Effect of different forms of dietary hydrogenated fats on LDL particle size

The association between consumption of red and processed meats with metabolic syndrome and its components in obese and overweight women: a cross-sectional study

OBJECTIVES

Previous studies have shown a relation between the consumption of different types of meats and chronic disorders. This study aims to investigate the association between red and processed meat intake with metabolic syndrome (MetS) and its components in healthy obese and overweight women.

METHODS

This cross-sectional study was conducted on Iranian women. The dietary assessment and body composition were measured by a validated food frequency questionnaire (FFQ) and bioelectrical impedance analysis, respectively. Blood samples were collected by standard protocols.

RESULTS

A total of 231 women (mean age 36.47 ± 8.44 years) were included in the current study. After controlling for potential confounders, there was a marginally significant associations between higher intake of processed meat with the MetS (OR:1.01, 95% CI: 0.94,2.94, P:0.06) and high serum triglycerides (TG) (OR:1.27, 95% CI: 0.94,2.98, P:0.07). There was a significant associations between high intake of red meats with lower odds of higher waist circumference (WC) (OR:0.31, 95% CI: 0.10,0.97, P:0.04). Also, there was a significant associations were found between high intake of processed meats with greater odds of having lower high-density lipoprotein cholesterol (HDL-c) (OR:0.64, 95% CI: 0.30,0.95, P:0.03).

CONCLUSIONS

The current study suggests that higher intakes of processed meat may be associated with the MetS in Iranian women with excess body weight, while this was not the case for red meat. More studies however are necessary in different communities to draw definitive conclusions.

Analysis of Vaccenic and Elaidic acid in foods using a silver ion cartridge applied to GC × GC-TOFMS

Background

Trans fatty acids (TFAs) are unsaturated fatty acids, with vaccenic acid (VA) and elaidic acid (EA) being the major constituents. While VA has been associated with beneficial effects on health and anti-cancer properties, EA is found in hardened vegetable oils and is linked to an increased risk of cardiovascular diseases. Therefore, this study aimed to develop a novel method for the quantitative measurement of VA and EA, aiming to accurately analyze individual TFA and apply it for the assessment of products containing TFAs.

Methods

The ratio of VA to EA (V/E ratio) was evaluated using a silver ion cartridge (SIC) solid phase extraction method removing cis-fatty acids (cis-FAs). Additionally, comparative analysis of the V/E ratio was conducted by the two methods (SIC treatment and untreated) using comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC × GC-TOFMS).

Results

The removal efficiency of cis-FAs was greater than 97.8%. However, the total TFA contents were not so different from SIC treatment. Moreover, this approach not only allowed for a more precise determination of the V/E ratio but also revealed a significant distinction between natural trans fatty acids (N-TFAs) and hydrogenated trans fatty acids (H-TFAs).

Conclusion

Therefore, the SIC coupled to the GC × GC-TOFMS presented in this study could be applied to discriminate N-TFA and H-TFA contents in dairy and fatty foods.

Effects of an Optimized Aged Garlic Extract on Cardiovascular Disease Risk Factors in Moderate Hypercholesterolemic Subjects: A Randomized, Crossover, Double-Blind, Sustainedand Controlled Study

The consumption of aged black garlic (ABG) has been related to improvements in several cardiovascular disease (CVD) risk factors. However, the extent of the beneficial effects depends on the garlic aging process and the amount and type of chemical compounds accumulated. The main objective of this study was to assess the effect of daily intake of a well-characterized ABG extract with a standardized S-allyl-L-cysteine (SAC) yield in combination with dietary recommendations regarding CVD risk factors in individuals with moderate hypercholesterolemia. Sixty-seven hypercholesterolemic individuals with low-density lipoprotein cholesterol levels ≥115 mg/dL were randomized in a crossover, double-blind, sustained, and controlled intervention study. The participants consumed 250 mg (1.25 mg SAC)/tablet/day ABG or a placebo for 6 weeks, with 3 weeks of washout. Blood and pulse pressure and other CVD risk biomarkers were determined at the beginning and end of each intervention. At 6 weeks, ABG extract reduced diastolic blood pressure (DBP) (mean (95% CI) −5.85 (−10.5; −1.3) mm Hg) compared to the placebo, particularly in men with a DBP > 75 mm Hg. The consumption of an improved ABG extract with 1.25 mg of SAC decreased DBP, particularly in men with moderate hypercholesterolemia. The potential beneficial effects of ABG may contribute to obtaining an optimal DBP.

Effect of carbohydrate-restricted dietary interventions on LDL particle size and number in adults in the context of weight loss or weight maintenance: a systematic review and meta-analysis

BACKGROUND

LDL particle size and number (LDL-P) are emerging lipid risk factors. Nonsystematic reviews have suggested that diets lower in carbohydrates and higher in fats may result in increased LDL particle size when compared with higher-carbohydrate diets.

OBJECTIVES

This study aimed to systematically review available evidence and conduct meta-analyses of studies addressing the association of carbohydrate restriction with LDL particle size and LDL-P.

METHODS

We searched 6 electronic databases on 4 January, 2021 for randomized trials of any length that reported on dietary carbohydrate restriction (intervention) compared with higher carbohydrate intake (control). We calculated standardized mean differences (SMDs) in LDL particle size and LDL-P between the intervention and control groups of eligible studies, and pooled effect sizes using random-effects models. We performed prespecified subgroup analyses and examined the effect of potential explanatory factors. Internal validity and publication bias were assessed using Cochrane's risk-of-bias tool and funnel plots, respectively. Studies that could not be meta-analyzed were summarized qualitatively.

RESULTS

This review summarizes findings from 38 randomized trials including a total of 1785 participants. Carbohydrate-restricted dietary interventions were associated with an increase in LDL peak particle size (SMD = 0.50; 95% CI: 0.15, 0.86; P < 0.01) and a reduction in LDL-P (SMD = -0.24; 95% CI: -0.43, -0.06; P = 0.02). The effect of carbohydrate-restricted dietary interventions on LDL peak particle size appeared to be partially explained by differences in weight loss between intervention groups and exploratory analysis revealed a shift from small dense to larger LDL subclasses. No statistically significant association was found between carbohydrate-restricted dietary interventions and mean LDL particle size (SMD = 0.20; 95% CI: -0.29, 0.69; P = 0.37).

CONCLUSIONS

The available evidence indicates that dietary interventions restricted in carbohydrates increase LDL peak particle size and decrease the numbers of total and small LDL particles.This review was registered at www.crd.york.ac.uk/prospero/ as CRD42020188745.

