Trans fatty acids and cardiovascular health: translation of the evidence base

Determination of factors associated with serum cholesterol response to dairy fat consumption in overweight adults: Secondary analysis from an RCT

Elevated intakes of saturated fatty acids (SFA) can adversely affect serum cholesterol levels. Dairy fat contains ~60% SFA, prompting healthy eating guidelines to recommend low-fat dairy. Physiological, and environmental factors influence inter-individual variance in response to food consumption. Evidence exploring the dairy matrix has differing effects of dairy fat consumption on serum cholesterol levels when consumed in the form of cheese. The extent of this variability and determinants of response to dairy fat are currently unknown. The objective of this study was to determine factors associated with lipid metabolism response to a dairy fat intervention, with a focus on serum cholesterol. A 6-week randomized parallel intervention trial was carried out in healthy volunteers (≥50 years, BMI ≥25 kg/m²). Participants (n = 104) consumed ~40 g dairy fat daily in addition to their usual diet, in 1 of 3 forms: butter, cheese, or reduced-fat cheese and butter. For this analysis, “response” was based on the percentage (%) change in serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) from pre- to post-intervention. Participants were divided into tertiles for each lipid response. The upper and lower tertiles were used to categorize participants as “responders” and “non-responders.” For TC and LDL-c, response was classified as a decrease, whereas “response” was defined as an increase for HDL-c. Clinical response was also considered, by calculating pre- and post-intervention prevalence of those meeting target levels of cholesterol recommendations. Participants demonstrating the largest % decrease (Tertile 1; “responders”) in TC had significantly higher levels of TC and HDL-c, at baseline, and lower levels of triglycerides (TAGs) compared to those in tertile 3 (i.e., TC non-responders). Those with the largest % decrease in LDL-c (Tertile 1: LDL-c responders) had higher baseline levels of LDL-c and lower levels of TAGs. Multiple regression analysis revealed that the % change in TC and LDL-c was associated with baseline TC, TAG, body weight and high-sensitivity C-reactive protein (hsCRP; P < 0.05). Previous work has demonstrated the dairy food matrix affects lipid response to dairy consumption. This study suggests that phenotypic differences may also influence response to dairy fat in overweight individuals.

Trans fatty acids in frequently consumed products from Serbian and Slovenian market

OBJECTIVES

Industrially produced trans fatty acid (iTFA) have adverse health effects and thus their consumption should be limited. The aim of this study was to determine and compare the iTFA content in frequently consumed food products by young adults from the Serbian and Slovenian market with supposedly elevated iTFA content in 2015. At the time of this study, there was no recommended limit of iTFA in both countries, and reduction of iTFA in foods was on voluntary basis.

METHODS

We determined iTFA content in food products, 19 from the Serbian and 22 from the Slovenian market, blinded and analysed in the same analytical run. Contents of fatty acids (FA) methyl esters were analysed by capillary gas chromatography with a flame ionisation detector. Heptadecanoic acid was used as internal standard. Individual FA along with TFA were expressed as percentages of total measured FA. The amount of each FA in the sample was then calculated from the response factor and the transformation factor of the FA from the FA methyl ester content.

RESULTS

Elaidic acid (C18:1t) was found as the most abundant TFA in analysed products, ranging from 0.52 g/100 g of total FA in chocolate candy up to 60.4 g/100 g in a salami from Serbian market. In Slovenian products, the values for elaidic acid were lower, 0.04-3.95 g/100 g of total FA, except in one type of wafers (24.3 g/100 g).

CONCLUSIONS

The majority of analysed products from the Serbian and three from Slovenian market exceeded the recommended WHO and EU limit of 2% iTFA of total fat in foods. Samples of frequently consumed salami, wafers, tea biscuits, and snacks were identified as products with potentially higher burden of iTFA in diets of young adults in Serbia.

