Consumption Of Rapeseed Oil Research Articles

Development of Oil Industry in Poland in the Context of the European Union

Oil industry is developing well in Poland. This study aimed to examine the development of the Polish oil industry after joining the European Union. The following questions were asked: What were the changes in the consumption of vegetable oils in Poland after EU enlargement in 2004? How did the production of vegetable oil change in Poland after EU enlargement in 2004? And has the liquidity of the Polish oil industry changed after EU enlargement in 2004? First, the changes in the oil industry were evaluated. This research proved the development of the fat industry. We used the regression model to analyze the impact of chosen factors on the economic situation of the oil industry in Poland. Rapeseed is the main source of oil for the edible oil and biodiesel industry. High prices of rapeseed increased the sown area of rapeseed. The production of crude rapeseed oil changed from 520.1 thousand tons in 2005 to 1440 thousand tons in 2023. Biofuels made from rapeseed oils are called first generation. Poland’s production of refined rapeseed oil changed from 386.5 thousand tons in 2005 to 541 thousand tons in 2023. These numbers confirm the development of edible oil and biofuel production. The gross profit increased from PLN 133 mln in 2005 to PLN 443.8 mln in 2023. The net profit of the fat industry increased from PLN 110 mln in 2005 to PLN 381.6 mln in 2023. The oil industry is characterized by high investment, which reached the level of PLN 232.9 mln in 2023. The investment rate in 2023 was PLN 1.96 %. The changes observed in the rapeseed market after Poland joined the EU affected the performance of vegetable oil and biofuel producers. The regression analysis proved the hypothesis that the monthly consumption of rapeseed oil is the main factor influencing the oil industry situation in Poland. The oil industry is important to the development of the whole economy. Particular attention should be paid to current liquidity, which is why a constant supply of money from sold oil and biodiesel is needed to cover costs.

MOF-derived nanozyme CuOx@C and its application for cascade colorimetric detection of phytosterols.

Phytosterols (PSs), a class of naturally occurring bioactive lipid compounds, have been found to possess a significant cholesterol-lowering effect. In developing countries, the consumption of rapeseed oil is the primary pathway of PS intake for the general population. However, developing low-cost, real-time, and high-throughput screening techniques for PSs remains a challenge. Here, a Cu-based nanocomposite CuOx@C was synthesized via a simple method of the calcination of HKUST-1 and systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The CuOx@C demonstrated excellent peroxidase-like (POD-like) activity, functioning as a peroxidase mimic to facilitate the catalysis of 3,3',5,5'-tetramethylbenzidine (TMB) into its oxidized form (oxTMB), thereby initiating a discernible color response. On the basis of this discovery, a CuOx@C-based colorimetric method for detecting total sterols in rapeseed was successfully constructed via cascade reactions. After optimizing the conditions, the high-throughput screening of total sterols in rapeseed could be completed in only 21min, which significantly facilitated the sensing of PSs. A linear range of 0.6-6mg/g was achieved for the detection of total sterols in rapeseed samples, thereby satisfying the requirements for detection. In addition, due to the high stability of CuOx@C and the specificity of cholesterol oxidase, the developed method had excellent stability and selectivity toward PSs, indicating that this work has huge prospects for commercial application. This innovative work overcomes the limitation of the instrumental method and provides a portable and reliable tool for total sterols detection. It can also facilitate the development of oilseeds with a high content of PSs.

The effects of replacing ghee with rapeseed oil on liver steatosis and enzymes, lipid profile, insulin resistance and anthropometric measurements in patients with non-alcoholic fatty liver disease: a randomised controlled clinical trial.