Small dense low-density lipoprotein-lowering agents

Metabolic disorders, including obesity, diabetes, and hyperlipidemia, as well as cardiovascular diseases (CVD), particularly atherosclerosis, are still leading causes of death worldwide. Plasma levels of low-density lipoprotein (LDL) are currently being considered as a critical risk factor for the diseases mentioned above, especially atherosclerosis. Because of the heterogeneous nature of LDL, many studies have already been conducted on its subclasses, especially small dense LDL (sdLDL). According to available evidence, sdLDL levels can be considered as an ideal alternative to LDL levels for monitoring CVD and early diagnosis of atherosclerosis. Recently, several researchers have focused on factors that are able to decrease sdLDL levels and improve health quality. Therefore, the purpose of this study is to describe the production process of sdLDL particles and review the effects of pharmaceutical and dietary agents as well as lifestyle on sdLDL plasma levels. In brief, their mechanisms of action are discussed. Apparently, cholesterol and LDL-lowering compounds are also effective in the reduction of sdLDL levels. In addition, improving lipid profile, especially the reduction of triglyceride levels, appropriate regimen, and lifestyle can decrease sdLDL levels. Therefore, all the aforementioned parameters should be taken into consideration simultaneously in sdLDL levels reducing strategies.

The Effects of a Nutrition Education Program on Dietary Intake and Biomarkers in HIV+ Adults

Background. People living with HIV (PLWH) have increased risk of cardiovascular disease (CVD). Dietary behavior modification may assist in the treatment of CVD, but the optimal dose of nutrition education is unknown. The current aim was to determine if a weekly 1-hour nutrition education program would improve multiple outcomes among PLWH. Methods. Participants (n = 62) were assessed on dietary intake, serum biomarkers, and physical characteristics at baseline and 3 months, and percent change was calculated. Participants were grouped into 3 attendance categories of the classes: none, fair, or good. Analyses of covariance were performed on the outcomes. Results. Calories, protein, fat, saturated fat, carbohydrate, sugar, added sugar, and glycemic load were significantly different (all P values <.05). Those who attended no class typically had increases in these variables versus those with fair or good attendance. High-density lipoprotein cholesterol (HDL-C; P = .006) and total cholesterol/HDL-C ratio ( P = .083) were different, as those who attended no class or had fair attendance worsened, but those with good attendance improved. Conclusions. Several outcomes improved more so among those with good class attendance versus those with either fair or no attendance. Thus, an interactive nutrition education program may be an effective tool to help improve the health of PLWH.

High consumption of ultra-processed food may double the risk of subclinical coronary atherosclerosis: the Aragon Workers' Health Study (AWHS)

BACKGROUND

Ultra-processed food (UPF) consumption, which is increasing worldwide, has recently been associated with an increased risk of death and cardiovascular disease. We aimed to assess whether consumption of UPF is directly associated with subclinical coronary atherosclerosis in middle-aged men.

METHODS

A computed tomography scan was performed on 1876 men from the Aragon Workers' Health Study, recruited from January 2011 to December 2014, to assess coronary calcium. All participants were free of coronary heart disease. Dietary intake was collected by a validated 136-item semi-quantitative food frequency questionnaire. UPF was defined according to the NOVA classification. Associations between consumption of total energy-adjusted UPF and Coronary Calcium Agatston Score (CACS)-categorized into CACS of 0, > 0 and < 100, and ≥ 100-were cross-sectionally assessed by generalized ordered logistic regression adjusted for main confounders.

RESULTS

No coronary calcium was detected in 60.2% of the participants, whereas 10.2% had a CACS ≥ 100. A significant dose-response association was observed between energy-adjusted UPF consumption and the risk of having a CACS ≥ 100, when compared with those in the lowest CACS categories (CACS of 0 together with CACS > 0 and < 100). The fully adjusted ORs (95% CI) of having a CACS ≥ 100 across quartiles of energy-adjusted UPF consumption (approximately 100 g/day in the lowest quartile (ref.) and 500 g/day in the highest) were 1.00 (ref.), 1.50 (0.93, 2.42), 1.56 (0.96, 2.52), and 2.00 (1.26, 3.16), p trend .005.

CONCLUSION

In this middle-aged worker's sample, approximately 500 g/day of UPF consumption was associated with a 2-fold greater prevalence of subclinical coronary atherosclerosis than consuming only 100 g/day, independently of total energy intake and other well-established cardiovascular risk factors.

Trans-fatty acids alter the gut microbiota in high-fat-diet-induced obese rats

The gut microbiota is directly influenced by dietary components, and it plays critical roles in chronic diseases. Excessive consumption of trans-fatty acids (TFA) is associated with obesity induced by alterations in gut microbiota, but the links between obesity and gut microbiota remain unclear. Therefore, studies examining the impact of TFA on intestinal microflora are essential. In our study, we performed 16S ribosomal RNA gene sequencing on faecal samples from Sprague-Dawley rats fed a basal diet (control (CON) group), high-fat (HF) diet (diet-induced obesity (DIO) group) or TFA diets (1 % TFA group and 8 % TFA group) for 8 weeks to investigate the effects of TFA/HF diets on obesity and gut microbiota composition. We found that the TFA/HF diets significantly induced obesity and changes in blood and brain physiological parameters of the rats. The relative abundance of the phyla Firmicutes and Bacteroidetes was inversely altered in the three test groups compared with the CON group. Proteobacteria increased slightly in the DIO, 1 % TFA and 8 % TFA groups. The genus Bacteroides increased in the DIO and 1 % TFA groups, but Muribaculaceae decreased in all experimental groups compared with the CON group. Moreover, significant differences were observed among clusters of orthologous group functional categories of the four dietary groups. Our observations suggested that the TFA/HF diets induced obesity and dysfunction of gut microbiota. Gut dysbiosis might mediate the obesity effects of TFA/HF diets.

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.

Feeding high-oleic peanuts to meat-type broiler chickens enhances the fatty acid profile of the meat produced

Early feeding trials using peanut meal prepared from normal-oleic peanuts helped to identify peanuts as a suitable alternative feed ingredient for poultry. Yet no studies to date have examined the use of high-oleic peanuts (HO-PN) as a feed ingredient for meat type chickens. Therefore, this study aimed to determine the effect of feeding whole unblanched HO-PN on the fatty acid profile of the meat produced from broilers. At hatch male chicks were randomly placed in raised wire cages, in 10 replicate pens per treatment with 10 chicks per pen, and fed with one of the 3 isocaloric, isonitrogenous diets ad libitum for 42 days: (1) conventional control of soybean meal + corn, (2) 10 to 12% HO-PN and corn diet, or (3) control diet spiked with ≈6.0% oleic acid oil. All body weights (BW) were collected, and broiler selection for processing was determined by individual BW within one-half a standard deviation of the experiment 42-D mean BW, with one bird selected per pen (10 replicate pens per treatment, 3 treatments, 10 birds selected per treatment, yielding a total sample size of 30 birds). Performance was determined weekly and breast samples were analyzed for fatty acid and amino acid profile. All data was analyzed using analysis of variance, with t-test mean comparisons at P < 0.05. BW were similar between broilers fed the HO-PN and control diet, while feed conversion ratio of broilers fed the HO-PN diet was significantly higher at weeks 2, 4, and 6 in comparison to the other treatments (P ≤ 0.03). Broilers fed with HO-PN diet had reduced carcass and pectoralis major weights in comparison to the other treatments. Chicken breast from broilers fed the HO-PN diet had significantly reduced saturated and trans fatty acid content in comparison to the controls (P ≤ 0.0002). Although additional studies must be conducted, this study suggests that feeding whole unblanched HO-PN to broiler chickens may serve as a means to enrich the meat produced with unsaturated fatty acids.