Study of rapeseed oil gelation induced by commercial monoglycerides using a chemometric approach

Commercial oleogelators rich in monoglycerides (MGs) are complex mixtures of acylglycerides with variable gelling properties, depending on the oil used and their concentration. In this study we developed a chemometric approach to identify the key parameters involved in gelling process. Analytical parameters have been defined, using GC and NMR analysis to identify fatty acids and acylglycerides composing the mixtures. Specific acylglyceride families and compound ratios were calculated to streamline the analytical results. To determine the key analytical parameters, artificial neural networks were used in a QSPR study related to the gelling properties measured by rheology through oscillatory experiments. At low oleogelator concentrations, the MGs especially rich in C16:0 and the ratio of specific isomers both have a positive influence on G'. For high oleogelator concentrations, C18:0-rich acylglycerides and unsaturated/saturated fatty acid ratios have a positive influence on G'. Conversely, at low concentrations, C18:0-rich acylglycerides show a lesser effect on G'.

Engineered M13 Peptide Carrier Promotes Angiogenic Potential of Patient-Derived Human Cardiac Progenitor Cells and In Vivo Engraftment

BACKGROUND

Despite promising advances in stem cell-based therapy, the treatment of ischemic cardiovascular diseases remains a big challenge due to both the insufficient in vivo viability of transplanted cells and poor angiogenic potential of stem cells. The goal of this study was to develop therapeutic human cardiac progenitor cells (hCPCs) for ischemic cardiovascular diseases with a novel M13 peptide carrier.

METHOD

In this study, an engineered M13 peptide carrier was successfully generated using a QuikChange Kit. The cellular function of M13 peptide carrier-treated hCPCs was assessed using a tube formation assay and scratch wound healing assay. The in vivo engraftment and cell survival bioactivities of transplanted cells were demonstrated by immunohistochemistry after hCPC transplantation into a myocardial infarction animal model.

RESULTS

The engineered M13^RGD+SDKP peptide carrier, which expressed RGD peptide on PIII site and SDKP peptide on PVIII site, did not affect morphologic change and proliferation ability in hCPCs. In contrast, hCPCs treated with M13^RGD+SDKP showed enhanced angiogenic capacity, including tube formation and migration capacity. Moreover, transplanted hCPCs with M13^RGD+SDKP were engrafted into the ischemic region and promoted in vivo cell survival.

CONCLUSION

Our present data provides a promising protocol for CPC-based cell therapy via short-term cell priming of hCPCs with engineered M13^RGD+SDKP before cell transplantation for treatment of cardiovascular disease.

Health-Associated Nutrition and Exercise Behaviors in Relation to Metabolic Risk Factors Stratified by Body Mass Index

This study aimed to investigate the relationships of nutrition and exercise behaviors on metabolic risk factors (MRF) when body mass index (BMI) was considered. Health-associated nutrition and exercise behaviors were assessed by a questionnaire, anthropometric values, blood pressure and biochemical determinations that were obtained from 4017 workers. The nutrition score was negatively associated with triglycerides in the overweight subgroup and with systolic blood pressure (SBP) in the obese subgroup. The exercise score was negatively associated with triglycerides and waist circumference (WC) and positively associated with SBP and high-density lipoprotein cholesterol (HDL-C) in the ideal weight subgroup as well as being negatively associated with WC and positively associated with HDL-C in the overweight subgroup. Similarly, the exercise score was negatively associated with WC and positively associated with SBP in the obese subgroup. However, no significant association was found between nutrition or exercise behavior and MRF in the underweight subgroup. In conclusion, the relationships of exercise and nutrition behaviors on MRF varied for different levels of BMI. Exercise showed a significant association with lower WC. Moreover, its effect showed a gradient trend in accordance with the levels of BMI. For ameliorating MRF, exercise seemed to have better effects than nutrition behavior, especially in the ideal weight subgroup.

Citation bias in the literature on dietary trans fatty acids and serum cholesterol

OBJECTIVE

Balanced citations are a necessary condition for a sound development of scientific knowledge, whereas selective citations may bias scientific consensus. In this study, we assess which determinants influenced the likelihood of being cited in the literature on trans fatty acids and cholesterol.

