Rationale and design of the TRANSFACT project phase I: a study to assess the effect of the two different dietary sources of trans fatty acids on cardiovascular risk factors in humans.
BACKGROUND
Detrimental effects of consumption of industrial trans fatty acids (TFA) from partially hydrogenated vegetable oils (PHVO) on cardiovascular disease (CVD) risk factors are well documented. However, very little information is available on the effect of natural sources of TFA coming from milk fat, dairy products and ruminant meat. In fact, due to the naturally low level of TFA in milk fat, it is almost impossible to conduct a clinical trial with a limited number of subjects (<200).


METHODS
To compare the effects of industrial and natural dietary sources of TFA, two specific test fats have been designed and produced. A substantial amount of milk fat (130 kg) enriched in TFA has been produced by modification of the cow's diet and selection of cows with the highest TFA content. The level obtained was approximately 4- to 7-fold higher than typically present in milk fat (approximately 20 instead of 3-6 g/100 g of total fatty acids). The control fat is composed of PHVO balanced in saturated fatty acids (lauric, myristic and palmitic). Both experimental fats contain about 20-22% of monounsaturated TFA and the volunteers' daily experimental fat intake (54 g), will represent about 12.0 g/day of TFA or 5.4% of the daily energy (based on 2000 kcal/day). These two test fats have been incorporated into food items and will be provided to 46 healthy subjects under a randomised, double blind, controlled, cross-over design. The primary outcome is high-density lipoprotein cholesterol (HDL-C), which is an independent risk factor for CVD. Other parameters such as low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and HDL-C level and subclasses will be also to be evaluated.


CONCLUSIONS
We have shown that it is technically feasible to perform a clinical trial on the comparative effects of natural and industrial sources of TFA isomers on CVD risk factors. Results are expected by mid-2006.
Chardigny
Jean-Michel
JM
INRA-Université d'Auvergne, Clermont-Ferrand, France.
Malpuech-Brugère
Corinne
C
Dionisi
Fabiola
F
Bauman
Dale E
DE
German
Bruce
B
Mensink
Ronald P
RP
Combe
Nicole
N
Chaumont
Patrice
P
Barbano
David M
DM
Enjalbert
Francis
F
Bezelgues
Jean-Baptiste
JB
Cristiani
Isabelle
I
Moulin
Julie
J
Boirie
Yves
Y
Golay
Pierre-Alain
PA
Giuffrida
Francesca
F
Sébédio
Jean-Louis
JL
Destaillats
Frédéric
F
D000328:Adult; D002318:Cardiovascular Diseases / Q000097:blood / Q000178:diet therapy*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D044242:Trans Fatty Acids / Q000627:therapeutic use*; D016896:Treatment Outcome
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D044242:Trans Fatty Acids