Trans fatty acids and lipid profile: A serious risk factor to cardiovascular disease, cancer and diabetes

Trans Fatty acids (TFAs) have long been used in food manufacturing due in part to their melting point at room temperature between saturated and unsaturated fats. However, increasing epidemiologic and biochemical evidence suggests that excessive trans fats in the diet are a significant risk factor for cardiovascular events as well as a risk factor for cancer and diabetes. A 2% absolute increase in energy intake from trans-fat has been associated with a 23% increase in cardiovascular risk. They increase the levels of low-density lipoprotein which is bad for health. Moreover, several epidemiological studies have been demonstrated that a high intake of TFAs increases the incidence of cancer and diabetes. On the other hand, total elimination of TFAs is not possible in a balanced diet due to their natural presence in dairy and meat products. Many products with almost 0.5 g trans-fat, if consumed over the course of a day, may approximate or exceed the 2 g maximum as recommended by the American Heart Association. The objective of the review to demonstrate the causal association between trans fatty acid intake and increase the risk of coronary heart disease through their influence on lipoprotein, association with atherosclerosis, stroke, diabetes and cancer.

Effect of elaidic acid on ABCA1 expression in raw 264.7 cells. Is it through PPAR-gamma?

In recent years, Trans Fatty Acids have shown a strong correlation with cardiovascular disease. However, the mechanisms explaining their atherogenicity are still unclear. ABCA1, which is involved in the reverse cholesterol transport pathway, has been considered as a new therapeutic target for cardiovascular disease. In vitro studies of the effects of PPAR-γ on lipid homeostasis in macrophage cells suggested a role for PPAR-γ in the regulation of ABCA1-dependent cholesterol efflux to apoA-I pathway. Thus, in this study we examined the effect of elaidic acid (EA) as the most abundant TFA on expression of ABCA1 and PPAR-γ in RAW 264.7 mouse macrophage cell line. Accordingly, after determining appropriate concentrations of EA using MTT, RAW 264.7 cells were treated with different concentrations of EA, and at the end, gene expression was assayed by Real-Time PCR. Our results shown that the expression of ABCA1 decreased in the treated group in comparison with the control group by 1.7, 2.3, and 5.1 fold, after 12 h treatment for 0.5, 1, and 2 mM EA concentration respectively. In addition, after 24 h treatment with EA, the rate of decreasing ABCA1 expression was 2.1, 2.6, 5.7 fold, respectively (P < 0.01). However, EA had no significant effect on PPAR-γ mRNA expression. Therefore, it could be concluded that the atherogenic effect of EA may be mediated by reducing ABCA1 expression in RAW 264.7 cells; however, this reduction has not mediated through altering PPAR-γ expression.

Association Between Plasma Trans-Fatty Acid Concentrations and Measures of Glucose Homeostasis and Cardiovascular Risk Factors in Adults in NHANES 1999-2000

There is limited evidence on the association between plasma trans-fatty acids (TFAs) and cardiometabolic risk factors. Therefore, we examined the association between plasma TFA concentrations and glucose homeostasis and cardiovascular (CV) risk factors in adult Americans from the 1999 to 2000 National Health and Nutrition Examination Survey participants. Derivatized TFAs were separated by capillary gas chromatography. Of the 1678 participants, 46.5% were men. The mean age was 50.5 years overall, with no significant difference between men and women ( P = .101). In age-, sex- and race-adjusted analyses, mean waist circumference, fat-free mass, fat mass, C-peptide, insulin, hemoglobin A_1c (HbA_1c), homeostatic model assessment of insulin resistance (HOMA-IR), serum triglycerides (TGs), and total cholesterol (TC) increased across increasing quarters of TFAs (for all P < .001), while mean serum high-density lipoprotein cholesterol decreased across increasing quarters of plasma TFAs ( P < .001). In multivariable adjusted linear regressions, there remained significant positive associations between all plasma TFAs and body mass index, waist circumference, fat-free mass, fat mass, C-peptide, insulin, fasting blood glucose, HOMA-IR, HbA_1c, TGs, low-density lipoprotein cholesterol, and TC ( P < .001). In conclusion, our findings support a possible association between plasma TFAs concentrations and measures of glucose homeostasis and several CV risk factors.

Development of a Spectrophotometric System to Detect White Striping Physiopathy in Whole Chicken Carcasses

Due to the high intensification of poultry production in recent years, white chicken breast striping is one of the most frequently seen myopathies. The aim of this research was to develop a spectrophotometry-based sensor to detect white striping physiopathy in chicken breast meat in whole chicken carcasses with skin. Experiments were carried out using normal and white striping breasts. In order to understand the mechanism involved in this physiopathy, the different tissues that conform each breast were analyzed. Permittivity in radiofrequency (40 Hz to 1 MHz) was measured using two different sensors; a sensor with two flat plates to analyze the whole breast with skin (NB or WSB), and a two needles with blunt-ended sensor to analyze the different surface tissues of the skinless breast. In the microwave range (500 MHz to 20 GHz), permittivity was measured as just was described for the two needles with blunt-ended sensor. Moreover, fatty acids composition was determined by calorimetry techniques from −40 °C to 50 °C at 5 °C/min after previously freeze-drying the samples, and pH, microstructure by Cryo-SEM and binocular loupe structure were also analyzed. The results showed that the white striping physiopathy consists of the partial breakdown of the pectoral muscle causing an increase in fatty acids, reducing the quality of the meat. It was possible to detect white striping physiopathy in chicken carcasses with skin using spectrophotometry of radiofrequency spectra.