STUDY DESIGN AND SETTING

We conducted a citation network analysis of the literature concerning trans fats and low density cholesterol and high density cholesterol. Each publication was scored on various potential determinants of citation, such as study outcome, study design, sample size, journal impact factor, and funding source. We applied random effect logistic regression to identify determinants of citation.

RESULTS

A network of 108 publications was identified, containing 5,041 potential citation paths and 669 utilized citation paths. Reporting statistically significant results was found to be a strong predictor of citation, together with sample size, journal impact factor, and the authority of the authors.

CONCLUSION

Within the literature on trans fat intake and cholesterol, selective citations are based on several grounds. Especially the effect of reporting significant results on citation requires special attention because disproportionate attention is paid to publications suggesting a harmful effect of trans fat on cholesterol.

9c11tCLA modulates 11t18:1 and 9t18:1 induced inflammations differently in human umbilical vein endothelial cells

Endothelial inflammation is recognized as the initial stage of a multistep process leading to coronary heart disease (CHD). Recently, the different effects of industrial trans fatty acids (elaidic acid, 9t18:1) and ruminant trans fatty acids (vaccenic acid, 11t18:1) on CHD have been reported in epidemiological and animal studies, however, the mechanism was not fully studied. Therefore, the objective of this study was to explore the underlying mechanism by which 9t18:1 and 11t18:1 affect human umbilical vein endothelial cells (HUVECs) inflammation. We found that 9c11t-CLA modulated the inflammation of HUVECs induced by 9t18:1 and 11t18:1. Fatty acid composition, pro-inflammatory factors, phosphorylation of MAPKs, and the TLR4 level in HUVECs altered by 11t18:1 induction, collectively suggest that the bio-conversion of 11t18:1 to 9c11tCLA might be the cause why 11t18:1 and 9t18:1 have distinct influences on endothelial injuries. It was concluded that it is biosynthesis of 9c11t CLA from11t18:1, and the modulation of TLR4-MAPK pathway by 9c11t CLA, which at least partially account for the slight effect of 11t18:1 on endothelial inflammation.

Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases

Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA), diabetes mellitus (DM), and cardiovascular disease (CVD). Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes) from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described.

Types of Obesity and Its Association with the Clustering of Cardiovascular Disease Risk Factors in Jilin Province of China

Cardiovascular disease (CVD) has become a serious public health problem in recent years in China. Aggregation of CVD risk factors in one individual increases the risk of CVD and the risk increases substantially with each additional risk factor. This study aims to explore the relationship between the number of clustered CVD risk factors and different types of obesity. A multistage stratified random cluster sampling design was used in this population-based cross-sectional study in 2012. Information was collected by face to face interviews. One-way analysis of variance (ANOVA), chi-square test, Kruskal-Wallis test and multiple logistic regression were used in this study. The prevalence of general obesity, central obesity and compound obesity were 0.3%, 36.1% and 14.7%, respectively. The prevalence of hypertension, hyperlipidemia and diabetes in the compound obesity group were higher than those in other groups (compound obesity > central obesity > general obesity > non-obesity), while smoking rate in the non-obesity group was higher than those in other groups (non-obesity > general obesity > central obesity > compound obesity). People with obesity were more likely to have one or more CVD risk factor compared with non-obesity subjects (general obesity (OR: 2.27, 95% CI: 1.13-4.56), central obesity (OR: 2.64, 95% CI: 2.41-2.89), compound obesity (OR: 5.09, 95% CI: 4.38-5.90). The results were similar when the number of clustered CVD risk factors was ≥ 2 and ≥ 3. As a conclusion, more than half of the residents in Jilin Province have a problem of obesity, especially central obesity. Government and health department should take measures to improve people's awareness of central obesity in Jilin Province of China. The prevalence of hypertension, hyperlipidemia and diabetes are associated with obesity types. Compound obesity has a greater risk to cluster multiple CVD risk factors than central obesity and general obesity. Taking measures to control obesity will reduce the prevalence of CVD in Jilin Province.

