Fatty acid composition of Greek margarines and their change in fatty acid content over the past decades

Thirty-one brands of margarines from the Greek market were analyzed for their fatty acid composition including trans-fatty acids by gas chromatography. Trans fatty acids (TFAs) were found within the range of 0.16-0.97% of total fat content, with no sample found to have TFA in a concentration more than 1% of the total fat content. Increased levels of either saturated or cis-unsaturated was observed in each brand. Saturated, cis-monounsaturated and cis-polyunsaturated were found in the ranges of 11.26-51.75%, 22.98-60.37% and 12.09-56.30% of total fat content respectively, with mean values of 30.81 ± 10.40%, 34.41 ± 10.46% and 34.28 ± 14.02% of total fat. The chemical analysis of Greek margarines over the past decades has indicated that the TFA content of Greek margarines has declined over the past 20 years by approximately 95%.     

Fatty acid composition of Greek margarines and their change in fatty acid content over the past decades

Thirty-one brands of margarines from the Greek market were analyzed for their fatty acid composition including trans-fatty acids by gas chromatography. Trans fatty acids (TFAs) were found within the range of 0.16–0.97% of total fat content, with no sample found to have TFA in a concentration more than 1% of the total fat content. Increased levels of either saturated or cis-unsaturated was observed in each brand. Saturated, cis-monounsaturated and cis-polyunsaturated were found in the ranges of 11.26–51.75%, 22.98–60.37% and 12.09–56.30% of total fat content respectively, with mean values of 30.81 ± 10.40%, 34.41 ± 10.46% and 34.28 ± 14.02% of total fat. The chemical analysis of Greek margarines over the past decades has indicated that the TFA content of Greek margarines has declined over the past 20 years by approximately 95%.     

Fatty acids and CHD

During the last century much evidence has accumulated to suggest that from a public health perspective the type of fat is more important than the amount of fat. Saturated and trans-fatty acids increase and both n-6 and n-3 PUFA decrease the risk of CHD. Most of the knowledge about the effects of dietary fatty acids on CHD risk is based on observational studies and controlled dietary experiments with intermediate end points (e.g. blood lipoprotein fractions). Information from high-quality randomised controlled trials on fatty acids and CHD is lacking. The Netherlands Institute for Public Health has calculated the potential health gain that can be achieved if the fatty acid composition of the current Dutch diet is replaced by the recommended fatty acid composition. The recommendations of The Netherlands Health Council are: saturated fatty acids <10% energy intake; trans-fatty acids <1% energy intake; fish consumption (an indicator of n-3 PUFA) once or twice weekly. Implementation of this recommendation could reduce the incidence of CHD in The Netherlands by about 25,000/year and the number of CHD-related deaths by about 6000/year and increase life expectancy from age 40 years onwards by 0.5 year. These projections indicate the public health potential of interventions that modify the fatty acid composition of the diet.     

Fat composition of vegetable oil spreads and margarines in the USA in 2013: a national marketplace analysis

Worldwide, the fat composition of spreads and margarines (“spreads”) has significantly changed over the past decades. Data on fat composition of US spreads are limited and outdated. This paper compares the fat composition of spreads sold in 2013 to that sold in 2002 in the USA. The fat composition of 37 spreads representing >80% of the US market sales volume was determined by standard analytical methods. Sales volume weighted averages were calculated. In 2013, a 14?g serving of spread contained on average 7.1?g fat and 0.2?g trans-fatty acids and provided 22% and 15% of the daily amounts recommended for male adults in North America of omega-3 α-linolenic acid and omega-6 linoleic acid, respectively. Our analysis of the ingredient list on the food label showed that 86% of spreads did not contain partially hydrogenated vegetable oils (PHVO) in 2013. From 2002 to 2013, based on a 14?g serving, total fat and trans-fatty acid content of spreads decreased on average by 2.2?g and 1.5?g, respectively. In the same period, the overall fat composition improved as reflected by a decrease of solid fat (from 39% to 30% of total-fatty acids), and an increase of unsaturated fat (from 61% to 70% of total-fatty acids). The majority of US spreads no longer contains PHVO and can contribute to meeting dietary recommendations by providing unsaturated fat.     