Genetic associations with lipoprotein subfraction measures differ by ethnicity in the multi-ethnic study of atherosclerosis (MESA)

A recent genome-wide association study associated 62 single nucleotide polymorphisms (SNPs) from 43 genomic loci, with fasting lipoprotein subfractions in European–Americans (EAs) at genome-wide levels of significance across three independent samples. Whether these associations are consistent across ethnicities with a non-European ancestry is unknown. We analyzed 15 lipoprotein subfraction measures, on 1677 African–Americans (AAs), 1450 Hispanic–Americans (HAs), and 775 Chinese–Americans (CHN) participating in the multi-ethnic study of atherosclerosis (MESA). Genome-wide data were obtained using the Affymetrix 6.0 and Illumina HumanOmni chips. Linear regression models between genetic variables and lipoprotein subfractions were adjusted for age, gender, body mass index, smoking, study center, and genetic ancestry (based on principal components), and additionally adjusted for Mexican/Non-Mexican status in HAs. A false discovery rate correction was applied separately within the results for each ethnicity to correct for multiple testing. Power calculations revealed that we did not have the power for SNP-based measures of association, so we analyzed phenotype-specific genetic risk scores (GRSs), constructed as in the original genome-wide analysis. We successfully replicated all 15 GRS–lipoprotein associations in 2527 EAs. Among the 15 significant GRS–lipoprotein associations in EAs, 11 were significant in AAs, 13 in HAs, and 1 in CHNs. Further analyses revealed that ethnicity differences could not be explained by differences in linkage disequilibrium, lipid lowering drugs, diabetes, or gender. Our study emphasizes the importance of ethnicity (here indexing genetic ancestry) in genetic risk for CVD and highlights the need to identify ethnicity-specific genetic variants associated with CVD risk.

Effects of a very high saturated fat diet on LDL particles in adults with atherogenic dyslipidemia: A randomized controlled trial

Background

Previous studies have shown that increases in LDL-cholesterol resulting from substitution of dietary saturated fat for carbohydrate or unsaturated fat are due primarily to increases in large cholesterol-enriched LDL, with minimal changes in small, dense LDL particles and apolipoprotein B. However, individuals can differ by their LDL particle distribution, and it is possible that this may influence LDL subclass response.

Objective

The objective of this study was to test whether the reported effects of saturated fat apply to individuals with atherogenic dyslipidemia as characterized by a preponderance of small LDL particles (LDL phenotype B).

Methods

Fifty-three phenotype B men and postmenopausal women consumed a baseline diet (55%E carbohydrate, 15%E protein, 30%E fat, 8%E saturated fat) for 3 weeks, after which they were randomized to either a moderate carbohydrate, very high saturated fat diet (HSF; 39%E carbohydrate, 25%E protein, 36%E fat, 18%E saturated fat) or low saturated fat diet (LSF; 37%E carbohydrate, 25%E protein, 37%E fat, 9%E saturated fat) for 3 weeks.

Results

Compared to the LSF diet, consumption of the HSF diet resulted in significantly greater increases from baseline (% change; 95% CI) in plasma concentrations of apolipoprotein B (HSF vs. LSF: 9.5; 3.6 to 15.7 vs. -6.8; -11.7 to -1.76; p = 0.0003) and medium (8.8; -1.3 to 20.0 vs. -7.3; -15.7 to 2.0; p = 0.03), small (6.1; -10.3 to 25.6 vs. -20.8; -32.8 to -6.7; p = 0.02), and total LDL (3.6; -3.2 to 11.0 vs. -7.9; -13.9 to -1.5; p = 0.03) particles, with no differences in change of large and very small LDL concentrations. As expected, total-cholesterol (11.0; 6.5 to 15.7 vs. -5.7; -9.4 to -1.8; p<0.0001) and LDL-cholesterol (16.7; 7.9 to 26.2 vs. -8.7; -15.4 to -1.4; p = 0.0001) also increased with increased saturated fat intake.

Conclusions

Because medium and small LDL particles are more highly associated with cardiovascular disease than are larger LDL, the present results suggest that very high saturated fat intake may increase cardiovascular disease risk in phenotype B individuals. This trial was registered at clinicaltrials.gov (NCT00895141).

Trial registration

Clinicaltrials.gov NCT00895141.

RNAi-mediated down-regulation of the expression of OsFAD2-1: effect on lipid accumulation and expression of lipid biosynthetic genes in the rice grain

BACKGROUND

The bran from polished rice grains can be used to produce rice bran oil (RBO). High oleic (HO) RBO has been generated previously through RNAi down-regulation of OsFAD2-1. HO-RBO has higher oxidative stability and could be directly used in the food industry without hydrogenation, and is hence free of trans fatty acids. However, relative to a classic oilseed, lipid metabolism in the rice grain is poorly studied and the genetic alteration in the novel HO genotype remains unexplored.

RESULTS

Here, we have undertaken further analysis of role of OsFAD2-1 in the developing rice grain. The use of Illumina-based NGS transcriptomics analysis of developing rice grain reveals that knockdown of Os-FAD2-1 gene expression was accompanied by the down regulation of the expression of a number of key genes in the lipid biosynthesis pathway in the HO rice line. A slightly higher level of oil accumulation was also observed in the HO-RBO.

CONCLUSION

Prominent among the down regulated genes were those that coded for FatA, LACS, SAD2, SAD5, caleosin and steroleosin. It may be possible to further increase the oleic acid content in rice oil by altering the expression of the lipid biosynthetic genes that are affected in the HO line.

Current Evidence Supporting the Link Between Dietary Fatty Acids and Cardiovascular Disease

Lack of consensus exists pertaining to the scientific evidence regarding effects of various dietary fatty acids on cardiovascular disease (CVD) risk. The objective of this article is to review current evidence concerning cardiovascular health effects of the main dietary fatty acid types; namely, trans (TFA), saturated (SFA), polyunsaturated (PUFA; n-3 PUFA and n-6 PUFA), and monounsaturated fatty acids (MUFA). Accumulating evidence shows negative health impacts of TFA and SFA; both may increase CVD risk. Policies have been proposed to reduce TFA and SFA consumption to less than 1 and 7 % of energy intake, respectively. Cardiovascular health might be promoted by replacing SFA and TFA with n-6 PUFA, n-3 PUFA, or MUFA; however, the optimal amount of PUFA or MUFA that can be used to replace SFA and TFA has not been defined yet. Evidence suggests of the potential importance of restricting n-6 PUFA up to 10 % of energy and obtaining an n-6/n-3 ratio as close as possible to unity, along with a particular emphasis on consuming adequate amounts of essential fatty acids. The latest evidence shows cardioprotective effects of MUFA-rich diets, especially when MUFA are supplemented with essential fatty acids; namely, docosahexaenoic acid. MUFA has been newly suggested to be involved in regulating fat oxidation, energy metabolism, appetite sensations, weight maintenance, and cholesterol metabolism. These favorable effects might implicate MUFA as the preferable choice to substitute for other fatty acids, especially given the declaration of its safety for up to 20 % of total energy.

Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies

OBJECTIVE

To systematically review associations between intake of saturated fat and trans unsaturated fat and all cause mortality, cardiovascular disease (CVD) and associated mortality, coronary heart disease (CHD) and associated mortality, ischemic stroke, and type 2 diabetes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, Cochrane Central Registry of Controlled Trials, Evidence-Based Medicine Reviews, and CINAHL from inception to 1 May 2015, supplemented by bibliographies of retrieved articles and previous reviews.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Observational studies reporting associations of saturated fat and/or trans unsaturated fat (total, industrially manufactured, or from ruminant animals) with all cause mortality, CHD/CVD mortality, total CHD, ischemic stroke, or type 2 diabetes.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data and assessed study risks of bias. Multivariable relative risks were pooled. Heterogeneity was assessed and quantified. Potential publication bias was assessed and subgroup analyses were undertaken. The GRADE approach was used to evaluate quality of evidence and certainty of conclusions.