Non-alcoholic fatty liver disease (NAFLD), which is a prevalent hepatic condition worldwide, is expected to develop into the leading reason for end-stage fatty liver in the forthcoming decades. Incorporating rapeseed oil into a balanced diet may be beneficial in improving NAFLD. The goal of this trial was to evaluate the impact of substituting ghee with rapeseed oil on primary outcomes such as fatty liver and liver enzymes, as well as on secondary outcomes including glycaemic variables, lipid profile and anthropometric measurements in individuals with NAFLD. Over 12 weeks, 110 patients (seventy men and forty women; BMI (mean) 28·2 (sd 1·6 kg/m2); mean age 42 (sd 9·6) years), who daily consumed ghee, were assigned to the intervention or control group through random allocation. The intervention group was advised to substitute ghee with rapeseed oil in the same amount. The control group continued the consumption of ghee and was instructed to adhere to a healthy diet. Results showed a significant reduction in the steatosis in the intervention group in comparison with the control group (P < 0·001). However, a significant change in the levels of alanine aminotransferase (–14·4 μg/l), γ-glutamyl transferase (–1·8 μg/l), TAG (–39·7 mg/dl), total cholesterol (–17·2 mg/dl), LDL (–7·5 mg/dl), fasting blood glucose (–7·5 mg/dl), insulin (–3·05 mU/l), Homeostatic Model Assessment for Insulin Resistance (–0·9), Quantitative Insulin-Sensitivity Check Index (+0·01), weight (–4·3 kg), BMI (–0·04 kg/m2), waist (–5·6 cm) and waist:height ratio (–0·04) was seen in the intervention group. The consumption of rapeseed oil instead of ghee caused improvements in liver steatosis and enzymes, glycaemic variables and anthropometric measurements among individuals with NAFLD.

Does Climate Change Affect Rapeseed Production in Exporting and Importing Countries? Evidence from Market Dynamics Syntheses

Globally, non-cereal crops such as vegetable oils and their associated products will surpass cereals in demand by 2050, according to the World Bank (WB). Despite being considered an energy-efficient food crop, the production and supply capability of rapeseed is mostly influenced by climate conditions. Aiming in this context, the study explored how temperature and rainfall patterns influence rapeseed production, as well as how rapeseed prices in major trading countries may influence production and consumption patterns in developing countries. To do this, a supply and demand model approach has been employed for major exporting (Canada) and importing countries, i.e., China, the United States (U.S.) along with Bangladesh, a developing nation. The baseline study period was considered from 1991 to 2018, and simulations were performed up to 2040. The findings revealed that the most important effect on rapeseed yield is directly related to changes in temperature, which are positively related to the growing season but negatively related to the maturity stages of rapeseed in all studied countries. Rapeseed exports from Canada are expected to rise by 2040, while imports from China and the U.S. will rise simultaneously. In Canada, the per capita consumption of rapeseed oil is expected to increase from 16 to 24 kg per year between 2019 and 2040. Over the projection period, oil per capita consumption has steadily increased in China, the U.S., and Bangladesh. The relative demand for rapeseed oil is projected to increase by 2060, according to representative concentration pathways (RCPs). Therefore, it is necessary to determine market prices considering the probable climatic effect and increasing market demand for rapeseed to sustain the international market access of trading nations.

Fragrant rapeseed oil consumption prevents blood cholesterol accumulation via promoting fecal bile excretion and reducing oxidative stress in high cholesterol diet fed rats

• Long-term effect of three rapeseed oils fed in hypercholesterolemic rats was tested. • Fragrant rapeseed oils lowered plasma cholesterol and boosted fecal bile acid efflux. • Fragrant rapeseed oils altered liver redox status and increased EPA and DHA output. • Such beneficial impact probably owed to high α-linolenic acid and polyphenols levels. We investigated the compositional changes and effects of long-term supplementation on blood lipids in three rapeseed oils [refined (RO), roasted at 120 °C (FO-120) and roasted at 150 °C (FO-150)]. Sixty Sprague-Dawley rats were fed either a basal diet or one of five high-cholesterol diets comprising lard, lard with cholestyramine, or three rapeseed oils for 12 weeks. Results showed that FO-120 and FO-150 alleviated plasma total cholesterol and increased fecal bile acid excretion, but RO had no significant effect. In the liver, cholesterol synthesis and conversion mRNA expression were altered by FO-120 or FO-150 feeding, like the inhibition of Hmgcr and activation of Cyp7a1 . Furthermore, FO-120 or FO-150 increased hepatic eicosapentaenoic and docosahexaenoic acid production and favorably improved hepatic redox status. Overall, the hypocholesterolemic effects may be attributed to their high levels of α-linolenic acid and polyphenols, linked closely to regulating cholesterol metabolism, promoting highly-unsaturated fatty acids synthesis, and reducing oxidative stress.