Fatty acids composition of Greek margarines. Margarine consumption by the population of Crete and its relationship to adipose tissue analysis

Ten brands of margarines from the Greek market were analysed. The fatty acid (FA) composition was estimated by using gas liquid chromatography (GLC) with a capillary column. A sample of Cretan olive oil was used as a control. The brands of the same margarines were bought and analysed twice (June and October 1991) in order to observe differences between batches. During the second part of the study it was possible to distinguish between the cis and trans isomers of the unsaturated fatty acids. The ratios of polyunsaturated/saturated, monounsaturated/polyunsaturated and saturated/monounsaturated (P/S, M/P, S/M) fatty acids were calculated as well as the ω-6/ω-3 ratio. Four brands contained at least 40% saturated fatty acids. Trans double bonds were additionally regarded as simple bonds and the conventional ratios were recalculated. The amount of the 18:1 trans fatty acid ranged from 5.40 to 9.54% and that of cis-trans and trans-cis 18:2 fatty acids from 0.40 to 3.65%. The 18:2 trans-trans fatty acids ranged from 0 to 1.23%. Food consumption surveys in Crete showed that in selective population samples, margarine consumption was approximately 9 g/day for children and 2 g/day for adults. The analysis of fatty acids in adipose tissue of 70 Cretan lawyers showed 0.90 ± 0.25% (0.46–1.67) for 4 trans isomers of oleic acid and 0.14 ± 0.06% (0.05–0.31) and 0.04 ± 0.01% (0.02–0.06) for trans-cis and cis-trans isomers of linoleic acid respectively. Although margarine consumption in Crete is still low, trans fatty acids content is reflected in the adipose fatty acid composition. The industry must consider the potential health risks that consumption of such margarines will have on the population, and they must try to improve their products.     

Consumption of a solid fat rich in lauric acid results in a more favorable serum lipid profile in healthy men and women than consumption of a solid fat rich in trans-fatty acids

Solid fats are used in food manufacturing to provide texture and firmness to foods. Such fats are rich in either saturated or trans-fatty acids, both of which increase the risk of coronary heart disease. Epidemiological and experimental studies suggest that trans-fatty acids increase risk more than do saturates because they lower serum high density lipoprotein (HDL) cholesterol. However, there appear to be differences between saturates in their effect on HDL cholesterol. We investigated whether the consumption of a solid fat rich in lauric acid (C12:0) would result in a more favorable blood lipid profile than the consumption of a solid fat rich in trans-fatty acids. We fed 32 healthy men and women two controlled diets in a 2 x 4-wk randomized crossover design. The diets consisted of a background diet supplemented with margarines. In the trans-diet, 9.2% of energy was provided by trans-fatty acids and 12.9% by saturated fatty acids. In the Sat-diet, energy intake was 0% from trans-fatty acids and 22.9% from saturated fatty acids. Lauric acid composed one third of all saturates in the Sat-diet. Serum HDL cholesterol was 0.36 mmol/L lower at the end of the trans-diet than at the end of the Sat-diet (95% confidence interval, -0.46 to -0.26), whereas serum low density lipoprotein cholesterol and triglyceride concentrations remained stable. Serum total cholesterol was 0.31 mmol/L (95% confidence interval, -0.48 to -0.14) lower at the end of the trans-diet than at the end of the Sat-diet. Consumption of a solid fat rich in lauric acid gives a more favorable serum lipoprotein pattern than consumption of partially hydrogenated soybean oil rich in trans-fatty acids. Thus, solid fats rich in lauric acids, such as tropical fats, appear to be preferable to trans-fats in food manufacturing, where hard fats are indispensable.     