RESULTS

For saturated fat, three to 12 prospective cohort studies for each association were pooled (five to 17 comparisons with 90,501-339,090 participants). Saturated fat intake was not associated with all cause mortality (relative risk 0.99, 95% confidence interval 0.91 to 1.09), CVD mortality (0.97, 0.84 to 1.12), total CHD (1.06, 0.95 to 1.17), ischemic stroke (1.02, 0.90 to 1.15), or type 2 diabetes (0.95, 0.88 to 1.03). There was no convincing lack of association between saturated fat and CHD mortality (1.15, 0.97 to 1.36; P=0.10). For trans fats, one to six prospective cohort studies for each association were pooled (two to seven comparisons with 12,942-230,135 participants). Total trans fat intake was associated with all cause mortality (1.34, 1.16 to 1.56), CHD mortality (1.28, 1.09 to 1.50), and total CHD (1.21, 1.10 to 1.33) but not ischemic stroke (1.07, 0.88 to 1.28) or type 2 diabetes (1.10, 0.95 to 1.27). Industrial, but not ruminant, trans fats were associated with CHD mortality (1.18 (1.04 to 1.33) v 1.01 (0.71 to 1.43)) and CHD (1.42 (1.05 to 1.92) v 0.93 (0.73 to 1.18)). Ruminant trans-palmitoleic acid was inversely associated with type 2 diabetes (0.58, 0.46 to 0.74). The certainty of associations between saturated fat and all outcomes was "very low." The certainty of associations of trans fat with CHD outcomes was "moderate" and "very low" to "low" for other associations.

CONCLUSIONS

Saturated fats are not associated with all cause mortality, CVD, CHD, ischemic stroke, or type 2 diabetes, but the evidence is heterogeneous with methodological limitations. Trans fats are associated with all cause mortality, total CHD, and CHD mortality, probably because of higher levels of intake of industrial trans fats than ruminant trans fats. Dietary guidelines must carefully consider the health effects of recommendations for alternative macronutrients to replace trans fats and saturated fats.

Is there a linear relationship between the dose of ruminant trans-fatty acids and cardiovascular risk markers in healthy subjects: results from a systematic review and meta-regression of randomised clinical trials

The effects of ruminant (R) trans-fatty acids (TFA) on the risk of CVD are still under debate. It could be argued that the lack of the effect of R-TFA may be the result of the small amount of their intake. Taking into consideration the growing available data from intervention studies, we carried out a systematic review and meta-regression to assess the impact of R-TFA intake levels on changes in the total cholesterol: HDL-cholesterol (TC:HDL-C) ratio. A systematic review of the literature was conducted and thirteen randomised clinical trials were included, yielding a total of twenty-three independent experimental groups of subjects. A univariate random-effects meta-regression approach was used to quantify the relationship between the dose of R-TFA and changes in the TC:HDL-C ratio. To consider several potential modifiers such as subject and dietary characteristics, a multivariate regression analysis was performed. We found no relationship between R-TFA intake levels of up to 4·19 % of daily energy intake (EI) and changes in cardiovascular risk factors such as TC:HDL-C and LDL-cholesterol (LDL-C):HDL-C ratios. In addition, a multivariate regression analysis that included other dietary variables, as well as subject baseline characteristics, confirmed that doses of R-TFA did not significantly influence the changes in the lipid ratio. Our findings showed that doses of R-TFA did not influence the changes in the ratios of plasma TC:HDL-C and LDL-C:HDL-C. These data suggest that TFA from natural sources, at least at the current levels of intake and up to 4·19 % EI, have no adverse effects on these key CVD risk markers in healthy people.

Plasma phospholipid trans-fatty acids levels, cardiovascular diseases, and total mortality: the cardiovascular health study

BACKGROUND

While self-reported trans-fatty acid (TFA) consumption is linked to coronary heart disease (CHD), relationships between objective biomarkers of TFA subtypes (t-16:1n9, total t-18:1, and cis/trans-(c/t-), t/c- and t/t-18:2) and cardiovascular disease (CVD) or total mortality are not well established.

METHODS AND RESULTS

We evaluated 2742 adults in the Cardiovascular Health Study, aged 74±5 years and free of prevalent CVD, with plasma phospholipid TFA measures in 1992. Incident fatal and nonfatal CHD events, CVD and non-CVD mortality, and total mortality were centrally adjudicated through 2010. Risks were assessed using Cox proportional hazards. During 31 494 person-years, 1735 total deaths and 639 total CHD events occurred. In the multivariate model including mutual adjustment for the 5 TFA subtypes, circulating t/t-18:2 was associated with higher total mortality (extreme quintile hazard ratio (HR)=1.23, 95% CI=1.04 to 1.44, P-trend=0.01), CVD mortality (HR=1.40, 95% CI=1.05 to 1.86, P-trend=0.02), and total CHD (HR=1.39, 95% CI=1.06 to 1.83, P-trend=0.01). t/c-18:2 was positively related to total mortality (HR=1.19, P-trend=0.05), total CHD (HR=1.67, P-trend=0.002), and nonfatal CHD (HR=2.06, P-trend=0.002) after mutual adjustment; these associations were insignificant without mutual adjustment. Neither t-16:1n9 nor t-18:1 was significantly associated with total mortality or CVD, nor was c/t-18:2 if we excluded early cases.

CONCLUSIONS

Among circulating TFAs, t/t-18:2 was most adversely associated with total mortality, mainly due to the increased risk of CVD. t/c-18:2 was also positively associated with total mortality and CHD, but only after adjustment for other TFAs. These results highlight the need for further investigation of dietary sources, nondietary determinants, and health effects of specific TFA subtypes, especially t-18:2 isomers.

Genetic risk scores associated with baseline lipoprotein subfraction concentrations do not associate with their responses to fenofibrate

Lipoprotein subclass concentrations are modifiable markers of cardiovascular disease risk. Fenofibrate is known to show beneficial effects on lipoprotein subclasses, but little is known about the role of genetics in mediating the responses of lipoprotein subclasses to fenofibrate. A recent genomewide association study (GWAS) associated several single nucleotide polymorphisms (SNPs) with lipoprotein measures, and validated these associations in two independent populations. We used this information to construct genetic risk scores (GRSs) for fasting lipoprotein measures at baseline (pre-fenofibrate), and aimed to examine whether these GRSs also associated with the responses of lipoproteins to fenofibrate. Fourteen lipoprotein subclass measures were assayed in 817 men and women before and after a three week fenofibrate trial. We set significance at a Bonferroni corrected alpha <0.05 (p < 0.004). Twelve subclass measures changed with fenofibrate administration (each p = 0.003 to <0.0001). Mixed linear models which controlled for age, sex, body mass index (BMI), smoking status, pedigree and study-center, revealed that GRSs were associated with eight baseline lipoprotein measures (p < 0.004), however no GRS was associated with fenofibrate response. These results suggest that the mechanisms for changes in lipoprotein subclass concentrations with fenofibrate treatment are not mediated by the genetic risk for fasting levels.

