The Biological Value of Oils and Fats II. The Growth-Retarding Substance in Rapeseed Oil

Male Sprague-Dawley rats, 3 weeks of age, were fed semisynthetic diets containing test oils at 20% by weight for 3 days, 1 week, and 16 weeks. The test oils contained up to 22.3% erucic acid. Growth retardation was evident in rats fed rapeseed oil high in erucic acid, and soybean oil and Tower rapeseed oil diets containing about 5% erucic acid. Cardiac triglyceride accumulation was found in rats fed diets containing about 5% erucic acid but not in rats fed Tower rapeseed oil which contains 0.2% of this acid. The cardiac free fatty acid levels were low, 50-100 pg/g of wet heart tissue, and were not affected by feeding diets containing about 5% erucic acid. Feeding a diet containing a high erucic acid rapeseed oil did result in higher free fatty acid levels but only at 3 days and 1 week; the level at 16 weeks was similar to the other oils. The fatty acid analysis of cardiac triglycerides and free fatty acids showed high percentages of erucic acid at 3 days and 1 week; at 16 weeks these levels had declined significantly. The results indicate that the accumulated erucic and eicosenoic acids, at 3 days and 1 week, accounted for the increase in cardiac free fatty acids when rats were fed the high erucic acid rapeseed oil. There appears to be no evidence that the early cardiac triglyceride or free fatty acid accumulation is related to the formation of the long term myocardial lesions.

Section: Disucssionsupporting

confidence: 92%

“…The result of feeding rats vegetable oil blends containing about 5 % 22:1 demonstrated the growth retarding effect of this acid (17). A temporary increase in cardiac TGs was evident, which could not be detected gravimetrically (% lipid), but had been demonstrated histologically by use of oil red 0 staining (4).…”

Section: Disucssionmentioning

confidence: 97%

The effect of dietary erucic acid on cardiac triglycerides and free fatty acid levels in rats

Kramer¹,

Hulan²

1978

“…Much of the unsaturation, however, is accounted for by the C20 and C22 monoenes, eicosenoic acid and erucic acid (Table II). Rapeseed oil has a lower coefficient of digestibility than most other dietary fats and oils (21) and is known to depress growth in rats (22) and to increase the concentration of cholesterol in adrenals and ovaries (23). Possibly the low tumor yield is related to some of these effects.…”

Section: Discussionmentioning

confidence: 99%

Effects of level and type of dietary fat on incidence of mammary tumors induced in female sprague‐dawley rats by 7,12‐dimethylbenz(α) anthracene

Carroll

Khor

1971

264

Female Sprague-Dawley rats on semisynthetic diets containing 10% and 20% by weight of corn oil developed more mammary adenocarcinomas after treatment with a single oral dose of 7,12-dimethylbenz(c0anthracene than similar rats on diets containing only 0.5% or 5% corn oil. Experiments with 10 different fats and oils fed at the 20% level indicated that unsaturated fats enhance the yield of adenocarcinomas more than saturated fats. Fibroadenomas and adenomas were also found in small numbers in all dietary groups but the yield did not seem to be influenced by level or type of dietary fat. The possible relevance of these findings to the incidence of breast cancer in humans is discussed.

“…t~UCIC ACID (A~*-docosenoic acid) is a major component fatty acid of rapeseed oil and seed oils of other Cruciferae (1)(2)(3). Its metabolism in mammalian tissues is of interest because rapeseed oil is widely used as an edible oil (4), and because feeding rapeseed oil to experimental animals produces various effects such as growth inhibition (5) and altered cholesterol metabolism (6), which appear to be due to its erucie acid content. Nervonie acid (• acid) is of little interest as a dietary component, but further information on its metaholie properties is desirable because of its occurrence in mammalian tissue lipids (3,7) and its close chemical relationship to erucie acid.…”

Section: Introduction Ementioning

confidence: 99%

Metabolism of¹⁴C‐labelled oleic acid, erucic acid and nervonic acid in rats

Carroll

1966

1-(14)C-Oleic acid, 2-(14)C-erucic acid and 2-(14)C-nervonic acid were administered to rats by tail-vein and the distribution of radioactivity in liver lipids was determined at intervals from 15 min to 6 hr after injection. High levels of activity were found after short time intervals which were mainly associated with triglycerides in the case of oleic acid and with free fatty acids in the case of erucic acid and nervonic acid. The activity in these lipids decreased with time and was later exceeded by that in more polar lipids. In rats given erucic acid or nervonic acid, sphingolipids were more highly labelled than glycerophosphatides. Nervonic acid showed little tendency to form a complex with serum albumin and erucic acid complexed less readily than palmitic acid.