincubation with TVA (1 µM) downregulated TNF-α induced nuclear factor kappa B subunit 1 gene expression. Preincubation of ECs with EA (50 µM) increased THP-1 monocyte adhesion. In contrast, preincubation of ECs with TVA (1 µM) reduced THP-1 monocyte adhesion, while preincubation of ECs with TVA (50 µM) decreased the level of surface expression of ICAM-1 seen following TNF-α stimulation. The results suggest that TVA has some anti-inflammatory properties, while EA enhances the response to an inflammatory stimulus. These findings suggest differential effects induced by the TFAs tested, fitting with the idea that industrial TFAs and ruminant TFAs can have different and perhaps opposing biological actions in an inflammatory context.

Changes in the fatty acid composition of steer subcutaneous fat, including biohydrogenation products, are minimal when finished on combinations of corn and barley grains and silages

Corn production in Western Canada has increased with development of short-season varieties partially offsetting the use of barley as a silage and grain source. The current study evaluated effects of silage and cereal-grain source on subcutaneous fat (SCF) composition of finishing cattle. Steers (465 ± 28.0 kg) were assigned to 24 pens (12 steers per pen) in a 2 × 3 factorial design for an 89 d finishing study. Diets contained corn silage or barley silage at 8% [dry matter (DM)] combined either dry-rolled barley grain (BG; 86% of DM), corn grain (CG; 85% of DM), or an equal blend of BG and CG (85% of DM). Bone-in ribeyes were collected from four steers per pen, and subcutaneous fatty acids were analyzed by gas chromatography. Feeding dry-rolled CG increased dietary fat and 18:2n-6 concentrations, resulting in small increases in 18:2n-6, total n-6 fatty acids, and n-6/n-3 ratios in SCF (P < 0.05). There were no changes in proportions of major trans-18:1 isomers (t10-18:1 or t11-18:1), the main natural isomer of conjugated linoleic acid (cis9,t11–18:2), or n-3 fatty acids. Substitution of dry-rolled CG for BG in finisher diets can, therefore, be done without substantially altering the fatty acid composition of beef fat, including polyunsaturated fatty acid biohydrogenation products.

Dietary Intake of trans Fatty Acids in the Slovenian Population

Consumption of trans fatty acids (TFAs) has been unequivocally linked to several adverse health effects, with the increased risk of cardiovascular disease being one of the most well understood. To reduce TFA-related morbidity and mortality, several countries have imposed voluntary or mandatory measures to minimize the content of industrial TFAs (iTFAs) in the food supply. In 2018, Slovenia introduced a ban on iTFAs on top of preceding voluntary calls to industry to reduce its use of partially hydrogenated oils (PHOs) as the main source of iTFAs. To investigate the consumption of TFAs, data available from the nationally representative dietary survey SI.Menu were analyzed. The survey consisted of two 24-h non-consecutive day recalls from 1248 study participants from three age groups (10–17, 18–64, 65–74 years old), combined with socio-demographic, socio-economic, and lifestyle parameters. The analyses demonstrated that, on average, TFAs accounted for 0.38–0.50% of total energy intake (TEI). However, 13% of adolescents, 29.4% of adults, and 41.8% of the elderly population still consumed more than 0.50% TEI with TFAs. The main sources of TFAs in the diet were naturally present TFAs from butter, meat dishes, and meat products, regardless of the age group. Results indicate that following the reformulation activities, the major sources of TFAs in the diets of the Slovenian population now represent foods which are natural sources of TFAs.

Cow's Milk and Dairy Consumption: Is There Now Consensus for Cardiometabolic Health?