Trends in agri-food choices for health since the 1960s: the case of fatty acids

The FA composition of our diet affects human health: SFAs and n-6 PUFAs in excess are a risk factor for a number of chronic diseases, while n-3 PUFAs have a protective role. These FAs should be considered together, since an excessively high n-6:n-3 ratio is linked to a strong pro-inflammatory effect. We reconstructed the FA composition of the French diet from the 1960s to the present to identify the main reasons for decreases or increases due to agriculture, food processing or food choices. From the 1960s to the late 1990s, the diet increased in SFA and n-6 PUFA levels and likely decreased in n-3 PUFA level. Consequently, food behaviors did not follow dietary recommendations. For SFAs, this was due to the sharp increase in cheese and, to a smaller extent, palm oil consumption. For n-6 PUFAs, it was due to the sharp increase in oil consumption, especially linoleic sunflower oil. For n-3 PUFAs, this was due mainly to replacement of grass by maize and soybean meal to feed ruminants. This trend has reversed since the 2000s: the SFA level decreased due to decreased consumption of palm oil and genetic improvements in pigs and poultry, n-6 PUFA level decreased due to increased consumption of oleic instead of linoleic sunflower oil, and n-3 PUFA level increased due to increased consumption of rapeseed oil. These changes are consistent with the FA composition observed in breast milk. Despite these improvements, however, the average dietary composition remains far from the recommendations, especially for n-3 PUFAs. We show the potential for improvement by supplementing animal feed with flaxseed and increasing consumption of oleic sunflower and rapeseed oils, at the expense of that of other oils.

A mind cleared by walnut oil: The effects of polyunsaturated and saturated fat on extinction learning

The treatment of anxiety-based psychopathology often hinges upon extinction learning. Research in nutritional neuroscience has observed that the regular consumption of perilla oil (50% alpha-linolenic acid (ALA)) facilitates extinction learning in rats (Yamamoto et al., 1988). However, acute facilitation of extinction learning by oils rich in ALA has not been reported for rats or humans, though the acute consumption of rapeseed oil (10% ALA) has been observed to improve cognitive processing speed in humans (Jones, Sünram-Lea, & Wesnes, 2012). For this reason, the present laboratory work examined the effects of adding walnut oil (12% ALA) to a chocolate milkshake on the acquisition, generalization, and extinction of a fear-based prediction in young adults. It compared performance between subjects. The other participants consumed a similar milkshake with either an equicaloric amount of cream (saturated fat), or with no added fat (control). Acquisition and generalization of the fear-based prediction were similar for all groups. However, those who consumed walnut oil extinguished most rapidly and profoundly. Implications for extinction learning are discussed.

Fish and rapeseed oil consumption in infants and mothers: dietary habits and determinants in a nationwide sample in Germany.

Fish and rapeseed oil are major sources of omega-3 polyunsaturated fatty acids (n-3 PUFA) in complementary food, but little is known about current consumption in Germany. We conducted a nationwide consumer survey to assess the consumption habits of fish and rapeseed oil and their determining factors in 985 mother-child dyads in Germany. One-fourth of infants ate fish as often as recommended, i.e. at least once per week. Half of the mothers stated that they mainly used rapeseed oil for self-prepared and/or commercial vegetable-potato-meat meals. In contrast, mothers more frequently met recommendations for fish consumption (41%), but used rapeseed oil (34%) less often for their own nutrition. Maternal eating behaviour was the most important predictor for both of these n-3 PUFA rich foods in infants' nutrition. In contrast to infants' fish consumption, rapeseed oil intake in infancy was found to be influenced by some further factors, i.e. mothers' social class and omega-3 knowledge, which were also key determinants of mothers' own fish and rapeseed oil consumption. To promote fish with complementary feeding, programs should focus on families whose mothers rarely eat fish. Nutritional campaigns to improve omega-3 knowledge-especially focusing on lower social classes-could be effective in increasing rapeseed oil consumption, although these programs should be combined with environmental improvements as it has been already started through the use of rapeseed oil in commercial baby jars.

Influence of Non-Oxidised and Oxidised Rapeseed Oil Consumption on Liver Metabolism Pathways and Non-Alcoholic Steatohepatitis Development in Rabbits

Abstract For 24 weeks, rabbits were fed feed containing non-oxidised or oxidised rapeseed oil. At the beginning of the experiment and every six weeks the rabbits were weighed and blood was taken. After the experiment was completed, their liver was dissected for biochemical and histological examinations. The activity of alanine aminotransferase, aspartate aminotrasferase, glutamate dehydrogenase, sorbitol dehydrogenase, and aldolase in blood plasma and liver were determined. Enzymes of the protein and liver metabolic pathways were determined using kinetic and spectrophotometric methods. The content of fatty acids was determined by means of fatty acid methyl ester concentration measurement using gas chromatography. It was found that the applied diet with oxidised rapeseed oil caused the development of slight liver steatosis and disturbances in the activity of enzymes involved in the liver pathways, despite the fact that it was a balanced diet, and differed only in the ratio of saturated to unsaturated fatty acids. The obtained results indicate that more profound oil oxidation and its increased supply in diet may result in the development of liver steatosis.