Trans fatty acids in the Portuguese food market

Consistent evidence exist on the harmful health effects of industrial trans fatty acids (TFA). In order to have accurate data on TFA intake and implement adequate measures to reduce their intake, each country should have updated estimates of TFA content in the diet. The objective of the present study was to provide data on the TFA content in food commercialized in the Portuguese market. The results on the TFA content of 268 samples acquired between October and December 2013 are reported. Samples were categorized as margarines and shortenings (n = 16), spreadable chocolate fats (n = 6), fried potatoes and chips (n = 25), industrial bakery (n = 4), breakfast cereals (n = 3), pastry products (n = 120), seasonings (n = 5), instant soups (n = 5), instant desserts (n = 6), chocolate snacks (n = 4), microwave popcorn (n = 4), cookies, biscuits and wafers (n = 53), and fast-food (n = 13), with butter (n = 4) included for comparison purposes. TFA were quantified by gas chromatography. Total TFA content in the fat ranged from 0.06% to 30.2% (average 1.9%), with the highest average values in the “biscuits, wafers and cookies” group (3.4% TFA), followed by the pastry group (2.0%). Fifty samples (19%) had TFA superior to 2% in the fat. These findings highlight there is still much need for improvement in terms of the TFA content in Portuguese foods, particularly in traditional pastry.

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Trans fatty acids content in Portuguese food is updated.

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Most food categories have very low TFA contents.

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Some fats used in local pastry have high TFA contents.

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Inaccurate fat designations might induce incorrect choices.

Are Chinese edible oils safe? A survey of trans fatty acid contents in Chinese edible oils

Nine different edible oil types from 7 cities in China were analyzed. Trans fatty acid (TFA) contents in edible oils were determined, TFA distribution characteristics were analyzed, and a risk assessment was performed. Total TFA contents varied from 0.075±0.011 to 2.243±0.770 g/100 g of oil, with a mean content of 0.66 g/100 g of oil. TFA contents differed among different oil types and among different cities. Generally speaking, oil samples from northern areas of China contained more TFA, and lard usually had higher levels of TFA than other oils. An exposure assessment showed that the estimated daily intake of TFA from Chinese edible oils was low, and a risk assessment indicated that there was a low risk for TFA consumption in Chinese edible oils.

Consumption Safety of Pastries, Confectioneries, and Potato Products as Related to Fat Content

STUDY AIM

To determine the content of the main groups of fatty acids in pastries, confectionery, and potato products, paying special attention to trans fatty acids and the products of fat oxidation and hydrolysis, as factors affecting the safety of consumption.

METHODS

A total of 157 products were collected in Poland in 2009-2010. In fats extracted from samples, products of oxidation and hydrolysis were assayed using peroxide (PV), anisidine (AnV), and acid (AV) values. The fatty acid (FA) composition, especially the trans FAs (TFAs) content, was determined by gas chromatography. When assessing the TFA intake, Household Budget Surveys were considered.

RESULTS

Highest content of fat was found for wafers with filling and crisps (32.3% and 29.3%, respectively). In 4 out of 9 groups of pastry and confectionery products studied, the quality of fat was decreased due to an excessive oxidation, as evidenced by a substantial content of secondary products of fat oxidation. The extracted fat was rich in SFA (on average, 50 g SFA/100 g FA) except fries and mixes. A great diversity of TFA content in fat of the products was found (0.1-24.8 g TFA/100 g FA). Wafers were characterized by the highest average content of TFA in the group of pastries (1.94 g TFA/100 g of product). Products of natural origin supplied 0.496 g of TFA per day, and those of industrial origin supplied about 1.5 g.

CONCLUSIONS

The average TFA consumption, about 2 g/day, does not seem to affect health. However, an excessive consumption of pastry and confectionery products may present a risk, due not only to TFA but also to a high consumption of toxic secondary oxidation lipid products. Moreover, because 75% of TFAs in the diet were isomers of industrial origin, their further limitation and monitoring of their level in food seems highly recommendable.