Cow's milk and dairy products derived from this complex food source have long been proposed as beneficial to human health, yet underlying clinical evidence of direct benefit continues to raise controversy. Limited evidence supports positive cardiometabolic effects of a number of dairy macro- and micronutrient components including whey protein and casein, unsaturated fats, milk fat globule membrane (MFGM) and polar phospholipids, vitamin D and calcium, in addition to non-bovine components including bacterial and yeast probiotics. More controversial remain lipid components trans fats, including trans vaccenic acid, trans palmitoleic acid, and conjugated cis trans linoleic acid (CLA), plus medium-chain and odd-chain dairy fats. New evidence is rapidly identifying multiple pathways by which these dairy nutrients may effect health. Processing, including fermentation and homogenization, may also have positive effects. Conversely, the high saturated fat content of dairy has long raised concern, aligned with international guidelines to minimize dietary intake of animal-origin saturated fatty acids (SFA) to achieve better cardiometabolic health. However, led in part by observational studies and meta-analyses showing dairy to have no or even an inverse association with cardiometabolic health, evidence from randomized controlled trials (RCTs) has been scrutinized over the last 5 years, and focus on low-fat dairy has been challenged. Recent evidence supports the hypothesis that adverse effects of SFAs on metabolic health may be ameliorated when these fats are consumed within a complex matrix such as milk, cheese or yogurt, and that dairy food categories may influence outcomes as much as total fat content. For example, yogurt and high-fat, high-SFA cheese have a negative association with risk of type 2 diabetes (T2D) in many, not all, published trials. However, large sample dairy RCTs of long duration with CVD or T2D incidence as primary endpoints are lacking. This is a clear research gap, with these clinical studies required if a causative link between dairy and improved cardiometabolic health is to be confirmed and in turn promoted through dietary guidelines. Current advisories from national guidance groups such as American Heart Association (AHA) and European Society of Cardiology (ESC) continue to promote consumption of low-fat dairy products, whilst liquid milk and yogurt remain part of nutrition guidelines from joint American Diabetes Association (ADA)/European Association for Study of Diabetes (EASD) reports, and as part of a "no-one-size-fits-all" answer to diet and T2D by the ADA in their most recent 2019 Consensus Report.

Ruminant and industrial trans-fatty acids consumption and cardiometabolic risk markers: A systematic review

The development of cardiometabolic diseases is related to conditions such as obesity, abdominal fat, insulin resistance, diabetes mellitus, elevated blood pressure and changes in lipid profile. The whole of Trans Fatty Acid (TFA) intake is associated with the increase of cardiometabolic risk factors. There are two main sources of TFA, the ruminant TFA (rTFA) which are produced by biohydrogenation in animal's rumen, and the industrial TFA (iTFA), produced by hydrogenation of vegetable oils, the individual effect of each group is still controversial. The aim of this study was to analyze the effect of industrially and ruminants TFA intake on cardiometabolic risk in adults. It was carried out a systematic search of the literature in October 2019 and two independent authors selected and extracted data from articles. After the selection process, nine clinical trials were included, and summary tables were constructed to present data for all outcomes. The results showed that both sources of TFA can increase cardiometabolic risk parameters, especially lipid profile. At levels up to 1.5%-7% of energy, the effect of rTFA seems to be greater than iTFA and it seems to be greater in women. However, rTFA seems to be less harmful than iTFA for High Density Lipoprotein cholesterol, although for total cholesterol and Low density Lipoprotein cholesterol it may be worse. In summary, both sources of TFA can increase cardiometabolic risk parameters, especially lipid profile. However, the dose of TFA and the whole composition of the food must be considered.

New and traditional foods in a modernized Mediterranean diet model

Mediterranean diet is definitely one of the healthiest dietary models. Next questions are: is the traditional Mediterranean diet adapted to the modern environmental and existential conditions? Could and/or should it be "modernized" to adapt to the various geographical, environmental, ethnic, and religious characteristics? If "modernization" is required, which traditional Mediterranean foods should be imperatively conserved as they are? Alternatively, which "new" foods-not traditional or not Mediterranean-could be introduced to help people to still respect the basic healthy Mediterranean diet principles? The present article intends to help solving these new questions.

A modelling approach to investigate the impact of consumption of three different beef compositions on human dietary fat intakes

OBJECTIVE

To apply a dietary modelling approach to investigate the impact of substituting beef intakes with three types of alternative fatty acid (FA) composition of beef on population dietary fat intakes.

DESIGN

Cross-sectional, national food consumption survey - the National Adult Nutrition Survey (NANS). The fat content of the beef-containing food codes (n 52) and recipes (n 99) were updated with FA composition data from beef from animals receiving one of three ruminant dietary interventions: grass-fed (GRASS), grass finished on grass silage and concentrates (GSC) or concentrate-fed (CONC). Mean daily fat intakes, adherence to dietary guidelines and the impact of altering beef FA composition on dietary fat sources were characterised.