Proceedings from the 2013 Canadian Nutrition Society Conference on Advances in Dietary Fats and Nutrition

The science of lipid research continues to rapidly evolve and change. New knowledge enhances our understanding and perspectives on the role of lipids in health and nutrition. However, new knowledge also challenges currently held opinions. The following are the proceedings of the 2013 Canadian Nutrition Society Conference on the Advances in Dietary Fats and Nutrition. Content experts presented state-of-the-art information regarding our understanding of fish oil and plant-based n-3 polyunsaturated fatty acids, nutrigenomics, pediatrics, regulatory affairs, and trans fats. These important contributions aim to provide clarity on the latest advances and opinions regarding the role of different types of fats in health.

Reduction in dietary trans fat intake is associated with decreased LDL particle number in a primary prevention population

BACKGROUND AND AIMS

Increased trans fat intake has been associated with an increased risk of cardiovascular disease (CVD). While the effect of trans fat on traditional lipids is known, it's association with LDL particle number (LDL-P), a novel marker of CVD risk, has not been established. The purpose of this study was to determine the association between trans fat intake and LDL-P over 1-year among individuals participating in a lifestyle intervention trial.

METHODS AND RESULTS

Family members (N = 400, 33% male, mean age 48 ± 13) of patients hospitalized with CVD who participated in a 1-year randomized controlled primary prevention lifestyle intervention trial and had complete dietary data and LDL-P measures at baseline and 1-year. Change in trans fat as a percentage of total diet and mean absolute change in LDL-P at 1-year was assessed using multivariate adjusted linear regression models. At baseline, there was a significant positive correlation between dietary trans fat intake and LDL-P (Beta = 37, p = 0.04). For every 1 percent change in trans fat intake there was a 27 nmol/L change in LDL-P (Beta = 27, p = 0.04) over 1-year which was independent of baseline predictors and confounders (age, sex, smoking, statin use, waist size and physical activity; Beta = 30, p = 0.03).

CONCLUSION

A reduction in trans fat intake over 1-year was significantly associated with a reduction in LDL-P independent of potential confounders. Healthcare providers should reinforce the beneficial impact of a healthy diet, and in particular modifications in trans fat intake on improving lipid profiles.

Differential effects of adulterated versus unadulterated forms of linoleic acid on cardiovascular health

According to the classic "diet-heart" hypothesis, high dietary intake of saturated fats and cholesterol combined with low intake of polyunsaturated fats can increase levels of serum cholesterol and lead to the development of atherogenic plaques and ultimately cardiovascular diseases. Recently, the beneficial health effects of omega-6 polyunsaturated fatty acids, particularly linoleic acid (LA), on cardiovascular health have been called into question with some scientists suggesting that consumption of LA should be reduced in Western countries. The focus of this critical review is on the controversy surrounding the effects of dietary intake of LA on cardiovascular health. Specifically, we critically examined the effects of both unadulterated and adulterated forms of LA on cardiovascular health outcomes based on findings from epidemiological studies and randomized controlled trials. Additionally, we address common concerns surrounding dietary intake of LA regarding its relationship with arachidonic acid, the ratio of omega-6 to omega-3 fatty acids, and its relationship with inflammation. Our critical review indicates that unadulterated forms of LA are cardioprotective and should be consumed as part of a healthy diet. In contrast, abundant evidence now indicates that adulterated forms of LA, predominantly hydrogenated vegetable oils, are atherogenic and should not be considered part of a healthy diet. The ability to adulterate the natural omega-6 fatty acid, LA, has contributed to mixed findings regarding the effects of this fatty acid on cardiovascular health. Thus, it is critical that the source of LA be taken into account when drawing conclusions about the physiological effects of this fatty acid. The findings of the present review are in line with current dietary recommendations of the American Heart Association.

Moderate compared to low dietary intake of trans-fatty acids impairs strength of old and aerobic capacity of young SAMP8 mice in both sexes

The senescence accelerated SAMP8 mouse is a model for sarcopenia and provides an opportunity to study the effects of lifelong dietary composition on the loss of physical function with age. We studied the effects of trans-fatty acids (2 % of total energy, TFA diet) on the loss of strength and aerobic exercise capacity (VO₂peak) with age. SAMP8 mice were studied at two ages (young, 25 weeks; old, 60 weeks) and on two diets (control vs TFA). Body composition, grip strength, VO₂peak, blood metabolites, and biochemical parameters were assessed. Body weight, fat mass, and body fat percentage all increased with age (p < 0.05) but were not significantly impacted by diet. There was a significant age-related decline in total grip strength as well as that normalized to fat-free mass (FFM) (p < 0.05) with a further decrease at old age in these metrics of strength on the TFA diet vs control diet (p < 0.05). Total VO₂peak exhibited no change with age or diet, but when normalized to FFM, VO₂peak exhibited age and TFA-related declines (p < 0.05). Intramuscular triacylglycerol (p < 0.05) and collagen content (p < 0.05) significantly increased with age, while blood triacylglycerol was increased by the TFA diet (p < 0.05). These data further characterize the SAMP8 mouse as a model for sarcopenia and indicate that dietary fatty acid composition can impact the degree of this age-related loss of physical function.

Biological activity and fatty acid composition of Caesar's mushroom

CONTEXT

Due to its pleasant aroma and flavor, Amanita caesarea (Scop.) Pers. (Amanitaceae) has been a famous macrofungus since ancient times. This species is also well known in Turkey where people consume it extensively.

OBJECTIVE

Evaluation of the medicinal importance of A. caesarea for human health.

MATERIALS AND METHODS

Antioxidant capacity of A. caesarea was studied using the methods of a scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radicals, β-carotene-linoleic acid assay, reducing power and estimation of phenolics. Chloroform, acetone and methanol extracts of A. caesarea were tested for their antimicrobial activity against four Gram-positive bacteria, five Gram-negative bacteria and one yeast by applying a micro dilution method. The fatty acids were estimated via the method of gas chromatography analysis.

