The Interaction of Dietary Fibers and Cholesterol upon the Plasma Lipids and Lipoproteins, Sterol Balance, and Bowel Function in Human Subjects

Abstract

A B S T R A C T To identify any metabolic effects of dietary fiber upon cholesterol metabolism in man, six adult volunteer subjects were fed eucaloric cholesterolfree formula diets, with and without added dietary fiber for two 4-wk periods. A large quantity of dietary fiber was fed, some 60 g of plant cell wall material (or 16 g of crude fiber) derived from corn, beans, bran, pectin, and purified cellulose. This provided about five times the fiber intake of the typical American diet. The addition offiber to the cholesterol-free diet did not change either the plasma cholesterol level (171+21 mg/dl, SEM, to 167+18) or the triglyceride (103±39 to 93±27 mg/dl). The excretion of both endogenous neutral steroids and bile acids were unchanged with fiber (505±41 to 636 ±75 mg/day and 194±23 to 266±47 mg/day, respectively). However, total fecal steroid excretion was increased 699±29 to 902±64 mg/day, P < 0.025). With fiber, intestinal transit time was decreased (59±9 to 35±8 h, P < 0.005), and both the wet and dry stool weights were greatly increased.A second group of six subjects was fed similar diets containing 1,000 mg cholesterol derived from egg yolk. The addition of fiber to the 1,000-mg cholesterol diet did not alter either plasma cholesterol level (233±26 to 223±36 mg/dl) or triglyceride (102±19 to 83±11 mg/ dl). The excretion of endogenous neutral steroids (618 ±84 to 571±59 mg/day), of bile acids (423±122 to 401 ±89 mg/day), and of total fecal steroids (1,041±175 to 972±+111 mg/day) were unchanged by fiber. The absorption of dietary cholesterol was not altered when

Effect of high-fiber diet on plasma high density lipoprotein (HDL) cholesterol level in streptozotocin-induced diabetic rats.

“…The cholesterol lowering effect of dietary fiber has been reported (Jenkins et 1975, Chen et al, 1979, but uniformly has not been achieved (Heaton & Pomare, 1974, Raymond et al, 1977. In the present study, we obtained the results showing that plasma cholesterol levels on the highfiber diet (Group A) were not significantly different from those on the control diet (Group B).…”

Cereal grains and coronary heart disease

“…Most of these 27 experiments were well designed, with control -test -control or crossover design or parallel control groups, and some were of long duration. In some studies all food was provided for the subjects in a metabolic unit (Jenkins et al, 1975;Kay & Truswell, 1977;Raymond et al, 1977;Stasse-Wolthuis et al, 1980). In the best of these reports with negative results, frequent measurements were made of plasma cholesterol concentrations.…”

Will a high-carbohydrate, low-fat diet lower plasma lipids and lipoproteins without producing hypertriglyceridemia?

“…41 With regard to dietary fiber effects on plasma triglyceride levels, a high-fiber diet did not lower triglyceride levels when body weight was maintained. 42 The effects of the high-carbohydrate diet on plasma LDL cholesterol during the acute challenge reflect a downward shift, although the effect of the high-carbohydrate diet may not have been fully appreciated because this dietary period had a duration of 10 days, which is insufficient to attain stability in cholesterol and LDL cholesterol levels. However, stability for plasma triglyceride and VLDL probably occurred because of their shorter turnover time.…”