Suppression by diets rich in fish oil of very low density lipoprotein production in man.

Abstract

A X bstract. The highly polyunsaturated fatty acids in fish oils lower the plasma triglyceride concentration. We have studied the effect of a diet rich in fish oil on the rate of production of the triglyceride-transporting very low density lipoprotein (VLDL). Seven subjects, five normal and two with hypertriglyceridemia received up to 30% of daily energy needs from a fish oil preparation that was rich in eicosapentaenoic acid and docosahexaenoic acid, w-3 fatty acids with five and six double bonds, respectively.Compared with a diet similarly enriched with safflower oil (in which the predominant fatty acid is the w-6 linoleic acid, with two double bonds), the fish oil diet lowered VLDL lipids and B apoprotein concentrations profoundly.High density lipoprotein lipids and Al apoprotein were also lowered, but the effect on low density lipoprotein (LDL) concentration was inconsistent.The daily production or flux of VLDL apoprotein B, calculated from reinjected autologous '25I-labeled lipoprotein, was substantially less in six subjects studied after 3 wk of fish oil, compared with after safflower oil. This effect on flux was more consistent than that on the irreversible fractional removal rate, which was increased in the four normolipidemic but inconsistent in the hyThis work was presented in part at

Effects of fish oil supplementation on apolipoprotein B100 production and lipoprotein metabolism in normolipidaemic males

“…This was observed without any change in BMI, lean body mass or diet. The results are similar to those observed by Nestel et al, 1984 who found a 73% decrease in pool size and a 55% decrease in production rate using a considerably higher dose of ®sh oil (up to 30% of daily energy needs). Hepatic and lipoprotein lipase activities did not change after n-3 PUFA supplementation, consistent with other studies (Desager et al, 1989;Bagdade et al, 1990).…”

“…A reduction in VLDL-C (750%) and plasma apoB100 was also observed in accordance with the literature (Nestel et al, 1984;Harris, 1989;Berg-Schmidt et al, 1993;Mori et al, 1994). The reduction of VLDL apoB100 means a diminished number of circulating VLDL particles, given that each lipoprotein particle contains only one apoB100 molecule.…”

“…Data on apoB kinetics are limited: Nestel et al, 1984 reported that ®sh oil supplementation reduced VLDL apoB synthesis using a radioisotopic technique. These studies have both practical and theoretical limitations: the use of radioactive tracer excludes certain groups of patients and makes repetitive studies on the same patient ethically dif®cult.…”

“…ApoB100 production and pool size were reduced in two studies in which lipoprotein kinetics were studied using radiolabelled lipoproteins, where the production rate was obtained indirectly from the catabolic rate (Illingworth et al, 1984;Nestel et al, 1984).…”

Overproduction of intestinal lipoprotein containing apolipoprotein B-48 in Psammomys obesus: impact of dietary n-3 fatty acids

“…Although the physiological basis of metabolic dyslipidaemia appears to be hepatic overproduction of apo-B-containing VLDL particles [46,47], emerging evidence suggests that intestinal overproduction of apo-B-48-containing lipoproteins in insulin-resistant states may be an important contributor to the elevation of circulating triglyceride-rich lipoproteins [17,18,48]. The present study demonstrated that intestinal cells, like hepatocytes [49,50], responded to n-3 FA and decreased the output of triglyceride-rich lipoproteins by lowering the synthesis of apo B-48 and by inhibiting the new formation of lipids. The suppression of apo B-48 was not due to changes in apo B transcription, since Apob 48 mRNA levels were unaffected.…”