Potential implication of aniline derivatives in the Toxic Oil Syndrome (TOS)

The Toxic Oil Syndrome (TOS) was an epidemic disease appeared in central Spain in 1981, causing over 400 deaths and affecting more than 20,000 people, mainly women and children. The disease was linked to the consumption of rapeseed oil denatured with aniline, illegally refined at the ITH oil refinery in Seville, mixed with other oils and sold as edible olive oil. Among the aniline derivatives detected in the oil batches generated by an uncontrolled deodorisation procedure during the refining process, fatty acid anilides were first postulated as the causal agents. Nevertheless, compounds identified as 3-( N-phenylamino)propane-1,2-diol (PAP) and its mono-, di-, and triacyl derivatives (mPAP, dPAP and tPAP, respectively), were subsequently considered better biomarkers of toxic oils and the best candidates for causing the intoxication. In this account, we will discuss the results obtained in recent years by our group concerning: (a) The effect of different variables intervening in the deodorisation process that could influence the formation of PAP derivatives. To this end we decided to take the aniline derivatives linked to oleic acid as compound models since this is the fatty acid present in highest amounts in rapeseed oil. The study was focused on the influence of different parameters on the formation of the diester PAP derivative (OOPAP) the monoester derivative (OPAP) and the corresponding amide (oleanilide, OA), and the interactions between any two of these variables. Of particular interest was the interaction observed between OOPAP and OA, due to its potential relevance to the final composition of the toxic oil model. (b) Xenobiochemical aspects of PAP derivatives, specifically: the stereospecific hydrolysis of OPAP and OOPAP by human pancreatic lipase, the in vitro activation of PAP by human and rat liver microsomes as well as by recombinant 450 enzymes, and the formation and stability of GSH and N-acetylcysteine adducts of a highly reactive iminoquinone intermediate generated in the biotransformation of PAP.

Continuous biodiesel production in a cascade of flow ideally stirred reactors

The continuous methanolysis of rapeseed oil catalyzed by KOH in a cascade of 4 flow stirred reactors at a steady state of 60 °C was studied. By comparing of the determined steady state concentrations of rapeseed oil, biodiesel and KOH in the reactors (under various initial concentrations of these components and feeding) with the assumed kinetic model the rate constants of the relevant differential rate equations for rapeseed oil consumption and biodiesel production were calculated.

The use of emulsification technologies to enhance rapeseed oil consumption during industrial Streptomyces rimosus fed-batch fermentations

The use of emulsification technologies to enhance rapeseed oil consumption during industrial Streptomyces rimosus fed-batch fermentations

The Use of Emulsification Technologies to Enhance Rapeseed Oil Consumption During Industrial Streptomyces rimosus Fed-batch Fermentations

Phase inversion temperature (PIT) and self-emulsification (SE) technologies were used to produce novel forms of oil feed for fed-batch fermentations. These novel forms were supplied with the aim of improving both oil utilisation and product titre whilst reducing fermentation broth viscosity. The study involved industrial Streptomyces rimosus fermentations fed with rapeseed oil (RSO) for the production of oxytetracycline. In all cases, oil utilisation increased when compared to the control process. Additionally, a very significant decrease (∼50%) in the final concentration of residual oil was also achieved when either the PIT or self-emulsifying technologies were used. Further, a significant decrease (∼75%) in the culture broth viscosity was also measured when using the self-emulsifying method. It was concluded that the measurable increase in the utilization of oil was due to the formation of smaller and more stable oil droplets when using such technologies and/or the lower broth viscosity, which increased the mass transfer from the complex fermentation medium to the cells. In all cases, the final oxytetracycline concentration and time of attenuation was not significantly different for any of the fermentation processes.

