Journal Name:
British Journal of Nutrition
Article Title:
Replacement of butter on bread by rapeseed oil and rapesedd oil-containing margarine: effects on plasma fatty acid composition and serum cholesterol
Date Written:
1992
Volume:
68
Number:
Page:
639
Author(s):
Sepp�nen-Laakso, T; Vanhanen, H.; Kohtam�ki, H.; Viikari, J.
Article:
Dietary fatty acids have been extensively studied in order to ascertain their effects on blood lipid profiles and hence coronary heart disease risk. In this European investigation, the effects of zero-erucic acid rapeseed oil (CO) and rapeseed/CO-containing margarine on plasma fatty acid composition and serum cholesterol were assessed in forty-three normocholesterolemic and hypercholesterolemic subjects. The volunteers consumed their either their habitual diet (n=11) or substituted CO (n=20) or CO margarine (n=23) for butter for 6 weeks. CO products represented, on average, 21% of total dietary fat and 8% of total energy intake. The mean amount of ALA derived from CO represented about 1.8 g/day and 0.8% of energy. The average level of trans fatty acids in the CO margarine diet was 3.7 g/day and 1.7% of total energy.
Following the substitution period, changes in the relative fatty acid composition of plasma PLs were reported which were closely related to dietary fatty acid intake and correlated with serum cholesterol levels. The proportion of ALA significantly increased in PLs of subjects consuming the CO diet at 3 weeks and returned to baseline levels at 6 weeks. In contrast, EPA levels were significantly elevated after 3 weeks and remained so by the end of the study in both the groups consuming the CO and the CO margarine. However, the increase in EPA content was greater in the CO group. In both groups, there was a significant reduction in saturated fatty acids as well as an increase in LA levels.
In the normocholesterolemic group consuming CO, serum cholesterol and LDL-C decreased by an average of 7.8% and 13.4%, respectively, without reductions in HDL-C. Serum cholesterol and LDL-C decreased by an average of 9.4% and 16.3%, respectively, in hypercholesterolemic subjects consuming CO. During margarine substitution, normocholesterolemic and hypercholesterolemic subjects exhibited similar reductions in serum cholesterol and LDL-C of on average 6.5% and 7.6%, respectively. Of the plasma phospholipids, ALA and the linoleic:stearic acid ratio, but not oleic acid, were most significantly correlated with reductions in serum cholesterol levels. The authors concluded that their results indicate that even small amounts of CO can serve as a source of dietary essential fatty acids, especially EPA which is the precursor for anti-thrombotic eicosanoids. In addition, the reduction in both dietary and phospholipid SFAs is beneficial for both serum cholesterol lowering as well as in the promotion of ALA metabolism, as SFAs have been reported to suppress the activity of elongase and desaturase enzymes. The substitution of butter with CO and CO margarine in this population also led to decreases in serum total and LDL-C without a reduction in HDL-C; results which would be expected to lower the risk of coronary heart disease., , , , , ,
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