Dietary polyunsaturated fatty acid intake during late pregnancy affects fatty acid composition of mature breast milk

ObjectiveThe aim of this study was to investigate how maternal polyunsaturated fatty acid intake at different periods during pregnancy affects the composition of polyunsaturated fatty acids in mature human milk.MethodsA prospective study was conducted involving 45 pregnant women, aged between 18 and 35 y, who had full-term pregnancies and practiced exclusive or predominant breast-feeding. Mature breast milk samples were collected after the 5th postpartum week by manual expression; fatty acid composition was determined by gas chromatography. Fatty acid intake during pregnancy and puerperium was estimated through multiple 24-h dietary recalls. Linear regression models, adjusted by postpartum body mass index and deattenuated, were used to determine associations between estimated fatty acids in maternal diet during each trimester of pregnancy and fatty acid content in mature human milk.ResultsA positive association was identified between maternal intake of eicosapentaenoic acid (β, 1.873; 95% confidence interval [CI], 0.545, 3.203) and docosahexaenoic acid (β, 0.464; 95% CI, 0.212–0.714) during the third trimester of pregnancy, as well as the maternal dietary ω-3 to ω-6 ratio (β, 0.093; 95% CI, 0.016–0.170) during the second and third trimesters and postpartum period, with these fatty acids content in mature breast milk.ConclusionsThe maternal dietary docosahexaenoic acid and eicosapentaenoic acid content during late pregnancy may affect the fatty acid composition of mature breast milk. Additionally, the maternal dietary intake of ω-3 to ω-6 fatty acid ratio, during late pregnancy and the postpartum period, can affect the polyunsaturated fatty acid composition of breast milk.     

Trends in the trans-fatty acid composition of the diet in a metropolitan area: the Minnesota Heart Survey

OBJECTIVE: In this study, we examine trends in dietary intake of trans-fatty acids from 1980-1982 to 1995-1997 using data collected as part of the Minnesota Heart Survey (MHS). DESIGN: The MHS is an ongoing observational epidemiologic study among independent cross-sectional probability samples of adults. Twenty-four-hour dietary recalls were collected on a subset of participants. To obtain trans-fatty acid intake estimates, the dietary recall records were recalculated using the University of Minnesota Nutrition Coordinating Center Food and Nutrient Database. Subjects/setting The survey population included noninstitutionalized adults aged 25 to 74 years residing in the Minneapolis-St. Paul, MN, metropolitan area. Statistical analysis Mean intake estimates were generated for each survey, and a generalized linear mixed model was used to test the null hypothesis of no difference in the age-adjusted sex-specific means between 1980-1982, 1985-1987, 1990-1992, and 1995-1997. RESULTS: Downward trends in dietary intake of trans-fatty acids were found between 1980-1982 and 1995-1997. For example, for men mean intake of total trans-fatty acids declined from 8.3 g per day in 1980-1982 to 6.2 g per day in 1995-1997 (P<.001). Represented as a percentage of energy, similar declines were seen with mean intake of total trans-fatty acids decreasing from 3.0% of total energy in 1980-1982 to 2.2% of total energy in 1995-1997 (P<.001). APPLICATIONS/CONCLUSIONS: It seems that intake of trans-fatty acids is on the decline. Consideration should be given to additional changes in the food supply and consumer food choices that may result in further reduction in consumption of trans-fatty acids.     

Nonhydrogenated cottonseed oil can be used as a deep fat frying medium to reduce trans-fatty acid content in french fries

