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| J Nutr 2000 Feb;130(2):243-8 |
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Low levels of viscous hydrocolloids
lower plasma cholesterol in rats primarily by impairing cholesterol
absorption.
Levrat-Verny MA, Behr S, Mustad V, Remesy C, Demigne C.
Unite des Maladies Metaboliques et Micronutriments, INRA de
Clermont-Ferrand/Theix, St. Genes-Champanelle, France.
Hydrocolloids have been proposed as cholesterol-lowering agents,
but their viscosity limits their use in human nutrition. A low
level (1 %) of hydrocolloids (guar gum, (GG); xanthan gum, (XG);
and konjac mannan) was investigated in rats fed 0.2 g/100 g
cholesterol diets. Food intake and body weight gain were not
altered by the diets. Bile flow and cholesterol bile flux were
not modified by diet, whereas the bile acid flux was greater
in rats fed hydrocolloid diets. The cecal pool of bile acids
was greater than control rats only in rats fed the XG diet (+71%,
P<0.001). The fecal excretion of neutral sterols was stimulated
in rats fed the hydrocolloid diets; cholesterol apparent digestibility
(60% in controls) was reduced to 30-36% in rats fed hydrocolloids.
Bile acid fecal excretion was not altered by diet treatment.
As a result, apparent steroid balance was about +40 micromol/d
in controls and only +10 to +20 micromol/d in rats fed hydrocolloids.
Both plasma cholesterol and triglycerides were significantly
lower than controls in rats fed XG, but only cholesterol was
lower in rats fed the GG diet. These effects were essentially
found in the d <1.040 kg/L fraction. Liver cholesterol content
was significantly lower than in controls in rats fed the GG
or XG diets. Liver HMG CoA reductase was not affected by the
hydrocolloid diets. In conclusion, a low percentage of viscous
hydrocolloids lowers plasma cholesterol in cholesterol-fed rats.
Inhibition of intestinal cholesterol absorption may be the primary
mechanism.
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