RESULTS

The scavenging effect of A. caesarea on DPPH radicals was measured as 40.91% at 0.5 mg/mL concentration, and its reducing power was 0.451 mg/mL at 1.2 mg/mL concentration. The phenolics found were catechin (32.5 mg/g), ferulic acid (7 mg/g), p-coumaric acid (6 mg/g) and cinnamic acid (6.2 mg/g). The highest minimum inhibitory concentration observed against the test microorganisms were with the acetone extract (4.8 µg/mL concentration) against Candida albicans. Thirty-seven different fatty acids were determined from A. caesarea, and oleic acid (58%) was the dominant component.

DISCUSSION AND CONCLUSION

Amanita caesarea had a high-antioxidant and -antimicrobial activity, and it also had important essential fatty acids required for human health. According to the results, this mushroom can be recommended as a major source of natural food.

Intake of trans fat and all-cause mortality in the Reasons for Geographical and Racial Differences in Stroke (REGARDS) cohort

BACKGROUND

A high intake of trans fatty acids decreases HDL cholesterol and is associated with increased LDL cholesterol, inflammation, diabetes, cancer, and mortality from cardiovascular disease. The relation between trans fat intake and all-cause mortality has not been established.

OBJECTIVE

The aim of this study was to determine the relation between trans fat intake and all-cause mortality.

DESIGN

We used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study-a prospective cohort study of white and black men and women residing in the continental United States. Energy-adjusted trans fat intake was categorized into quintiles, and Cox-regression was used to evaluate the association between trans fat intake and all-cause mortality.

RESULTS

During 7 y of follow-up, there were 1572 deaths in 18,513 participants included in REGARDS. From the first to the fifth quintile of trans fat intake, the mortality rates per 1000 person-years of follow-up (95% CIs) were 12.8 (11.3, 14.5), 14.3 (12.7, 16.2), 14.6 (13.0, 16.5), 19.0 (17.1, 21.1), and 23.6 (21.5, 25.9), respectively. After adjustment for demographic factors, education, and risk factors for mortality, the HRs (95% CIs) for all-cause mortality were 1.00, 1.03 (0.86, 1.23), 0.98 (0.82, 1.17), 1.25 (1.05, 1.48), and 1.24 (1.05, 1.48), respectively (P-trend = 0.004). The population attributable risk due to trans fat intake was 7% (95% CI: 5%, 8%).

CONCLUSION

Higher trans fat intake is associated with an increased risk of all-cause mortality.

High levels of very long-chain saturated fatty acid in erythrocytes correlates with atherogenic lipoprotein profiles in subjects with metabolic syndrome

AIM

Very long chain saturated fatty acid (VLCFA) levels in erythrocytes are associated with metabolic syndrome (MS). However, the relationship between levels of the VLCFA ligonoceric acid (C24:0) in erythrocytes and the atherogenic lipoprotein profiles and inflammatory state in MS remain unclear.

METHODS

Based on the International Diabetes Federation (IDF) definition of MS, 195 apparently healthy males were assigned to either an MS group (n=38) or a non-MS group (n=157). Fatty acid composition of erythrocytes was determined by gas liquid chromatography.

RESULTS

Erythrocytes from the MS group had a significantly higher level of C24:0 than cells from the non-MS group (4.06±0.48% versus 3.88±0.34%; p=0.03). C24:0 levels were significantly correlated with several components of MS. The C24:0 levels showed a significant negative correlation with LDL and HDL particle size. Multivariate linear regression analysis showed that C24:0 levels were independently correlated with LDL particle size after adjusting for age and each MS criterion. C24:0 levels were also positively correlated with log-transformed high-sensitivity CRP levels (p=0.04).

CONCLUSION

C24:0 levels in erythrocytes are associated with specific atherogenic lipoprotein profiles and inflammation status in subjects with MS.

Effects of trans fatty acids on glucose homeostasis: a meta-analysis of randomized, placebo-controlled clinical trials

BACKGROUND

Although evidence from cohort studies has suggested that trans fatty acid (TFA) consumption may be associated with insulin resistance and diabetes, randomized placebo-controlled trials (RCTs) have yielded conflicting results.

OBJECTIVE

In a meta-analysis, we combined all available RCTs that examined the role of TFA intake on glucose homeostasis.

DESIGN

A systematic review of PubMed was performed, and a total of 7 RCTs were included in the meta-analysis. Primary outcomes were glucose and insulin concentrations. Secondary outcomes were total, LDL-, and HDL-cholesterol and triglyceride concentrations. The pooled effect size (ES) was calculated through fixed- and random-effects meta-analyses. The potential existence of publication bias was evaluated by using funnel-plot analysis. Metaregression analysis was performed to evaluate for potential dose-response relations between the ES of outcomes and TFA intake.

RESULTS

Increased TFA intake did not result in significant changes in glucose or insulin concentrations. Increased TFA intake led to a significant increase in total and LDL-cholesterol [ES (95% CI): 0.28 (0.04, 0.51) and 0.36 (0.13, 0.60), respectively] and a significant decrease in HDL-cholesterol concentrations [ES (95% CI): -0.25 (-0.48, -0.01)]. Our analysis also showed the absence of publication bias and any dose-response relations between the ES and TFA intake.

CONCLUSIONS

Increased TFA intake does not result in changes in glucose, insulin, or triglyceride concentrations but leads to an increase in total and LDL-cholesterol and a decrease in HDL-cholesterol concentrations. There is no evidence to support a potential benefit of the reduction of dietary TFA intake on glucose homeostasis.

Trans fat involvement in cardiovascular disease

Coronary heart disease is becoming a worldwide epidemic and diet and lifestyle are well known contributing factors. Identifying the kinds of foods that may have a cardioprotective or cardiotoxic effect and understanding their molecular mechanisms of action has become of increasing importance. Through largely epidemiological evidence, trans fatty acid (TFA) intake has been associated with a variety of cardiovascular complications including atherosclerosis. Traditionally, industrial TFAs (iTFAs) have been associated with these deleterious cardiovascular effects. However, there is a current body of research that suggests that ruminant trans fats (rTFAs) may have a cardioprotective role within the heart. The molecular mechanisms whereby TFAs are delivering their effects are largely unknown. In the following review, we discuss recent in vitro, animal and epidemiological research to better understand the effect of TFAs in the diet on cardiovascular disease, particularly atherosclerosis.

