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

Effects of environmental factors on edible oil quality of organically grown Camelina sativa

The aim of the present study was to evaluate the potential for the production of edible oil from organically grown camelina ( Camelina sativa L. Crantz), focusing on the influence of environmental factors on nutritional quality parameters. Field experiments with precrop barley were conducted in Norway in the growing seasons 2007, 2008, and 2009. Trials were fully randomized with two levels of nitrogen (N) fertilization, 0 and 120 kg total N ha(-1), and two levels of sulfur (S) fertilization, 0 and 20 kg total S ha(-1). Weather conditions, that is, temperature and precipitation, were recorded. Additional experiments were performed in the years 2008 and 2009 to evaluate the effects of replacing precrop barley with precrop pea. Seed oil content was measured by near-infrared transmittance, and crude oil compositions of fatty acids, phytosterols, tocopherols, and phospholipids were analyzed by chromatography and mass spectrometry. Results showed significant seasonal variations in seed oil content and oil composition of fatty acids, tocopherols, phytosterols, and phospholipids that to a great extent could be explained by the variations in weather conditions. Furthermore, significant effects of N fertilization were observed. Seed oil content decreased at the highest level of N fertilization, whereas the oil concentrations of α-linolenic acid (18:3n-3), erucic acid (22:1n-9), tocopherols, and campesterol increased. Pea compared to barley as precrop also increased the 18:3n-3 content of oil. S fertilization had little impact on oil composition, but an increase in tocopherols and a decrease in brassicasterol were observed. In conclusion, organically grown camelina seems to be well suited for the production of edible oil. Variations in nutritional quality parameters were generally small, but significantly influenced by season and fertilization.

Cardiac lipid changes in rats fed oils enriched in saturates and their apparent relationship to focal heart lesions

Weanling male Sprague-Dawley rats were fed diets containing 20% by weight corn, soybean or low erucic acid rapeseed oils or mixtures of the latter two with cocoa butter or triolein for 1, 2, 3 or 4 weeks. These diets previously had been fed to the same strain of rats for 16 weeks, and a reduction in the incidence of focal heart lesions had been observed with the addition of cocoa butter, but not triolein. The cardiac lipid classes and the fatty acid and alkenyl ethers of the cardiac phospholipids were analyzed to determine if changes could be attributed to the observed cardiopathological response, and at what time. Cardiac lipid classes changed during post-weaning development, but only triacylglycerol was diet-related. A number of fatty acid changes were observed in the cardiac phospholipids which reflected the relative concentration of saturates, monounsaturates, linoleic acid and linolenic acid in the diet, but only the changes in saturates and the C22 polyunsaturated fatty acids from the linolenic acid family appeared to be related to the incidence of focal heart lesions. Arachidonic acid and the total C22 polyunsaturated fatty acids remained fairly constant throughout the feeding trial. Cardiac diphosphatidylglycerol was least affected by dietary manipulation, while nervonic acid increased in cardiac sphingomyelin when small amounts of erucic acid were present in the diet. Fatty acid changes were essentially completed after one week on the experimental diets, whereas changes in the alkenyl ethers took two to three weeks.

Reduction of myocardial necrosis in male albino rats by manipulation of dietary fatty acid levels

A comprehensive statistical analysis had shown a significant correlation between the incidence of myocardial lesions in male albino rats and the concentration of certain dietary fatty acids. To test this result under controlled conditions, male rats were fed for 16 weeks diets containing 20% by weight soybean oil or a low erucic acid rapeseed (LEAR) oil. Both dietary oils contained substantial amounts of linolenic acid, and both groups developed a high incidence of myocardial necrosis. The addition of dietary saturated fatty acids to the oil in the form of cocoa butter significantly lowered the incidence of heart lesions in both groups. The addition of cocoa butter resulted in increased absorption of saturates and increased growth. Replacement of the cocoa butter by at least an equal amount of synthetic triolein resulted in no significant changes in the cardiopathogenic response compared to the original oils, thus ensuring that the reduction in heart lesions associated with the addition of cocoa butter was not due to dilution of cardiopathogenic compounds in the original vegetable oils. These results support the hypothesis that myocardial lesions in male rats are related to the balance of dietary fatty acids and not to cardiotoxic contaminants in the oils. Changes in the dietary fatty acids did not appear to influence the proportion of the cardiac phospholipids, but their fatty acid composition was markedly influenced. Dietary linolenic acid affected the C22 polyunsaturated fatty acids (PUFA) and dietary saturates increased the level of saturates in cardiac phospholipids. The level of arachidonic acid and total C22 PUFA did not appear to be affected by diet.

Comparative studies on composition of cardiac phospholipids in rats fed different vegetable oils

Male Sprague-Dawley rats were fed diets for 1 or 16 weeks, containing 20% by weight vegetable oils differing widely in their oleic, linoleic and linolenic acid content. No significant changes were observed in the level of the cardiac lipid classes. The fatty acid composition of the 2 major phospholipids, phosphatidylcholine and phosphatidylethanolamine, showed a remarkable similarity between diets in the concentration of total saturated, C22 polyunsaturated and arachidonic acids. Monounsaturated acids were incorporated depending on their dietary concentration, but the increases were moderate. Dietary linolenic acid rapidly substituted C22 polyunsaturated fatty acids of the linoleic acid family (n-6) with those from the linolenic acid family (n-3). The results suggest that dietary linolenic acid of less than 15% does not inhibit the conversion of linoleic to arachidonic acid but the subsequent conversion of arachidonic acid to the C22 polyunsaturates was greatly reduced. Significant amounts of dietary monounsaturated fatty acids were incorporated into cardiac cardiolipin accompanied by increases in polyunsaturated fatty acids, apparently to maintain an average of 2 double bonds/molecule. The cardiac sphingomyelins also accumulated monounsaturated fatty acids depending on the dietary concentration. It is quite evident from the results of this study that the incorporation of oleic acid and the substitution of linolenic for linoleic acid-derived C22 polyunsaturated fatty acids into cardiac phospholipids was related to the dietary concentration of these fatty acids and was not peculiar to any specific oil. Even though it is impossible to estimate the effect of such changes in cardiac phospholipids on membrane structure and function, results are discussed which suggest that the resultant membrane in the Spragu-Dawley male rat is more fragile, leading to greater cellular breakdown and focal necrosis.