DIETARY FAT AND CHOLESTEROL METABOLISM FqCAL ELIMINATION OF BILE ACIDS AND OTHER LIPIDS

Gordon, Hymie; Lewis, Barry; Eales, L; Brock, J. F.

doi:10.1016/s0140-6736(57)91636-7

Cited by 103 publications

(18 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Previous work has shown that unsaturated fats elevate the rate of cholesterol synthesis in experimental animals with concomitant shifts of cholesterol into liver (19). Others have reported similar shifts into muscle (20) (17,24,25) ; others, like the present study, have utilized a "radioactivity balance" method (9,10,16). The methodological problems involved in direct fecal analysis have been set forth previously by Sj6vall (26).…”

Section: Methodssupporting

confidence: 53%

“…This conclusion is also consistent with the findings of Hellstrbm and Lindstedt (30) and of Steinberg and associates (31) showing no consistent correlation between the type of dietary fat and the turnover of biliary cholic acid. However, some investigators have reported that unsaturated fats increase bile acid excretion (24,25), others that they enhance sterol excretion (9,10,23). Still other studies show evidence for small changes in both fractions (16,29 Summary The fecal excretion of radioactive sterols and bile acids after intravenous injection of cholesterol-4-14C-labeled lipoproteins was studied in six subjects on liquid formula diets providing 607% of calories as fat.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Sterol and bile acid excretion in man and the effects of dietary fat.

Avigan¹,

Steinberg²

1965

J. Clin. Invest.

View full text Add to dashboard Cite

It is now well established that diets rich in saturated fatty acids lead to high levels of serum cholesterol, whereas diets rich in unsaturated fatty acids tend to be associated with lower levels. The mechanism by which these changes in serum cholesterol are induced by dietary fat is not known. One possible explanation for these effects would be either inhibition of cholesterol biosynthesis by unsaturated fats or stimulation of synthesis by saturated fats. The effects on synthesis, if any, could, in turn, be either the result of a direct action of the dietary fat on the biosynthetic system or of a secondary adjustment to any change in the rate of oxidation and excretion of cholesterol and its metabolites. Alternatively, changes in dietary fat might not affect the turnover rate, but cause a shift of part of the serum cholesterol pool, either from or into tissue compartments.Finally, the changes in serum cholesterol might reflect a primary effect not on sterol metabolism per se, but on the metabolism of lipoproteins, direct or mediated through effects on the metabolism of one or several of the moieties making up the macromolecule. These might act singly or in combination.In the present studies we have administered cholesterol-4-14C to subjects fed liquid formula diets containing saturated or unsaturated fat and subsequently measured the specific radioactivity of plasma cholesterol as a function of time. Simultaneously, the fecal excretion of sterol and bile acid was measured by a radioactivity balance method.

show abstract

Section: Methodssupporting

confidence: 53%

Section: Methodsmentioning

confidence: 99%

Sterol and bile acid excretion in man and the effects of dietary fat.

Avigan¹,

Steinberg²

1965

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…Early reports of augmented fecal excretion of bile acids in man (26)(27)(28)(29)(30)(31), of nonacidic or neutral sterols in man (31,32), the rat (9,33,34), and the rabbit (35), or of both bile acids and neutral sterols in man (36)(37)(38) and the rat (19,(39)(40)(41) agreed that an increased fecal excretion of cholesterol accompanied the hypocholesteremic effect of substituting polyunsaturated for saturated fatty acids in the diet. Hellman, Rosenfeld, Insull, and Ahrens (42) suggested that this increase fecal loss accounted for the fate of the cholesterol leaving the plasma under these conditions.…”

Section: Introductionmentioning

confidence: 99%

Effect of dietary fat on the fecal excretion of cholesterol and its degradation products in man