SETTING

Ireland.

PARTICIPANTS

Beef consumers (n 1044) aged 18-90 years.

RESULTS

Grass-based feeding practices improved dietary intakes of a number of individual FA, wherein myristic acid (C14 : 0) and palmitic acid (C16 : 0) were decreased, with an increase in conjugated linoleic acid (C18 : 2c9,t11) and trans-vaccenic acid (C18 : 1t11; P < 0·05). Improved adherence with dietary recommendations for total fat (98·5 %), SFA (57·4 %) and PUFA (98·8 %) was observed in the grass-fed beef scenario (P < 0·001). Trans-fat intakes were increased significantly in the grass-fed beef scenario (P < 0·001).

CONCLUSIONS

To the best of our knowledge, the present study is the first to characterise the impact of grass-fed beef consumption at population level. The study suggests that habitual consumption of grass-fed beef may have potential as a public health strategy to improve dietary fat quality.

Progress towards eliminating industrially produced trans-fatty acids in the Canadian marketplace, 2013-2017

OBJECTIVE

To assess the prevalence of partially hydrogenated oils (PHO), hydrogenated oils (HO) and/or both in Canadian packaged foods in 2013 and 2017 and to determine the mean trans-fatty acid (TFA) content of products declaring such oils.

DESIGN

Repeated cross-sectional study of the Food Label Information Program.

SETTING

Food labels (n 32 875) were collected from top Canadian grocery retailers in 2013 and 2017. Proportions of products declaring PHO, HO and/or both in the Ingredients List were calculated by year and food category. The percentage contribution of TFA (g) to total fat (g) was calculated and compared against the voluntary TFA limits, defined as <2 % of total fat content for fats and oils, and <5 % for all other foods. Foods exceeding limits were identified. The mean TFA content (in g/serving and per 100 g) was calculated for products with these oils.

RESULTS

The use of PHO, HO and/or both significantly decreased in Canadian foods from 2013 to 2017 (0·8 to 0·2 %, 5 to 2·4 % and 5·7 to 2·6 %, respectively, for PHO, HO and/or both). The mean TFA content of products containing PHO increased (0·34 to 0·57 g TFA/serving); although it was not statistically significant, it is still concerning that TFA content increased. The TFA content significantly decreased in foods with HO (0·24 to 0·16 g TFA/serving, P < 0·05) during 2013-2017.

CONCLUSIONS

Products with PHO continue to be present in the Canadian marketplace, despite voluntary efforts to eliminate them. Products with HO should also be monitored, as they can also contribute to TFA content in foods.

Fatty acids and cardiometabolic health: a review of studies in Chinese populations

Rapid nutrition transition from plant-based traditional diet to westernized diet has led to dramatically heightening burdens of cardiometabolic diseases in China in past decades. Recently, national surveys reported that poor dietary quality including low marine n-3 fatty acids and high intakes of red meat and processed meat was associated with considerably elevated cardiometabolic deaths. Previous studies mainly from Western population-based cohorts have indicated that not only fat quantity but also quality linked with different cardiometabolic outcomes. Compared with Western peoples, Asian peoples, including Chinese, are known to have different dietary patterns and lifestyle, as well as genetic heterogeneities, which may modify fatty acid metabolism and disease susceptibility in certain degree. To date, there were limited prospective studies investigating the relationships between fatty acids and cardiometabolic disease outcomes in Chinese, and most existing studies were cross-sectional nature and within one or two region(s). Notably, shifting dietary patterns could change not only amount, types, and ratio of fatty acids accounting for overall energy intake, but also their food sources and ratio to other macronutrients. Moreover, large geographic and urban-rural variations in prevalence of cardiometabolic diseases among Chinese may also reflect the effects of socioeconomic development and local diets on health status. Therefore, current review will summarize available literatures with more focus on the Chinese-based studies which may extend current knowledge about the roles of fatty acids in pathogenesis of cardiometabolic diseases for Asian populations and also provide useful information for trans-ethnic comparisons with other populations.