OBJECTIVE: The purpose of this research study was to evaluate the fatty acid profile, in particular trans-fatty acids, of french fries fried in nonhydrogenated cottonseed oil as compared with french fries fried in partially hydrogenated canola oil and french fries fried in partially hydrogenated soybean oil. DESIGN: Cottonseed oil, partially hydrogenated canola oil, and partially hydrogenated soybean oil were subjected to a temperature of 177 degrees C for 8 hours per day, and six batches of french fries were fried per day for 5 consecutive days. French fries were weighed before frying, cooked for 5 minutes, allowed to drain, and reweighed. Oil was not replenished and was filtered once per day. Both the oil and the french fries were evaluated to determine fatty acid profiles, trans-fatty acids, and crude fat. STATISTICAL ANALYSIS: A randomized block design with split plot was used to analyze the data collected. Least-squares difference was used as the means separation test. RESULTS: No significant differences were found between fries prepared in the three oil types for crude fat. Fatty acid profiles for the french fries remained stable. The french fries prepared in cottonseed oil were significantly lower in trans-fatty acids. The combined total of the trans-fatty acid content and saturated fatty acid content were lower in french fries prepared in cottonseed oil. CONCLUSIONS: Because deep fat frying remains a popular cooking technique, health professionals should educate the public and the food service industry on the benefits of using nonhydrogenated cottonseed oil as an alternative to the commonly used hydrogenated oils.     

Fatty acid and sterol composition of frozen and freeze-dried New Zealand Green Lipped Mussel (Perna canaliculus) from three sites in New Zealand

In view of previously reported anti-inflammatory bioactivity of the New Zealand Green Lipped Mussel (NZGLM), the overall lipid profile and fatty acid and sterol composition of the NZGLM from various sites in New Zealand (Hallam Cove, Port Ligar. Little Nikau) were investigated using thin layer chromatography (TLC) and gas liquid chromatography (GLC). Samples were either frozen (F) or freeze-dried (FD) soon after collection. It was also thought prior to the study, there may be differences in the dietary sources of phytoplankton between the sites, responsible for the bioactivity, however data collected in New Zealand reported no difference in the type of phytoplankton, but a difference in the quantity. There were no major significant differences in the major components of the lipid, fatty acid and sterol composition between FD or frozen samples, nor were there any significant differences in the major composition between sites. The only major difference was between total lipid composition of the freeze-dried and frozen samples due to the removal of water during freeze-drying. Total lipid content on a dry weight basis in FD samples was 8.4 g/100 g tissue and was significantly higher than frozen samples (P < 0.05) and there was no significant site variation. The lipid class content between sites was also not significantly different as judged by TLC. Triglyceride (TG) lipid fraction appeared to be the most prominent in the frozen and FD samples. The free fatty acid (FFA) band was the next most prominent band and was visually more prominent in the frozen samples. Sterol esters (SE) were detected in higher amounts in the frozen samples compared with the FD samples. Phospholipid (PL) and sterols (ST) were distributed throughout all samples. Polyunsaturated fatty acids (PUFA) were the main group of fatty acids in both FD and frozen samples (45-46%), most of which were omega-3 (n-3) fatty acids (40-41%). Saturated fatty acids (SFA) accounted for approximately one quarter of total fatty acids, with little variation between FD and frozen samples. The major fatty acids of the NZGLM were docosahexaenoic acid (DHA: 22:6 n-3) (19% in both FD and frozen samples), eicosapentaenoic acid (EPA; 20:5 n-3) and palmitic acid (16:0) (15% in both FD and frozen samples). Cholesterol was the most prominent sterol (31% of total sterols). Other major sterols included desmosterol/brassicasterol (co-eluting), 24-methylenecholesterol, trans-22-dehydrocholesterol, 24-nordehydrocholesterol and occelasterol. This study is unique as it compares the lipid composition of the NZGLM from three sites in New Zealand with the additional effect of processing. This is the second comparative study investigating the lipid, fatty acid and sterol composition of the NZGLM with added interest in the effect of freeze-drying on the lipid content of the mussel. This study showed that there were no major significant differences in lipid, sterol and fatty acid composition between the FD and frozen samples of the NZGLM for three sites in New Zealand. Food chain studies and further research is warranted to investigate the presence and role of major and minor lipid components of the NZGLM.     