Consumption of ultra-processed foods and their impact on the diet of young adults

OBJECTIVE To evaluate the consumption of ultra-processed foods, its associated factors, and its influence on nutrient intake in young adults. METHODS In 2004-2005, the individuals belonging to the Pelotas birth cohort of 1982 were identified for a home interview. A total of 4,297 individuals were interviewed and 4,202 individuals were included in the study (follow-up rate of 77.4%). Diet was assessed using a questionnaire on dietary intake and the percentage of daily caloric intake attributed to ultra-processed foods as well as the intake of macro- and micronutrients were estimated. The association between cohort characteristics and the consumption of ultra-processed foods was assessed using linear regression. Analysis of variance and Pearson's Chi-square test were used to evaluate the association between the quintiles of the consumption of ultra-processed food, nutrient intake and adequacy of nutrient intake, respectively. RESULTS The consumption of ultra-processed foods corresponded to 51.2% of the total caloric intake. The consumption of ultra-processed foods was higher among women, individuals with higher education, and individuals who were never poor and eutrophic. The increased consumption of ultra-processed foods was positively correlated with the consumption of fat, cholesterol, sodium, iron, calcium, and calories (p < 0.001) and was negatively correlated with the consumption of carbohydrates, protein, and dietary fiber (p < 0.001). CONCLUSIONS The high consumption of ultra-processed foods and its positive correlation with the intake of sodium, cholesterol, and fats underscores the need to perform interventions aimed at decreasing the intake of this food group.

Home-schooled children are thinner, leaner, and report better diets relative to traditionally schooled children

OBJECTIVE

To examine and compare the relationships among diet, physical activity, and adiposity between home-schooled children (HSC) and traditionally schooled children (TSC).

DESIGN AND METHODS

Subjects were HSC (n = 47) and TSC (n = 48) aged 7-12 years old. Dietary intakes were determined via two 24-h recalls and physical activity was assessed with 7 days of accelerometry. Fat mass (FM), trunk fat, and percent body fat (%BF) were measured by dual-energy X-ray absorptiometry (DXA).

RESULTS

Relative to HSC, TSC demonstrated significantly higher BMI percentiles, FM, trunk fat, and %BF; consumed 120 total kilocalories more per day; and reported increased intakes of trans fats, total sugar, added sugars, calcium, and lower intakes of fiber, fruits, and vegetables (P < 0.05). At lunch, TSC consumed significantly more calories, sugar, sodium, potassium, and calcium compared to HSC (P < 0.05). Physical activity did not differ between groups. Traditional schooling was associated with increased consumption of trans fat, sugar, calcium (P < 0.05); lower intakes of fiber, and fruits and vegetables (P < 0.05); and higher FM, %BF, and trunk fat (P < 0.01), after adjustment for covariates.

CONCLUSIONS

These data suggest HSC may consume diets that differ in energy and nutrient density relative to TSC, potentially contributing to differences in weight and adiposity.

Fatty acids as biocompounds: their role in human metabolism, health and disease--a review. Part 1: classification, dietary sources and biological functions

BACKGROUND

Fatty acids are substantial components of lipids and cell membranes in the form of phospholipids. This review consists of two parts. The present part aims at describing fatty acid classification, dietary sources and biological functions. The second part will focus on fatty acid physiological roles and applications in human health and disease.

RESULTS

In humans, not all fatty acids can be produced endogenously due to the absence of certain desaturases. Thus, specific fatty acids termed essential (linoleic, alpha-linolenic) need to be taken from the diet. Other fatty acids whose synthesis depends on essential fatty acid intake include eicosapentaenoic acid and docosahexaenoic acid, found in oily fish. Dietary sources of saturated fatty acids are animal products (butter, lard) and tropical plant oils (coconut, palm), whereas sources of unsaturated fatty acids are vegetable oils (such as olive, sunflower, and soybean oils) and marine products (algae and fish oils). Saturated fatty acids have been related to adverse health effects, whereas unsaturated fatty acids, especially monounsaturated and n-3 polyunsaturated, are thought to be protective. In addition, trans fatty acids have been shown to have negative effects on health, whereas conjugated fatty acids might be beneficial. Lastly, fatty acids are the main components of lipid classes (triacylglycerols, phospholipids, cholesteryl esters, non-esterified fatty acids).