Plasma Trans Fatty Acid Levels, Cardiovascular Risk Factors and Lifestyle: Results from the Akershus Cardiac Examination 1950 Study

Intake of industrially produced trans fatty acids (iTFAs) has previously been associated with dyslipidemia, insulin resistance, hypertension and inflammation, as well as increased cardiovascular (CV) morbidity and mortality. iTFA intake declined in Norway after the introduction of legislative bans against iTFA consumption. However, the relationship between the current iTFA intake and CV health is unclear. The aim of the present study was to investigate the association between current iTFA intake, reflected by plasma iTFA levels, and established CV risk factors. We also examined the associations between plasma ruminant TFA levels and CV risk factors. In this cross-sectional study, we included 3706 participants from a Norwegian general population, born in 1950 and residing in Akershus County, Norway. The statistical method was multivariable linear regression. Plasma iTFA levels were inversely associated with serum triglycerides (p < 0.001), fasting plasma glucose (p < 0.001), body mass index (p < 0.001), systolic and diastolic blood pressure (p = 0.001 and p = 0.03) and C-reactive protein (p = 0.001). Furthermore, high plasma iTFA levels were associated with higher education and less smoking and alcohol consumption. We found that plasma ruminant trans fatty acids (rTFA) levels were favorably associated with CV risk factors. Furthermore, plasma iTFA levels were inversely associated with CV risk factors. However, our results might have been driven by lifestyle factors. Overall, our findings suggest that the current low intake of iTFAs in Norway does not constitute a threat to CV health.

Mechanisms of Action of trans Fatty Acids

Human studies have established a positive association between the intake of industrial trans fatty acids and the development of cardiovascular diseases, leading several countries to enact laws that restrict the presence of industrial trans fatty acids in food products. However, trans fatty acids cannot be completely eliminated from the human diet since they are also naturally present in meat and dairy products of ruminant animals. Moreover, bans on industrial trans fatty acids have not yet been instituted in all countries. The epidemiological evidence against trans fatty acids by far overshadows mechanistic insights that may explain how trans fatty acids achieve their damaging effects. This review focuses on the mechanisms that underlie the deleterious effects of trans fatty acids by juxtaposing effects of trans fatty acids against those of cis-unsaturated fatty acids and saturated fatty acids (SFAs). This review also carefully explores the argument that ruminant trans fatty acids have differential effects from industrial trans fatty acids. Overall, in vivo and in vitro studies demonstrate that industrial trans fatty acids promote inflammation and endoplasmic reticulum (ER) stress, although to a lesser degree than SFAs, whereas cis-unsaturated fatty acids are protective against ER stress and inflammation. Additionally, industrial trans fatty acids promote fat storage in the liver at the expense of adipose tissue compared with cis-unsaturated fatty acids and SFAs. In cultured hepatocytes and adipocytes, industrial trans fatty acids, but not cis-unsaturated fatty acids or SFAs, stimulate the cholesterol synthesis pathway by activating sterol regulatory element binding protein (SREBP) 2-mediated gene regulation. Interestingly, although industrial and ruminant trans fatty acids show similar effects on human plasma lipoproteins, in preclinical models, only industrial trans fatty acids promote inflammation, ER stress, and cholesterol synthesis. Overall, clearer insight into the molecular mechanisms of action of trans fatty acids may create new therapeutic windows for the treatment of diseases characterized by disrupted lipid metabolism.

A Review of Lipidomics of Cardiovascular Disease Highlights the Importance of Isolating Lipoproteins

