[Comparative physiological effects of partially hydrogenated herring and rapeseed oils in the rat. 1. Mean-term effects on growth, organ weights and heart histology].

Two partially hydrogenated herring oils, containing 15% or 30% of C 22: 1, supplemented or not with linoleic (maize oil), have been fed for 16 weeks to growing rats (15% by weight in the diet), and their effects have been compared to those of peanut oil (controls), and to those of 2 mixtures of rapeseed oil and peanut oil having similar C 22:1 contents (15% and 30%). On the basis of equal amounts of ingested food, the growth of the rats is lower with herring and rapeseed oil than with peanut oil; this phenomenon is emphasized in the case of the non--C 18:2--supplemented herring oils. Herring and rapeseed oils induce an increase of liver particularly with the one having the highest content of trans fatty acids. Heart lesions have been observed in rats feed herring or rapeseed oils, not in the control group. The frequency of these lesions is greater with rapeseed oil (11/13) than with herring oils (11/24). This result suggests that erucic acid (cis delta 13 docosenoic acid) is more pathogenic than at least some of its isomers present in the hydrogenated herring oils (particularly the trans isomers). In the second part of this paper, we report the effects of the tested dietary fats on organ lipids after very short-term (3-7 days) or mean-term (16 weeks) experiments.