Induction of c-fos messenger RNA by 3-( N-phenylamino)-1,2-propanediol esters, compounds related to Toxic Oil Syndrome

The Toxic Oil Syndrome (TOS) was a toxic epidemic disease, related to the consumption of rapeseed oil denatured with aniline that affected more than 20,000 people in Spain and resulted in more than 330 deaths after its sudden appearance in 1981. It has been reported that the fatty acid esters of 3-( N-phenylamino)-1,2-propanediol (PAP) have shown a strong association with TOS. These PAP-esters could be absorbed and metabolized in a similar way than phospholipids. This is of interest because some products of phospholipid metabolism are important mediators in downstream pathways involved in the regulation of different nuclear factors. In particular, phospholipase D activity is involved in the activation of c-fos. Thus, we have investigated the effect of different PAP-esters in the induction of c-fos in lung fibroblasts. Results indicate that PAP-esters rapidly induced the expression of c-fos in a dose–dependent manner. In addition, both butanol and propranolol prevent this induction pointing to the involvement of phospholipase D in this activation. These results suggest that deregulation of some nuclear factors such as AP-1 could be involved in the pathogenesis of TOS.

Neurologic outcomes of toxic oil syndrome patients 18 years after the epidemic.

Toxic oil syndrome (TOS) resulted from consumption of rapeseed oil denatured with 2% aniline and affected more than 20,000 persons. Eighteen years after the epidemic, many patients continue to report neurologic symptoms that are difficult to evaluate using conventional techniques. We conducted an epidemiologic study to determine whether an exposure to toxic oil 18 years ago was associated with current adverse neurobehavioral effects. We studied a case group of 80 adults exposed to toxic oil 18 years ago and a referent group of 79 adult age- and sex-frequency-matched unexposed subjects. We interviewed subjects for demographics, health status, exposures to neurotoxicants, and responses to the Kaufman Brief Intelligence Test (K-BIT), Programa Integrado de Exploracion Neuropsicologica (PIEN), and Goldberg depression questionnaires and administered quantitative neurobehavioral and neurophysiologic tests by computer or trained nurses. The groups did not differ with respect to educational background or other critical variables. We examined associations between case and referent groups and the neurobehavioral and neurophysiologic outcomes of interest. Decreased distal strength of the dominant and nondominant hands and increased vibrotactile thresholds of the fingers and toes were significantly associated with exposure to toxic oil. Finger tapping, simple reaction time latency, sequence B latency, symbol digit latency, and auditory digit span were also significantly associated with exposure. Case subjects also had statistically significantly more neuropsychologic symptoms compared with referents. Using quantitative neurologic tests, we found significant adverse central and peripheral neurologic effects in a group of TOS patients 18 years after exposure to toxic oil when compared with a nonexposed referent group. These effects were not documented by standard clinical examination and were found more frequently in women.

Rendimiento diagnóstico de la indicación de ecocardiografía en el seguimiento de los pacientes con «síndrome del aceite tóxico»

Toxic oil syndrome is an epidemic, multisystemic disease that appeared in Spain in 1981, and was caused by the consumption of rapeseed oil denatured with 2% aniline. The disease is similar to eosinophilia-myalgia syndrome. One of the cardiovascular disorders caused by this syndrome is pulmonary hypertension. We conducted a study to assess the validity of our indications for echocardiography in the follow-up of cardiovascular disorders in patients with this disease. These patients are followed at our center with a standardized protocol for annual check-ups. From December 1997 through July 2002, a total of 1993 patients were examined. In this period we performed a total of 487 echocardiographic studies in 424 patients. The clinical records were reviewed to assess the indications for echocardiography according to the most recent guidelines for the clinical application of echocardiography of the American College of Cardiology and American Heart Association, and the indications were grouped into several categories. The diagnosis was recorded from the cardiologist's reports at the hospital where echocardiography was done. We calculated the sensitivity, specificity and positive likelihood ratio. 67% of the echocardiographic examinations were indicated to investigate possible pulmonary hypertension. About one-tenth of the studies (476 studies, 9.9%) led to a diagnosis of pulmonary hypertension. Sensitivity was highest (83%) for suspected pulmonary hypertension. Specificity was very high for most of the other indications. This study does not allow us to draw general conclusions about the cardiovascular disorders associated with toxic oil syndrome. However, echocardiography appears to be a good follow-up technique to diagnose complications such as pulmonary hypertension in these patients.

Absorption and effects of 3-(N-phenylamino)-1,2-propanediol esters in relation to toxic oil syndrome.