Ruminant-produced trans-fatty acids raise plasma total and small HDL particle concentrations in male Hartley guinea pigs

Although trans-fatty acid (tFA) intake has been positively associated with coronary heart disease (CHD), the relative effect of consuming industrially produced (IP)- compared with ruminant-produced (RP)-tFA on CHD risk factors is unclear. This study was designed to examine the effects of feeding partially hydrogenated vegetable oil (PHVO), IP-tFA source, and butter oil (BO), RP-tFA source, on the development of atherosclerosis and risk factors associated with CHD. Forty-eight male Hartley guinea pigs were fed a hypercholesterolemic diet containing (9% by weight) PHVO, BO, coconut oil (CO; positive control), or soybean oil (SO; negative control) for 8 or 12 wk (n = 6/group). Morphological analysis revealed that none of the groups developed atherosclerosis. Plasma and hepatic lipids did not differ between the tFA groups, but total and small HDL particles were significantly higher in the BO group than in the PHVO group and mean HDL particle size was significantly smaller in the BO group than in the PHVO group. Compared with the other treatment groups, the SO treatment resulted in significantly lower total cholesterol (TC) and LDL cholesterol in plasma, whereas hepatic TC was significantly higher in the SO group than in the other treatment groups. Plasma and hepatic cholesterol concentrations did not differ between the tFA and CO treatments. These results demonstrate that when fed at a high dose, IP- and RP-tFA had the same effect on established CHD risk factors in male Hartley guinea pigs. The effects of RP-tFA on HDL particle sizes and concentrations warrant further investigation.

Food sources of individual plasma phospholipid trans fatty acid isomers: the Cardiovascular Health Study

BACKGROUND

The overall consumption of trans fatty acids (TFAs) increases the risk of coronary artery disease. However, multiple TFA isomers exist, each with potentially different health effects. Different food sources of these specific TFA isomers are not well established.

OBJECTIVE

Our objective was to determine the major independent food sources of specific TFA isomers.

DESIGN

We investigated relations of major potential food sources of TFAs, as assessed by serial food-frequency questionnaires, with 10 plasma phospholipid TFA isomers [5 trans (t-) 18:1, 3 t-18:2, and 2 t-16:1] in 3330 older adults in the Cardiovascular Health Study, a community-based multicenter cohort. Stepwise regression was used to identify independent major food sources of individual plasma phospholipid TFA isomers, which were adjusted for demographic, lifestyle, and dietary factors.

RESULTS

All 5 t-18:1 isomers were similarly associated with foods commonly made with partially hydrogenated vegetable oils (PHVOs), including biscuits (0.51 higher SD of total 18:1 fatty acid concentrations per serving/d, P < 0.01), chips and/or popcorn (0.33 higher SD per serving/d, P = 0.02), margarine (0.32 higher SD per serving/d, P < 0.001), fried foods (0.32 higher SD per serving/d, P = 0.04), and bakery foods (0.23 higher SD per serving/d, P = 0.02). Each of the t-18:2 isomers were associated only with bakery foods (0.50 higher SD of total 18:2 fatty acid concentrations per serving/d, P < 0.001). Ruminant foods were major correlates of t-16:1n-7, including red meats (0.72 higher SD per serving/d, P < 0.001), butter (0.43 higher SD per serving/d, P < 0.001), and higher-fat dairy (0.37 higher SD per serving/d, P < 0.001). In contrast, t-16:1n-9 were derived mainly from margarine (0.31 higher SD per serving/d, P < 0.001).

CONCLUSIONS

t-18:1 Isomers are similarly derived from multiple PHVO-containing foods. In contrast, t-18:2 and t-16:1n-9 isomers are derived from more-specific types of PHVO-containing foods. Ruminant foods are major sources of t-16:1n-7. Different TFA isomers and dietary sources should be considered when investigating health effects and interventions to lower TFAs.

Soy constituents: modes of action in low-density lipoprotein management

Reviewed here are the modes of action of soy components used as ingredients in foods, which can lower plasma levels of low-density lipoprotein (LDL) and cholesterol, which are markers for the risk for atherosclerosis. Soy ingredients act via more than one mode of action including the following: LDL absorption suppression, cholesterol efflux stimulation, LDL resorption stimulation, LDL oxidation prevention, LDL particle size increase, cholesterol synthesis reduction, and bile secretion increase. Individual genetics, lifestyle, and nutrition habits alter LDL management and a better understanding of the various modes of actions of soy ingredients may facilitate the composition of effective ingredient cocktails. The optimization of food components offers further alternatives to LDL management to augment drug therapy for patients who are unable to reach their target LDL cholesterol levels or who are suffering from side effects or drug insensitivity.

Trans fatty acids: effects on metabolic syndrome, heart disease and diabetes

The major dietary sources of trans fatty acids (TFAs) in most countries are partially hydrogenated vegetable oils. TFA consumption is a modifiable dietary risk factor for metabolic syndrome, diabetes mellitus, and coronary heart disease. Here, we review the available data on various effects of TFAs, including metabolic and signaling pathways that mediate these effects, affected tissues, and relationships with clinical end points. TFA consumption causes metabolic dysfunction: it adversely affects circulating lipid levels, triggers systemic inflammation, induces endothelial dysfunction, and, according to some studies, increases visceral adiposity, body weight, and insulin resistance. Dietary TFAs influence the function of multiple cell types, including hepatocytes, adipocytes, macrophages and endothelial cells. Among dietary fats and nutrients, TFAs seem to have a unique cardiometabolic imprint that is linked to insulin-resistance and metabolic-syndrome pathways. Consistent with these adverse physiological effects, consumption of even small amounts of TFAs (2% of total energy intake) is consistently associated with a markedly increased incidence of coronary heart disease. Relationships between TFA consumption and diabetes mellitus have been less consistent, possibly owing to differences in study designs. Nevertheless, the documented adverse effects of TFAs underscore their potential to cause harm and the importance of policy measures to minimize consumption of industrially produced TFAs.

Association between trans-fatty acids in erythrocytes and pro-atherogenic lipid profiles among Canadian Inuit of Nunavik: possible influences of sex and age

Dietary exposure to trans-fatty acids (TFA) is likely to be high among Canadian Inuit; yet no data are available on the physiological effects of TFA in this population. The purpose of the present study was to assess the association between TFA and plasma lipid profiles in Inuit men and women living in Nunavik (Québec, Canada). In a cross-sectional, population-based survey, a total of 795 Nunavik Inuit eligible participants gave a blood sample. Exposure to TFA was assessed by their relative proportion in erythrocyte membrane. We performed multiple regression analysis using plasma lipids or their linear combinations as the dependent variables and TFA as the main predictor, adjusting for potential confounders. The associations varied markedly between the sexes and according to age. In men (n 357, aged 36.3 (sd 14.3) years, TFA 1.24 (sd 0.54) %), TFA tended to be negatively associated with HDL-cholesterol (HDL-C), apoA1 and LDL particle size, and positively associated with non-HDL-C, LDL-cholesterol (LDL-C), apoB100, the apoB100:apoA1 ratio and the ratios of total cholesterol (TC), LDL-C and TAG to HDL-C. No such trends were observed in women (n 438, aged 37.0 (sd 14.1) years, TFA 1.16 (sd 0.54) %), except for HDL-C and apoA1 in women aged 50 years and more. These results suggest that TFA could raise the risk of CHD in Inuit men at least through their physiological effects on plasma lipids. The differential associations reported in pre- and postmenopausal women need to be reproduced in other populations and in experimental studies addressing the influence of sex hormones in response to dietary fats.