Cutting-edge lipidomic profiling measures hundreds or even thousands of lipids in plasma and is increasingly used to investigate mechanisms of cardiovascular disease (CVD). In this review, we introduce lipidomic techniques, describe distributions of lipids across lipoproteins, and summarize findings on the association of lipids with CVD based on lipidomics. The main findings of 16 cohort studies were that, independent of total and high-density lipoprotein cholesterol (HDL-c), ceramides (d18:1/16:0, d18:1/18:0, and d18:1/24:1) and phosphatidylcholines (PCs) containing saturated and monounsaturated fatty acyl chains are positively associated with risks of CVD outcomes, while PCs containing polyunsaturated fatty acyl chains (PUFA) are inversely associated with risks of CVD outcomes. Lysophosphatidylcholines (LPCs) may be positively associated with risks of CVD outcomes. Interestingly, the distributions of the identified lipids vary across lipoproteins: LPCs are primarily contained in HDLs, ceramides are mainly contained in low-density lipoproteins (LDLs), and PCs are distributed in both HDLs and LDLs. Thus, the potential mechanism behind previous findings may be related to the effect of the identified lipids on the biological functions of HDLs and LDLs. Only eight studies on the lipidomics of HDL and non-HDL particles and CVD outcomes have been conducted, which showed that higher triglycerides (TAGs), lower PUFA, lower phospholipids, and lower sphingomyelin content in HDLs might be associated with a higher risk of coronary heart disease (CHD). However, the generalizability of these studies is a major concern, given that they used case-control or cross-sectional designs in hospital settings, included a very small number of participants, and did not correct for multiple testing or adjust for blood lipids such as HDL-c, low-density lipoprotein cholesterol (LDL-c), or TAGs. Overall, findings from the literature highlight the importance of research on lipidomics of lipoproteins to enhance our understanding of the mechanism of the association between the identified lipids and the risk of CVD and allow the identification of novel lipid biomarkers in HDLs and LDLs, independent of HDL-c and LDL-c. Lipidomic techniques show the feasibility of this exciting research direction, and the lack of high-quality epidemiological studies warrants well-designed prospective cohort studies.

Dietary fatty acids and CD36-mediated cholesterol homeostasis: potential mechanisms

Currently, the prevention and treatment of CVD have been a global focus since CVD is the number one cause of mortality and morbidity. In the pathogenesis of CVD, it was generally thought that impaired cholesterol homeostasis might be a risk factor. Cholesterol homeostasis is affected by exogenous factors (i.e. diet) and endogenous factors (i.e. certain receptors, enzymes and transcription factors). In this context, the number of studies investigating the potential mechanisms of dietary fatty acids on cholesterol homeostasis have increased in recent years. As well, the cluster of differentiation 36 (CD36) receptor is a multifunctional membrane receptor involved in fatty acid uptake, lipid metabolism, atherothrombosis and inflammation. CD36 is proposed to be a crucial molecule for cholesterol homeostasis in various mechanisms including absorption/reabsorption, synthesis, and transport of cholesterol and bile acids. Moreover, it has been reported that the amount of fatty acids and fatty acid pattern of the diet influence the CD36 level and CD36-mediated cholesterol metabolism principally in the liver, intestine and macrophages. In these processes, CD36-mediated cholesterol and lipoprotein homeostasis might be impaired by dietary SFA and trans-fatty acids, whereas ameliorated by MUFA in the diet. The effects of PUFA on CD36-mediated cholesterol homeostasis are controversial depending on the amount of n-3 PUFA and n-6 PUFA, and the n-3:n-6 PUFA ratio. Thus, since the CD36 receptor is suggested to be a novel nutrient-sensitive biomarker, the role of CD36 and dietary fatty acids in cholesterol metabolism might be considered in medical nutrition therapy in the near future. Therefore, the novel nutritional target of CD36 and interventions that focus on dietary fatty acids and potential mechanisms underlying cholesterol homeostasis are discussed in this review.

Bioactivity and health effects of ruminant meat lipids. Invited Review

Ruminant meat (RM) is an excellent source of high-quality protein, B vitamins and trace minerals and plays an important role in global food and nutrition security. However, nutritional guidelines commonly recommend reduced intake of RM mainly because of its high saturated fatty acid (SFA) content, and more recently because of its perceived negative environmental impacts. RM is, however, rich in heart healthy cis-monounsaturated fatty acids and can be an important source of long-chain omega-3 (n-3) fatty acids in populations with low fish consumption. In addition, RM is a source of bioactive phospholipids, as well as rumen-derived bioactive fatty acids including branched-chain, vaccenic and rumenic acids, which have been associated with several health benefits. However, the role of bioactive RM lipids in maintaining and improving consumers' health have been generally ignored in nutritional guidelines. The present review examines RM lipids in relation to human health, and evaluates the effectiveness of different feeding strategies and possibilities for future profile and content improvement.