CONCLUSION

Fatty acids are important biocompounds which take part in complex metabolic pathways, thus having major biological roles. They are obtained from various dietary sources which determine the type of fat consumed and consequently health outcome.

Drugs and lifestyle for the treatment and prevention of coronary artery disease: comparative analysis of the scientific basis

In this article, we compare two strategies for atherosclerosis treatment: drugs and healthy lifestyle. Statins are the principal drugs used for the treatment of atherosclerosis. Several secondary prevention studies have demonstrated that statins can significantly reduce cardiovascular events including coronary death, the need for surgical revascularization, stroke, total mortality, as well as fatal and non-fatal myocardial infarction. These results were observed in both men and women, the elderly, smokers and non-smokers, diabetics and hypertensives. Primary prevention studies yielded similar results, although total mortality was not affected. Statins also induce atheroma regression and do not cause cancer. However, many unresolved issues remain, such as partial risk reduction, costs, several potential side effects, and long-term use by young patients. Statins act mainly as lipid-lowering drugs but pleiotropic actions are also present. Healthy lifestyle, on the other hand, is effective and inexpensive and has no harmful effects. Five items are associated with lower cardiac risk: non-smoking, BMI ≤25, regular exercise (30 min/day), healthy diet (fruits, vegetables, low-saturated fat, and 5-30 g alcohol/day). Nevertheless, there are difficulties in implementing these measures both at the individual and population levels. Changes in behavior require multidisciplinary care, including medical, nutritional, and psychological counseling. Participation of the entire society is required for such implementation, i.e., universities, schools, media, government, and medical societies. Although these efforts represent a major challenge, such a task must be faced in order to halt the atherosclerosis epidemic that threatens the world.

Ruminant and industrial sources of trans-fat and cardiovascular and diabetic diseases

The various positional isomers of oleic acid (18 : 1Δ9c or 9c-18 : 1) may have distinct biological effects. Detrimental effects of consumption of industrial trans-fatty acids (TFA) (elaidic acid; 18 : 1Δ9t) from partially hydrogenated vegetable oils on CVD risk factors are well documented. In addition, epidemiological data suggest that chronic consumption of industrial sources of TFA could alter insulin sensitivity and predispose for type 2 diabetes. However, intervention studies on this issue have remained inconclusive. Moreover, very little information is available on the effect of natural sources of TFA (vaccenic acid; 18 : 1Δ11t) coming from dairy products and ruminant meat on the development of CVD and type 2 diabetes. The review focuses on the impact of the consumption of ruminant TFA in relation to cardiovascular risk factors, inflammation and type 2 diabetes.

Does adherence to the Mediterranean diet have a protective effect against active and passive smoking?

OBJECTIVE

To investigate the existing evidence about whether adherence to the Mediterranean diet may have a role as an effect modifier of active and passive smoking on human health.

STUDY DESIGN

Review.

METHODS

An overview of emerging evidence and published studies that cover the interaction between the Mediterranean diet and smoking.

RESULTS

Both epidemiological and laboratory studies have shown that the Mediterranean diet has a protective effect against biochemical and molecular processes that lead to cancer, cardiovascular disease and respiratory illness. Based on the high daily intake of vitamins and antioxidants, the Mediterranean diet is comprised of a number of compounds that could alter certain outcomes related to smoking. Studies have indicated that certain diseases attributable to smoking, such as lung cancer, asthma and cardiovascular disease, are inversely associated with certain antioxidants and lipids.

CONCLUSIONS

The literature indicates that the existence of a partial interaction between adherence to the Mediterranean diet and the health effects of smoking is possible. Further research is needed to lead to a conclusive statement on this hypothesis.

Differential impact of milk fatty acid profiles on cardiovascular risk biomarkers in healthy men and women

BACKGROUND/OBJECTIVES

The objective of this study was to evaluate the impact of three specific ruminant (R) milk fats resulting from modification of the cow's diet on cardiovascular risk factors in healthy volunteers. R-milk fats were characterized by increased content in total trans fatty acids (R-TFAs) and parallel decrease in saturated fatty acids (SFAs).