Moore¹,

Anderson²,

Taylor³

et al. 1968

J. Clin. Invest.

134

View full text Add to dashboard Cite

Fecal bile acid and neutral sterol excretion rates were determined in five healthy young men when serum cholesterol changes were induced by isocaloric substitution of an unsaturated (safflower oil) for a saturated fat (butter). The isotope balance method was used after the intravenous injection of cholesterol-4-14C. A feces extraction method is presented which permits essentially complete separation of fecal neutral sterols and bile acids.There was a significant increase in the total excretion of the fecal end products of cholesterol metabolism from 966 + 42 mg/day on saturated fat to 1147 + 45 mg/day on unsaturated fat, and the increase was equally distributed between the neutral sterol and bile acid fractions. With the substitution of dietary fats, regardless of the sequence of their feeding, there was a 28% reduction in serum cholesterol concentration during ingestion of the unsaturated fat. There were reciprocal changes in serum cholesterol levels and fecal steroid excretion with the substitution of one type of fat for the other. The changes in plasma cholesterol content were more than adequately balanced by the reciprocal changes in fecal cholesterol end product excretion.The findings in this study agree with several previous reports in supporting the hypothesis that the hypocholesteremic action of dietary unsaturated fatty acids is associated with an increase in the fecal loss of bile acids and neutral sterols.

show abstract

“…Further, the composition of fatty acids such as linoleate, may influence cholesterol metabolism. (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). We found that linoleate had no effect on the half-life of cholesterol, though it lowered plasma cholesterol (20).…”

Section: Discussionmentioning

confidence: 93%

Effect of fat intake on cholesterol turnover and bile acid formation.

Iritani

Fukuda

Ibamoto

1977

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

View full text Add to dashboard Cite

SummaryThree groups of male rats were maintained on diets con taining different amounts of fat. After one week on such regimens, they were injected intraperitoneally with cholesterol-3H. During the following 28 days, the radioactivity and quantity of fecal cholesterol and its metabolites were determined. The coprostanol excretion was the about same in all groups and the bile acids excretion increased with increasing fat intake; however, compared to the fat-free group, the excretion of the injected cholesterol-3H was greater in the 3% fat group and less in the 10% fat group. Consequently, the specific radioactivity of bile acids was lower in the 10% group than in the others. The half life of labelled cholesterol was 12.6, 16.0 and 22.2 days for the 3%,10% fat and fat-free groups, respectively. Rather than a fat-free diet, a low fat diet of 3% or so, would be of more advantage in eliminating choleste rol by increasing the formation of bile acids to emulsify the fat. In the 10% fat group, however, the enlarged pool size of bile acid probably delayed cholesterol metabolism to bile acids.The influence of fat feeding on cholesterol metabolism has been reported by many investigators. The absorption of cholesterol increases with the amount of fat intake with an upper limit (1), although the fatty acid composition of the carrier fat affects the extent of sterol absorption (2). Several workers have re ported that fat influenced the biosynthesis and excretion of cholesterol, but with conflicting results. In the experiments of SABINE et al. (3) and JANSEN et al. (4) with mice, the high-fat diet suppressed cholesterol synthesis; whereas with rats, HILL et al. (5,6), using similar diets, found an increase in hepatic synthesis of cholesterol from acetate after feeding fat. BORTZ (7) also observed that fat feed ing to rats maintained on a fat-free diet brought about a decrease in fatty acid synthesis and an increase in cholesterol synthesis. Further, the composition of fatty acids such as linoleate, may influence cholesterol metabolism. (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). We found that linoleate had no effect on the half-life of cholesterol, though it lowered plasma cholesterol (20).On the other hand, the relation between the amount of fat intake and chole sterol metabolism is not so clear. Bile acids, the metabolites of cholesterol, are necessary for the digestion and absorption of fat, so fat intake may accelerate the metabolism of cholesterol. The present experiments were therefore designed to examine the effects of varied amounts of dietary fat on overall cholesterol metabolism, using fat with a balanced composition of fatty acids.

show abstract

DIETARY FAT AND CHOLESTEROL METABOLISM FqCAL ELIMINATION OF BILE ACIDS AND OTHER LIPIDS

Cited by 103 publications

References 10 publications

Sterol and bile acid excretion in man and the effects of dietary fat.

Sterol and bile acid excretion in man and the effects of dietary fat.

Effect of dietary fat on the fecal excretion of cholesterol and its degradation products in man

Effect of fat intake on cholesterol turnover and bile acid formation.

Contact Info

Product

Resources

About