Trans-palmitoleic acid (trans-9-C16:1, or trans-C16:1 n-7): Nutritional impacts, metabolism, origin, compositional data, analytical methods and chemical synthesis. A review

Since the early 2010s, dietary trans-palmitoleic acid (trans-9-hexadecenoic acid, trans-9-C16:1 in the Δ-nomenclature, trans-C16:1 n-7 in the Ω-nomenclature, TPA) has been epidemiologically associated with a lower risk of type 2 diabetes in humans. Thanks to these findings, TPA has become a nutrient of interest. However, there is a lot of unresolved crucial questions about this dietary fatty acid. Is TPA a natural trans fatty acid? What kind of foods ensures intakes in TPA? What about its metabolism? How does dietary TPA act to prevent type 2 diabetes? What are the biological mechanisms involved in this physiological effect? Clearly, it is high time to answer all these questions with the very first review specifically dedicated to this intriguing fatty acid. Aiming at getting an overview, we shall try to give an answer to all these questions, relying on appropriate and accurate scientific results. Briefly, this review underlines that TPA is indeed a natural trans fatty acid which is metabolically linked to other well-known natural trans fatty acids. Knowledge on physiological impacts of dietary TPA is limited so far to epidemiological data, awaiting for supplementation studies. In this multidisciplinary review, we also emphasize on methodological topics related to TPA, particularly when it comes to the quantification of TPA in foods and human plasma. As a conclusion, we highlight promising health benefits of dietary TPA; however, there is a strong lack in well-designed studies in both the nutritional and the analytical area.

[Trans fatty acids and conjugated linoleic acid in food: origin and biological properties]

Introduction

Trans fatty acids (TFA) are minor lipid components present in different foods, including ruminant derived products, which have received great attention due to their relationship with cardiovascular disease risk. The origin of TFA in food is mainly related to the industrial hydrogenation processes of unsaturated vegetable oils, but they can also occur naturally in the digestive tract of ruminants by enzymatic biohydrogenation reactions. Both mechanisms generate similar TFA compounds. However, TFA consumption may exert different biological effects depending on the isomeric distribution, which is strongly influenced by the dietary source (i.e., industrial or natural). Industrial hydrogenated vegetable fats are rich in elaidic (trans-9 18:1) and trans-10 18:1 fatty acids, among others. In contrast, vaccenic acid (trans-11 18:1) is the major TFA isomer detected in milk and other ruminant derived products. Vaccenic acid is the physiological precursor of conjugated linoleic acid, a bioactive lipid with beneficial effects on human health. This article provides updated information on the biological effects and potential bioactive properties of TFA considering both, their chemical structure and provenance.

Eighteen‑carbon trans fatty acids and inflammation in the context of atherosclerosis

Endothelial dysfunction is a pro-inflammatory state characterized by chronic activation of the endothelium, which leads to atherosclerosis and cardiovascular disease (CVD). Intake of trans fatty acids (TFAs) is associated with an increased risk of CVD. This risk is usually associated with industrial TFAs (iTFAs) rather than ruminant TFAs (rTFAs); however it is not clear how specific TFA isomers differ in their biological activity and mechanisms of action with regard to inflammation. Here we review the literature on 18‑carbon TFAs, including the research associating their intake or levels with CVD and studies relating 18‑carbon TFA exposure to modulation of inflammatory processes. The evidence associating iTFAs with CVD risk factors is fairly consistent and studies in humans usually show a relation between iTFAs and higher levels of inflammatory markers. In contrast, studies in humans, animals and in vitro suggest that rTFAs have null or mildly beneficial effects in cardiovascular health, metabolic parameters and inflammatory markers, although the evidence is not always consistent. More studies are needed to better identify the beneficial and detrimental effects of the different TFAs, including those with 18 carbons.

Probabilistic Quantitative Assessment of Coronary Heart Disease Risk From Dietary Exposure to Industrially Produced Trans-Fatty Acids in Partially Hydrogenated Oils