SUBJECTS/METHODS

A total of 111 healthy, normolipemic men and women have been recruited for a monocentric, randomized, double-blind and parallel intervention, 4-week controlled study. Volunteers consumed three experimental products (butter, dessert cream and cookies) made with one of the three specific milk fats (55 g fat per day). During the first week (run-in period), the subjects consumed on a daily basis dairy products containing 72% SFA/2.85% R-TFA (called 'L0'). For the next 3 weeks of the study (intervention period), the first group continued to consume L0 products. The second group received dairy products containing 63.3% SFA/4.06% R-TFA (called 'L4'), and the third group received dairy products containing 56.6% SFA/12.16% R-TFA (called 'L9').

RESULTS

Plasma concentrations of high-density lipoprotein (HDL)-cholesterol were not significantly altered by either diet (P=0.38). Compared to L0 diet, L4 diet contributed to reduce low-density lipoprotein (LDL)-cholesterol (-0.14+/-0.38 mmol/l, P=0.04), total cholesterol (-0.13+/-0.50 mmol/l, P=0.04), LDL-cholesterol/HDL-cholesterol (-0.14+/-0.36, P=0.03) and total cholesterol/HDL-cholesterol (-0.18+/-0.44, P=0.02).

CONCLUSIONS

Different milk fat profiles can change cardiovascular plasma parameters in human healthy volunteers. A limited increase of the R-TFA/SFA ratio in dairy products is associated with an improvement in some cardiovascular risk factors. However, a further increase in R-TFA/SFA ratio has no additional benefit.

Dietary intake of trans fatty acids as a cardiovascular risk factor in a population of Italian teenagers

Trans fatty acids are unsaturated fatty acids produced by the partial hydrogenation of polyunsaturated oils. Over the last few years, an increasing interest on these fatty acids has been shown because of their role in the pathogenesis of cardiovascular diseases. To date, major scientific associations strongly recommend consuming a low intake of trans fatty acids for the prevention of cardiovascular diseases, but data on the consumption of these fatty acids in the general population are still lacking. We conducted this observational study on a population of Italian teenagers in order to evaluate the consumption of trans fatty acids in the diet. We studied 81 Italian teenagers, 45 males and 36 females, with a median age of 16 years. To assess their consumption of trans fatty acids, we used the "High School Survey", a questionnaire prepared by the Harvard Medical School. Total calories of the studied population were 2359.2 +/- 591.5 kcal/day with a mean intake of trans fatty acids of 3.24 +/- 1.48 g/day, corresponding to 1.23% of the total energy. A relevant proportion of subjects, namely 51 (62.9%), exceeded the limit contribution of 1% of energy from trans fatty acids. Their intake of total calories and trans fatty acids significantly increased according to their increasing age (p = 0.0003 for trend). Our data, therefore, obtained in a limited population of Italian adolescents, showed that a consistent proportion of adolescents does not follow the nutritional recommendations for intake of trans fatty acids, likely increasing their risk of cardiovascular diseases.

Creating a fatty acid methyl ester database for lipid profiling in a single drop of human blood using high resolution capillary gas chromatography and mass spectrometry

Capillary gas chromatography (CGC) in combination with mass spectrometry (MS) was optimized for the separation and detection of the fatty acids occurring in the lipid fraction of blood. A fingertip blood sample (ca. 50 microL) was transesterified into the methyl esters and analyzed on a 100 m x 0.25 mm ID column coated with a biscyanopropyl polysiloxane (HP-88) stationary phase. The method was retention time locked. Programmed temperature vaporization injection (PTV) in the solvent venting mode was applied to minimize the sample size, while maintaining high sensitivity. The total analysis time was ca. 60 min. Retention times and both electron impact (EI) and positive chemical ionization (PCI) mass spectrometry were combined to elucidate the fatty acids according to alkyl chain, degree of unsaturation and position of the double bonds. Using extracted ion chromatograms about 100 fatty acids and related compounds were detected in blood samples and most of them were identified. This work resulted in a very large fatty acid methyl esters database, containing retention time and mass spectral information that will be applied to metabolomic studies.