Polyunsaturated fatty acids and conjugated linoleic acid isomers in breast milk are associated with plasma non-esterified and erythrocyte membrane fatty acid composition in lactating women

Maternal adipose tissue is a major contributor to breast milk long-chain fatty acids, probably through the pool of plasma NEFA. The fatty acid composition of the erythrocyte membrane (EM) is a biochemical index of the intake of fatty acids not synthesized endogenously and of PUFA and long-chain PUFA fatty acid status. The present study investigated the associations between breast milk fatty acid composition and the composition of plasma NEFA and of EM fatty acids with special reference to PUFA, long-chain PUFA and conjugated linoleic acid (CLA). The detailed fatty acid composition of mature breast milk was also reported. Thirty-three healthy, lactating Brazilian women donated milk samples; of these, twenty-four also donated blood samples in an observational cross-sectional study. Breast milk fatty acid composition presented several associations with NEFA and EM composition, which explained most (> or =50 %) of the variability of selected milk PUFA, long-chain PUFA and CLA. Milk CLA was associated with fatty acids that are markers of dairy fat intake in the diet, NEFA and EM. In general, breast milk n-3 fatty acids and CLA, but not n-6 fatty acids, were associated with EM composition, whereas both the n-6 and n-3 fatty acids and CLA in milk were associated with NEFA composition, possibly owing to its role as a direct source of fatty acids for breast milk. These findings emphasize the contribution of the NEFA pool derived from the adipose tissue to the long-chain fatty acid composition of breast milk.     

中国市售桶装植物油脂肪酸的研究

目的对市售桶装植物油中脂肪酸进行分析,探讨其组分及含量特点。通过植物油中各类脂肪酸比例的特点,分析脂肪酸特征。方法从北京、云南、浙江、湖南、河南、哈尔滨、江苏、甘肃8个地区,选取市场普遍销售的或各地自产的品牌桶装植物油,共计8个品种,每个样品采集2个不同批号。对植物油脂进行皂化和甲酯化后,利用岛津GC2014气相色谱仪对样品进行气相色谱分析。结果市售桶装植物油主要以棕榈酸、油酸、亚油酸和α-亚麻酸为主,反式脂肪酸的平均含量为1.05g/100g。植物油的饱和脂肪酸∶单不饱和脂肪酸∶多不饱和脂肪酸的比值范围为1∶1.6～9.4∶0.9～7.4;多不饱和脂肪酸中n-6/n-3的比值范围为0.37～289.5∶1。结论市售桶装植物油反式脂肪酸含量低,但脂肪酸组成比例大多不符合中国营养学会提出的标准,并且多数缺乏n-3多不饱和脂肪酸。     

Dietary manipulation of the disappearance of trans-octadecenoates in rat tissues

The effects of dietary manipulations on the fate of trans-octadecenoates deposited in the tissues of rats were examined. Male rats were fed on a 15% fat diet containing trans-octadecenoic acids (46.6% of total fatty acids) for 35 days followed by various diets free of trans-fatty acids. After removal of trans-fatty acids from the diet, there were phased disappearances of trans-octadecenoates from the circulation; a rapid and broad reduction in one day and a slow and gradual reduction thereafter. The rate of the initial reduction in serum trans-octadecenoates was highest on a high fat (20%) diet in relation to low fat (1 or 5%) diets. However, the disappearance rate at the later stage was apparently the same among the various groups and trans-fatty acid contents in the serum declined to about 10% of the initial value in 2 weeks and thereafter. After 35 days, the concentration of trans-octadecenoates remaining in the adipose tissue was markedly lower in rats fed on a high protein (40%) diet. The effects of dietary fat type and cholesterol on the fate of serum trans-octadecenoates were virtually the same, but livers from rats fed on the cholesterol-free safflower oil diet contained more trans-fatty acids than those from rats fed on the corresponding olive oil diet. Thus, the amounts of trans-fatty acids stored in the tissues cannot be merely predicted from serum levels. It seems that both dietary fat and protein affect the metabolic rate of trans-octadecenoates in rats.     