We conducted a probabilistic evaluation of changes in coronary heart disease (CHD) risk and public health burdens from industrially produced trans-fatty acids (IP-TFAs) exposure from the uses of partially hydrogenated oils in food. Our analyses used four quantitative methods based on human studies considering the uncertainty associated with risk parameters for CHD and IP-TFA daily dietary exposure of 0.05% of energy. Method 1 used experimental controlled feeding trial data for changes in low-density lipoprotein cholesterol; Method 2 used changes in both low-density lipoprotein cholesterol and high-density lipoprotein cholesterol; Method 3 used changes in a combination of three emerging CHD risk factor biomarkers; and method 4 used prospective observational studies of CHD cases associated with long-term dietary exposure of trans-fatty acids. We estimated mean percent changes in CHD risk and annual CHD cases in U.S. adults, with lower and upper 95% uncertainty intervals. Our results show that consuming 0.05% of energy from IP-TFA, instead of cis-monounsaturated fatty acids, can cause annual mean increases in CHD cases of 814 (510–1151, method 1), 1502 (990–2043, method 2), or 6877 (3611–10 694, method 4) in U.S. adults. Results for method 3 were intermediate between those for methods 2 and 4. Sensitivity analyses using alternate risk parameters or an alternate exposure scenario resulted in minor changes in public health burden estimates. The results demonstrate that IP-TFA exposure as low as 0.05% of energy from partially hydrogenated oil uses in food can cause substantial public health burdens in the United States from increased CHD risk.

Industrially produced trans fat in popular foods in 15 countries of the former Soviet Union from 2015 to 2016: a market basket investigation

OBJECTIVE

To minimise the intake of industrially produced trans fat (I-TF) and decrease the risk of coronary heart disease, several countries have implemented a legislative restriction on I-TF in foods. The objective of this study was to investigate the presence of I-TF in biscuits/cakes/wafers in 15 countries of the former Soviet Union that all have a high coronary mortality rate compared with countries in Western Europe.

METHODS

Three large supermarkets in 15 capitals were visited in 2015 or 2016. Prepackaged biscuits/cakes/wafers were bought if the list of ingredients disclosed that the product contained more than 15 g of fat per 100 g of product and if partially hydrogenated fat or a similar term, including margarine, refined fat or confectionery fat, were mentioned. Samples of the foods were subsequently analysed for total fat and TF.

RESULTS

Some 994 products contained more than 2% total fat as I-TF (illegal in Denmark). In Armenia, 91 different products had a mean value (SD) of 21 (11)% fat as I-TF. In Estonia, there were eight products with 14 (10)% fat as I-TF. The other 13 countries had values between those of Armenia and Estonia. In several countries, a major portion of the products was imported from Russia and Ukraine. The mean shelf life (SD) of 673 packages was 218 (75) days. The % TF in the fat of the products produced in Russia and in Ukraine in relation to the date of production both declined by approximately 10% points during the 2-year collection period.

CONCLUSIONS

The findings suggest that I-TF is used in popular foods in all 15 countries of the former Soviet Union. Therefore, these findings indicate a possible way for some reduction of the high coronary mortality rate in these countries.

Consumption of cashew nuts does not influence blood lipids or other markers of cardiovascular disease in humans: a randomized controlled trial

Background

The US Food and Drug Administration (FDA) approved a qualified health claim for tree nuts and reduction of cardiovascular disease. However, cashews are excluded from that claim due to their content of saturated fats, which is predominantly stearic acid. Because stearic acid is neutral with respect to blood lipids, several studies have been conducted to test the effect of cashew nuts on blood lipids, and these studies have produced conflicting results.

Objectives

The aim of this study was to conduct a highly controlled intervention to determine the effect of cashews fed at the amount specified in the health claim on risk factors for cardiovascular disease.

Methods

A total of 42 adults participated in a controlled-feeding study conducted as a randomized crossover trial with 2 treatment phases. The volunteers were provided the same base diet in both treatment phases, with no additions during the control phase and with the addition of 1.5 servings (42 g) of cashews/d for the cashew nut phase. During the cashew nut phase, the amount of all foods was decreased proportionally to achieve isocaloric overall diets in the 2 phases. After 4 wk of intervention, assessments included blood lipids, blood pressure, central (aortic) pressure, augmentation index, blood glucose, endothelin, proprotein convertase subtilisin/kexin type 9 (PCSK9), adhesion molecules, and clotting and inflammatory factors.

Results

There were no significant differences in blood lipids, blood pressure, augmentation index, blood glucose, endothelin, adhesion molecules, or clotting factors in this weight-stable cohort. PCSK9 was significantly decreased after cashew consumption, although there was no change in LDL cholesterol.

Conclusions

Consumption of 1.5 servings of cashew nuts/d, the amount associated with the FDA qualified health claim for tree nuts and cardiovascular disease, did not positively or adversely affect any of the primary risk factors for cardiovascular disease. This trial was registered at clinicaltrials.gov as NCT02628171.