Toxic Oil Syndrome (TOS) was an epidemic disease related to the consumption of rapeseed oil denatured with aniline that made its sudden appearance in Spain in 1981. The fatty acid esters of 3-(N-phenylamino)-1,2-propanediol (PAP), which is a chemical class of by-products resulting from the reaction of aniline with oil components, have shown a strong association with TOS-related oils. These compounds also show some structural similarities to platelet-activating factor (PAF). In search of a toxic agent that could explain the widespread systemic effects observed in TOS patients, we investigated the intestinal absorption and biotransformation of the different PAP esters found in TOS-related oil samples and the possible pathophysiological effect of these mediators and their metabolic products if acting as PAF analogs. Results indicate that PAP esters are absorbed in the gastrointestinal tract and are distributed and stored in different organs, particularly in the liver and brown adipose tissue. PAP in these organs showed different patterns of fatty acids, indicating the ability of the gastrointestinal tract to modify the fatty acid composition of the parent PAP. Thus, the fatty acid profile of the PAP esters found in intestine appears to be related to the type of oil used as vehicle. Some of these PAP esters, when a long acyl chain was present in the sn-1 position of the molecule, showed an inhibitory effect on the PAF synthesis. This is an important observation in line with the systemic nature of the disease.

Production and consumption of rapeseed oil on a global scale

European Journal of Lipid Science and TechnologyVolume 103, Issue 7 p. 447-449 Production and Consumtion Production and consumption of rapeseed oil on a global scale Frank D. Gunstone, Corresponding Author Frank D. Gunstone [email protected] The Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland. Phone: +44-1382-562-731, Fax: +44-1382-562-516The Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland. Phone: +44-1382-562-731, Fax: +44-1382-562-516Search for more papers by this author Frank D. Gunstone, Corresponding Author Frank D. Gunstone [email protected] The Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland. Phone: +44-1382-562-731, Fax: +44-1382-562-516The Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland. Phone: +44-1382-562-731, Fax: +44-1382-562-516Search for more papers by this author First published: 12 July 2001 https://doi.org/10.1002/1438-9312(200107)103:7<447::AID-EJLT447>3.0.CO;2-QCitations: 24 The figures cited in this paper have been taken from the publications of Oil World (ISTA Mielke GmbH, Hamburg, Germany) and particularly Oil World 2020 (published 1999) and Oil World Annual 2000 (published 2000). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume103, Issue7July 2001Pages 447-449 RelatedInformation

Production and consumption of rapeseed oil on a global scale

Production and consumption of rapeseed oil on a global scale

Dietary trans α-linolenic acid does not inhibit Δ5- and Δ6-desaturation of linoleic acid in man

Dietary trans monoenes have been associated with an increased risk of heart disease in some studies and this has caused much concern. Trans polyenes are also present in the diet, for example, trans α-linolenic acid is formed during the deodorisation of α-linolenic acid-rich oils such as rapeseed oil. One would expect the intake of trans α-linolenic acid to be on the increase since the consumption of rapeseed oil in the western diet is increasing. There are no data on trans α-linolenic acid consumption and its effects. We therefore carried out a comprehensive study to examine whether trans isomers of this polyunsaturated fatty acid increased the risk of coronary heart disease. Since inhibition of Δ6-desaturase had also been linked to heart disease, the effect of trans α-linolenic acid on the conversion of [U-13C]-labelled linoleic acid to dihomo-γ-linolenic and arachidonic acid was studied in 7 healthy men recruited from the staff and students of the University of Edinburgh. Thirty percent of the habitual fat was replaced using a trans ‘free’- or ‘high’ trans α-linolenic acid fat. After at least 6 weeks on the experimental diets, the men received 3-oleyl, 1,2-[U-13C]-linoleyl glycerol (15 mg twice daily for ten days). The fatty acid composition of plasma phospholipids and the incorporation of 13C-label into n-6 fatty acids were determined at day 8, 9 and 10 and after a 6-week washout period by gas chromatography-combustion-isotope ratio mass spectrometry. Trans α-linolenic acid of plasma phospholipids increased from 0.04 ? 0.01 to 0.17 ? 0.02 and cis ? -linolenic acid decreased from 0.42 ? 0.07 to 0.29 ? 0.08 g/100 g of fatty acids on the high trans diet. The composition of the other plasma phospholipid fatty acids did not change. The enrichment of phosphatidyl 13C-linoleic acid reached a plateau at day 10 and the average of the last 3 days did not differ between the low and high trans period. Both dihomo-γ-linolenic and arachidonic acid in phospholipids were enriched in 13C, both in absolute and relative terms (with respect to 13C-linoleic acid). The enrichment was slightly and significantly higher during the high trans period (P<0.05). Our data suggest that a diet rich in trans α-linolenic acid (0.6% of energy) does not inhibit the conversion of linoleic acid to dihomo-γ-linolenic and arachidonic acid in healthy middle-aged men consuming a diet rich in linoleic acid.