Subcutaneous adipose-tissue fatty acids and vitamin E in humans: relation to diet and sampling site

The influence of diet and sampling site on subcutaneous adipose-tissue fatty acid composition and vitamin E content was examined in 20 healthy subjects. A dietary history and adipose-tissue biopsies from the buttock were obtained from 14 individuals. In another six individuals, samples were taken from both waist and buttock. The relative dietary intake of both polyunsaturated and saturated fatty acids correlated with the relative content in adipose tissue (r = 0.6, p = 0.02). Adipose-tissue vitamin E was strongly associated with dietary intake (r = 0.76, p = 0.004). The content of n - 3 (omega-3) fatty acids in adipose tissue was shown to influence adipose-tissue vitamin E negatively. Waist and buttock fat differed (p less than 0.05) with regard to fatty acid composition whereas no systematic variation was seen in the vitamin E content. The use of adipose-tissue biopsies in epidemiologic studies as measures of the habitual relative intake of fatty acids and vitamin E is suggested.     

The effect of storage on serum fatty acids]

To investigate the effect of storage on serum fatty acids, we examined the composition of serum fatty acids in samples from healthy men stored at different temperatures for various periods of time. The following experimental storage conditions were studied: 1) 4 degrees C for three weeks, 2) -20 degrees C for 12 months and 3) -80 degrees C for 24 months. The fatty acid composition did not change after two-week storage at 4 degrees C. At -20 degrees C, there was a decline in the content of docosapentaenoic acid (22: 5, omega 3) after one month, and docosahexaenoic acid (22: 6, omega 3) after three months. However, omega 3-polyunsaturated fatty acid as a whole did not show a significant change. At -80 degrees C, there was a decline of docosapentaenoic acid after three months, arachidonic acid (20: 4, omega 6) after 12 months, and linoleic acid (18: 2, omega 6) after 24 months. As a whole, omega 3-polyunsaturated fatty acids did not change. Omega 6-Polyunsaturated fatty acids significantly declined 5% after 24 months. Therefore, it is recommended that serum fatty acids be measured within two weeks at 4 degrees C, within a few months at -20 degrees C and within one year at -80 degrees C to estimate the composition of the major fatty acids.     

Fatty acid composition of sweet bakery goods and chocolate products and evaluation of overall nutritional quality in relation to the food label information

The study aimed to determine fatty acid (FA) composition of some sweet bakery goods and chocolate products on Turkey market (n = 35) and to evaluate their overall nutritional quality in relation with the nutritional facts on the label. Moreover,“trans fatty acid (TFA)-free” declaration on the label was checked with the current labelling regulations in Turkey. Majority of the sample groups represented the prevalence of palmitic and oleic acid; on the other hand, it was difficult to specify a sample group with a specific FA. Erucic acid, for which European Commission set maximum limits, was not detected in any of the samples. It was observed that total saturated fatty acids (SFA) constituted more than 44 % of total FA. In all cases, total TFA content was lower than 1 % of total FA. Based on nutritional facts on the label, that type of products provide higher energy with the main source of fat and carbohydrates. Therefore, consumption of those products in a diet should be limited not to gain an excess amount of body weight and to have adverse health effects related to higher SFA content. This study can be regarded as a case surveillance study by providing updated data that can be used by Nutritionals and authorities to make risk assessments on consumer health.     

Compositional Changes and Enrichment of Mediterranean Finfish During Pan Frying With Virgin Olive Oil

Eight species of small Mediterranean finfish were prepared and pan-fried in virgin olive oil, according to traditional Greek culinary practices. The changes in their proximate composition, energy content, fatty acids, squalene, cholesterol, β-sitosterol, campesterol, and stigmasterol were investigated. Pan-fried fish contained more protein, total fat, monounsaturated fatty acids, energy, and cholesterol and were enriched in squalene and phytosterols than the raw samples. The results suggest that fish pan-fried in olive oil can be classified as highly nutritive in regard to its protein, major fatty acid classes, n-6/n-3 ratios, and total fat content. It provides an additional intake of squalene and phytosterols for Mediterranean people.     

