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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 [+ or - ]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. European Journal of Clinical Nutrition (2010) 64, 752-759; doi: 10.1038/ejcn.2010.73; published online 19 May 2010 Keywords: human nutrition; lipids; trans fatty acids; milk fat; cardiovascular risk factors; cholesterol, Introduction Over 2 million people in European Union are dying from cardiovascular disease (CVD) every year (European Heart Network, 2008). The subsequent cost is estimated to 192 billion per year [...]

Objective: To collect (i) baseline data and (ii) execute a large multicentre study examining the effect of trans alpha-linolenic acid on its incorporation into plasma lipids and on risk factors for coronary heart disease., Design: Male volunteers were recruited and the habitual diet assessed by a 4-d weighed record. Fatty acid composition of plasma and platelet lipids were determined by gas chromatography at baseline. After a 6 week run-in period on a trans 'free' diet, male volunteers were randomised to consume 0.6 % of energy trans alpha-linolenic acid or to continue with a diet 'low' in trans alpha-linolenic acid for 6 weeks., Setting: Three European university research departments supported by the research and development departments of the food industry., Subjects: Male volunteers (88) recruited by local advertisement., Methods: Replacement of 30 % of the fat of the habitual diet by margarine, oil and foods. Rapeseed oil was deodorised especially to produce the trans 'free' and 'high' trans foods for this study. The incorporation and conversion of trans alpha-linolenic acid into plasma lipids and platelets was assessed by gas chromatography and dietary compliance was verified by 4-d weighed record., Results: Less trans alpha-linolenic acid isomers are incorporated into human plasma lipids in French volunteers than in Dutch or Scottish volunteers consuming their habitual diets. Trans 'free' alpha-linolenic acid-rich oil can be produced by careful deodorization during refining. The 'high' trans diet provided 1410+/-42 mg/d trans isomers of alpha-linolenic acid, whilst the 'low' trans group consumed 60+/-75 mg/d. The change in plasma lipid and platelet fatty acid composition documented that trans linolenic isomers are incorporated and converted to a trans isomer of eicosapentaenoic acid. Only the 15-trans alpha-linolenic acid is incorporated into plasma cholesteryl esters. The group consuming low trans diet had a slightly higher intake of fat, especially saturated and monounsaturated fat., Conclusions: Trans 'free' rapeseed oil, rich in alpha-linolenic acid, can be produced by careful deodorization. Dietary records show good compliance. Dietary trans isomers of alpha-linolenic acid are incorporated in plasma lipids and converted to long-chain polyunsaturated fatty acids. Their effects on risk factors for coronary heart disease and their metabolism will be reported elsewhere., Sponsorship: European Commission (FAIR 95-0594 grant). European Journal of Clinical Nutrition (2000) 54, 104-113

Objective: The aim of the present study was to identify the trans isomers of C18 fatty acids in some human milk samples., Subjects: Ten human milk samples from French women were collected in a local milk bank in order to assess their trans mono and polyunsaturated fatty acids (PUFA) content., Intervention: The fatty acid profile was examined using methyl and isopropyl ester derivatives. The combination of gas-liquid chromatography, high-performance liquid chromatography and silver nitrate thin-layer chromatography was needed to describe the detailed fatty acid compositions, including the trans isomers of unsaturated C18 fatty acids., Results: All the samples contained trans isomers of C18:1 acid (mean level 1.9 +/- 0.2% of total fatty acids), with trans vaccenic acid being the major isomer. The samples also contained various isomers of linoleic and alpha-linolenic acid, but at lower levels. Trans isomers of PUFA are the same as those present in deodorised or deep-fried oils. One sample presented an abnormally high degree of isomerisation of alpha-linolenic acid (almost 50%). This was related to the dietary habit or consuming foods that were deep-fried in rapeseed oil. This milk sample also contained some cyclic fatty acid monomers., Conclusion: The human milk samples collected in this study contained some trans fatty acids, including isomers of essential fatty acids. This should be taken into account in the dietary intake of the newborn.