Compositional Changes and Enrichment of Mediterranean Finfish During Pan Frying With Virgin Olive Oil

Eight species of small Mediterranean finfish were prepared and pan-fried in virgin olive oil, according to traditional Greek culinary practices. The changes in their proximate composition, energy content, fatty acids, squalene, cholesterol, β-sitosterol, campesterol, and stigmasterol were investigated. Pan-fried fish contained more protein, total fat, monounsaturated fatty acids, energy, and cholesterol and were enriched in squalene and phytosterols than the raw samples. The results suggest that fish pan-fried in olive oil can be classified as highly nutritive in regard to its protein, major fatty acid classes, n-6/n-3 ratios, and total fat content. It provides an additional intake of squalene and phytosterols for Mediterranean people.     

德阳市市售食品中反式脂肪酸含量的调查及检测方法的改进

目的 对食品中反式脂肪酸的检测方法进行改进,以便了解德阳市市售食品中反式脂肪酸的含量,为进一步评估反式脂肪酸对德阳市市民健康的影响提供依据。方法 采用分层随机抽样的方法采集德阳市市售烘焙食品、巧克力及糖类、膨化食品、含油小吃、肉及肉制品和奶及奶制品等6类食品共112份样品,采用柱前衍生-气相色谱法对样品中的反式脂肪酸含量进行检测。结果 各种脂肪酸甲酯出峰良好,检出限为0.0065～0.0069 g/100 g,回收率为78.24%～90.10%,相对标准偏差（RSD%）为4.13%;反式脂肪酸含量最高的为烘焙食品（1.407 g/100 g）,其次为肉及肉制品（1.341 g/100 g）、巧克力及糖类（1.269 g/100 g）,最后是含油小吃（0.932 g/100 g）、膨化食品（0.691 g/100 g）和奶及奶制品（0.445 g/100 g）。结论 该方法缩短了检测时间,能够很好地完成食品中反式脂肪酸含量的检测。反式脂肪酸在食品中普遍存在,德阳市居民每日从食物中摄入的反式脂肪酸含量远低于WHO的建议限值（1%）。     

Site-specific differences in the fatty acid composition of abdominal adipose tissue in an obese population from a Mediterranean area: relation with dietary fatty acids, plasma lipid profile, serum insulin, and central obesity.

BACKGROUND: Abdominal obesity is associated with coronary risk, although causality is not well established. OBJECTIVE: In an obese Mediterranean population, we measured the fatty acid composition of adipose tissue, its relation with dietary fatty acids and central fat deposition, and its influence on plasma lipids and insulin. DESIGN: Adipose tissue samples were obtained from 84 obese patients (29 men, 55 women) aged 30-70 y (body mass index, in kg/m(2): 27-35). We measured concentrations of insulin and lipids in plasma and fatty acids in subcutaneous, omental, and perivisceral fat. Dietary fatty acid intake was assessed with a 7-d diet record. RESULTS: The population studied was normolipidemic and normoinsulinemic. There were important differences in fatty acid composition between tissue sites: saturated fatty acids were higher and monounsaturated fatty acids were lower in perivisceral than in subcutaneous fat (P < 0.05). Significant correlations were found for oleic, linoleic, alpha-linolenic, and total n-6 polyunsaturated fatty acids between the subject's habitual diet and adipose tissue composition. Oleic and n-3 fatty acids from adipose regions were negatively correlated with apolipoprotein B and triacylglycerols; adipose tissue 22:1n-9, 20:2n-6, stearic acid, and eicosapentaenoic acid were positively correlated with HDL and apolipoprotein A; and adipose tissue myristic acid was negatively correlated with apolipoprotein A (P < 0.05). Central obesity was positively associated with n-6 polyunsaturated fatty acids and inversely associated with monounsaturated fatty acids and n-3 polyunsaturated fatty acids in adipose tissue (P < 0.05). CONCLUSION: The differences found in the composition and metabolism of perivisceral, omental, and subcutaneous fats may indicate that their atherogenic capacities also differ.